In-co-doped Bi1-xVO4 drenched sulfur-doped g-C3N4 nanocomposite: A type-II photo(electro)catalytic system for visible-light-driven water-splitting and toxic removal applications

A promising alternative technology for the direct utilization and conversion of renewable energy sources is essential in order to overcome energy crises owing to the limited source of fossil fuels. Herein, we report the partial substitution of different amounts (x = 0.3, 0.5, 0.7) of indium (In3+) in the Bi3+ sites of BiVO4 through a one-pot hydrothermal route without additives. The as-prepared Bi1-xInxVO4 was impregnated on 2D S-doped g-C3N4 via the total solvent evaporation method. The optical, electronic, and catalytic properties of the synthesized Bi1-xInxVO4/S-g-C3N4 materials were systematically investigated through computational and experimental methods. Under simulated solar irradiation, the Bi0.7In0.3VO4/S-g-C3N4 exhibits PEC-OER lower overpotentials of 118 mV and 126 mV at 10 and 20 mA/cm(2), respectively, and in contrast, the Bi0.3In0.7VO4/S-g-C3N4 shows maximum photocurrent density of 15.3 mA/cm(2) at 1.23 V (vs RHE). Furthermore, the Bi0.7In0.3VO4/S-g-C3N4 exhibits 91.7% photodegradation of tetracycline hydrochloride (TCH) with a high rate constant (k') of 0.0147 min(-1). The plausible charge transfer mechanism for the enhanced photo(electro)catalytic performance of Bi1-xInxVO4/S-g-C3N4 was expressed as consistent with the experimental and computational results. The In3+ substitution can lead to increased water oxidation potential and charge carrier mobility, and the S-doped g-C3N4 helps to passivate the photoanode for enhanced PEC stability and efficiency. Therefore, the above results confirm the robust photoelectrocatalytic performance of Bi1-xInxVO4/S-g-C3N4 systems in energy production and environmental remediation applications.