A general method to diverse silver/mesoporous–metal–oxide nanocomposites with plasmon-enhanced photocatalytic activity

Abstract

Incorporating plasmonic Ag nanoparticles into mesoporous metal–oxide (MMO) semiconductors will achieve collective effect to greatly increase the photocatalysis. This work demonstrated a general two-step method to obtain diverse Ag/MMO composite photocatalysts with plasmon-enhanced photocatalytic activity. Several typical MMO (TiO2, ZnO, and CeO2) semiconductors were synthesized by integrating evaporation-induced self-assembly and in situ pyrolysis of metal precursors. Different amounts of Ag nanoparticles were then loaded in these MMO semiconductors through a facile photodeposition process. The Ag nanocrystals with sizes of 50–100nm were embedded in MMO semiconductors, endowing the Ag/MMO composites notable visible light absorption. The photocatalytic activities of the as-prepared diverse photocatalysts were studied systematically. The influencing factors including MMO species, mesoporous structure, and Ag loading amount on the photocatalytic activity were discussed in detail. The Ag/MMO composites exhibited much improved photocatalytic activity than their pure MMO semiconductors. The mesoporous TiO2 with the Ag-loading amount of 5wt.% exhibited the best photocatalytic performance for photodegrading both methylene blue and phenol under a simulated sunlight. The enhancement in photocatalysis is attributed to the synergistic effect of the mesoporous structures for efficient mass transfer as well as the Ag nanoparticles providing plasmonic enhanced light absorption.