Influence of localized surface plasmon resonance on shape changes of nanostructures: Investigation using metal nanoblocks in halide solutions

Photoinduced shape changes of metal nanostructures in halide solutions were investigated using gold and silver nanoblocks (NBs) patterned on a glass substrate, instead of nanoparticles dispersed in solution. It was found that size reduction of the NBs by halide etching was enhanced by photoirradiation. Furthermore, it was revealed that the halide etching efficiency corresponded to the intensity of the electric field induced by localized surface plasmon resonance (LSPR) of the NBs. The enhancement of halide etching by LSPR was explained on the basis of electron transfer reactions from metal NBs. Throughout this study, it was demonstrated that metal NBs fabricated on a substrate constitute a powerful system to investigate photoinduced shape changes of nanostructures, because of their defined shape, position, and configuration.