贵金属负载的棒状ZnO复合光催化剂的制备及其提升的光催化性能

摘要

In the present work,we successfully synthesized ZnO nanorods under hydrothermal conditions,which have been utilized as the matrix to fabricate various noble metal (Pt,Pd,and Ru)-supported ZnO photocatalysts by subsequent reduction with ethylene glycol.In terms of systematic characterization,it was found that the Pt particles in the Pt/ZnO composite have small size with narrow size distribution,while the Pd particles in the Pd/ZnO composite have a larger size distribution due to aggregation.On the other hand,no Ru particles were practically observed in the Ru/ZnO composite.In the photodegradation of a methylene blue solution under UV light irradiation,both Pt/ZnO and Pd/ZnO exhibited significantly enhanced photocatalytic activity compared with the ZnO nanorods,whereas no noticeable increase of catalytic activity could be observed in the case of Ru/ZnO.Furthermore,the photocatalvtic activitv of the Pt/ZnO catalyst was higher than that of Pd/ZnO,due to its small-sized and uniform Pt particles.Therefore,noble metal particles with small size and high dispersion contribute to the enhancement of the photocatalytic performance of ZnO materials.After detailed investigation of various Pt/ZnO composites with different Pt Ioadings,it was demonstrated that the optimal Pt loading required to maximally improve the photocatalytic performance of ZnO nanorods corresponds to 3.2％.%以水热制备的ZnO纳米棒为基底,通过乙二醇液相还原法负载不同贵金属颗粒(Pt、Pd、Ru)构筑贵金属负载的ZnO纳米棒复合光催化剂.实验结果表明在制备条件相同时,Pt/ZnO样品中Pt颗粒尺寸较小,分布均匀;Pd/ZnO样品中Pd颗粒尺寸较大且团聚严重;Ru/ZnO样品则几乎没有Ru颗粒负载.在紫外光照射下降解亚甲基蓝的反应中,Pt/ZnO表现出最高的光催化性能,Pd/ZnO样品次之,而Ru/ZnO则表现出与ZnO纳米棒相似的光催化活性;表明小尺寸和大小均匀的贵金属颗粒对ZnO纳米棒的催化性能有着显著的提升作用.对Pt/ZnO来说,当Pt载量为3.2％时Pt/ZnO催化剂的光催化活性最高.