具有高效可见光活性的AgCl/AgVO_3异质结光催化剂的原位合成

以水热法合成的AgVO_3为前驱体,在其表面通过原位离子交换法合成AgCl/AgVO_3异质结光催化剂,利用XRD、SEM和UV-Vis等对其结构、形貌和光吸收性能进行表征,并以酸性橙-Ⅱ模拟环境中染料污染物,考察了AgCl/AgVO_3异质结的可见光催化性能。结果表明,AgCl/AgVO_3异质结光催化剂具有高效的可见光催化活性,在可见光照射下15 min,酸性橙-Ⅱ降解率达到80%,循环使用4次后,降解率仍能保持60%。自由基捕获实验结果表明,h~+和·O_2~-为光催化反应中的主要活性物种。光催化性能的提高主要归因于AgCl/AgVO_3异质结构的形成,这利于光生电子-空穴对转移和分离。最后探讨了增强AgCl/AgVO_3光催化性能的可能机理。

In situsynthesis of AgCl/AgVO3 heterojunction photocatalyst with high visible-light activity

AgCl/AgVO₃ was synthesized through in situ ion exchange process using AgVO₃as precursor which was obtained by hydrothermal method.The structure, morphology and optical absorption property of the prepared samples were characterized by XRD, SEM, UV-vis.And its photocatalytic performance under visible light was investigated using acid orange-II as simulated pollutants.The results showed that AgCl/AgVO₃ heterojunction photocatalysts had high visible light activity.Degradation efficiency was up to 80% under visible light irradiation for 15 minutes.And degradation efficiency remained 60% after reuse of 4 times.According to active radical trapping experiments,h⁺ and ·$O_{2}^{-}$ radicals were two main active species in photocatalytic reaction.The enhanced photocatalytic performance was mainly attributed to formation of AgCl/AgVO₃ heterostructure,which was beneficial to transfer and separation of photo-generated electron-hole pairs.Finally,possible mechanism of the enhanced photocatalytic performance of AgCl/AgVO₃ was discussed.