Synthesis and characterization of vanadium oxides by hydrothermal method for hydrogen production under visible light

Hydrogen production from water splitting through semiconductor photocatalysts is a promising green process for the manufacture of new energy carriers. In this paper, we report the test results of various types of vanadium oxides as the photocatalysts for hydrogen-production. The hydrothermal-synthesis method was employed to synthesize the vanadium oxides, V₆O₁₃, VO₂(B) and VO₂(M) from V₂O₅. From the results of cyclic voltammogram and the UV-vis spectra, the potential band structure for each sample was constructed. As a consequence, the relative NHE potential was achieved, and all the vanadium oxides prepared in this study were qualified as the visible-light-responsive photocatalysts for hydrogen production. The accumulative amount of hydrogen-production within four hours illumination increased in the order of V₆O₁₃ > VO₂(M) > V₂O₅ > VO₂(B). This tendency is mainly determined by the values of reduction potential in the band structure. The DRIFT technique as well as temperature programmed desorption procedures reveal that Brønsted and Lewis acidities may associate with the capability on hydrogen production.