Bi2Sn2O7的不同水热法制备及其可见光光催化除As（III）性能分析

摘要

Bi2Sn2O7, synthesized through different hydrothermal routes (the microwave hydrothermal method (MH-BSO) and the traditional hydrothermal method (TH-BSO)), was used for photocatalytic removal of arsenic from aqueous solution. The as-synthesized Bi2Sn2O7 products were characterized by X-ray diffraction (XRD), N2 sorption-desorption, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), transmission electron microscopy (TEM), electron spin resonance (ESR), X-ray photoelectron spectra (XPS), and electrochemistry technology. Under visible light irradiation, the MH-BSO sample exhibited a higher photocatalytic activity (up to 98.7%) than that of the TH-BSO sample during the oxidization of arsenite (AsO3)3-. The active species, O2-•and hVB+, were identified as the primary active species responsible for As(III) oxidation. In addition, a possible mechanism for the photo-oxidation of As(III) over Bi2Sn2O7 is proposed.%利用微波和普通水热法合成出了具有可见光响应的Bi2Sn2O7纳米光催化剂，并用X射线衍射(XRD)、氮气吸脱附、紫外-可见漫反射光谱(UV-Vis DRS)、扫描电镜(SEM)、透射电镜(TEM)、电子顺磁共振谱(ESR)、X射线光电子能谱(XPS)等技术对样品的晶相、比表面积、光吸收性能、形貌、光催化活性物种等结构与性质进行了系统表征，比较微波水热Bi2Sn2O7(MH-BSO)与普通水热Bi2Sn2O7(TH-BSO)形貌和微结构，并考察两者在可见光光照下光催化氧化As(III)的性能差别。实验结果表明，MH-BSO具有更细小的粒径和更大的比表面积，而在可见光照射下，MH-BSO样品比TH-BSO样品具有更好的As(III)的光催化氧化能力(可达98.7%)。此外，对Bi2Sn2O7纳米光催化剂氧化去除As(III)的光催化机理进行初步探索，结果表明超氧自由基(O2－•)和空穴(hVB＋)是主要起作用的中间反应活性物种。