Ag2O气凝胶吸附-光降解处理微污染物

Adsorption-Photodegradation of Micropollutants by Ag2O Aerogel

针对粉末状光催化剂处理废水中污染物存在强烈的聚集倾向、复杂的操作和易引起二次污染等问题,以Ag2O为粉末状光催化剂模型,采用简单的浸渍法结合光还原法构筑了Ag2O气凝胶可见光响应型光催化剂。选择亚甲基蓝(MB)和孔雀石绿(MG)为模型染料,考察了该气凝胶对低含量污染物的吸附性,以橙黄二(OII)为模型染料研究了Ag2O气凝胶的光催化性能。结果表明,在60 min时已基本达到吸附平衡,其吸附率分别可达98.7%和93.0%。吸附动力学均符合准2级动力学方程,Freundlich模型能很好地拟合等温吸附过程,表明Ag2O气凝胶对MB和MG的吸附以多层吸附为主。Ag2O气凝胶在30 min内对OII的光降解率已达95.6%,表现出优异的光催化性能。

Aimed at the problem of the nanoparticles(NPs) in powder form with a strong tendency to agglomerate, demanding the intricate operations to extract the catalysts for recycling, and the lost powders may lead to the secondary pollution and so on in wastewater treatment. Ag2O aerogel photocatalyst with visible light response was prepared by simple dipping and photoreduction method, and Ag2O as the powder-like photocatalyst model. Methylene blue(MB) and malachite green(MG) were selected as model dyes to investigate the adsorption properties of the aerogel for low content pollutants, and orgnge II(OII) was used as model dye to research the photocatalytic performance of Ag2O aerogel. The results showed that the adsorption equilibrium was basically reached at 60 min, and the adsorption rates were up to 98.7% and 93.0%, respectively. The adsorption kinetics were in accordance with the pseudo-second-order kinetic equation, and the Freundlich model could well fit the isothermal adsorption process, indicating that the adsorption of MB and MG by Ag2O aerogel was dominated by multi-layer adsorption. The photodegradation rate of OII by Ag2O aerogel was 95.6% within 30 min, showing excellent photocatalytic performance.