Fabrication of Ag based ternary nanocomposite system for visible-light photocatalytic hydrogen evolution reaction

Solar driven visible photocatalytic H-2 evolution using semiconductors is recognized as one of the most promising routes for clean energy technology; however, efficient visible light utilization and charge separation are the key roles in a photocatalyst system for high activity. Herein, Ag based ternary nanocomposite system, Ag2S/Ag/Ag3VO4 was synthesized by chemical reduction and subsequent hydrothermal methods. The prepared nanocomposites were characterized by Powder X-ray diffraction, X-ray photoelectron spectroscopy, Scanning and transmission electron microscopy, UV-vis diffuse reflectance and photoluminescence spectroscopy methods. The Ag2S/Ag/Ag3VO4 ternary nanocomposite system displayed a higher photocatalytic H-2 evolution activity than that of pure Ag3VO4, Ag2S and their binary composites under visible light irradiation. In the present work, Ag2S/Ag/Ag3VO4 exhibited a photocatalytic H-2 evolution activity of similar to 8.5 mmol.g(-1). The enhanced photocatalytic activity can be attributed to the improved visible light absorption and effective charge separation between Ag3VO4 and Ag2S via the electron shuttle mediator Ag.