A simple preparation method of Ti/TiO2/BiVO4 and implications for enhanced photoelectrocatalytic performance under visible light illumination

A minimalist approach to fabricate the synthetic composite Ti/TiO₂/BiVO₄ was proposed. Concurrently, the photoelectrocatalytic performance and activity of the Ti/TiO₂/BiVO₄ electrode were evaluated. Specifically, the relationship between composition, morphology, and photocurrent response was initially discussed. Then, the transient photocurrent, linear sweep voltammetry, photoconversion efficiency, and electrochemical impedance spectroscopy were employed to test the photoelectrochemical performance. To evaluate the photoelectrocatalytic activity of this composite electrode, rhodamine B (RhB) degradation under optimized experimental conditions was selected as a typical case study. Compared with other similar electrodes, the present electrode had a short preparation time, excellent photocurrent response, high RhB removal, and high stability. Based on the measurements of trapping experiments, Mott−Schottky spectroscopy (M−S), UV–visible diffuse reflectance spectra (UV–Vis DRS), electron paramagnetic resonance (EPR), and degradation intermediate products, a possible photoelectrocatalytic degradation mechanism of Ti/TiO₂/BiVO₄ was proposed. According to our results, ·O₂⁻ should be the dominant oxidative species. The Z-scheme heterojunction of Ti/TiO₂/BiVO₄ has a new microstructure with potential in wastewater treatment.