Electronic structure and enhanced photoelectrocatalytic performance of RuxZn1−xO/Ti electrodes
Yanqun Shao, Keke Feng, Jie Guo, Rongrong Zhang, Sijiang He, Xinli Wei, Yu‐Ting Lin, Zhanghao Ye, Kongfa Chen
Abstract
Abstract Modification is one of the most important and effective methods to improve the photoelectrocatalytic (PEC) performance of ZnO. In this paper, the Ru x Zn 1− x O/Ti electrodes were prepared by thermal decomposition method and the effect of Ru content on those electrodes’ electronic structure was analyzed through the first-principles calculation. Various tests were also performed to observe the microstructures and PEC performance. The results showed that as the Ru 4+ transferred into ZnO lattice and replaced a number of Zn 2+ , the conduction band of ZnO moved downward and the valence band went upward. The number of photogenerated electron-hole pairs increased as the impurity levels appeared in the band gap. In addition, ZnO nanorods exhibited a smaller grain size and a rougher surface under the effect of Ru. Meanwhile, the RuO 2 nanoparticles on the surface of ZnO nanorods acted as the electron-transfer channel, helping electrons transfer to the counter electrode and delaying the recombination of the electron-hole pairs. Specifically, the Ru x Zn 1− x O/Ti electrodes with 9.375 mol% Ru exhibited the best PEC performance with a rhodamine B (RhB) removal rate of 97%, much higher than the combination of electrocatalysis (EC, 12%) and photocatalysis (PC, 50%), confirming the synergy of photoelectrocatalysis.