磷钨酸表面修饰TiO_2光催化降解空气污染物

Photocatalytic degradation of air pollutant over TiO_2 modified with phosphatotungstic acid.

以磷钨酸水溶液湿法浸渍表面修饰TiO2制备了磷钨酸/二氧化钛复合催化剂,并进行了H2-TPR、BET比表面、TG-DTA、FTIR、UV-vis表征.以含甲醛、丙酮的模拟污染空气,研究其在复合光催化剂作用下的光催化降解行为.结果表明,修饰剂磷钨酸含量为21.9%时,光催化降解甲醛的效果最佳;该反应随修饰剂磷钨酸含量的增加,甲醛的部分还原产物甲醇含量增加,说明HPW与TiO2产生了明显的协同作用,改变了TiO2光催化反应历程,由此推导出可能的反应机理;修饰剂磷钨酸含量为21.9%时,光催化降解丙酮的效果也最好,去除率达到100%.

Phosphatotungstic acid/titanium dioxide catalyst was prepared with TiO2 powder modified using impregnation with aqueous solution of phosphatotungstic acid, and characterised with H2-TPD, BET specific surface, TG-DTA, FTIR and UV-vis. Photocatalytic performance of the catalyst was studied under the action of compound photo-catalyst using simulated polluted air containing formaldehyde and acetone. The effect of catalytic degradation of fomaldyde was the best when the content of the modifier phosphatotungstic acid was 21.9%; in this reaction increased with increasing of the modifier, the content of the partial reduction product methanol increased. It illustrated that there produced obvious synergy between HPW and TiO2, changed the course of TiO2 photocatalysis, from which the probable reaction mechanism was inferred. The photocatalytic degradation effect of acetone was the best when the content of the modifier phosphatotungstic acid was 21.9%, with removal rate reaching 100%.