Nanocomposite of BiPO4 and reduced graphene oxide as an efficient photocatalyst for hydrogen evolution

Nanocomposites of BiPO₄ and reduced graphene oxide (BiPO₄/RGO) synthesized by hydrothermal method, hydrazine reduction, and UV-assisted photoreduction method were studied as photocatalysts for hydrogen evolution from ethanol aqueous solution under irradiation. The incorporation of RGO into BiPO₄ significantly enhanced the photocatalytic activity for H₂ evolution, and the photocatalytic activity increases in the order of BiPO₄/RGO-hydrothermal > BiPO₄/RGO-photoreduction > BiPO₄/RGO-hydrazine. The optimum proportion of GO is 2 wt% for all the samples prepared by different methods. The rate of H₂ production calculated for BiPO₄/RGO-hydrothermal (with 2 wt% GO) nanocomposite was about 306 μmol/h/g, which was almost 2 times as high as that for bare BiPO_4. The XRD, Raman and XPS characterization suggested that the original GO was successfully reduced to RGO. The more intimate contact between BiPO₄ and RGO, the higher photocurrent responses and the higher reduction degree of RGO was consistent with the higher photocatalytic performance.