201010949 九、發明說明 【發明所屬之技術領域】 本發明係關於一種具有1〇面體之箱型形狀之氧化鈦粒 子之製造方法。 【先前技術】 最近，有報告指出一種具有10面體之箱型形狀、且主 ^ 要由銳欽礦（anatase)型結晶所成之氧化駄粒子（以下，稱 爲「10面體氧化鈦粒子」）及其製造方法（專利文獻1、2 及非專利文獻1參照）。此外，在此等之報告中，亦報告 1 〇面體氧化鈦粒子係以光觸媒而高活性者。 在上述文獻所報告之10面體氧化鈦粒子之製造方法， ' 幾乎都是將含有四氯化鈦及氧氣之氣體，在某種條件下， 急速加熱再急速冷卻之方法。然而，以此種方法所得到之 10面體氧化鈦粒子，其粒子徑幾乎都在100 nm以上者。 φ 因此，在過去之製造方法中，欲選擇性地獲得粒子徑在 100 nm以下之10面體氧化鈦粒子，便有其困難，從而其 課題即係存在於具有1〇面體之箱型形狀、且又將粒子徑減 小者。 另一方面，在得到微粒子氧化鈦之方法上，已知有將 四氯化鈦以氣相進行氧化時，使用氧氣及水蒸氣作爲氧化 性氣體之方法（專利文獻3參照）。 專利文獻1 :國際公開04/06343 1號手冊 專利文獻2:特開2006-52099號公報 -5- 201010949 專利文獻3 :特許第3656355號公報 非專利文獻1:草野•寺田•阿部•大谷’第98回觸 媒討論會（平成18年9月）討論會A預稿集，234頁 【發明內容】 發明之掲示 發明所欲解決之課題 φ 有鑒於傳統上存在之此種問題點’本發明之目的係提 供一種能選擇性且有效率地製造小粒徑之1 〇面體氧化鈦粒 子之氧化鈦粒子之製造方法。 解決課題之手段 本發明者們，爲解決上述課題而重複地努力進行檢討 ，其結果發現在將四氯化鈦以氣相高溫進行氧化時，如在 特定條件下併用：急速加熱再急速冷卻之方法、以及使用 水蒸氣作爲氧化性氣體之方法時，可選擇性地獲得粒子徑 在100 nm以下之10面體氧化鈦粒子。 亦即，本發明係提供以下之手段。 [1] 一種氧化鈦粒子之製造方法，其係藉由將含有四 氯化鈦蒸氣之氣體、及含有水蒸氣之氧化性氣體進行接觸 ，而選擇性地製造具有10面體之箱型形狀、且粒子徑又在 1 nm~ 10 0 nm範圍之10面體氧化鈦粒子的氧化鈦粒子之製 造方法；其特徵爲包含：將各自已在500°C以上預熱之含 有四氯化鈦蒸氣之氣體、及含有水蒸氣之氧化性氣體加以 -6- 201010949 混合，而送入加熱至800°C以上之環境之步驟。 [2] 如前項[1]之氧化鈦粒子之製造方法，其中該含有 四氯化鈦蒸氣之氣體係含有四氯化鈦蒸氣及氧氣之混合氣 體。 [3] 如前項[1]或[2]之氧化鈦粒子之製造方法，其中該 含有水蒸氣之氧化性氣體係含有水蒸氣及氧氣之混合氣體 〇 φ [4]如前項[1]至[3]中任一項之氧化鈦粒子之製造方法 ，其中在該加熱至800 °C以上之環境之氣體的滯留時間係 在300毫秒以下。 [5] 如前項[4]之氧化鈦粒子之製造方法，其中該滯留 時間係100毫秒以下。 [6] 如前項[1]至[5]中任一項之氧化鈦粒子之製造方法 ，其中該含有四氯化鈦蒸氣之氣體中之四氯化鈦濃度係 3~40體積％。 • [7]如前項[1]至[6]中任一項之氧化鈦粒子之製造方法 ，其中該含有四氯化鈦蒸氣之氣體中之（氧氣（〇2換算）之 物質量[mol] )/ (四氯化鈦之物質量[mol])之比例係 0.1 ~7 ° [8] 如前項[1]至[7]中任一項之氧化鈦粒子之製造方法 ，其中該含有水蒸氣之氧化性氣體中之水蒸氣之濃度係 1〇~80體積 ％。 [9] 如前項[1]至[8]中任一項之氧化鈦粒子之製造方法 ，其中該含有水蒸氣之氧化性氣體中之（氧氣（〇2換算）之 201010949 物質量[mol]) / (水蒸氣之物質量[mol])之比例係Ο.1〜5 〇 [1 0 ]如前項[1 ]至[9 ]中任一項之氧化鈦粒子之製造方 法，其中該含有水蒸氣之氧化性氣體之量，相對於含有四 氯化鈦蒸氣之氣體之量’以體積比計’係0.5~5倍。 [11] 如前項π]至[ίο]中任一項之氧化鈦粒子之製造方 法，其中由該含有四氯化鈦蒸氣之氣體及含有水蒸氣之氣 體所合倂氣體之組成，係四氯化鈦：氧氣：水蒸氣=1 : 0·5〜13 : 0.3〜5 (體積比）。 [12] 如前項[11]之氧化鈦粒子之製造方法，其中由該 含有四氯化鈦蒸氣之氣體及含有水蒸氣之氣體所合倂氣體 之組成，係四氯化鈦：氧氣：水蒸氣=1 : 1〜6 : 0.3~3 ( 體積比）。 發明之效果 • 如上所述，本發明之氧化鈦粒子之製造方法，其係藉 由將四氯化鈦以氣相在高溫下進行氧化時，在一定條件下 將：急速加熱再急速冷卻之方法以及使用水蒸氣作爲氧化 性氣體之方法，加以倂用之方法，從而可選擇性且有效率 地製造一種粒子徑在1 nm~100 nm範圍之10面體氧化鈦粒 子。此外，所得到之小粒徑之氧化鈦粒子，其係適合作爲 光觸媒材料者。因此，根據本發明，可在工業上將適當的 10面體氧化鈦粒子作爲光觸媒材料而製造。 201010949 【實施方式】 實施發明之最佳型態 以下，茲就本發明之氧化鈦粒子之製造方法，參照圖 面加以詳細地說明。 本發明之氧化鈦粒子之製造方法，其係藉由將含有四 氯化鈦蒸氣之氣體、及含有水蒸氣之氧化性氣體進行接觸 ，而選擇性地製造具有10面體之箱型形狀、且粒子徑又在 0 1 nm〜100 nm範圍之10面體氧化鈦粒子的氧化鈦粒子之製 造方法；其特徵爲包含：將各自已在5〇〇 °C以上預熱之含 有四氯化鈦蒸氣之氣體、及含有水蒸氣之氧化性氣體加以 混合，而送入加熱至800 °C以上之環境之步驟。 具體言之，本發明所謂「1 〇面體氧化鈦粒子」，係指 與上述專利文獻1所定義之氧化鈦粒子爲相同地，具有1〇 面體之箱型形狀之氧化鈦粒子。 此外，所謂「選擇性地製造10面體氧化鈦粒子」，係 Φ 指將所得到之氧化鈦粉末任意地進行取樣’並用電子顯微 鏡觀察時，當任意之視野所觀察到的氧化鈦粒子至少在 8 0 %以上時，即該當上述之條件。 本發明所謂「含有水蒸氣之氧化性氣體」’係指含有 水蒸氣、且與四氯化鈦蒸氣以高溫進行接觸時’可使氧化 鈦生成之氣體。在本發明中，所謂含有水蒸氣之氧化性氣 體，以至少含有氧氣及水蒸氣之2成份氣體爲較佳。含有 水蒸氣之氧化性氣體之具體例子’有：含有氧氣（〇2)及水 蒸氣之氣體、或含有臭氧（〇3)及水蒸氣之氣體等。此外’ -9- 201010949 含有水蒸氣之氧化性氣體，可爲將此等氣體加以混合者， 亦可爲此等氣體藉由不活性氣體進行稀釋者。因此，含有 水蒸氣之氧化性氣體，可使用水蒸氣及氧氣之混合氣體、 水蒸氣及不活性氣體之混合氣體、水蒸氣及氧氣及不活性 氣體之混合氣體等，進一步，氧氣及不活性氣體之混合氣 體，亦可使用空氣。 另一方面，在本發明中，含有四氯化鈦蒸氣之氣體， φ 例如可使用四氯化鈦蒸氣及不活性氣體之混合氣體、四氯 化鈦蒸氣及氧氣之混合氣體、四氯化鈦蒸氣及氧氣及不活 性氣體之混合氣體等。此外，氧氣及不活性氣體之混合氣 體，亦可使用空氣。 在本發明中，含有四氯化鈦蒸氣之氣體，其重要者係 :於預熱步驟中不會使氧化鈦生成者。 然而，上述含有四氯化鈦蒸氣之氣體，如僅係四氯化 鈦蒸氣及不活性氣體之混合氣體時，其混合氣體在被送入 # 加熱至800 °C以上之環境時，四氯化鈦蒸氣及氧氣之混合 會不充足，欲選擇性地得到10面體形狀者將有其困難。 因此，在本發明中，含有四氯化鈦蒸氣之氣體，係以 使用四氯化鈦蒸氣及氧氣之混合氣體、或四氯化鈦蒸氣及 氧氣及不活性氣體之混合氣體之任一者爲較佳。 在本發明中，如含有四氯化鈦蒸氣之氣體與含有水蒸 氣之氧化性氣體一接觸時，就會立即產生反應。因此，爲 選擇性地得到1 0面體氧化鈦粒子時，接觸時之溫度係十分 重要的。具體而言，四氯化鈦蒸氣含有水蒸氣之氧化性氣 -10- 201010949 體，必須要在接觸前，即先各自預熱在500 °C以上。如預 熱未達500 °C時，在使含有四氯化鈦蒸氣之氣體與含有水 蒸氣之氣體進行接觸時，就無法得到良好的10面體氧化鈦 粒子。 在本發明中，含有四氯化鈦蒸氣之氣體與含有水蒸氣 之氧化性氣體接觸後，必須將此等氣體送入加熱至8 0 0 °C 以上之環境中。其並以接觸後，立即送入加熱至800 °C以 φ 上之環境中者爲較佳。再者，在加熱至800 °C以上之環境 中之氣體滯留時間，係以300毫秒以下爲較佳，並以1 00毫 秒以下爲最佳。氣體之滯留時間如超過300毫秒時，所得 到之氧化鈦粒子之粒子徑會變大，且金紅石（rutile)型結 晶亦會變多，很難得到良好的1 0面體氧化鈦粒子。 在本發明中，含有四氯化鈦蒸氣之氣體中之四氯化鈦 濃度，係以3〜40體積％爲較佳。四氯化鈦濃度如未達3體 積％時，所得到之1 〇面體氧化鈦粒子之比例會變少。另一 方面，四氯化鈦濃度如超過40體積％時，氧化鈦粒子之粒 子徑會變大。因此，含有四氯化鈦蒸氣之氣體中之四氯化 鈦濃度，係以3〜40體積％之範圍爲較佳，並以15〜30體積％ 之範圍爲最佳。 在本發明中，含有四氯化鈦蒸氣之氣體中之（氧氣 (〇2換算）之物質量[mol]) / (四氯化鈦之物質量[m〇l]) 之比例，係以〇.1~7爲較佳。 該値如未達〇· 1時，所得到之1 0面體氧化鈦粒子之比 例會減少。另一方面，該値如超過7時，氧化鈦粒子之粒 -11 - 201010949 子徑就會變大。因此，含有四氯化鈦蒸氣之氣體中之（氧 氣（〇2換算）之物質量[mol] )/ (四氯化鈦之物質量[mol] )之比例，係以0.1 ~7之範圍爲較佳，並以2〜5之範圍爲最 佳。 在本發明中，含有水蒸氣之氧化性氣體中之水蒸氣濃 度，係以10〜80體積％爲較佳。水蒸氣之濃度如未達10體 積％時，氧化鈦粒子之粒子徑會變大。另一方面，水蒸氣 @ 之濃度如超過80體積％時，所得到之10面體氧化鈦粒子之 比例會減少。因此，含有水蒸氣之氧化性氣體中之水蒸氣 濃度，係以10〜80體積％之範圍爲較佳，並以15~40體積％ 之範圍爲最佳。 在本發明中，含有水蒸氣之氧化性氣體中之（氧氣 (〇2換算）之物質量[mol]) / (水蒸氣之物質量[mol])之 比例，係以0.1~5爲較佳。該値如未達〇.1時，所得到之1〇 面體氧化鈦粒子之比例會減少。另一方面，該値如超過5 ❹ 時，所得到之1 0面體氧化鈦粒子之比例會減少。因此，含 有水蒸氣之氧化性氣體中之（氧氣（〇2換算）之物質量[mol] )/ (水蒸氣之物質量[mol])之比例，係以〇」~5之範圍 爲較佳，並以0.5〜3之範圍爲最佳。 在本發明中，含有水蒸氣之氧化性氣體之量，相對於 含有四氯化鈦蒸氣之氣體之量，以體積比計，係以〇.5 ~5 倍爲較佳。該體積比如未達0.5倍時，氧化鈦粒子之粒子 徑會變大。另一方面，該體積比如超過5倍時，10面體氧 化鈦粒子之比例會減少。因此，含有水蒸氣之氧化性氣體 -12- 201010949 之量，相對於含有四氯化鈦蒸氣之氣體之量’以體積比計 ，係以0.5〜5倍之範圍爲較佳，並以〇.8~2之範圍爲最佳。 在本發明中，由含有四氯化鈦蒸氣之氣體及含有水蒸 氣之氣體所合倂氣體中，四氯化鈦及氧氣及水蒸氣之體積 比（四氯化鈦：氧氣：水蒸氣）係以1 : 〇·5〜13 : 0.3~5 ( 體積比）之範圍爲較佳，並以四氯化鈦：氧氣：水蒸氣= 1: 1~6: 0.5~3(體積比）之範圍爲最佳。 @ 如超過此範圍時，很難選擇性地得到1 〇面體氧化鈦粒 子。其原因目前尙不明瞭，惟推定係與：四氯化鈦因水蒸 氣而加水分解時之濃度、速度、加水分解以後之未反應四 氯化鈦與氧氣之反應速度、以及在反應區域之滯留時間等 有關者。 如上所述，適用於本發明之氧化鈦粒子之製造方法， 係將四氯化鈦以氣相在高溫下進行氧化時，在上述條件下 倂用：急速加熱再急速冷卻之方法以及使用水蒸氣作爲氧 • 化性氣體之方法，而可選擇性且有效率地製造粒子徑在1 nm〜100 nm範圍之10面體氧化鈦粒子。此外，所得到之小 粒徑之氧化鈦粒子，其係適合作爲光觸媒材料者。因此， 根據本發明，可在工業上將適當的10面體氧化鈦粒子作爲 光觸媒材料而製造。 其次，圖1中係表示：在適合本發明之氧化鈦粒子之 製造方法上所使用反應裝置之一例。 該反應裝置，如圖1所示，係具備有：用以使含有四 氯化鈦蒸氣之氣體、及含有水蒸氣之氧化性氣體進行接觸 -13- 201010949 之反應管1、用以將該反應管1之一部（加熱部1a)局部地 進行加熱之紅外線電器爐2、用以將反應管1內所生成之氧 化鈦粉末回收之生成物回收部3。 具體而言，反應管1，可使用例如由石英等所成之圓 筒管。此外，在反應管1，在用以將含有水蒸氣之氧化性 氣體導入之導入管4連接於一端側（上流側）之同時’該 用以將含有四氯化鈦蒸氣之氣體導入之導入管5則由一端 @ 側（上流側）插入於內部。 在導入管4之上流側，係設有例如：將水及氧氣（〇2) 及氮氣導入之導入口 4a、及將該導入口 4a所導入之水進 行氣化之氣化器6。由導入口 4a所導入之含有水蒸氣之氧 化性氣體（含有水蒸氣及氧氣（〇2)及氮氣），係藉由通過 氣化器6，而變成水蒸氣、氧氣（02)、及氮氣之混合氣體 ，並由導入管4被導入反應管1。 在導入管5之上流側，係設有例如：將四氯化鈦 φ (TiCl4)導入之導入口 5a、將氧氣（02)導入之導入口 5b、及 將該導入口 5a所導入之四氯化鈦（TiCl4)進行氣化之氣化 器7»從而，由導入口 5a所導入之含有四氯化鈦（TiCU)蒸 氣之氣體（含有四氯化鈦及氧氣（〇2))，係藉由通過氣化 器6，而變成四氯化鈦（TiCl4)蒸氣及氧氣（〇2)之混合氣體 ，並由導入管5被導入反應管1。 此外，如前所述，導入管5係由反應管1之一端側（上 流側）開始被收容於反應管1之內部。接著，在導入管5之 前端上係照射由紅外線電器爐2而來之紅外線。接著，由 -14- 201010949 反應管1之他端側（下流側）開始，則插入有緩衝物8。緩 衝物8，係將導入於反應管1內之氣體導引至成爲高溫之反 應管1之外周側者，其例如有將石英管之先端作成尖銳形 狀且閉塞者。此外，緩衝物8的先端在反應管1內與導入管 5的先端成相對方向，該導入管5之先端部分及緩衝物8之 先端部分，係位置在反應管1之加熱部la上。此外，緩衝 物8，亦具有使在後述之反應區B上之氣體之滞留時間縮 φ 短之功能。 在加熱部la之反應管1，係纏繞著白金板。加熱部la ，則藉由該白金板與紅外線電器爐2之組合，而能夠急速 加熱再急速冷卻。亦即，藉由使紅外線電器爐2所照射之 紅外線，由白金板吸收並發熱，而僅讓與白金接觸之部分 局部地被加熱。藉此，可將加熱部la加熱至120 0°C左右 。此外，加熱部1 a之溫度，藉由將紅外線電器爐2之紅外 線照射以溫度控制器（未圖示）加以控制，即可任意地加 • 以設定。 再者，在白金板纏繞之加熱部la之中，在導入管5之 . 先端前，係含有四氯化鈦蒸氣之氣體及含有水蒸氣之氧化 性氣體被預熱之部分（所謂「預熱區A」）：而由導入管 5之先端往下流，更具體言之，係由導入管5之先端到加熱 部1 a之端部爲止’則係將四氯化鈦以氣相在高溫下進行 氧化之部分（所謂「反應區B」）。 生成物回收部3係袋濾器，其係將通過連接於反應管1 之他端側（下流側）之排出管9而在反應管1內所生成之氧 -15- 201010949 化鈦粉末加以回收。再者，在生成物回收部3’其係以排 出管9不會發生閉塞，且可由下游以幫浦（未圖示）吸引 者爲較佳。 在具有上述構成之反應裝置中，係將：由導入管4導 入於反應管1之含有水蒸氣之氧化性氣體、及通過導入管5 ' 之含有四氯化鈦蒸氣之氣體，各自於預熱區A預熱至500 。(：以上後，再於反應區B進行混合’而加熱至800°C以上 @ 。含有四氯化鈦蒸氣之氣體及含有水蒸氣之氧化性氣體’ 係於反應區B接觸後立即發生反應’所得到之反應氣體’ 則以3 00毫秒以下之滯留時間通過反應區B。然後，通過 反應區B之氣體，被立即冷卻後再送回生成物回收部3。 在使用此種反應裝置時，因爲在將四氯化鈦以氣相高 溫進行氧化時，可倂用：急速加熱再急速冷卻之方法、以 及使用水蒸氣作爲氧化性氣體之方法之故’在上述條件下 ，即可選擇性且有效率地製得具有1〇面體之箱型形狀、且 ^ 粒子徑在1 nm〜1〇〇 nm範圍之10面體氧化鈦粒子。 實施例 以下茲舉出實施例進一步地詳細說明本發明之效果。 惟本發明並不受這些實施例之任何限制；其可在不變更要 旨之範圍內做適當的變更而實施。 實施例1 在實施例1中’係使用上述圖1所示之反應裝置’並於 -16- 201010949 下述條件下實際地進行氧化鈦粉末之製造。 亦即，在反應管1之加熱部1 a上將白金板纏繞約1 〇 cm左右，在該部分（加熱部la)上使紅外線加熱爐2之紅 外線照射之情形下，將紅外線加熱爐2以溫度控制器控制 ，同時使白金板之表面溫度達到12〇〇°C ° 反應管1係使用內徑21.4 mm之石英管。緩衝物8’係 使用外徑12.7 mm之石英管’並將該先端作成約30°之尖 銳形狀且閉塞者。此外，加熱部1a之橫斷面積’係2·3 cm2 ° 將含有四氯化鈦蒸氣之氣體導入之導入管5之先端’ 係配置於：由纏繞有白金板之加熱部la (白金板之寬度係 10 cm，因此加熱部la之寬度亦爲1〇 cm)之上流先端起 算之6 cm下流處，到此作爲預熱區A。由導入管5之先端 起之下流處，直至加熱部1 a之下流先端爲止處，則爲高 熱之反應區B ( 4 cm)。 在含有水蒸氣之氧化性氣體，係使用含有水蒸氣及氧 氣（〇2)及氮氣之混合氣體。水、氧氣、及氮氣之混合氣體 在由導入口 4a導入，並使其通過氣化器6之後，再由導入 管5之先端將含有水蒸氣之氧化性氣體導入於反應管1。再 者，通過氣化器6後之混合氣體之組成，係水蒸氣：氧氣 :氮氣= 20: 20: 60(體積比），且以流量合計係成爲 600 NmL/min之情形下而導入混合氣體。 在含有四氯化鈦蒸氣之氣體，係使用四氯化鈦蒸氣及 氧氣（〇2)之混合氣體。將TiCl4由導入口 5a導入，再將氧 -17- 201010949 氣（〇2)由導入口 5b導入’且使其通過氣化器7之後’再由 導入管5之先端導入於反應管1。此外，通過氣化器7後之 混合氣體之組成，係四氯化鈦：氧氣=20 : 80 (體積比） ，且以流量合計係成爲6〇〇 NmL/min之情形下而導入混合 氣體。 再者，全反應氣體之組成，係四氯化鈦：氧氣：水蒸 氣=1: 5: 1，且在反應區B之反應氣體之滯留時間，約 爲5 0毫秒。 比較例1 除含有水蒸氣之氧化性氣體，改成不含水蒸氣之氧化 性氣體，亦即將氧氣及氮氣之混合氣體由導入口 4a導入 以外，其餘均與實施例1在同樣之條件下進行氧化鈦粉末 之製造。 φ 比較例2 除不導入含有水蒸氣之氧化性氣體，僅將四氯化鈦蒸 氣及氧氣（02)之混合氣體（四氯化鈦濃度爲6%)由導入管 5慢慢地（3 00 NmL/min )導入以外，其餘均與實施例1在 同樣之條件下進行氧化鈦粉末之製造。 接著，將此等實施例1、比較例1、及比較例2所得到 之氧化鈦粉末，以電子顯微鏡進行觀察。 以下，茲將實施例1、比較例1、及比較例2之各製造 條件、以及所得到之氧化鈦粒子之觀察結果，整理如表1 -18- 201010949 中所示者。此外，氧化鈦粉末，係採用任意採樣之3處所 之粉末，各自導入於掃描型電子顯微鏡之試料室中，並於 5處所以上之視野下進行觀察。201010949 IX. Description of the Invention [Technical Field] The present invention relates to a method for producing a titanium oxide particle having a box shape of a 1-facet body. [Prior Art] Recently, there has been reported a cerium oxide particle having a box-shaped shape of a decahedron and mainly composed of an anatase type crystal (hereinafter, referred to as "10-facet titanium oxide particle". ") and its manufacturing method (refer to Patent Documents 1, 2 and Non-Patent Document 1). In addition, in these reports, it is also reported that the titanium oxide particles of the facet are highly active with photocatalyst. The method for producing a 10-faceted titanium oxide particle reported in the above document is a method in which a gas containing titanium tetrachloride and oxygen is rapidly heated under a certain condition and then rapidly cooled. However, the 10-facet titanium oxide particles obtained by such a method have a particle diameter of almost 100 nm or more. φ Therefore, in the conventional manufacturing method, it is difficult to selectively obtain a 10-faceted titanium oxide particle having a particle diameter of 100 nm or less, and the problem is that it exists in a box shape having a 1-facet body. And the particle diameter is reduced. On the other hand, in the method of obtaining fine titanium oxide, a method of using oxygen gas and water vapor as an oxidizing gas when titanium tetrachloride is oxidized in a gas phase is known (refer to Patent Document 3). Patent Document 1: International Publication No. 04/06343 No. 1 Patent Document 2: JP-A-2006-52099-A-5-201010949 Patent Document 3: Patent No. 3365355 Non-Patent Document 1: Kusano, Terada, Abe, Otani 98 Catalyst Workshop (September 1999) Seminar A Pre-collection, 234 pages [Invention] The invention is intended to solve the problem to be solved by the invention. In view of the conventional problem, the present invention It is an object of the invention to provide a process for producing titanium oxide particles of a small particle size titanium oxide particle selectively and efficiently. Means for Solving the Problems As a result of intensive efforts to solve the above problems, the present inventors have found that when titanium tetrachloride is oxidized at a high temperature in a gas phase, it is used under a specific condition: rapid heating and rapid cooling. When the method and the method using water vapor as the oxidizing gas, the 10-sided titanium oxide particles having a particle diameter of 100 nm or less can be selectively obtained. That is, the present invention provides the following means. [1] A method for producing titanium oxide particles by selectively contacting a gas containing titanium tetrachloride vapor and an oxidizing gas containing water vapor to form a box shape having a decahedron And a method for producing titanium oxide particles of a 10-faceted titanium oxide particle having a particle diameter in the range of 1 nm to 100 nm; characterized in that it comprises: titanium tetrachloride vapor which has been preheated at 500 ° C or higher. The gas and the oxidizing gas containing water vapor are mixed in -6-201010949, and fed to an environment heated to 800 ° C or higher. [2] The method for producing titanium oxide particles according to the above [1], wherein the gas system containing titanium tetrachloride vapor contains a mixed gas of titanium tetrachloride vapor and oxygen. [3] The method for producing a titanium oxide particle according to the above [1] or [2], wherein the oxidizing gas system containing water vapor contains a mixed gas of water vapor and oxygen 〇 φ [4] as in the above [1] to [ The method for producing a titanium oxide particle according to any one of the preceding claims, wherein the residence time of the gas in the environment heated to 800 ° C or higher is 300 msec or less. [5] The method for producing titanium oxide particles according to the above [4], wherein the residence time is 100 milliseconds or less. [6] The method for producing titanium oxide particles according to any one of [1] to [5] wherein the concentration of titanium tetrachloride in the gas containing titanium tetrachloride vapor is 3 to 40% by volume. [7] The method for producing a titanium oxide particle according to any one of the above [1] to [6] wherein the mass of the oxygen (in terms of 〇2) [mol] in the gas containing titanium tetrachloride vapor The method of producing the titanium oxide particles according to any one of the above items [1] to [7], wherein the water vapor is contained in the method of producing a titanium oxide. The concentration of water vapor in the oxidizing gas is from 1% to 80% by volume. [9] The method for producing a titanium oxide particle according to any one of the above [1] to [8], wherein the oxygen-containing oxidizing gas (201010949 mass [mol] of oxygen (in terms of 〇2)) The method of producing the titanium oxide particles according to any one of the above items [1] to [9], wherein the water vapor is contained in the water vapor. The amount of the oxidizing gas is 0.5 to 5 times the volume ratio of the gas containing titanium tetrachloride vapor. [11] The method for producing a titanium oxide particle according to any one of the above items, wherein the composition of the gas containing the titanium tetrachloride vapor and the gas containing the water vapor is tetrachloro Titanium: Oxygen: Water vapor = 1: 0·5 to 13: 0.3 to 5 (volume ratio). [12] The method for producing titanium oxide particles according to the above [11], wherein the composition of the gas containing the titanium tetrachloride vapor and the gas containing water vapor is titanium tetrachloride: oxygen: water vapor =1 : 1 to 6 : 0.3 to 3 (volume ratio). Advantageous Effects of Invention According to the method for producing titanium oxide particles of the present invention, when titanium tetrachloride is oxidized in a gas phase at a high temperature, a method of rapidly heating and rapid cooling under certain conditions is employed. And a method of using water vapor as an oxidizing gas, and a method of using the same, thereby selectively and efficiently producing a 10-faceted titanium oxide particle having a particle diameter in the range of 1 nm to 100 nm. Further, the obtained titanium oxide particles having a small particle diameter are suitable as a photocatalyst material. Therefore, according to the present invention, an appropriate octahedral titanium oxide particle can be industrially produced as a photocatalytic material. [Embodiment] BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing titanium oxide particles of the present invention will be described in detail with reference to the drawings. The method for producing titanium oxide particles of the present invention is characterized in that a gas having a titanium tetrachloride vapor and an oxidizing gas containing water vapor are brought into contact with each other to selectively produce a box shape having a decahedron and A method for producing titanium oxide particles of a 10-faceted titanium oxide particle having a particle diameter in the range of 0 1 nm to 100 nm; characterized in that it comprises: titanium tetrachloride vapor which has been preheated at 5 ° C or higher The gas and the oxidizing gas containing water vapor are mixed and fed to an environment heated to 800 ° C or higher. Specifically, the "1 〇 体 氧化钛 氧化钛 氧化钛 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 In addition, "selectively producing a tensahedral titanium oxide particle" means that the obtained titanium oxide powder is arbitrarily sampled' and observed by an electron microscope, and the titanium oxide particles observed in an arbitrary field of view are at least When it is more than 80%, it should be the above conditions. The term "oxidizing gas containing water vapor" as used in the present invention means a gas which can form titanium oxide when it contains water vapor and is in contact with titanium tetrachloride vapor at a high temperature. In the present invention, the oxidizing gas containing water vapor is preferably a two-component gas containing at least oxygen and water vapor. Specific examples of the oxidizing gas containing water vapor include a gas containing oxygen (〇2) and water vapor, a gas containing ozone (〇3) and water vapor, and the like. In addition, -9-201010949 contains an oxidizing gas containing water vapor, which may be used for mixing such gases, or may be diluted by an inert gas. Therefore, the oxidizing gas containing water vapor can be a mixed gas of steam and oxygen, a mixed gas of steam and an inert gas, a mixture of water vapor and oxygen and an inert gas, and further, oxygen and an inert gas. Air can also be used as a mixed gas. On the other hand, in the present invention, a gas containing titanium tetrachloride vapor, φ, for example, a mixed gas of titanium tetrachloride vapor and an inert gas, a mixed gas of titanium tetrachloride vapor and oxygen, titanium tetrachloride can be used. A mixture of steam and oxygen and an inert gas. In addition, air may be used as a mixture of oxygen and an inert gas. In the present invention, a gas containing titanium tetrachloride vapor is important in that the titanium oxide is not formed in the preheating step. However, when the gas containing titanium tetrachloride vapor is a mixed gas of only titanium tetrachloride vapor and an inert gas, the mixed gas is tetrachlorinated when it is sent to an environment heated to 800 ° C or higher. The mixing of titanium vapor and oxygen will be insufficient, and it will be difficult to selectively obtain a 10-faceted shape. Therefore, in the present invention, the gas containing titanium tetrachloride vapor is either a mixed gas of titanium tetrachloride vapor and oxygen, or a titanium tetrachloride vapor and a mixed gas of oxygen and an inert gas. Preferably. In the present invention, when a gas containing titanium tetrachloride vapor is brought into contact with an oxidizing gas containing water vapor, a reaction occurs immediately. Therefore, in order to selectively obtain the 10 surface oxide titanium oxide particles, the temperature at the time of contact is very important. Specifically, the titanium tetrachloride vapor contains water vapor oxidizing gas -10- 201010949, which must be preheated at 500 ° C or higher before contact. When the preheating is less than 500 °C, when a gas containing titanium tetrachloride vapor is brought into contact with a gas containing water vapor, good 10 facet titanium oxide particles cannot be obtained. In the present invention, after the gas containing titanium tetrachloride vapor is brought into contact with the oxidizing gas containing water vapor, it is necessary to feed the gas to an environment heated to 80 ° C or higher. It is preferably fed to the environment heated to 800 ° C in φ immediately after contact. Further, the gas residence time in an environment heated to 800 ° C or higher is preferably 300 msec or less, and preferably 100 sec or less. When the residence time of the gas exceeds 300 msec, the particle diameter of the obtained titanium oxide particles becomes large, and the rutile type crystals also become large, and it is difficult to obtain good 10 surface oxide titanium oxide particles. In the present invention, the concentration of titanium tetrachloride in the gas containing titanium tetrachloride vapor is preferably from 3 to 40% by volume. When the concentration of titanium tetrachloride is less than 3% by volume, the ratio of the obtained titanium oxide particles of the bismuth is small. On the other hand, when the concentration of titanium tetrachloride is more than 40% by volume, the particle diameter of the titanium oxide particles becomes large. Therefore, the concentration of titanium tetrachloride in the gas containing titanium tetrachloride vapor is preferably in the range of 3 to 40% by volume, and more preferably in the range of 15 to 30% by volume. In the present invention, the ratio of the mass of the oxygen (in terms of 〇2) [mol] / (the mass of titanium tetrachloride [m〇l]) in the gas containing titanium tetrachloride vapor is 〇 .1~7 is preferred. If the amount is less than 〇·1, the ratio of the obtained zero-surface titanium oxide particles is reduced. On the other hand, when the amount exceeds 7, the particle diameter of the titanium oxide particles becomes larger. Therefore, the ratio of the mass of oxygen (in terms of 〇2) [mol] / (the mass of titanium tetrachloride) [mol] in the gas containing titanium tetrachloride vapor is in the range of 0.1 to 7. Preferably, it is preferably in the range of 2 to 5. In the present invention, the water vapor concentration in the oxidizing gas containing water vapor is preferably 10 to 80% by volume. When the concentration of water vapor is less than 10% by volume, the particle diameter of the titanium oxide particles becomes large. On the other hand, when the concentration of water vapor @ exceeds 80% by volume, the ratio of the obtained 10-facet titanium oxide particles is reduced. Therefore, the water vapor concentration in the oxidizing gas containing water vapor is preferably in the range of 10 to 80% by volume, and more preferably in the range of 15 to 40% by volume. In the present invention, the ratio of (the mass of oxygen (in terms of 〇2) [mol]) / (the mass of water vapor [mol]) in the oxidizing gas containing water vapor is preferably 0.1 to 5. . If the enthalpy is less than 〇1, the ratio of the obtained titanium oxide particles of the bismuth is reduced. On the other hand, when the enthalpy exceeds 5 Torr, the ratio of the obtained zero-surface titanium oxide particles is reduced. Therefore, the ratio of (the mass of oxygen (in terms of 〇2) [mol]) / (the mass of water vapor [mol]) in the oxidizing gas containing water vapor is preferably in the range of 〇"~5". And the range of 0.5 to 3 is the best. In the present invention, the amount of the oxidizing gas containing water vapor is preferably 5% to 5% by volume based on the amount of the gas containing titanium tetrachloride vapor. When the volume is less than 0.5 times, the particle diameter of the titanium oxide particles becomes large. On the other hand, when the volume is more than 5 times, the proportion of the octahedral titanium oxide particles is reduced. Therefore, the amount of the oxidizing gas containing water vapor -12-201010949 is preferably in the range of 0.5 to 5 times by volume relative to the amount of the gas containing titanium tetrachloride vapor, and is preferably 〇. The range of 8~2 is the best. In the present invention, the volume ratio of titanium tetrachloride and oxygen and water vapor (titanium tetrachloride: oxygen: water vapor) in the gas combined with the gas containing titanium tetrachloride vapor and the gas containing water vapor The range of 1: 〇·5~13 : 0.3~5 (volume ratio) is preferred, and the range of titanium tetrachloride: oxygen: water vapor = 1: 1~6: 0.5~3 (volume ratio) is optimal. @ If it exceeds this range, it is difficult to selectively obtain 1 〇 facet titanium oxide particles. The reason for this is unclear, but it is presumed that the concentration and speed of titanium tetrachloride due to water vapor decomposition, the reaction rate of unreacted titanium tetrachloride and oxygen after hydrolysis, and the retention in the reaction zone Time and other related parties. As described above, in the method for producing titanium oxide particles according to the present invention, when titanium tetrachloride is oxidized in a gas phase at a high temperature, it is used under the above conditions: rapid heating and rapid cooling, and use of steam. As a method of oxygenating a gas, a 10-miched titanium oxide particle having a particle diameter in the range of 1 nm to 100 nm can be selectively and efficiently produced. Further, the obtained titanium oxide particles having a small particle diameter are suitable as a photocatalytic material. Therefore, according to the present invention, an appropriate tenahedral titanium oxide particle can be industrially produced as a photocatalyst material. Next, Fig. 1 shows an example of a reaction apparatus used in a method for producing titanium oxide particles of the present invention. The reaction apparatus, as shown in Fig. 1, is provided with a reaction tube for contacting a gas containing titanium tetrachloride vapor and an oxidizing gas containing water vapor to -13 to 10,910,949 for the reaction. An infrared electric furnace 2 in which one of the tubes 1 (heating portion 1a) is locally heated, and a product collecting portion 3 for recovering the titanium oxide powder generated in the reaction tube 1. Specifically, as the reaction tube 1, a cylindrical tube made of, for example, quartz or the like can be used. Further, in the reaction tube 1, the introduction tube 4 for introducing the oxidizing gas containing water vapor is connected to the one end side (upstream side) while the introduction tube for introducing the gas containing titanium tetrachloride vapor 5 is inserted inside by the @@ side (upstream side). On the flow side of the introduction pipe 4, for example, an inlet port 4a for introducing water and oxygen (?2) and nitrogen gas, and a vaporizer 6 for vaporizing the water introduced into the inlet port 4a are provided. The water vapor-containing oxidizing gas (containing water vapor and oxygen (〇2) and nitrogen gas) introduced from the inlet 4a is passed through the gasifier 6 to become steam, oxygen (02), and nitrogen. The gas is mixed and introduced into the reaction tube 1 by the introduction tube 4. On the flow side of the introduction pipe 5, for example, an introduction port 5a into which titanium tetrachloride φ (TiCl4) is introduced, an introduction port 5b through which oxygen (02) is introduced, and tetrachloride introduced into the introduction port 5a are provided. The gasifier 7» which is vaporized by titanium (TiCl4), thereby introducing a gas containing titanium tetrachloride (TiCU) vapor (containing titanium tetrachloride and oxygen (〇2)) introduced from the inlet 5a From the gasifier 6, it becomes a mixed gas of titanium tetrachloride (TiCl4) vapor and oxygen (?2), and is introduced into the reaction tube 1 by the introduction pipe 5. Further, as described above, the introduction tube 5 is housed inside the reaction tube 1 from the one end side (upstream side) of the reaction tube 1. Next, the infrared rays from the infrared electric furnace 2 are irradiated on the leading end of the introduction tube 5. Next, starting from the other end side (downstream side) of the reaction tube 1 from -14 to 201010949, the buffer 8 is inserted. The buffer 8 guides the gas introduced into the reaction tube 1 to the outer peripheral side of the reaction tube 1 which is a high temperature, and for example, the tip end of the quartz tube is formed into a sharp shape and is closed. Further, the tip end of the buffer 8 is opposed to the tip end of the introduction tube 5 in the reaction tube 1, and the tip end portion of the introduction tube 5 and the tip end portion of the buffer 8 are positioned on the heating portion 1a of the reaction tube 1. Further, the buffer 8 also has a function of shortening the residence time of the gas in the reaction zone B to be described later. The reaction tube 1 of the heating unit 1a is wound with a platinum plate. The heating unit 1a can be rapidly heated and rapidly cooled by the combination of the platinum plate and the infrared electric furnace 2. That is, the infrared rays irradiated by the infrared electric furnace 2 are absorbed by the platinum plate and generate heat, and only the portion in contact with the platinum is partially heated. Thereby, the heating portion 1a can be heated to about 120 °C. Further, the temperature of the heating portion 1a can be arbitrarily set by controlling the infrared rays of the infrared electric furnace 2 to be controlled by a temperature controller (not shown). Further, in the heating portion 1a of the platinum plate, before the tip end, the gas containing titanium tetrachloride vapor and the portion containing the oxidizing gas containing water vapor are preheated (so-called "preheating" Zone A"): while flowing from the tip end of the introduction pipe 5, more specifically, from the tip end of the introduction pipe 5 to the end of the heating portion 1a, the titanium tetrachloride is used in the gas phase at a high temperature. The part where oxidation takes place (so-called "reaction zone B"). The product recovery unit 3 is a bag filter that recovers oxygen -15-201010949 titanium oxide powder generated in the reaction tube 1 by a discharge pipe 9 connected to the other end side (downstream side) of the reaction tube 1. Further, in the product recovery unit 3', the discharge tube 9 is not blocked, and it is preferable that the product is sucked downstream by a pump (not shown). In the reaction apparatus having the above configuration, the oxidizing gas containing water vapor introduced into the reaction tube 1 from the introduction tube 4 and the gas containing titanium tetrachloride vapor introduced into the tube 5' are preheated. Zone A is preheated to 500. (: After the above, mixing in the reaction zone B and heating to 800 ° C or higher @. The gas containing titanium tetrachloride vapor and the oxidizing gas containing water vapor ' reacts immediately after contact in the reaction zone B' The obtained reaction gas ' passes through the reaction zone B at a residence time of 300 msec or less. Then, the gas passing through the reaction zone B is immediately cooled and sent back to the product recovery section 3. When using such a reaction apparatus, When the titanium tetrachloride is oxidized at a high temperature in the gas phase, it can be used: a method of rapid heating and rapid cooling, and a method of using water vapor as an oxidizing gas. Under the above conditions, it can be selectively and The monohedral titanium oxide particles having a box shape of a monohedron and having a particle diameter in the range of 1 nm to 1 〇〇 nm are efficiently obtained. Examples Hereinafter, the present invention will be further described in detail by way of examples. The present invention is not limited to these examples; it can be carried out with appropriate modifications without departing from the spirit and scope of the invention. Embodiment 1 In the embodiment 1, the reaction shown in Fig. 1 described above is used. The apparatus 'produces the titanium oxide powder substantially under the following conditions from -16 to 201010949. That is, the platinum plate is wound around the heating portion 1 a of the reaction tube 1 by about 1 〇cm, in the portion (heating portion) La) In the case of infrared irradiation of the infrared heating furnace 2, the infrared heating furnace 2 is controlled by a temperature controller while the surface temperature of the platinum plate is 12 〇〇 ° C °. The reaction tube 1 is used with an inner diameter of 21.4 mm. The quartz tube. The buffer 8' is a quartz tube having an outer diameter of 12.7 mm and the tip is made into a sharp shape of about 30° and is occluded. Further, the cross-sectional area of the heating portion 1a is 2·3 cm 2 °. The tip end of the introduction tube 5 into which the gas of the titanium tetrachloride vapor is introduced is disposed by the heating portion la around which the platinum plate is wound (the width of the platinum plate is 10 cm, so the width of the heating portion 1a is also 1 cm). The 6 cm downstream of the upstream end is used as the preheating zone A. The flow zone from the tip end of the inlet pipe 5 until the tip of the heating section 1 a is the hot zone B ( 4 cm) In the case of oxidizing gases containing water vapor, a mixed gas of water vapor and oxygen (〇2) and nitrogen. A mixed gas of water, oxygen, and nitrogen is introduced into the inlet 4a and passed through the gasifier 6, and then the water is supplied from the tip end of the inlet pipe 5 The oxidizing gas of the vapor is introduced into the reaction tube 1. Further, the composition of the mixed gas after passing through the gasifier 6 is water vapor: oxygen: nitrogen = 20: 20: 60 (volume ratio), and the total flow rate is obtained. A mixed gas is introduced at a rate of 600 NmL/min. A gas containing titanium tetrachloride vapor is used as a mixed gas of titanium tetrachloride vapor and oxygen (〇2). TiCl4 is introduced from the inlet 5a, and then oxygen is introduced. -17- 201010949 Gas (〇2) is introduced into the reaction tube 1 by the introduction of the inlet port 5b and passing it through the gasifier 7 and then from the tip end of the introduction tube 5. Further, the composition of the mixed gas after passing through the gasifier 7 is titanium tetrachloride: oxygen = 20: 80 (volume ratio), and the mixed gas is introduced in the case where the total flow rate is 6 〇〇 NmL/min. Further, the composition of the total reaction gas is titanium tetrachloride: oxygen: water vapor = 1: 5: 1, and the residence time of the reaction gas in the reaction zone B is about 50 msec. Comparative Example 1 An oxidizing gas containing water vapor was changed to an oxidizing gas containing no water vapor, that is, a mixed gas of oxygen and nitrogen was introduced from the introduction port 4a, and the others were oxidized under the same conditions as in Example 1. Manufacture of titanium powder. φ Comparative Example 2 Except that the oxidizing gas containing water vapor is not introduced, only the mixed gas of titanium tetrachloride vapor and oxygen (02) (concentration of titanium tetrachloride is 6%) is slowly introduced into the tube 5 (3 00) The production of the titanium oxide powder was carried out under the same conditions as in Example 1 except for the introduction of NmL/min. Next, the titanium oxide powders obtained in Example 1, Comparative Example 1, and Comparative Example 2 were observed under an electron microscope. Hereinafter, the respective production conditions of Example 1, Comparative Example 1, and Comparative Example 2, and the observation results of the obtained titanium oxide particles are as shown in Table 1-18-201010949. Further, the titanium oxide powder was obtained by using three samples of any of the samples, and each of them was introduced into a sample chamber of a scanning electron microscope, and observed at five places in the upper field of view.
參 -19- 201010949Reference -19- 201010949
結果 0 。旨 ^ | 陌靼 2屮 不形成10面體形狀 0 ° i 梁7 聽Ο [S m 2 if 反應區之 滯留時間 50毫秒 50毫秒 200毫秒 m 赵瞰 1^1 ·Ν 樣Ini 陋趙 β a 1°| 1ξΒ| i= m B S S ή m m 僅反應區4cm 合計反應 氣體之組成 TiCl4: 〇2： H20 =1:5: 1 TiCl4: 〇2： H20 =1:6:0 TiCl4: 〇2： H2〇 =1:14:0 g鹦餵題 应餐强·· Z ^ μ ^ ' Η- 600NmL/min H2〇： 〇2： N2=20: 20: 60 600NmL/min H2〇： 〇2： N2=0: 40: 60 璀 g聽撖璀 | ^ g S -N .. 斯Μ强·. 4π抵-Μ强 600NmL/min TiCl4： 〇2=20: 80 600NmL/min TiCl4: 〇2=20: 80 300NmL/min TiCl4： 〇2： N2=6: 84: 10 實施例1 比較例1 比較例2 -20- 201010949 如表1所示者，在實施例1所得到之氧化鈦粉末，其粒 子徑係5 0〜9 0 nm之範圍之1〇面體氧化鈦粒子。 另一方面，在比較例1所得到之氧化鈦粉末，其並非 1 〇面體氧化鈦粒子，且粒子徑亦顯示有30〜200 nm範圍之 廣泛分布。 " 此外’在比較例2所得到之氧化鈦粉末，其雖係1 0面 體氧化鈦粒子，惟粒子徑顯示有70~150 nm範圍之廣泛分 & 布，且含有粒子徑大者。 如上所述，根據本發明，可選擇性且有效率地製造具 有10面體之箱型形狀、且粒子徑在1 nm〜100 nm範圍之10 面體氧化鈦粒子。 產業上可利用性 根據本發明之製造方法，可選擇性且有效率地製造粒 子徑在1 nm~ 10 0 nm範圍之1〇面體氧化欽粒子。此外，所 φ 得到之小粒徑氧化鈦粒子，其係適合作爲光觸媒材料者。 因此’根據本發明，可在工業上將適當的10面體氧化鈦粒 子作爲光觸媒材料而製造。 【圖式簡單說明】 圖1 :係適合於本發明之氧化鈦粒子之製造上使用之 反應裝置之一例的部件圖。 【主要元件符號說明】 -21 - 201010949 1 :反應管 1 a :加熱部 2 :紅外線電器爐 3 :生成物回收部 4 :導入管 5 :導入管 6 :氣化器Result 0.旨 ^ | 靼 2靼 does not form a 10 facet shape 0 ° i beam 7 listen Ο [S m 2 if reaction zone retention time 50 milliseconds 50 milliseconds 200 milliseconds m Zhao Jing 1 ^ 1 · Ν sample Ini 陋 Zhao β a 1°| 1ξΒ| i= m BSS ή mm Reaction zone only 4cm Composition of reaction gas TiCl4: 〇2: H20 =1:5: 1 TiCl4: 〇2: H20 =1:6:0 TiCl4: 〇2: H2 〇=1:14:0 g Puffin feed problem should be strong ·· Z ^ μ ^ ' Η- 600NmL/min H2〇: 〇2: N2=20: 20: 60 600NmL/min H2〇: 〇2: N2= 0: 40: 60 璀g listen 撖璀 | ^ g S -N .. 斯Μ强·. 4π Μ - barely 600NmL / min TiCl4: 〇 2 = 20: 80 600NmL / min TiCl4: 〇 2 = 20: 80 300NmL/min TiCl4: 〇2: N2=6: 84: 10 Example 1 Comparative Example 1 Comparative Example 2 -20- 201010949 As shown in Table 1, the titanium oxide powder obtained in Example 1 has a particle diameter system. 1 〇 plane titanium oxide particles in the range of 5 0 to 9 0 nm. On the other hand, the titanium oxide powder obtained in Comparative Example 1 was not a one-facet titanium oxide particle, and the particle diameter also showed a wide distribution in the range of 30 to 200 nm. " Further, the titanium oxide powder obtained in Comparative Example 2 is a 10% titanium oxide particle, but the particle diameter shows a wide range of <RTIgt; As described above, according to the present invention, it is possible to selectively and efficiently produce a 10-faceted titanium oxide particle having a box shape of a decahedron and having a particle diameter of 1 nm to 100 nm. Industrial Applicability According to the production method of the present invention, it is possible to selectively and efficiently produce a ruthenium oxide particle having a particle diameter in the range of 1 nm to 100 nm. Further, the small-diameter titanium oxide particles obtained by φ are suitable as photocatalyst materials. Therefore, according to the present invention, an appropriate tenahedral titanium oxide particle can be industrially produced as a photocatalytic material. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a part of a reaction apparatus suitable for use in the production of titanium oxide particles of the present invention. [Description of main component symbols] -21 - 201010949 1 : Reaction tube 1 a : Heating unit 2 : Infrared electric furnace 3 : Product recovery unit 4 : Introduction tube 5 : Introduction tube 6 : Gasifier
7 :氣化器 8 :緩衝物 9 :排出管7: gasifier 8: buffer 9: discharge tube
-22-twenty two