A new CdS/Bi_1-xIn_xTaO₄ 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 Bi_1-xIn_xTaO₄ combined with CdS, among which the solid solutions Bi_1-xIn _xTaO₄ (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 Bi _0.5In_0.5TaO₄ solid solution shows the best photocatalytic performance among the Bi_1-xIn_xTaO ₄ solid solutions. And in the absence of noble metals, the 30% CdS/Bi_0.5In_0.5TaO₄ (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/Bi_0.5In_0.5TaO ₄ composites.