Insight into the development and proceedings of Au@Al–CeVO4 catalysts for water splitting: an advanced outlook for hydrogen generation with sunlight

Abstract

In this study, we report a promising approach and new catalysts, namely Au@Al–CeVO₄ photocatalysts, for sustainable hydrogen production from water splitting. Al doping into CeVO₄ was done hydrothermally to enhance the electron quenching centres. The structural and optical properties of as-synthesized catalysts were evaluated with XRD, SEM, BET, AFM, EIS and UV-vis–DRS techniques. The purity and chemical compositions were confirmed with EDX and XPS techniques. Electron impedance spectroscopy and photoluminescence were used to ensure the charge transfer mechanism for water splitting on Au@Al–CeVO₄. Photocatalytic reactions were done in a quartz reactor, whereas hydrogen generation activities were monitored on a GC-TCD (Shimadzu-2010/Japan). The presence of Au cocatalysts on Al–CeVO₄ surfaces offers more highly localized electrons to accelerate water reduction. The results of this study show that Au_1.0@Al–CeVO₄ was the most active catalyst, delivering 52.93 mmol g⁻¹ h⁻¹ of hydrogen compared to bare CeVO₄ or Al–CeVO₄ catalysts that deliver 2.57 and 8.69 mmol g⁻¹ h⁻¹, respectively. It has been found that gold loading and Al doping reduce the back reaction by localized surface plasmon electrons and electron quenching, respectively. In addition, gold cocatalysts and Al doping enhanced the catalytic sites and light harvesting ability of Au@Al–CeVO₄. On the basis of these results, it can be concluded that the aforementioned approach shows eventual promise to replace conventional technologies used for hydrogen generation.