Hydrothermal Synthesis of Z-Scheme FeWO4/BiVO4 Nanocomposite for Photocatalytic Degradation of Tetracycline

Abstract

A visible-light-active FeWO4/BiVO4 heterostructured photocatalyst was fabricated by decorating irregular BiVO4 nanoplates with FeWO4 nanoparticles for the photocatalytic degradation of tetracycline. The as-prepared composites were systematically characterized using PXRD, FESEM, HRTEM, XPS, UV-Vis spectroscopy and photoluminescence (PL) analysis to investigate their structural, morphological, optical and electronic properties. Among the different compositions studied, 0.15 FeWO4/BiVO4 showed the best photocatalytic performance, with 99% degradation of tetracycline (20 mg L–1) and a rate constant of 0.0471 min–1. This result demonstrates the enhanced photocatalytic efficiency of the optimized composite toward tetracycline degradation. This rate constant was approximately six and eight times higher than those of pristine BiVO4 (0.0083 min–1) and FeWO4 (0.0061 min–1), respectively. The enhanced photocatalytic performance is attributed to improved visible-light absorption, favourable Z-scheme interfacial charge transfer, reduced electron–hole recombination and enhanced generation of reactive oxygen species. These findings highlight the potential of FeWO4/BiVO4 heterostructures as visible-light-driven photocatalysts for removal of tetracycline from aqueous environments.