200810831 九、發明說明 【發明所屬之技術領域】 本發明係有關，光觸媒及其製造方法，與使用其之光 觸媒塗佈劑，光觸媒分散體，光觸媒體者。更詳細而言， 係有關藉由白色螢光燈等光照射，具有優越之觸媒活性的 光觸媒者。 【先前技術】 光觸媒，係照射具有其帶隙以上之能量的波長之光時 而激勵，顯現強力之觸媒活性者。尤其，有機物、或NOx 等一部份無機物之氧化•分解力大，可利用其低成本、環 境負荷小之光作爲能源之故，近年來進展至環境淨化或對 脫臭、防污、殺菌等之應用。又，光觸媒激勵時，發現其 表面爲親水性、與水之接觸角降低；利用此作用，亦可發 展對防濁、防污之應用。光觸媒一般使用氧化物或硫化物 等之金屬化合物，尤其具有高光觸媒活性之微粒子的氧化 鈦、氧化鋅等。氧化鈦、氧化鋅等，激勵光之波長在 4 OOnm之紫外線區域。例如氧化鈦粒子之內部及/或表面 ，含有氧化鐵、氫氧化鐵、鹼式氫氧化鐵等鐵化合物，可 提升光觸媒活性（參照專利文獻1 )。又，氧化鈦粒子之 表面，負載10〜100 A之氧化鐵的微粒子，可提高太陽光之 利用效率（參照專利文獻2 )。亦有在銳鈦礦型氧化鈦之 粒子表面，負載氧化亞鐵、氧化鐵、磁鐵礦等鐵氧化物， 藉由照射可見光線可得高活性之提案（參照專利文獻3 ) -5- 200810831 專利文獻1 :特開平7-3 03 83 5號公報 專利文獻2 :特開平6-3 92 8 5號公報 專利文獻3 :特開2003 - 1 908 1 1號公報 【發明內容】 〔發明所欲解決之課題〕 • 藉由可見光照射而具有光觸媒活性之光觸媒，不必要 紫外線燈等特別的光源，可使用太陽光或白色螢光燈等光 源之故，期望光觸媒的應用領域更加廣濶；專利文獻2及 3記載之光觸媒，在白色螢光燈之光照射下的光觸媒活性 並不充分。因此，本發明以提供，藉由白色螢光燈等照射 ，具有優越之光觸媒活性的光觸媒及其製造方法爲目的。 〔課題之解決手段〕 ® 本發明的工作同仁，以該專利文獻1爲基準，爲開發 即使爲白色螢光燈亦具有優越之活性的氧化鈦光觸媒，經 - 深入探討不斷硏究之結果發現，在各種鐵化合物中，藉由 - 倂用含白色螢光燈之光，吸收400〜500nm的波長之光的鹼 式氫氧化鐵；含有如此之鹼式氫氧化鐵與氧化鈦的光觸媒 ，在白色螢光燈之光的照射下，與以同一條件測定不使用 鹼式氫氧化鐵之氧化鈦比較，具有約2倍以上的光觸媒活 性，完成本發明。 即，本發明具有下述之特徵。 -6- 200810831 (1)其係至少含有鹼式氫氧化鐵與氧化鈦之光觸媒 。藉由鹼式氫氧化鐵吸收400〜5 OOnm的波長之光，使氧化 鈦顯現光觸媒活性。如此之光觸媒，在照射含有 400〜500nm的波長之光的白色螢光燈之光時，乙醛分解反 應速度常數，相對於以同一條件測定該氧化鈦之乙醛分解 速度常數，具有約2倍以上之光觸媒活性。 (2 )本發明之光觸媒的製造方法，係至少將鹼式氫 氫化鐵與氧化鈦混合，較佳爲在含有含鹼金屬元素及/或 鹼土類金屬元素之氧化鈦的媒液中，藉由添加鐵化合物進 行反應，在該氧化鈦之粒子表面負載鹼式氫氧化鐵而含有 鹼式氫氧化鐵與氧化鈦。 (3 )在至少含有鹼式氫氧化鐵與氧化鈦之光觸媒中 ，藉由予以配合黏合劑可作爲光觸媒塗佈劑；或藉由予以 配合分散媒可作爲光觸媒分散體；又，將至少含有鹼式氫 氧化鐵與氧化鈦之光觸媒成形，可固定於基材上。 〔發明之功效〕 本發明之光觸媒，在具有400〜500nm之波長的白色螢 光燈等光照射下，具有優越的光觸媒活性之故，不必要紫 外線燈等特殊的光源，即使螢光燈等室內照明或太陽光， 可有效的使NOx或有機之環境污染物質予以分解。親水 性效果亦可期待之故，適合使用爲淨化材料、脫臭材料、 防污材料、殺菌材料、防濁材料等。又，使用氧化鈦、鹼 式氫氧化鐵等價格較低廉的材料之故，能提供低成本之光 200810831 觸媒。 進而，本發明之光觸媒，可作爲塗佈劑、分散體等液 狀組成物；又，可成形，作爲固定於基材之光觸媒體；使 用其，能賦於防污性或親水性等功能性。 〔發明之實施形態〕 本發明係至少含有鹼式氫氧化鐵與氧化鈦之光觸媒； 藉由鹼式氫氧化鐵吸收400〜500nm的波長之光，使氧化鈦 顯現光觸媒活性。因此，光觸媒活性係以測定在照射含有 400〜500nm的波長之光的白色螢光燈之光時，乙醛分解反 應速度常數作爲評估基準（參照後述之評估1)，藉此予 以評估活性。如此進行評估之本發明的光觸媒之活性，相 對於以同一條件測定之氧化鈦本身的活性（以乙醛分解反 應速度常數評估），較佳爲約2倍以上，更佳爲約5倍以 上，再佳爲約7倍以上，最佳爲約1 0倍以上。本發明之 光觸媒，以至少含有鹼式氫氧化鐵與氧化鈦者爲佳，爲藉 由鹼式氫氧化鐵吸收400〜500nm的波長之光，使氧化鈦顯 現光觸媒活性，以鹼式氫氧化鐵與氧化欽相互作用之程度 的接合狀態爲佳，以此等堅固接合的狀態更佳。爲如此之 狀態時，以將鹼式氫氧化鐵與氧化鈦予以混合爲佳，較佳 爲使用混合機進行混合，更佳爲在懸浮狀態使用攪拌機等 將鹼式氫氧化鐵與氧化欽予以混合。較佳爲鹼式氫氧化鐵 負載於氧化鈦之粒子表面。鹼式氫氧化鐵之負載形態沒有 特別的限制；爲吸附於氧化鈦粒子表面時，亦可爲氧化鈦 -8 - 200810831 粒子在表面具有羥基與氫鍵結而堅固結合之狀態。本發明 之光觸媒、光觸媒塗佈劑、光觸媒分散體及光觸媒體中， 除鹼式氫氧化鐵、氧化鈦以外，亦可含有氧化鋅、硫化鎘 等光觸媒性物質，各種吸附劑等，其含有之形態沒有特別 的限制。 本發明之光觸媒所含的鹼式氫氧化鐵，係FeOOH或 Fe203 · ηΗ20之化學式所示的化合物；可使用α態、/3態 、r態等結晶性者，或無定形者。尤其，α -鹼式氫氧化 鐵，對400〜5 00nm的波長之光的吸收效果高，可賦予具有 更優越之活性的光觸媒，甚爲適合。鹼式氫氧化鐵之含量 可適當設定，相對於鹼式氫氧化鐵與氧化鈦之合量，以Fe 換算，以0.01〜5重量％之範圍爲佳，0.05〜2重量％之範圍 更佳。氧化鈦含有鹼式氫氧化鐵或負載；更詳細而言，含 有或負載α態之鹼式氫氧化鐵，可採用例如美斯鮑爾分光 法或電子顯微鏡等予以確認。 本發明之光觸媒中所含的氧化鈦，除一般的鈦氧化物 以外，含有無水氧化鈦、含水氧化鈦、水合氧化鈦、氫氧 化鈦、鈦酸等；爲銳鈦礦型或金紅石型等結晶形時沒有特 別的限制，亦可爲不定形、亦可爲此等之混合者。此等之 中尤其以結晶性高者，光觸媒活性高之故，較爲適合；金 紅石型氧化鈦之激發光的波長，比銳鈦礦稍大之故，以具 有銳鈦礦型結晶之氧化鈦較佳。又，氧化鈦之一部份，可 爲鈦酸鹼金屬鹽、鈦酸鹼土類金屬鹽等複合氧化物；如此 之氧化鈦的內部，含有構成其複合氧化物的鹼金屬元素、 -9- 200810831 鹼土類金屬元素之故，極爲適合。又，氧化鈦中’其 不造成不良影響時，可含有選自V、Fe、Co、Ni、Cxi 、Ru、Rh、Pd、Ag、Au之一種以上的異種元素或氧 等異種元素之化合物。氧化鈦之大小沒有特別的限制 由BET法測定之比表面積，以10〜400m2/g之範圍爲 以10〜200m2/g之範圍更佳，以10〜100m2/g之範圍又 ，30〜80m2/g之範圍最適合。比表面積比該範圍小時 機物、氮氧化物等處理對象物質之吸附力下降分解效 低之故，甚不適合；過大時，過爲微細，難以獲得結 高者，極不適合。 氧化鈦之粒子形狀亦無特別的限制，可使用真球 略球狀、各向異性形狀等定形粒子、或粒塊狀等不定 子等。尤其，具有各向異性形狀者時，可輕易獲時優 光觸媒活性，極爲適合。本發明所謂「各向異性形狀 係指一般而言稱呼爲紡錘狀粒子、棒狀粒子、針狀粒 板狀粒子等者；將一個之一次粒子以最穩定之狀態靜 平面上，以二個平行線將在平面上之投影像挾持，其 線之間隔爲最小時的距離爲粒子之寬度或短軸徑w、 平行線以直角方向之二個平行線將粒子挾持時的距離 子之長度或長軸徑1，在最大穩定面以平行面挾持之 爲粒子高度h時，滿足l>w- h者而言。長軸徑、短 、高度，可將一次粒子自電子顯微鏡照相中，藉由約 個粒子之算術平均値求得。本發明使用之具有各向異 狀的氧化鈦之大小，以上述之BET法測定，比表面 激發 、Zn 化物 ，藉 佳， 更佳 ，有 率降 晶性 狀、 形粒 越之 」， 子、 止於 平行 此2 爲粒 距離 軸徑 1000 性形 積以 -10- 200810831 10〜200m2/g 之範圍爲佳，10〜100m2/g之範圍更佳， 3 0〜8 0m2/g之範圍最適合。如此之各向異性形狀粒子，以 具有10〜5 00nm之範圍的平均長軸徑，1〜25nm之範圍的平 均短軸徑者爲佳；其中，軸比（平均長軸徑/平均短軸徑 )爲1 . 5以上之紡錘狀粒子、棒狀粒子、針狀粒子爲佳； 軸比爲1.5〜10之範圍時更佳，最佳爲2〜7之範圍。 又，含有氧化鈦與鹼式氫氧化鐵之光觸媒，含有鹼金 屬元素及/或鹼土類金屬元素時，可具有優越的光觸媒活 性之故，甚爲適合。可使氧化鈦粒子之表面具有鹼金屬元 素、鹼土類金屬元素，如先前之記載亦可含有於內部；進 而，亦可含有於鹼式氫氧化鐵之內部，亦可存在於鹼式氫 氧化鐵的表面，或亦可存在於選自此等之任2個處所以上 。尤其，氧化鈦之內部及/或表面含有時，可使鹼式氫氧 化鐵堅固負載等，能具有優越的光觸媒活性之故，極爲適 合。又，氧化鈦之一部份可爲鈦酸鹼金屬鹽、鈦酸鹼土類 金屬鹽之複合氧化物。驗金屬元素有鈉、鉀、鋰等。驗土 類金屬元素有鈣、鎂、鋇、緦、鈹等。其中以鈉吸收 400〜500nm的波長之光容易生成鹼式氫氧化鐵，較爲適合 。驗金屬兀素及/或驗土類金屬兀素之含量，相對於鹼式 氫氧化鐵與氧化鈦之含量，以氧化物換算（例如，Na20、 K2〇 ' Li2〇、CaO、MgO、BaO、SrO、BeO 等）表示時， 以0.01〜30重量％之範圍爲佳，0.05〜15重量％之範圍更佳 ，0.0 5〜5重量％之範圍最佳。鹼金屬元素、鹼土類金屬元 素之含有形態，可爲離子、金屬、或氧化物、氫氧化物、 11 - 200810831 氯化物等化合物之任一，沒有特別的限制。還有，本發明 之化學組成，亦包含鹼式氫氧化鐵之含量等，爲 X射線之分析値。 其次’製造至少含有鹼式氫氧化鐵與氧化鈦的本發明 之光觸媒時，可採用： (a)將預先製造之鹼式氫氧化鐵與氧化鈦，使用韓 歇爾混合機、萊氏混合機、愛氏混合機、擂櫃機等混合機 、乳鉢•乳棒等混合措施；使用球磨機、膠體磨機等粉碎 混合機予以混合之方法；或將鹼式氫氧化鐵與氧化欽，以 懸浮狀態使用攪拌機予以混合之方法， (b )將鈦化合物與鐵化合物之混合液、及後述之鹼 性化合物混合、中和，進行反應，使鹼式氫氧化鐵與氧化 鈦之雙方析出的方法， (c )在預先製造之氧化鈦的懸浮液中，添加鐵化合 物進行反應，於氧化鈦之存在下生成鹼式氫氧化鐵的方法 ， (d )在預先製造之鹼式氫氧化鐵的懸浮液中，添加 鈦化合物進行反應，於鹼式氫氧化鐵之存在下生成氧化鈦 的方法等。採用此等方法之際，因應需求亦可含有氧化鋅 、硫化鎘等光觸媒性物質，各種吸附劑等。 預先製造鹼式氫氧化鐵時，可使用在硫酸亞鐵、硝酸 亞鐵、氯化亞鐵等亞鐵化合物之溶液中，添加氫氧化鈉、 氫氧化鉀、氨、胺、碳酸鈉等鹼性化合物，將亞鐵化合物 之一部份或全部進行中和；其次，調整pH、同時送入空 -12- 200810831 氣、氧等氣體予以氧化之方法；在硫酸鐵、硝酸鐵、氯化 鐵等鐵化合物之溶液中’添加氫氧化鈉、氫氧化鉀'氨' 胺、碳酸鈉等鹼性化合物’將鐵化合物例如在10〜70 °c之 溫度進行中和後’使用熟成處理或加熱處理或水熱處理之 方法。使用鹼性之鈉化合物時，容易生成吸收400〜 5 OOnm之光的鹼式氫氧化鐵，甚爲適合。此方法中之熟成 處理，係將中和生成物保持於中和溫度一定時間’生成鹼 式氫氧化鐵之處理，熟成時間以1 〇分鐘〜5小時較爲適合 。加熱處理，係將中和生成物在媒液中50〜200 °C之範圍進 行，更佳爲在70〜1〇〇 °c的範圍加熱生成驗式氫氧化鐵之處 理，加熱時間以1 〇分鐘〜5小時較爲適合。加熱處理之溫 度低於50時，在短時間難以進行脫水，氫氧化鐵難以充 分改性成爲鹼式氫氧化鐵之故，極不適合。水熱處理，係 將中和生成物，使用壓熱器等高溫高壓裝置在1 〇〇 °c以上 ，較佳爲150〜2 0 0 °C之範圍加熱，在因應其溫度之水蒸氣 壓下生成鹼式氫氧化鐵的處理，加熱時間以1 0分鐘〜5小 時較爲適合。水熱處理之溫度高於200 °C時，過度進行脫 水，容易改性至氧化鐵，甚不適合。所得鹼式氫氧化鐵， 可使用通常的方法，進行適當之過濾、洗淨、乾燥等操作 〇 預先製造氧化鈦時，可使用眾所周知的方法。例如 (1 )將氧化鈦等予以中和之方法； (2 )將硫酸鈦、硫酸鈦基等加熱水解之方法； (3 )將該（1 ) 、（ 2 )之方法所得的生成物，使用 -13- 200810831 燒成或水熱處理之方法。又，具有各向異性形狀之氧化鈦 ，亦可使用以眾所周知的方法所製造者。例如，將含水氧 化鈦以氫氧化鈉、碳酸鈉、草酸鈉等鹼性鈉化合物處理後 ，可使用鹽酸予以處理之方法。以如此之方法所得的氧化 鈦係微粒子，所謂紡錘狀者之故，適合使用。所得氧化鈦 可使用通常的方法，進行適當之過濾、洗淨、乾燥等操作 〇 # 採用後述之（B)方法的預先含有鹼金屬元素、鹼土 類金屬元素之氧化鈦，係將上述之方法所得之氧化鈦或下 述記載之氧化鈦先驅物，與鹼金屬、鹼土類金屬的氫氧化 物、碳酸鹽、硫酸鹽、氯化物、氧化物等，較佳爲鈉化合 物進行混合，予以燒成而得。氧化鈦先驅物，係指藉由燒 成成爲氧化鈦之化合物而言。例如，硫酸鈦、硫酸鈦基、 氯化鈦、烷氧基鈦等。將含水氧化鈦、氫氧化鈦燒成作爲 氧化鈦時，含水氧化鈦、氫氧化鈦屬於氧化鈦先驅物。又 ® ，預先含有鹼金屬元素、鹼土類金屬元素的氧化鈦，在該 (1 )之方法中，將氧化鈦以大過剩之鹼金屬、鹼土類金 . 屬的驗性化合物予以中和；更佳爲，在驗金屬、驗土類金 . 屬之鹼性化合物的溶液中’添加氯化鈦予以中和而得。同 樣的，具有各向異性形狀之氧化鈦，係將含水氧化鈦或氯 化鈦，以大過剩之鹼性鈉化合物處理後，較佳爲在鹼性鈉 化合物之溶液中添加含水氧化鈦進行處理後，藉由鹽酸處 理的方法而得。以此方法所得之具有各向異性形狀的氧化 鈦、鈉以離子之狀態被含有於粒子內部。 -14- 200810831 本發明之氧化鈦，係將氧化鈦預先燒成者，或將氧化 鈦先驅物燒成而得者，氧化鈦之結晶性高，含有之羥基或 水分之量適度減少，光觸媒活性進一步提高之故極爲適合 。燒成溫度以200〜700 °C之範圍爲佳；燒成溫度低於此範 圍時，難以獲得光觸媒活性之改良效果，甚不適合。高於 此範圍時，不僅難以獲得改良效果，生成或成長的光觸媒 之粒子間容易造成燒結，極不適合。較佳之燒成溫度範圍 爲200〜600°C，更佳之範圍爲300〜600°C。燒成時間、燒 成氣體環境等條件，可適當設定；燒成時間，以例如1〜1 〇 小時之程度較適合，燒成氣體環境，以’在空氣或含氧氣體 之氣體環境下、或氮、氬等惰性氣體環境下進行較適合。 本發明中，如該（c)記載，在預先製造之氧化鈦的 懸浮液中添加鐵化合物進行反應，於氧化鈦之存在下生成 鹼式氫氧化鐵時，在氧化鈦之粒子表面容易負載鹼式氫氧 化鐵，負載之鹼式氫氧化鐵與氧化鐵相互作用可顯現優越 之光觸媒活性，更爲適合。此方法中更佳之方法爲： (A )在含氧化鈦之媒液中，添加鐵化合物，進行氧 化或熟成處理、加熱處理或水熱處理予以反應之方法， (B)使用含有鹼金屬元素及/或鹼土類金屬元素之氧 化鈦，與鐵化合物接觸，藉由自氧化鈦溶出之鹼金屬元素 、鹼土類金屬元素，將鐵化合物進行中和；使其中和生成 物氧化或進行熟成處理、加熱處理或水熱處理，予以反應 之方法、進而 (C )在媒液中，含有氧化鈦與鹼金屬元素及/或鹼土 -15- 200810831 類金屬元素之化合物後，添加鐵化合物進行中和，使其中 和生成物氧化或進行熟成處理、加熱處理或水熱處理，予 以反應之方法。（B ) gB載之方法’係不必要另外添加中 和劑之鹼性化合物，步驟甚爲合理；爲本發明之最適合的 方法。又，依（B )及（c )記載之方法時，可使鹼式氫氧 化鐵負載於氧化鈦粒子之表面，同時含有鹼金屬元素及/ 或鹼土類金屬元素。還有’ （C)之方法，亦可在媒液中 分別添加鐵化合物與驗金屬兀素及/或驗土類金屬元素， 亦可同時並行添加。 上述之（A) 、( B ) 、（C)的方法中，可使用水、 醇、甲苯等無機系、有機系之液體作爲媒液，工業上水之 處理容易較爲適合。使用亞鐵化合物作爲鐵化合物，在其 溶液中添加氫氧化鈉、氫氧化鉀、氨、胺、碳酸鈉等鹼性 化合物，使亞鐵化合物之一部份或全部中和；接著，調整 pH，同時送入空氣或氧等氣體進行氧化，亦可在氧化鈦粒 子負載氫氧化鐵；使用鐵化合物時，不必要氧化之步驟， 甚爲適合。採用水系媒液時，以使用水溶性鐵化合物爲佳 。水溶性之鐵化合物有，例如硝酸鐵、硫酸鐵、氯化鐵等 。鹼金屬化合物、鹼土類金屬化合物，有此等之氫氧化物 、碳酸鹽、硫酸鹽、氯化物、氧化物等；本發明之光觸媒 中，鹼金屬元素以含有鈉者爲佳之故，以使用鈉化合物較 適合。該氧化鈦與鐵化合物之接觸，氧化鈦粒子之內部或 外部所含有之鹼金屬元素、鹼土類金屬元素容易游離，可 促進與鐵化合物的反應之故，以在酸性下進行爲佳。媒液 -16- 200810831 之ρ Η以3以下爲佳，更佳爲2以下。ρ Η調整時，可使用 硫酸、鹽酸、硝酸、氫氟酸等。 將如此而得之含有氧化鈦與鹼式氫氧化鐵的生成物粉 碎時，可使用通常的方法，進行適當之過濾、洗淨、乾燥 等操作；因應需求亦可進行粉碎。乾燥，係在鹼式氫氧化 鐵不改性爲氧化鐵的溫度下進行，例如以在2 0 0 °C以下之 溫度進行爲佳。過濾、洗淨之際，使媒液之pH爲中性附 近，較佳爲調整pH至7左右後進行時，氧化鈦凝聚可提 升洗淨性之故甚爲適合；媒液中未反應之鐵化合物存在時 ，氫氧化鐵析出之故，預先進行過濾、洗淨，將未反應之 鐵化合物去除後再分散於媒液中；相反的將媒液之pH調 整於中性附近，進行過濾、洗淨爲佳。中和劑可使用氫氧 化物、碳酸鹽等鹼性鹼金屬化合物、鹼性鹼土類金屬化合 物、或氨、胺等。再分散使用之媒液，以水爲佳。 光觸媒反應中實際使用本發明之光觸媒時，因應需求 固定於基材上，將光觸媒成形•造粒作爲成形體使用較爲 方便。基材有，例如由金屬、瓷磚、多孔體、水泥、混凝 土、玻璃、塑料、纖維、木材、紙等各種材質所形成；其 形狀可使用板狀、波浪板狀、蜂巢狀、球狀、曲面狀等各 種形狀者。 將光觸媒固定於基材時，將該光觸媒作成光觸媒塗佈 劑，此塗佈劑塗佈或噴射於基材表面後，可使用乾燥或燒 成之方法。光觸媒塗佈劑中至少含有黏合劑。黏合劑可使 用無機系樹脂、有機系樹脂。藉由光觸媒反應難以分解之 -17- 200810831 黏合劑，以例如聚合性矽化合物、水泥、混凝土、石膏、 聚矽氧樹脂、氟樹脂等爲佳，其中聚合性矽化合物耐久性 高，比較容易處理且泛用性高，甚爲適合。聚合性矽化合 物有，例如水解性矽烷或其水解生成物或其部份縮合物、 水玻璃、膠體二氧化矽、有機聚矽氧烷等。可使用此等之 中的1種、亦可2種以上混合使用。水解性矽烷，至少含 有1個烷氧基、鹵基等水解性基之故，其中烷氧基矽烷之 穩定性、經濟性甚佳，尤其四甲氧矽烷、四乙氧基矽烷等 四烷氧基矽烷反應性高，甚爲適合。水玻璃可使用矽酸鈉 系、矽酸鉀系、矽酸鋰系，其中以矽酸鈉系之穩定性高之 故，極爲適合。矽酸鈉系之水玻璃，Na20與Si02之莫耳 比爲2〜4的範圍時，硬化性高；從穩定性與硬化性之平衡 而言，以該莫耳比爲3之3號水玻璃最爲適合。膠體二氧 化矽或有機聚矽氧烷，可使用具有矽烷醇基者。塗佈劑中 ，進而可含有水、或醇類、烴類、醚類、醚醇類、酯類、 醚酯類、酮類等非水溶劑作爲分散媒；因應與黏合劑之相 溶性，可適當選擇此等之1種或含有2種以上的混合溶劑 而使用。塗佈劑中之固形份濃度以0.05〜50重量％之範圍 爲佳，以0.1〜40重量％之範圍更佳。光觸媒以含有固形份 中之20〜95重量％爲佳，以40〜95重量％之範圍更佳。 塗佈劑中，除光觸媒及黏合劑、或分散媒以外，在不 損及本發明之效果的範圍，亦可含有p Η調整劑、分散劑 、消泡劑、乳化劑、著色劑、增量劑、殺霉菌劑、硬化助 劑、增黏劑等各種添加劑，塡充劑等。此等添加劑或塡充 -18 - 200810831 劑s不揮發性時，以選擇藉由光觸媒作用難以分解之無機 系者爲佳。 本發明之光觸媒，可預先分散於分散媒而成分散體。 調製使用分散體之光觸媒塗佈劑時，可輕易獲得高度的分 散性之故，甚爲適合。或者，不使用黏合劑，將分散體稀 釋至適當的濃度塗佈於基材表面，或噴塗後、經乾燥、燒 成’將光觸媒固定於基材上。分散體之分散媒，與配合於 塗佈劑之分散媒相同，或選擇相溶性高者。又，分散體中 可配合分散劑，因應分散媒可適當選擇分散劑之種類。分 散劑有，例如（1 )界面活性劑{( a )陰離子系〔羧酸鹽 、硫酸酯鹽、磺酸鹽、磷酸酯鹽等〕、（b)陽離子系〔 烷基胺鹽、烷基胺之4級銨鹽、芳香族4級銨鹽、雜環4 級銨鹽等〕'(c )兩性〔甜菜鹼型、胺基酸型、烷基胺 氧化物、含氮雜環型等〕、（d)非離子系〔醚型、醚酯 型、酯型、含氮型等〕等、（2)聚矽氧系分散劑〔烷基 改性聚矽氧烷、聚環氧烷改性聚矽氧烷等〕、（3 )磷酸 鹽系分散劑〔磷酸鈉、焦磷酸鈉、原磷酸鈉、偏磷酸鈉、 三聚磷酸鈉等〕、（4 )烷醇胺類〔胺基甲基丙醇、胺基 甲基丙二醇等〕等。其中，羧酸鹽系之界面活性劑，尤其 高分子型者可將氧化鈦高度分散，甚爲適合。具體而言， 有聚丙烯酸鹽{〔 CH2CH ( COOM ) 〕n，Μ爲鹼金屬、驗 土類金屬、銨等，以下均同}，丙烯酸鹽-丙烯醯胺共聚物 { ( CH2CH ( COOM ) ] η- [ ch2ch ( CONH2 ) m ) }，丙烯 酸-順丁烯二酸鹽共聚物{〔 CH2CH ( COOH) 〕η· -19- 200810831 〔CH2CH ( COOM ) CH ( COOM ) 〕m}，乙烯-順丁 烯二酸 鹽共聚物{〔CH2CH2〕η- [ CH ( COOM) CH ( COOM)] m} ，烯烴·順丁烯二酸鹽共聚物{〔（^2011(尺）〕11-〔CH ( COOM ) CH ( COOM ) 〕m}，苯乙烯·順丁烯二酸鹽 共聚物{〔 CH2CH(C6H5)〕n-〔 CH(COOM)CH(COOM)〕m} 等。分散體中之光觸媒的配合量，以5〜90重量％之範圍爲 佳，10〜80重量％之範圍更佳。又，分散劑之配合量，相 對於光觸媒以0.01〜20重量％之範圍爲佳，0.01〜10重量％ 之範圍更佳。 將光觸媒成形而使用時，因應需求可與黏土、矽藻土 、有機系樹脂、無機系樹脂等黏合劑混合後，成形爲任意 之形狀。 【實施方式】 〔實施例〕 其次，以實施例說明本發明；本發明並非限定於此等 〔實施例1〕 (1)在Ti02 200g/l之濃度的四氯化鈦水溶液700ml 中，添加Na20 1 00g/l之濃度的氫氧化鈉水溶液。其後調 整系之pH爲7後，進行過濾，洗淨至濾液的導電率爲 100// S/cm爲止，進行乾燥即得氧化鈦。 此氧化鈦，係具有平均長軸徑 64nm、平均短軸徑 -20 - 200810831 13nm (軸比4·9 )、比表面積160m2/g之金紅石型結晶的 紡錘狀二氧化鈦，氧化鈦粒子之內部含有1.7重量％的作 爲Na20之鈉。 (2)在純水0.5L中，添加該紡錘狀二氧化鈦50g， 進行攪拌成爲分散液，使用硫酸調整pH爲1。其次，添 加相對於氧化鈦以Fe換算相當於0.2重量％之硝酸鐵水溶 液，進行混合，藉由氧化鈦中所含有之鈉成份將硝酸鐵中 和，繼續於90°C進行加熱1小時。加熱處理後，過濾；將 所得氧化鈦拉子之脫水濾餅，再分散於純水0.5L。將再分 散液之pH，以氫氧化鈉中和至7左右後，經過濾、洗淨 ，於1 1 〇°C乾燥1天1夜後，以擂櫃機粉碎，即得本發明 之光觸媒（試料A)。 此試料A中，α -鹼式氫氧化鐵負載於氧化鈦粒子表 面，藉由梅斯鮑爾分光法以分析確認。又，試料Α含有 α-鹼式氨氧化鐵以Fe換算0.2重量％，1.7重量％之Na2〇 的鈉。 〔實施例2〕 將實施例1所使用之未燒成的紡錘狀二氧化鈦，於 3 50°C下燒成5小時，即得具有比表面積爲63m2/g，平均 長軸徑爲3 8nm，平均短軸徑爲19nm (軸比2.0 )、鈉之 含量爲Na20 0.26重量％的金紅石型之燒成紡錘狀二氧化 駄（試料a )。 除使用此燒成之紡錘狀二氧化鈦，替代未燒成之紡錘 -21 - 200810831 狀二氧化鈦以外，與實施例1同樣進行，即得本發明之光 觸媒（試料B)。 此試料B中，^ -鹼式氫氧化鐵負載於氧化鈦粒子表 面，藉由梅斯鮑爾分光法以分析確認。又’試料B含有 α-鹼式氫氧化鐵以Fe換算0.19重量％，0.26重量％之 Na20的鈉。 〔實施例3〕 (1 )將80g/l之硫酸鈦基的水溶液1L於85°C之溫度 加熱保持3小時，使其水解。將如此所得之水解生成物， 經過濾、洗淨、乾燥，即得氧化鈦。此氧化鈦係具有銳鈦 礦型結晶之球狀氧化鈦；具有平均粒徑4.5nm、比表面積 320m2/g，鹼金屬元素及驗土類金屬元素未分析到。 (2 )在純水0.5L中，添加該紡錘狀二氧化鈦50g， 進行攪拌成爲分散液，使用硫酸調整pH爲1。其次，添 加相對於氧化鈦以Fe換算相當於0.2重量％之硝酸鐵水溶 液與氫氧化鈉，進行混合，將硝酸鐵中和，繼續於90 °C進 行加熱處理1小時。加熱處理後經過濾，將所得氧化鈦之 脫水濾餅再分散於純水0.5L。以氫氧化鈉中和至再分散液 之pH成爲7左右後，經過濾、洗淨，於110°C乾燥1天1 夜後，以擂櫃機粉碎，即得本發明之光觸媒（試料C)。 此試料C，α -鹼式氫氧化鐵負載於氧化鈦粒子表面， 藉由梅斯鮑爾分光法以分析確認。又，試料C含有α -鹼 式氫氧化鐵以Fe換算0.25重量％，鈉等鹼金屬元素、鹼 -22- 200810831 土類金屬元素未分析到。 〔實施例4〕 將實施例1所使用之紡錘狀二氧化鈦與α -鹼式氫氧 化鐵（石原產業公司製，Ν-600 )，採用擂櫃機進行混合 ，即得本發明之光觸媒（試料D)。 此試料D，α -鹼式氫氧化鐵之存在，藉由梅斯飽爾 分光法以分析確認。又，試料D含有α ·鹼式氫氧化鐵以 Fe換算爲0·75重量％、1.19重量％之Na20的鈉。 〔實施例5〕 將實施例1所使用之紡錘狀二氧化鈦的懸浮液與α -氫氧化鐵（石原產業公司製，Ν - 6 0 0 )之懸浮液，置入具 備攪拌機之容器中進行混合，其後經過濾、洗淨，於1 1 〇 °C乾燥1天1夜後，以擂櫃機粉碎，即得本發明之光觸媒 (試料E )。 此試料E，藉由梅斯鮑爾分光法以分析確認α -鹼式氫 氧化鐵之存在。又，試料Ε含有α -鹼式氫氧化鐵以Fe換 算爲0.75重量％、1.19重量％之Na2〇的納。 〔比較例1〕 以使用實施例1之紡錘狀氧化鈦作爲比較試料（試料 F ) ° • 23 - 200810831 〔比較例2〕 以使用實施例2之燒成紡錘狀氧化鈦作爲比較試料（ 試料G)。 〔比較例3〕 以使用實施例3之球狀氧化鈦作爲比較試料（試料Η )° 〔比較例4〕 除不進行添加硝酸鐵後之加熱處理以外，與實施例2 同樣進行即得光觸媒（試料I )。試料I中，藉由梅斯鮑 爾分光法以分析確認負載氫氧化鐵。 〔比較例5〕 將實施例2所得之試料Β，於空氣中350Ϊ：之溫度下 ® 加熱1小時，即得光觸媒（試料J)。試料J中，藉由梅 斯鮑爾分光法以分析確認負載氧化鐵。 . 〔比較例6〕 以使用實施例4之α-鹼式氫氧化鐵（石原產業公司 製，Ν-600 )作爲比較試料（試料& )。 <評估1>乙醛分解活性之評估 將實施例1〜5及比較例1〜6所得之試料（Α〜K) O.lg -24· 200810831 ，均勻展開於6xm p之容器。在容量爲2L之撓性袋中塡 充乙醛與合成空氣，調整乙醛濃度爲2 1 Oppm。在500ml 之可分離燒瓶中設置該容器後，與撓性袋連接，藉由泵以 31/分鐘之速度，使系內之氣體循環，進行反應。到達吸附 平衡後（30分鐘之程度），以5700勒克司之白色螢光燈 進行光照射5 0 0小時。由取樣口以注射筒採取系內之氣體 ，以氣相色譜儀測定乙醛濃度。乙醛濃度之減少速度常數 (K )以下式1計算，評估光觸媒活性。此乙醛之分解反 應速度常數大，則光觸媒活性優越。結果如表1所示。本 發明所得之光觸媒，藉由含有氧化鈦與驗式氫氧化鐵，在 白色螢光燈之光照射下的光觸媒活性高。又，本發明之光 觸媒在紫外線照射下之光觸媒活性亦局，可有效利用紫外 光再加上可見光之故，具有優越之光觸媒活性。 式 1 : In ( C/Co ) =-kt k :反應速度常數（1/h) t :反應時間（h ) C :光照射後之乙醛濃度（PPm ) C〇 ··光照射開始時之乙醛濃度（PPm) •25- 200810831 〔表1〕 試料 反應速度常數 (k)(l/h) 實施例1 A 3.1 實施例2 B 5.0 實施例3 C 1.2 實施例4 D 1.3 實施例5 E 1.7 比較例1 F 0.6 比較例2 G 0.2 比較例3 Η 0·6 比較例4 I 0.6 比較例5 J 0.8 比較例6 K 0.3 在400〜700nm之波長區域，測定實施例2、比較例4 、5所得之試料B、I、J的反射光譜’與實施例2使用之 氧化鈦（試料a)的反射光譜；由在各波長之試料B、I、 J的反射光譜減去氧化鈦（試料a )之反射光譜’求得試 料B、I、J中所含鐵化合物之吸收光譜。其結果如圖1〜3 所示。負載α-鹼式氫氧化鐵之試料B，在400〜5 OOnm之 範圍具有高吸收尖峰。自此吸收尖峰，吸收鹼式氫氧化鐵 的白色螢光燈之光所含400〜5 OOnm的波長之光；藉由此吸 收，氧化鈦顯現光觸媒活性。因此，藉由本發明之光觸媒 -26- 200810831 倂用白色螢光燈之光中所含400〜5 00nm的波長之 色螢光燈之光照射下提高光觸媒活性。 使用實施例1、2所得之試料A、B，將膠體 在黏合劑中，調製使用純水爲分散媒之塗佈劑。 水於分散劑中，使用聚丙烯酸鹽系高分子爲分散 分散體。將此等塗佈劑及水分散體，滴下於6cm ，均勻展開後，於1 1 〇°C之溫度下乾燥1 2小時， 媒體。其後，進行與評估1同樣的試驗之結果， 吸收白色螢光燈之光所含400〜500nm的波長之光 氧化鐵，在白色螢光燈之光照射下，確認穩定的 媒活性。而且，在紫外線照射下亦提高光觸媒活 效利用紫外線加上可見光之故，確認具有優越之 性。 即使將實施例1、2所得之試料A、B，使用 •造粒作爲光觸媒成形體，藉由倂用吸收白色螢 所含4 0 0〜5 0 0 n m的波長之光的鹼式氫氧化鐵，確 螢光燈之光照射下，可穩定提高光觸媒活性。而 外線照射下亦能提高光觸媒活性，能有效利用紫 可見光之故，確認具有優越之光觸媒活性。 〔產業上利用性〕 本發明之光觸媒，藉由倂用吸收白色螢光燈 400〜500nm的波長之光的鹼式氫氧化鐵，相對於 螢光燈等光，具有優越的光觸媒活性；在照射τ 光，在白 二氧化矽 又，將純 劑，即得 P之容器 即得光觸 藉由倂用 的鹼式氫 提高光觸 性，可有 光觸媒活 黏土成形 光燈之光 認在白色 且，在紫 外線加上 等光所含 照射白色 可見光（ -27- 200810831 4〇〇〜8〇〇nm的波長之光）之環境下，可利用爲淨化材料、 半斗防污材料、殺囷材料、防濁材料等廣範圍的用 【圖式簡單說明】 ® 1爲貫施例2之試料B的差份吸收光譜。 圖2爲比較例4之試料I的差份吸收光譜。 圖3、爲比較例5之試料j的差份吸收光譜。[Technical Field] The present invention relates to a photocatalyst, a method for producing the same, a photocatalyst coating agent using the same, a photocatalyst dispersion, and a photo-touching device. More specifically, it relates to a photocatalyst having excellent catalytic activity by light irradiation such as a white fluorescent lamp. [Prior Art] A photocatalyst is excited by irradiating light having a wavelength of energy higher than the band gap, and exhibits a strong catalytic activity. In particular, organic matter or a part of inorganic substances such as NOx have a large oxidation/decomposition power, and can be used as an energy source by using low-cost, low-environment light, and has progressed to environmental purification or deodorization, antifouling, sterilization, etc. in recent years. Application. Further, when the photocatalyst is excited, it is found that the surface is hydrophilic and the contact angle with water is lowered. With this action, it is also possible to develop an application against turbidity and antifouling. As the photocatalyst, a metal compound such as an oxide or a sulfide is used, and in particular, titanium oxide, zinc oxide or the like having fine photocatalytic activity fine particles. Titanium oxide, zinc oxide, etc., the wavelength of the excitation light is in the ultraviolet region of 400 nm. For example, the inside and/or the surface of the titanium oxide particles contain an iron compound such as iron oxide, iron hydroxide or basic ferric hydroxide, and the photocatalytic activity can be enhanced (see Patent Document 1). Further, the surface of the titanium oxide particles is loaded with fine particles of iron oxide of 10 to 100 A, and the utilization efficiency of sunlight can be improved (see Patent Document 2). In the case of the surface of the anatase-type titanium oxide particles, iron oxides such as ferrous oxide, iron oxide, and magnetite are supported, and high activity can be obtained by irradiation with visible light (refer to Patent Document 3) -5 - 200810831 Patent Document 1: Japanese Laid-Open Patent Publication No. Hei No. Hei 7-3 03 83 No. 5 Patent Publication No. JP-A No. Hei. No. Hei. Problem to be solved] • Photocatalysts that have photocatalytic activity by visible light irradiation, and unnecessary light sources such as ultraviolet lamps are not required, and light sources such as sunlight or white fluorescent lamps can be used, and application fields of photocatalysts are expected to be more extensive; Patent Literature The photocatalysts described in 2 and 3 have insufficient photocatalytic activity under the illumination of white fluorescent lamps. Accordingly, the present invention has an object of providing a photocatalyst having excellent photocatalytic activity and a method for producing the same by irradiation with a white fluorescent lamp or the like. [Means for Solving the Problem] The work of the present invention is based on the research and development of the titanium oxide photocatalyst which has excellent activity even in the case of a white fluorescent lamp. Among various iron compounds, a basic iron hydroxide which absorbs light of a wavelength of 400 to 500 nm by using light containing a white fluorescent lamp; a photocatalyst containing such basic iron hydroxide and titanium oxide, in white Under the irradiation of the light of the fluorescent lamp, the photocatalytic activity of about twice or more is obtained as compared with the measurement of the titanium oxide which does not use the basic iron hydroxide by the same conditions, and the present invention has been completed. That is, the present invention has the following features. -6- 200810831 (1) It is a photocatalyst containing at least basic iron hydroxide and titanium oxide. The titanium oxide exhibits photocatalytic activity by absorbing light of a wavelength of 400 to 50,000 nm by basic iron hydroxide. In such a photocatalyst, when irradiating light of a white fluorescent lamp containing light having a wavelength of 400 to 500 nm, the acetaldehyde decomposition reaction rate constant is about twice as high as the acetaldehyde decomposition rate constant of the titanium oxide measured under the same conditions. The above photocatalyst activity. (2) The method for producing a photocatalyst according to the present invention, wherein at least the basic hydrogen hydride is mixed with titanium oxide, preferably in a vehicle containing titanium oxide containing an alkali metal element and/or an alkaline earth metal element, The iron compound is added to carry out a reaction, and basic iron hydroxide is supported on the surface of the particles of the titanium oxide to contain basic iron hydroxide and titanium oxide. (3) in a photocatalyst containing at least basic iron hydroxide and titanium oxide, by using a binder as a photocatalyst coating agent; or by dispersing a dispersing medium as a photocatalyst dispersion; and further containing at least a base The photocatalyst of iron hydroxide and titanium oxide is formed and fixed on the substrate. [Effect of the Invention] The photocatalyst of the present invention has excellent photocatalytic activity under light irradiation such as a white fluorescent lamp having a wavelength of 400 to 500 nm, and does not require a special light source such as an ultraviolet lamp, even indoors such as a fluorescent lamp. Illumination or sunlight can effectively decompose NOx or organic environmental pollutants. The hydrophilic effect can also be expected, and it is suitable for use as a purification material, a deodorizing material, an antifouling material, a sterilizing material, an anti-clouding material, and the like. In addition, low-cost materials such as titanium oxide and basic ferric hydroxide can be used to provide low-cost light 200810831 catalyst. Further, the photocatalyst of the present invention can be used as a liquid composition such as a coating agent or a dispersion, and can be formed as a photo-contacting medium fixed to a substrate, and can be used for imparting antifouling properties or hydrophilic properties. . [Embodiment of the Invention] The present invention is a photocatalyst containing at least basic iron hydroxide and titanium oxide; and light having a wavelength of 400 to 500 nm is absorbed by basic iron hydroxide to exhibit photocatalytic activity of titanium oxide. Therefore, the photocatalytic activity is measured by measuring the acetaldehyde decomposition reaction rate constant as an evaluation criterion (refer to Evaluation 1 described later) when irradiating light of a white fluorescent lamp containing light having a wavelength of 400 to 500 nm. The activity of the photocatalyst of the present invention thus evaluated is preferably about 2 times or more, more preferably about 5 times or more, based on the activity of the titanium oxide itself measured by the same conditions (as assessed by the acetaldehyde decomposition reaction rate constant). Further preferably, it is about 7 times or more, and most preferably about 10 times or more. The photocatalyst of the present invention preferably contains at least basic iron hydroxide and titanium oxide, and absorbs light having a wavelength of 400 to 500 nm by basic iron hydroxide to cause photocatalytic activity of the titanium oxide to form a basic iron hydroxide. The state of bonding with the degree of interaction with the oxidized chin is preferred, and the state of strong bonding is better. In such a state, it is preferred to mix the basic iron hydroxide with titanium oxide, preferably by mixing with a mixer, and more preferably mixing the basic iron hydroxide with the oxidizing agent in a suspended state using a stirrer or the like. . Preferably, the basic iron hydroxide is supported on the surface of the particles of titanium oxide. The supported form of the basic iron hydroxide is not particularly limited; in the case of being adsorbed on the surface of the titanium oxide particles, the titanium oxide -8 - 200810831 particles may have a state in which a hydroxyl group and a hydrogen bond are strongly bonded to the surface. The photocatalyst, the photocatalyst coating agent, the photocatalyst dispersion, and the photocontact medium of the present invention may contain, in addition to the basic iron hydroxide or titanium oxide, a photocatalytic substance such as zinc oxide or cadmium sulfide, and various adsorbents. There are no special restrictions on the form. The basic iron hydroxide contained in the photocatalyst of the present invention is a compound represented by a chemical formula of FeOOH or Fe203·ηΗ20; and crystallinity such as an α state, a /3 state, or an r state, or an amorphous form can be used. In particular, α-basic iron hydroxide has a high absorption effect on light having a wavelength of 400 to 500 nm, and is highly suitable for imparting a photocatalyst having superior activity. The content of the basic iron hydroxide can be appropriately set, and it is preferably 0.01 to 5% by weight, more preferably 0.05 to 2% by weight, based on the total amount of the basic iron hydroxide and the titanium oxide. The titanium oxide contains basic iron hydroxide or a support; more specifically, the basic iron hydroxide containing or supporting the α state can be confirmed by, for example, Mesbauer spectrometry or electron microscopy. The titanium oxide contained in the photocatalyst of the present invention contains anhydrous titanium oxide, hydrous titanium oxide, hydrous titanium oxide, titanium hydroxide, titanic acid, etc. in addition to general titanium oxide; and is anatase or rutile. The crystal form is not particularly limited, and may be amorphous or may be a mixture of the same. Among them, especially those with high crystallinity and high photocatalytic activity are suitable; the illuminate type titanium oxide has a wavelength of excitation light which is slightly larger than that of anatase, and has an oxidation of anatase crystal. Titanium is preferred. Further, a part of the titanium oxide may be a composite oxide such as an alkali metal titanate or an alkali metal salt of titanate; and the inside of the titanium oxide contains an alkali metal element constituting the composite oxide thereof, -9- 200810831 Alkaline earth metal elements are extremely suitable. Further, in the case where no adverse effect is caused in the titanium oxide, a compound selected from a heterogeneous element selected from the group consisting of V, Fe, Co, Ni, Cxi, Ru, Rh, Pd, Ag, and Au, or a heterogeneous element such as oxygen may be contained. The size of the titanium oxide is not particularly limited, and the specific surface area measured by the BET method is preferably in the range of 10 to 400 m 2 /g in the range of 10 to 200 m 2 /g, and in the range of 10 to 100 m 2 /g, and 30 to 80 m 2 / The range of g is most suitable. When the specific surface area is smaller than this range, the adsorption power of the object to be treated such as organic matter and nitrogen oxides is low, and it is not suitable. When it is too large, it is too fine, and it is difficult to obtain a high rise, which is extremely unsuitable. The shape of the particles of the titanium oxide is not particularly limited, and a shaped particle such as a spherical shape or an anisotropic shape, or an indeterminate such as a lumps may be used. In particular, when it has an anisotropic shape, it is easy to obtain excellent photocatalytic activity, which is extremely suitable. The term "anisotropic shape" as used in the present invention is generally referred to as a spindle-shaped particle, a rod-shaped particle, a needle-shaped granular particle, or the like; a primary particle is placed in a stable state on a stationary surface in two parallel directions. The line will hold the image on the plane, and the distance between the lines is the smallest, the width of the particle or the short axis diameter w, and the length of the distance when the parallel line is held by two parallel lines in the direction of the right angle. The shaft diameter is 1, when the maximum stable surface is held by the parallel surface as the particle height h, which satisfies l>w-h. The long axis diameter, shortness, and height can be used for the primary particles from the electron microscope. The arithmetic mean of the particles is obtained. The size of the titanium oxide having an anisotropy used in the present invention is determined by the BET method described above, and is better than the surface excitation, the Zn compound, preferably, the rate of crystallinity, The more the shape is, the more the sub-parallel is. The distance between the two is the grain diameter. The shape of the product is preferably -10- 200810831 10~200m2/g, and the range of 10~100m2/g is better. 3 0~ The range of 80 m2/g is most suitable. Such anisotropically shaped particles preferably have an average major axis diameter in the range of 10 to 500 nm, and an average minor axis diameter in the range of 1 to 25 nm; wherein the axial ratio (average long axis diameter / average short axis diameter) The spindle-shaped particles, the rod-shaped particles, and the acicular particles are preferably 1.5 or more; the axial ratio is preferably in the range of 1.5 to 10, and most preferably in the range of 2 to 7. Further, when a photocatalyst containing titanium oxide and basic ferric hydroxide contains an alkali metal element and/or an alkaline earth metal element, it is excellent in photocatalytic activity. The surface of the titanium oxide particles may have an alkali metal element or an alkaline earth metal element, and may be contained in the interior as described above; or may be contained in the interior of the basic iron hydroxide or in the basic iron hydroxide. The surface may be present at any two locations selected from these. In particular, when the inside and/or the surface of the titanium oxide is contained, the basic iron hydroxide can be strongly loaded and the like, and the photocatalytic activity can be excellent, which is extremely suitable. Further, a part of the titanium oxide may be a composite oxide of an alkali metal titanate or an alkali metal titanate. The metal elements are sodium, potassium, lithium, and the like. The soil-like metal elements are calcium, magnesium, strontium, barium, strontium and the like. Among them, it is preferable to use sodium to absorb light having a wavelength of 400 to 500 nm to easily form basic iron hydroxide. The content of metal quercetin and/or soil-based metal quercetin is converted in terms of oxide relative to the content of basic iron hydroxide and titanium oxide (for example, Na20, K2〇' Li2〇, CaO, MgO, BaO, When it is represented by SrO, BeO or the like, it is preferably in the range of 0.01 to 30% by weight, more preferably 0.05 to 15% by weight, and most preferably 0.05 to 5% by weight. The form of the alkali metal element or the alkaline earth metal element may be any one of an ion, a metal, or an oxide, a hydroxide, or a compound such as 11 - 200810831 chloride, and is not particularly limited. Further, the chemical composition of the present invention also includes the content of basic iron hydroxide and the like, and is an analysis of X-rays. Secondly, when the photocatalyst of the present invention containing at least basic iron hydroxide and titanium oxide is produced, it is possible to use: (a) a pre-manufactured basic iron hydroxide and titanium oxide, using a Hanschel mixer, a Ley mixer Mixing machine such as Ai's mixer, sputum cabinet, nipple, milk stick, etc.; mixing method using a pulverizing mixer such as a ball mill or a colloid mill; or using basic iron oxyhydroxide and oxidized chin in suspension. (b) a method in which a mixture of a titanium compound and an iron compound and a basic compound described later are mixed and neutralized to carry out a reaction to precipitate both of the basic iron hydroxide and the titanium oxide, (c) a method of adding an iron compound to a suspension of pre-manufactured titanium oxide to form a basic iron hydroxide in the presence of titanium oxide, and (d) in a suspension of pre-manufactured basic iron hydroxide; A method in which a titanium compound is added to carry out a reaction, and titanium oxide is formed in the presence of basic iron hydroxide. When these methods are used, photocatalytic substances such as zinc oxide and cadmium sulfide, various adsorbents, and the like may be contained depending on the demand. When pre-manufacturing basic iron hydroxide, an alkali solution such as sodium hydroxide, potassium hydroxide, ammonia, amine or sodium carbonate may be added to a solution of a ferrous compound such as ferrous sulfate, ferrous nitrate or ferrous chloride. a compound that neutralizes part or all of the ferrous compound; secondly, a method of adjusting the pH and simultaneously feeding the gas of -12-200810831 gas, oxygen, etc.; in the ferric sulphate, ferric nitrate, ferric chloride, etc. In the solution of the iron compound, 'addition of a basic compound such as sodium hydroxide, potassium hydroxide 'ammonia' amine or sodium carbonate', after the iron compound is neutralized, for example, at a temperature of 10 to 70 ° C, 'use a ripening treatment or heat treatment or Hydrothermal treatment method. When an alkaline sodium compound is used, it is easy to form a basic iron hydroxide which absorbs light of 400 to 500 nm, which is suitable. The ripening treatment in this method is to treat the neutralized product at a neutralization temperature for a certain period of time to produce a basic iron hydroxide, and the ripening time is preferably from 1 minute to 5 hours. The heat treatment is carried out by neutralizing the product in the range of 50 to 200 ° C in the vehicle liquid, more preferably in the range of 70 to 1 ° ° C to generate the iron hydroxide, and the heating time is 1 〇. Minutes ~ 5 hours are more suitable. When the temperature of the heat treatment is less than 50, it is difficult to perform dehydration in a short time, and it is difficult for the iron hydroxide to be sufficiently modified to become basic iron hydroxide, which is extremely unsuitable. In the hydrothermal treatment, the neutralized product is heated in a temperature range of 1 〇〇 ° C or more, preferably 150 to 200 ° C, using a high temperature and high pressure device such as an autoclave, and is generated under water vapor pressure in response to the temperature. The treatment of the basic iron hydroxide is suitable for heating for 10 minutes to 5 hours. When the temperature of the hydrothermal treatment is higher than 200 °C, it is excessively dehydrated and easily modified to iron oxide, which is not suitable. The obtained basic iron hydroxide can be subjected to an appropriate filtration, washing, drying or the like by a usual method. 〇 When a titanium oxide is previously produced, a well-known method can be used. For example, (1) a method of neutralizing titanium oxide or the like; (2) a method of heating and hydrolyzing titanium sulfate or a titanium sulfate base; (3) using the product obtained by the methods (1) and (2), -13- 200810831 Method of firing or hydrothermal treatment. Further, titanium oxide having an anisotropic shape can also be produced by a known method. For example, a method in which aqueous titanium oxide is treated with an alkaline sodium compound such as sodium hydroxide, sodium carbonate or sodium oxalate can be treated with hydrochloric acid. The titanium oxide-based fine particles obtained by such a method are suitable for use as a so-called spindle. The obtained titanium oxide can be subjected to an appropriate method of filtration, washing, drying, etc. using the usual method. 〇 The titanium oxide containing an alkali metal element or an alkaline earth metal element in advance, which is described in the method (B), is obtained by the above method. The titanium oxide or the titanium oxide precursor described below is preferably mixed with a sodium compound, a hydroxide, a carbonate, a sulfate, a chloride, an oxide, or the like of an alkali metal or an alkaline earth metal, and is fired. Got it. The titanium oxide precursor refers to a compound which is formed into titanium oxide by firing. For example, titanium sulfate, titanium sulfate, titanium chloride, titanium alkoxide, and the like. When hydrous titanium oxide or titanium hydroxide is fired as titanium oxide, the hydrous titanium oxide or titanium hydroxide is a titanium oxide precursor. Further, a titanium oxide containing an alkali metal element or an alkaline earth metal element in advance, wherein in the method (1), the titanium oxide is neutralized with an excess of an alkali metal or an alkaline earth metal-based test compound; It is obtained by adding titanium chloride to neutralize the solution of the basic compound in the metal and soil test. Similarly, the titanium oxide having an anisotropic shape is obtained by treating the aqueous titanium oxide or titanium chloride with a large excess of the sodium compound, preferably by adding the aqueous titanium oxide to the solution of the basic sodium compound. Thereafter, it is obtained by a method of hydrochloric acid treatment. Titanium oxide and sodium having an anisotropic shape obtained by this method are contained in the inside of the particles in an ion state. -14- 200810831 The titanium oxide of the present invention is obtained by pre-baking titanium oxide or firing a titanium oxide precursor, and the titanium oxide has high crystallinity, and the amount of hydroxyl or water contained therein is moderately reduced, and photocatalytic activity is obtained. It is extremely suitable for further improvement. The firing temperature is preferably in the range of 200 to 700 ° C; when the firing temperature is lower than this range, it is difficult to obtain an effect of improving the photocatalytic activity, and it is not suitable. When it is above this range, it is difficult to obtain an improvement effect, and it is easy to cause sintering between the particles of the photocatalyst which is formed or grown, which is extremely unsuitable. The preferred firing temperature ranges from 200 to 600 ° C, more preferably from 300 to 600 ° C. The firing time, the firing gas atmosphere, and the like can be appropriately set; the firing time is suitably, for example, 1 to 1 hour, and the gas atmosphere is fired in a gas atmosphere of air or an oxygen-containing gas, or It is suitable to be carried out under an inert gas atmosphere such as nitrogen or argon. In the present invention, as described in (c), an iron compound is added to a suspension of titanium oxide prepared in advance to carry out a reaction, and when basic ferric hydroxide is formed in the presence of titanium oxide, alkali is easily supported on the surface of the titanium oxide particles. Ferric hydroxide, supported by basic iron hydroxide and iron oxide can exhibit superior photocatalytic activity and is more suitable. A more preferable method in this method is: (A) adding an iron compound to a medium containing titanium oxide, performing an oxidation or ripening treatment, a heat treatment or a hydrothermal treatment, and (B) using an alkali metal element and/or Or a titanium oxide of an alkaline earth metal element, in contact with an iron compound, neutralizing the iron compound by an alkali metal element or an alkaline earth metal element eluted from the titanium oxide; oxidizing or aging the resultant product, and performing heat treatment or heat treatment Or a hydrothermal treatment, a method of reacting, and (C) containing a compound of a titanium oxide and an alkali metal element and/or an alkaline earth element - 1510, 200810831 metal element in a vehicle, and then adding an iron compound for neutralization to neutralize A method in which the product is oxidized or subjected to a aging treatment, a heat treatment or a hydrothermal treatment. (B) The method of gB is not necessary to additionally add a basic compound of a neutralizing agent, and the steps are quite reasonable; it is the most suitable method of the present invention. Further, according to the method described in (B) and (c), the basic iron hydroxide can be supported on the surface of the titanium oxide particles and contain an alkali metal element and/or an alkaline earth metal element. In addition, the method of (C) may also be carried out by adding an iron compound and a metalloid and/or a soil-respecting metal element to the medium, or simultaneously adding them in parallel. In the above methods (A), (B), and (C), inorganic or organic liquids such as water, alcohol, and toluene can be used as the vehicle liquid, and industrial water treatment is easily suitable. Using a ferrous compound as an iron compound, adding a basic compound such as sodium hydroxide, potassium hydroxide, ammonia, an amine or sodium carbonate to the solution to neutralize part or all of the ferrous compound; then, adjusting the pH, At the same time, a gas such as air or oxygen is supplied for oxidation, and it is also possible to carry iron hydroxide on the titanium oxide particles; when an iron compound is used, a step of unnecessary oxidation is preferable. When an aqueous medium is used, it is preferred to use a water-soluble iron compound. The water-soluble iron compound is, for example, iron nitrate, iron sulfate, iron chloride or the like. Alkali metal compound, alkaline earth metal compound, such as hydroxide, carbonate, sulfate, chloride, oxide, etc.; in the photocatalyst of the present invention, the alkali metal element is preferably sodium, and sodium is used. Compounds are more suitable. When the titanium oxide is in contact with the iron compound, the alkali metal element or the alkaline earth metal element contained in the inside or the outside of the titanium oxide particles is easily released, and the reaction with the iron compound is promoted, and it is preferably carried out under acidic conditions. The liquid - -16- 200810831 ρ Η is preferably 3 or less, more preferably 2 or less. When ρ Η is adjusted, sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, or the like can be used. When the product containing titanium oxide and basic ferric hydroxide obtained in this manner is pulverized, it can be subjected to an appropriate filtration, washing, drying, or the like by a usual method, and may be pulverized according to the demand. Drying is carried out at a temperature at which the basic iron hydroxide is not modified to iron oxide, and is preferably carried out at a temperature of, for example, 200 ° C or lower. When filtering and washing, the pH of the vehicle is near neutral, preferably after adjusting the pH to about 7, and the titanium oxide agglomerates to improve the detergency; the unreacted iron in the medium When the compound is present, the iron hydroxide is precipitated, filtered and washed in advance, and the unreacted iron compound is removed and dispersed in the vehicle. Conversely, the pH of the medium is adjusted to the neutral vicinity, and the mixture is filtered and washed. The net is better. As the neutralizing agent, a basic alkali metal compound such as a hydroxide or a carbonate, a basic alkaline earth metal compound, or ammonia, an amine or the like can be used. The vehicle is dispersed and used, preferably water. When the photocatalyst of the present invention is actually used in the photocatalytic reaction, it is convenient to use the photocatalyst to form and granulate as a molded body when it is fixed to the substrate in accordance with the demand. The substrate is formed of various materials such as metal, ceramic tile, porous body, cement, concrete, glass, plastic, fiber, wood, paper, etc.; the shape can be plate-shaped, wave-shaped, honeycomb-shaped, spherical, curved. Shapes and other shapes. When the photocatalyst is fixed to the substrate, the photocatalyst is used as a photocatalyst coating agent. After the coating agent is applied or sprayed onto the surface of the substrate, a drying or baking method can be used. The photocatalyst coating agent contains at least a binder. An inorganic resin or an organic resin can be used as the binder. -17-200810831 adhesive which is difficult to decompose by photocatalytic reaction, such as a polymerizable hydrazine compound, cement, concrete, gypsum, polyoxyxylene resin, fluororesin, etc., wherein the polymerizable hydrazine compound has high durability and is relatively easy to handle. And the generality is high, it is very suitable. The polymerizable hydrazine compound may, for example, be a hydrolyzable decane or a hydrolyzate thereof or a partial condensate thereof, water glass, colloidal cerium oxide, organic polyoxyalkylene or the like. One type of these may be used, or two or more types may be used in combination. The hydrolyzable decane contains at least one hydrolyzable group such as an alkoxy group or a halogen group, and the alkoxy decane has excellent stability and economy, particularly tetraalkoxy such as tetramethoxy decane or tetraethoxy decane. The hydrazine is highly reactive and is very suitable. As the water glass, sodium citrate, potassium citrate or lithium silicate can be used, and among them, sodium citrate is highly stable. Sodium citrate-based water glass, when the molar ratio of Na20 to SiO 2 is in the range of 2 to 4, the hardenability is high; from the balance between stability and hardenability, the Moire ratio is 3 to 3 water glass. Most suitable. For colloidal ruthenium dioxide or organopolyoxane, those having a stanol group can be used. The coating agent may further contain water or a nonaqueous solvent such as an alcohol, a hydrocarbon, an ether, an ether alcohol, an ester, an ether ester or a ketone as a dispersion medium; and the compatibility with the binder may be used. One of these types or a mixture of two or more kinds of solvents is appropriately selected and used. The solid content concentration in the coating agent is preferably in the range of 0.05 to 50% by weight, more preferably in the range of 0.1 to 40% by weight. The photocatalyst preferably contains 20 to 95% by weight of the solid content, more preferably 40 to 95% by weight. The coating agent may contain, in addition to the photocatalyst, the binder, or the dispersion medium, a p Η adjusting agent, a dispersing agent, an antifoaming agent, an emulsifier, a coloring agent, and an increment, insofar as the effects of the present invention are not impaired. Various additives such as agents, fungicides, hardening aids, tackifiers, and the like. When such additives or additives are not volatile, it is preferred to select inorganic agents which are difficult to decompose by photocatalytic action. The photocatalyst of the present invention can be dispersed in a dispersion medium in advance to form a dispersion. When a photocatalyst coating agent using a dispersion is prepared, it is easy to obtain a high degree of dispersibility, which is suitable. Alternatively, the dispersion may be applied to the surface of the substrate at a suitable concentration without using a binder, or after spraying, dried, and fired to fix the photocatalyst to the substrate. The dispersion medium of the dispersion is the same as the dispersion medium to be blended with the coating agent, or one having a high compatibility is selected. Further, a dispersant may be blended in the dispersion, and the type of the dispersant may be appropriately selected depending on the dispersing medium. The dispersing agent is, for example, (1) a surfactant {(a) an anion [carboxylate, sulfate, sulfonate, phosphate, etc.], (b) a cation [alkylamine salt, alkylamine a quaternary ammonium salt, an aromatic quaternary ammonium salt, a heterocyclic quaternary ammonium salt, etc.] (c) amphoteric (betaine type, amino acid type, alkylamine oxide, nitrogen-containing heterocyclic type, etc.), (d) nonionic system (ether type, ether ester type, ester type, nitrogen type, etc.), (2) polyfluorene-based dispersant [alkyl modified polyoxyalkylene, polyalkylene oxide modified poly矽 等 等, etc., (3) phosphate dispersant [sodium phosphate, sodium pyrophosphate, sodium orthophosphate, sodium metaphosphate, sodium tripolyphosphate, etc.], (4) alkanolamines [aminomethyl propyl acrylate] Alcohol, aminomethyl propylene glycol, etc., etc. Among them, a carboxylate-based surfactant, especially a polymer type, is highly suitable for highly dispersing titanium oxide. Specifically, there are polyacrylate {[CH2CH(COOM)]n, bismuth is an alkali metal, soil-measuring metal, ammonium, etc., the following are the same}, acrylate-acrylamide copolymer { (CH2CH (COOM)] Η- [ ch2ch ( CONH2 ) m ) }, acrylic acid-maleate copolymer {[CH2CH(COOH)]η· -19- 200810831 [CH2CH (COOM ) CH ( COOM ) ] m}, ethylene-cis Butenediate copolymer {[CH2CH2]η- [ CH (COOM) CH (COOM)] m} , olefin·maleate copolymer {[(^2011(尺)]11-[CH ( COOM ) CH ( COOM ) 〕 m}, styrene·maleate copolymer {[CH2CH(C6H5)]n-[CH(COOM)CH(COOM)]m}, etc. Photocatalyst in dispersion The compounding amount is preferably in the range of 5 to 90% by weight, more preferably in the range of 10 to 80% by weight. Further, the amount of the dispersing agent is preferably 0.01 to 20% by weight based on the photocatalyst, and 0.01 to 10% by weight. When the photocatalyst is molded and used, it can be mixed with a binder such as clay, diatomaceous earth, organic resin or inorganic resin to form an arbitrary shape. [Examples] Next, the present invention will be described by way of examples; the present invention is not limited thereto (Example 1) (1) Na20 100 g is added to 700 ml of an aqueous solution of titanium tetrachloride having a concentration of 200 g/l of Ti02. A sodium hydroxide aqueous solution having a concentration of /1, and then adjusting the pH of the solution to 7, and then filtering and washing until the conductivity of the filtrate is 100 / / S / cm, and drying to obtain titanium oxide. A spindle-shaped titanium oxide having a rutile crystal having an average major axis diameter of 64 nm, an average minor axis diameter of -20 - 200810831 13 nm (axial ratio of 4. 9 ), and a specific surface area of 160 m 2 /g, and the inside of the titanium oxide particles contains 1.7% by weight (2) 50 g of the spindle-shaped titanium oxide was added to 0.5 L of pure water, and the mixture was stirred to obtain a dispersion liquid, and the pH was adjusted to 1 by using sulfuric acid. Next, the addition was 0.2% by weight in terms of Fe with respect to titanium oxide. The aqueous solution of ferric nitrate is mixed, and the iron nitrate is neutralized by the sodium component contained in the titanium oxide, and heating is continued at 90 ° C for 1 hour. After the heat treatment, it is filtered; the obtained titanium oxide pull-off dewatering cake , and then dispersed in pure water 0. 5L. The pH of the redispersion is neutralized to about 7 with sodium hydroxide, filtered, washed, dried at 1 1 ° C for 1 day and 1 night, and then pulverized by a cabinet machine to obtain the present invention. Photocatalyst (sample A). In the sample A, α-basic iron hydroxide was supported on the surface of the titanium oxide particles, and was confirmed by analysis by Mesbauer spectroscopy. Further, the sample Α contained α-basic iron oxyhydroxide in an amount of 0.2% by weight in terms of Fe and 1.7% by weight of sodium of Na2?. [Example 2] The unfired spindle-shaped titanium oxide used in Example 1 was calcined at 35 ° C for 5 hours to obtain a specific surface area of 63 m 2 /g and an average major axis diameter of 38 nm. A rutile-type fired spindle-shaped cerium oxide having a short-axis diameter of 19 nm (axial ratio of 2.0) and a sodium content of 0.25% by weight of Na20 (sample a). The photocatalyst of the present invention (sample B) was obtained in the same manner as in Example 1 except that the fired spindle-shaped titanium oxide was used instead of the unfired spindle-21 - 200810831 titanium dioxide. In the sample B, the ?-basic iron hydroxide was supported on the surface of the titanium oxide particles, and was confirmed by analysis by Mesbauer spectroscopy. Further, Sample B contained α-basic iron hydroxide in an amount of 0.19% by weight in terms of Fe and 0.26% by weight of sodium Na20. [Example 3] (1) 1 L of an aqueous solution of 80 g/l of a titanium sulfate-based solution was heated and maintained at a temperature of 85 ° C for 3 hours to be hydrolyzed. The hydrolyzate thus obtained is filtered, washed, and dried to obtain titanium oxide. This titanium oxide is a spherical titanium oxide having an anatase crystal; it has an average particle diameter of 4.5 nm and a specific surface area of 320 m 2 /g, and an alkali metal element and a soil-like metal element are not analyzed. (2) 50 g of the spindle-shaped titanium oxide was added to 0.5 L of pure water, and the mixture was stirred to obtain a dispersion liquid, and the pH was adjusted to 1 using sulfuric acid. Next, an aqueous solution of ferric nitrate equivalent to 0.2% by weight in terms of Fe and sodium hydroxide in terms of Fe were added and mixed, and iron nitrate was neutralized, and heat treatment was continued at 90 °C for 1 hour. After the heat treatment, the resulting dehydrated cake of titanium oxide was redispersed in 0.5 L of pure water through filtration. After neutralizing with sodium hydroxide until the pH of the redispersion is about 7, it is filtered, washed, dried at 110 ° C for 1 day and 1 night, and then pulverized by a cabinet machine to obtain a photocatalyst of the present invention (sample C). . This sample C, α-alkali ferric hydroxide was supported on the surface of the titanium oxide particles, and was confirmed by analysis by Mesbauer spectroscopy. Further, Sample C contained α-alkali iron hydroxide in an amount of 0.25% by weight in terms of Fe, and an alkali metal element such as sodium or a base metal element of alkali-22-200810831 was not analyzed. [Example 4] The photocatalyst (sample D) of the present invention was obtained by mixing the spindle-shaped titanium oxide used in Example 1 and α-basic ferric hydroxide (manufactured by Ishihara Sangyo Co., Ltd., Ν-600) by a cabinet machine. ). The presence of this sample D, α-alkali ferric hydroxide was confirmed by analysis by Metzing spectrophotometry. Further, Sample D contained sodium of Na20 which is α·basic iron hydroxide in terms of Fe in an amount of 0.75% by weight and 1.19% by weight. [Example 5] A suspension of the spindle-shaped titanium oxide used in Example 1 and a suspension of α-iron hydroxide (manufactured by Ishihara Sangyo Co., Ltd., Ν-600) were placed in a container equipped with a stirrer and mixed. Thereafter, it was filtered, washed, and dried at 1 1 ° C for 1 day and 1 night, and then pulverized by a cabinet machine to obtain a photocatalyst (sample E) of the present invention. This sample E was confirmed by Metzbauer spectroscopy to confirm the presence of α-base iron oxyhydroxide. Further, the sample Ε contained α-basic ferric hydroxide in an amount of 0.75 wt% and 1.19 wt% of Na2〇 in terms of Fe. [Comparative Example 1] Using the spindle-shaped titanium oxide of Example 1 as a comparative sample (sample F) ° 23 - 200810831 [Comparative Example 2] The fired spindle-shaped titanium oxide of Example 2 was used as a comparative sample (sample G) ). [Comparative Example 3] Using the spherical titanium oxide of Example 3 as a comparative sample (sample Η) ° [Comparative Example 4] A photocatalyst was obtained in the same manner as in Example 2 except that the heating treatment after the addition of ferric nitrate was not carried out. Sample I). In the sample I, the supported iron hydroxide was confirmed by analysis by Mesbauer spectroscopy. [Comparative Example 5] The sample obtained in Example 2 was heated at a temperature of 350 Torr in air for 1 hour to obtain a photocatalyst (sample J). In the sample J, the supported iron oxide was confirmed by analysis by Mesbauer spectroscopy. [Comparative Example 6] The α-basic iron hydroxide (manufactured by Ishihara Sangyo Co., Ltd., Ν-600) of Example 4 was used as a comparative sample (sample &). <Evaluation 1> Evaluation of acetaldehyde decomposition activity The samples (Α~K) O.lg -24·200810831 obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were uniformly spread on a 6 x m p container. The acetaldehyde and synthetic air were charged in a flexible bag having a capacity of 2 L, and the acetaldehyde concentration was adjusted to 2 1 Oppm. After the container was placed in a 500 ml separable flask, it was connected to a flexible bag, and the reaction was carried out by circulating a gas in the system at a rate of 31 / minute by a pump. After reaching the adsorption equilibrium (30 minutes), light irradiation was performed for 5,500 hours with a white fluorescent lamp of 5,700 lux. The gas in the system was taken from the sampling port by a syringe, and the concentration of acetaldehyde was measured by a gas chromatograph. The reduction rate constant (K) of the acetaldehyde concentration was calculated by the following formula 1, and the photocatalytic activity was evaluated. When the decomposition rate constant of the acetaldehyde is large, the photocatalytic activity is excellent. The results are shown in Table 1. The photocatalyst obtained by the present invention has high photocatalytic activity under light irradiation of a white fluorescent lamp by containing titanium oxide and iron hydroxide. Further, the photocatalyst of the present invention has a photocatalytic activity under ultraviolet irradiation, and can effectively utilize ultraviolet light plus visible light to have superior photocatalytic activity. Formula 1: In ( C / Co ) = -kt k : reaction rate constant (1/h) t : reaction time (h ) C : acetaldehyde concentration after light irradiation (PPm ) C〇·· at the beginning of light irradiation Acetaldehyde concentration (PPm) • 25- 200810831 [Table 1] Sample reaction rate constant (k) (l/h) Example 1 A 3.1 Example 2 B 5.0 Example 3 C 1.2 Example 4 D 1.3 Example 5 E 1.7 Comparative Example 1 F 0.6 Comparative Example 2 G 0.2 Comparative Example 3 Η 0·6 Comparative Example 4 I 0.6 Comparative Example 5 J 0.8 Comparative Example 6 K 0.3 In the wavelength range of 400 to 700 nm, Example 2 and Comparative Example 4 were measured. 5: reflectance spectra of the obtained samples B, I, and J and the reflectance spectrum of the titanium oxide (sample a) used in Example 2; and the titanium oxide (sample a) was subtracted from the reflectance spectra of the samples B, I, and J at the respective wavelengths. The reflection spectrum of the 'reaction spectrum of the iron compound contained in the samples B, I, and J. The results are shown in Figures 1 to 3. Sample B loaded with α-basic ferric hydroxide had a high absorption peak in the range of 400 to 50,000 nm. From this absorption peak, the light of the white fluorescent lamp absorbing the basic iron hydroxide contains light having a wavelength of 400 to 500 nm; by this absorption, the titanium oxide exhibits photocatalytic activity. Therefore, the photocatalyst activity of the photocatalyst -26-200810831 of the present invention is enhanced by the light of a fluorescent lamp having a wavelength of 400 to 500 nm contained in the light of the white fluorescent lamp. Using the samples A and B obtained in Examples 1 and 2, a colloid was used in the binder to prepare a coating agent using pure water as a dispersion medium. As the water, a polyacrylate-based polymer is used as a dispersion dispersion in the dispersant. These coating agents and aqueous dispersions were dropped to 6 cm, uniformly spread, and dried at a temperature of 1 1 ° C for 12 hours, and the medium was used. Then, as a result of the same test as in Evaluation 1, the light-oxidized iron having a wavelength of 400 to 500 nm contained in the light of the white fluorescent lamp was absorbed, and the stable medium activity was confirmed under the irradiation of the white fluorescent lamp. Further, under the ultraviolet irradiation, the photocatalyst is also effectively activated by ultraviolet rays and visible light, and it is confirmed to have superior properties. Even in the samples A and B obtained in the first and second embodiments, the granulation was used as the photocatalyst molded body, and the basic iron hydroxide containing the light of the wavelength of 400 to 50,000 nm which absorbs the white fluorescein was used. Under the illumination of the fluorescent light, the photocatalytic activity can be stably improved. The external photocatalyst can also enhance the photocatalytic activity, and can effectively utilize the violet visible light to confirm the superior photocatalytic activity. [Industrial Applicability] The photocatalyst of the present invention has excellent photocatalytic activity with respect to light such as a fluorescent lamp by using a basic iron hydroxide which absorbs light of a wavelength of 400 to 500 nm of a white fluorescent lamp; τ light, in the white cerium oxide, the pure agent, that is, the container of P, the light touches the basic hydrogen to improve the light contact, and the light of the photocatalyst live clay forming light is recognized in white and It can be used as a purification material, a half bucket antifouling material, a killing material, etc. under the environment of ultraviolet light and white light (27-200810831 4〇〇~8〇〇nm wavelength). A wide range of anti-clouding materials, such as a simple description of the drawing, ® 1 is the differential absorption spectrum of the sample B of the second embodiment. 2 is a differential absorption spectrum of Sample I of Comparative Example 4. Fig. 3 is a differential absorption spectrum of sample j of Comparative Example 5.
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