Synthesis of mesoporous silica-supported Ag nanorod-based bimetallic catalysts and investigation of their plasmonic activity under visible light irradiation

A series of bimetallic M/Ag ( where M represents Pd, Ru, Ni and Co metallic species) nanorod (NR)-based plasmonic photocatalysts with 0.5 wt% loading of M on Ag (1.0 wt%) are prepared within the mesoporous channels of SBA-15. The chemical structure, morphology and optical properties of M/Ag/SBA-15 are well characterized by UV-vis spectroscopy, TEM, FT-EXAFS, XPS and N-2 adsorption-desorption measurement studies. Subsequently, the photocatalytic activity is assessed by hydrogen production from ammonia borane ( AB) and chemical reduction of 4-nitrophenol (NP) to 4-aminophenol (AP) under visible light irradiation. The enhanced catalytic activities under light irradiation in comparison with dark conditions are explained by a plausible photocatalytic and charge separation mechanism to envisage the tentative reaction pathway. Finally, the reusability of the catalyst is evaluated via four consecutive catalytic runs.