LaVO4 with alkali metal doping for enhanced photocatalytic water splitting

Abstract

It is essential to design and fabricate semiconductor-based photocatalysts with excellent activity to split H₂O into H₂ and O₂ using sunlight because of the depletion of fossil resources and environmental pollution. LaVO₄ is a visible light catalyst with a narrow band gap, satisfactory stability, and a low price. Therefore, in this work, alkali metal-doped LaVO₄ was manufactured. Alkali metal-modified LaVO₄ was prepared by a hydrothermal method as a photocatalyst for water splitting under visible light illumination, and a series of characterizations was carried out. The results showed that alkali metal doping improved the catalytic performance of pure LaVO₄ and mainly optimized the hydrogen and oxygen production of Na-doped LaVO₄ so that a maximum H₂ and O₂ evolution of 2.83 and 0.71 μmol g⁻¹ h⁻¹, respectively was obtained. The superior photocatalytic activity of Na-doped LaVO₄ was mainly attributed to synergistic effects, including the extended visible-light response and improved charge separation. This study provides a new idea for the design of a highly efficient LaVO₄-based water-cracking photocatalyst.