In this work ,the Bi2O3 samples were synthesized via a liquid precipitation method with a precursor of Bi(NO3 )3 · 5H2O .The structure and morphology of the samples obtained at different pH values (3 and 8) of reacting solution were investigated using XRD and SEM ,respectively .The results suggested that the Bi5O7NO3 was obtained from the precursor , then transformed to β-Bi2O3 and α-Bi2O3 at pH = 3 .The higher pH range (pH = 8) could further improve phase transformation process .Thus , the pH value of reacting solution strongly affected the phase composition and transformation process . Furthermore ,the photocatalytic activity of the obtained samples was evaluated by degradation of RhB .The results indicated that the Bi5O7NO3 exhibited the higher photocatalytic activity than α-BiO3 .%以硝酸铋为原料,氨水为沉淀剂,调节pH分别为3和8,通过液相沉淀法制得了Bi2O3样品.利用X射线衍射(XRD)和扫描电子显微镜(SEM)等研究不同pH对Bi2O3晶相及相变过程的影响.结果表明,不同pH制备得到的样品均发生如下过程:前驱体转变为Bi5O7NO3,Bi5O7NO3分解为 β-Bi2O3以及 β-Bi2O3相变为 α-Bi2O3,且较高pH促进Bi5O7NO3分解为 β-Bi2O3以及 β-Bi2O3相变为 α-Bi2O3的进程.以光催化降解罗丹明B(RhB)为指标反应,考察了不同晶相Bi2O3的光催化性能.结果表明,与 α-Bi2O3相比,Bi5O7NO3具有更高的光催化性能.
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