ZSM-5分子筛硅铝比对TiO_(2)/ZSM-5光催化性能的影响

Effects of SiO_(2)/Al_(2)O_(3) ratio of ZSM-5 zeolite on photocatalytic performance of TiO_(2)/ZSM-5

为了研究ZSM-5分子筛中硅铝物质的量比变化对TiO_(2)/ZSM-5光催化性能的影响,通过水热合成法制备了5种不同硅铝比的ZSM-5分子筛,并以此为载体通过浸渍-煅烧法制备了TiO_(2)/ZSM-5复合材料。对制备材料的物化性能以及光电学性能进行了分析,并对光催化实验中的活性组分进行了研究。结果表明:当ZSM-5分子筛中硅铝物质的量比为120时,制备的TiO_(2)/ZSM-5复合材料吸附性较好,负载TiO_(2)后光响应程度最高,光生电子(e^(-))和空穴(h^(+))复合率低且电阻最小,紫外光照100 min时罗丹明B(Rh-B)的降解率为99.6%,TOC去除率为60.4%。同时,实验发现羟基自由基(·O_(2)^(-))是光催化反应过程中的主要活性组分。

Variation of silicon-aluminum ratios in ZSM-5 will affect ZSM-5 zeolite properties.In order to study silicon-aluminum ratio effects of ZSM-5 zeolites on photocatalytic performance of TiO_(2)/ZSM-5,five ZSM-5 zeolites with different silicon-aluminum ratios were prepared by a hydrothermal synthesis method,and TiO_(2)/ZSM-5 composite materials were prepared via impregnation-calcination.The physical,chemical and photoelectric properties of the prepared materials were analyzed and active components in photocatalytic reactions were studied.The results show that the TiO_(2)/ZSM-5 composite has better absorbability,highest photo response and lower recombination rate of photo-generated e^(-)and h^(+),when the silicon-aluminum ratio is 120.The degradation rate of Rhodamine B(Rh-B)was 99.6%and the TOC degradation rate was 60.4%when exposed to ultraviolet light for 100 min.Meanwhile,·O_(2)^(-)was found as the main active component in the photocatalytic reaction.