Fabrication, characterization, and visible-light photocatalytic performance of ternary plasmonic composites

Abstract

h i g h l i g h t s• W-Ti-SBA15 composites with low TiO 2 /SiO 2 mass ratios and their Agcontained analogs were fabricated.• These composites showed enhanced photocatalytic performance in comparison to those with high TiO 2 /SiO 2 mass ratios.• Photocatalysis mechanism of these Ag-W-Ti-SBA15 plasmonic composites was proposed. t r a c tA group of mesoporous WO 3 -TiO 2 -contained SBA15 composites (W-Ti-SBA15) and their Ag-contained plasmonic analogs were fabricated and then systematically characterized by a collection of analytical techniques. Original mesoporous structures with highly ordered channels were well-maintained and WO 3 -TiO 2 could form spherical clusters that were gradually reduced in size accompanying with the decrease of TiO 2 /SiO 2 mass ratios. Deposited Ag species were confirmed as zero-valence Ag by X-ray photoelectron spectroscopy analysis and exerted almost no effect on the morphology, microstructure, and textural but optical property, by which the visible-light harvesting ability of composites was remarkably strengthened owing to the localized surface plasmonic resonance (LSPR) induced by the metallic Ag. Under visible-light irradiation, W-Ti-SBA15 composites showed satisfactory photocatalytic performance that could be further enhanced by using their Ag-contained ternary plasmonic analogs. The enhancement of photocatalytic efficiency was mainly attributed to the favorable mesoporous morphology, the suitable band alignment, and the LSPR effect. Eventually, a possible photocatalysis mechanism was primarily proposed on the base of reactive radical species trapping experiments.