本研究比較了反滴定法與反向化學沉澱法兩個製程對於氧化鉍之相組成差異，使用反向化學沉澱法以不同反應環境濃度在室溫下合成3個不同相組成比例的混合相δ/γ-Bi2O3，吸收光譜結果發現兩相的吸收波段均落在可見光範圍內，可利用可見光作為光催化的能量來源，PL光譜分析可證實混合相可降低電子電洞復合率且δ/γ-Bi2O3在特定相組成比例下的樣品DG(95 %的δ及5 %的γ)展現出比純δ-Bi2O3更高的羅丹明染料降解效率。透過比對實驗結果與兩相能帶結構推測降解反應機制，發現電洞與超氧離子為 Bi2O3 降解羅丹明B系統之主要活性反應因子；亦確認兩相接面間光激發載子的移動方向，激發後電子 δ-Bi2O3 由移動至γ-Bi2O3，而電洞則是相反方向，且因兩相價帶位能差異，有效使電子電洞分離，提高降解RhB的效能。

The present study demonstrates the synthesis of δ/γ mixed phase bismuth (III) oxide (Bi2O3) at room temperature using a reprecipitation method. Photoluminescence spectroscopic analysis confirms that the mixed phase could form the homojunction to reduce the electron–hole pair recombination rate and that δ/γ Bi2O3 under a specific phase composition ratio (δ : γ = 95:5) exhibits higher Rhodamine B dye degradation than pure δ-Bi2O3 and γ-Bi2O3, respectively. By comparing the experimental results and the two-phase energy band structure to speculate the degradation reaction mechanism, this study finds that the holes and superoxide ions are the main active reaction factors of the Bi2O3 degradation system for Rhodamine B.

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