Ag/AgCl复合粉末的制备及光催化性能研究

AgCl光催化剂可以有效避免纳米TiO_2只对紫外光响应造成的缺陷和不足。围绕Ag/AgCl复合粉体的制备及其对催化降解有机污染物的性能进行研究,采用四种不同的方法制备了Ag/AgCl复合粉体,在波长λ420 nm的可见光下考察了Ag/AgCl复合粉体对甲基橙的降解能力,并探讨了其催化机理。结果发现,催化剂的活性与复合粉体样品的形貌结构有很大关联。以AgNO_3作为Ag源,利用乙醇将部分AgNO_3还原为纳米银颗粒,并利用聚乙烯吡咯烷酮(PVP)作为高分子保护剂制备出的Ag/AgCl复合粉体表现出良好的可见光催化活性和稳定性,在20 min内几乎将甲基橙完全降解,该光催化剂对甲基橙的一级降解反应常数为4.99×10~(-2)。

Preparation and photocatalytic properties of Ag/AgCl composite powders

Defects and deficiencies caused by the only response of nano-titania dioxide to UV light can be avoided by AgCl photocatalyst.In this paper,the Ag/AgCl composite powders were prepared by four different methods,and their properties of catalytic degradation on organic pollutants were studied.The degradation ability of the Ag/AgCl composite powders on methyl orange was evaluated under the visible-light (λ＞420 nm).The catalysis mechanism of the Ag/AgCl composite powders was discussed.The results demonstrate that the catalyst activity is related to the morphology and structure of the composite powders.Using AgNO3 as the source of Ag and polyvinylpyrrolidone (PVP) as the polymer protective agent,Ag/AgCl composite powders prepared by ethanol to reduce part of AgNO3 to silver nanoparticles exhibit the excellent visible-light photocatalytic activity and stability.The methyl orange is almost completely degraded within 20 min,and the first order degradation reaction of the photocatalyst to methyl orange is 4.99×10-2.