Enhancement of plasmonic activity by Pt/Ag bimetallic nanocatalyst supported on mesoporous silica in the hydrogen production from hydrogen storage material

Abstract

Recent advancements in plasmonic catalysis have witnessed rapid developments in solar-to-chemical energy conversion utilizing Ag, Au and Cu metal nanoparticles (NPs). In this study, visible light responsive bimetallic Pt/Ag nanocatalyst supported on mesoporous silica, was successfully prepared by a two-step method viz. MW assisted alcohol reduction, followed by Pt deposition by the assistance of localized surface plasmon resonance (LSPR) effect of Ag NPs. The obtained catalysts were characterized by UV–vis, transmission electron microscopy (TEM), XAFS, XPS and N2-physisorption measurement studies. The performance of prepared catalysts was explored for the visible light enhanced catalytic activity in the hydrogen (H2) production from ammonia borane (NH3-BH3: AB). A great enhancement for Pt(0.25)/Ag/SBA-15 (0.25 wt% of Pt on 1.0 wt% of Ag) was observed by a factor of 2.8, which is highest among our previously reported results of spherical bimetallic NPs. A plausible photocatalytic and charge separation mechanism has been proposed to envisage the tentative reaction pathway.