A new CdS/Bi1−xInxTaO4 heterostructured photocatalyst containing solid solutions for H2 evolution from water splitting

A new strategy has been put forward to improve the performance of photocatalytic H2 evolution of tantalate-based catalysts through designing solid solutions Bi1−xInxTaO4 combined with CdS, among which the solid solutions Bi1−xInxTaO4 (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0) were firstly synthesized by the citrate method using cheap and environment-friendly Ta2O5. The experimental results reveal that the Bi0.5In0.5TaO4 solid solution shows the best photocatalytic performance among the Bi1−xInxTaO4 solid solutions. And in the absence of noble metals, the 30% CdS/Bi0.5In0.5TaO4 (30CBITO) catalyst exhibits good photocatalytic hydrogen evolution from water splitting with a rate of H2 production of 511.75 μmol h−1 g−1 under simulated sunlight irradiation. And the rate of hydrogen evolution does not markedly change for 60 h. Their compositions, structures and morphologies were characterized by UV–vis diffusion reflectance spectroscopy (DRS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). A photocatalytic enhancement mechanism was put forward to elucidate the superior photocatalytic activity and long-term stability of the heterostructured CdS/Bi0.5In0.5TaO4 composites.