Tuning the Photocatalytic Performance of Tungsten Oxide by Incorporating Cu3V2O8 Nanoparticles for H2 Evolution Under Visible Light Irradiation

Abstract

The green energy production through water splitting under visible light irradiation has become an emerging challenge in the 21st century. Photocatalysis, being a cost-competitive and efficient technique, has grabbed much more attention for environmental applications, especially for hydrogen evolution. In this article, the hybrid Cu3V2O8-WO3 nanostructures were prepared through the hydrothermal method by using copper acetate, ammonium metavanadate, and Na2WO4 · 2H2O as precursors. The varying contents of Cu3V2O8 in WO3 were 0.2%, 0.5%, 1.0%, 2.0%, and 3.0%. The X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), UV-Vis, and photoluminescence (PL) emission spectroscopy were used to investigate the structural, morphological, surface area, and optical properties of prepared samples. The average crystalline size of the pure WO3 ranges from 10 to 15 nm and 70 to 195 nm for an optimal composite sample. The structural phase of the hybrid WO3-Cu3V2O8 nanoparticles was found to transfer from monoclinic to hexagonal by incorporating the Cu3V2O8 contents. The enhanced photocatalytic performance for hydrogen evolution was observed for 2% Cu3V2O8-WO3 composite sample. The key to this enhancement lies at the heterojunction interface, where charge separation occurs. In addition, the excellent photocatalytic activity was attributed to a higher surface area, efficient charge separation, and extended visible light absorption. This work provides an in-depth understanding of efficient separation of charge carriers and transfer processes and steer charge flow for efficient solar-to-chemical energy applications.