Tungsten doping effect on bismuth vanadate (W-doped BiVO₄) under visible-light irradiation for photocatalysis

Photocatalysis (PC) wastewater treatment has received significant attention in recent years due to its potential applications in purified water, environmental remediation, degradation of organic pollutants in wastewater, and water splitting. In this research, a simple hydrothermal method was used to synthesize tungsten-doped bismuth vanadate (W-doped BiVO₄) photocatalyst with dopant concentrations of 0, 0.5, 1.0, 2.0, and 3.0 wt%. Ethanol-dissolved bismuth vanadate and tetrahydrofuran-dissolved tungsten hexacarbonyl were used as precursors. The 1.0 wt% W-doped BiVO₄ had a specific surface area (SSA) of 18 m²/g, and the optical energy band gap was determined to be 2.30 eV using UV–visible measurements. The photocatalytic efficacy of W-doped BiVO₄ was evaluated by assessing the degradation of Rhodamine-B (Rh-B) in aqueous solutions under visible (400–800 nm) irradiation, with the photocatalytic activity measured as a function of tungsten concentration. The maximum photoactivity for the degradation of Rh-B was observed in W-doped BiVO₄ at 1.0 wt% with a large specific surface area, which may be attributed to the incorporation of W into the BiVO₄ crystal lattice and changes in surface characteristics. This study presents a novel platform for developing and manufacturing photocatalytic materials that enhance charge separation and fast transfer for highly effective water treatments.