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

Noble Metal-Supported Rod-Like ZnO Photocatalysts with Enhanced Photocatalytic Performance

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。

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 photocatalytic activity of the Pt/ZnO catalyst was higher than that of Pd/ZnO, due to its small-sized anduniform 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%.