Study on Effects of Atomic Size Defects on Hot Electron Generation of Noble Metal Nanoparticle to Design Novel Photocatalytic System

Abstract

In this study, we investigate the effects of surface defects of atomic size, which is one important fundamental issue to study the performance of heterogeneous catalysis by utilizing the hot electron (HE) phenomenon, on the generation of HE of gold nanocube through discrete dipole approximation (DDA) calculation. The cubic-shaped structure is considered to investigate the sole influences of defects on HE generation, where the plasmon resonance direction is a key factor. Interestingly, we find that in the monomer system, silver doping defect is enhanced the generation and lifetime of HEs. Furthermore, the effects of depth of defect region and nanoparticle size are investigated. Next, to improve the performance of HEs generation, the dimer structure is considered. Although the absorption enhancement is reduced, the amount of HE generation is enhanced by plasmon coupling effect. Especially, the generation of HEs is maximized when silver is doped in the direction of propagated light, not the gap junction. It indicates that in the dimer system, silver doping defect can form a favorable site for photocatalytic reaction and, by extension, it has the possibility of suggestion of novel photocatalytic system. This is a promising study for improving the performance of plasmon-mediated photocatalyst using HEs compared to conventional methods, which are tunable LSPR intensity and wavelength through size, structure shape, plasmon coupling and ambient medium.