Plasmon-Enhanced Photocatalysis Based on Ag Plasmonic Nanospheres and ZnO Nanoparticles: Synthesis and Study Mechanisms Governing the Plasmonic Photocatalytic Performance

Abstract

This work presents an overview of the findings in current research focusing on the investigations of localized surface plasmon resonance effects (LSPR) on photocatalytic activities of ZnO/noble metal nanocomposites. Nanocomposites of (Ag or Au)/ZnO were prepared by mixing the prepared Au and Ag nanospheres with ZnO nanoparticles. The plasmonic photocatalytic efficiency of the nanocomposites was then investigated by photodecomposition of methylene blue (MB) and the enhancement was compared to the pure ZnO performance. A quantitative study of the mechanisms governing the plasmonic photocatalysts performance showed that the LSPR-induced radiative energy transfer from the Ag nanospheres plasmon states to the ZnO nanoparticles could be the main reason for the observed photocatalytic activity enhancement. Based on our results, the increase in the concentration of charge carriers at the semiconductor surface could be responsible for the improvement of photocatalytic performance. It was found that the diameter size and concentrations of Ag nanospheres in the composites were two main factors by their adjustment one can improve and optimize their photocatalytic performance of nanocomposites. The highest photocatalytic activity enhancement was observed for the composite containing 4.5 wt% of Ag nanospheres with mean diameter size of 100 nm. Also, it was found that the Au/ZnO nanocomposite showed a little enhancement in plasmonic photocatalytic performance compared to the Ag/ZnO nanocomposite.