Improved Photocatalytic Hydrogen Production Performance Over NaTaO3/Reduced Graphene Oxide Composite Photocatalyst

NaTaO3/reduced graphene oxide (RGO) composite were prepared via a two-step hydrothermal method. The as-prepared NaTaO3/RGO composite were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and X-ray photoelectron spectroscopy (XPS). The results indicated the reduction of graphene oxide and the chemical bonding between RGO and NaTaO3 are achieved simultaneously. As a result, NaTaO3/RGO composite possessed efficient charge separation properties. Hence, in the photocatalytic measurement toward the H-2 production from an aqueous Na2S/Na2SO3 solution under UV illumination, a significant improvement in the H-2 production rate was observed over NaTaO3/RGO composite, compared to the pure NaTaO3 and mechanically mixed NaTaO3-RGO composite with the same RGO content. In particular, the photocatalytic H-2 production rate over NaTaO3/2% RGO with RGO content of 2 wt% was 3.82 times higher than that of pure NaTaO3. Moreover, the photocatalytic hydrogen production performance of NaTaO3/2% RGO was rather stable. A plausible electron transfer mechanism was proposed to discuss the improved photocatalytic H-2 production performance.