Construction of two dimensional Sr2Ta2O7/S-doped g-C3N4 nanocomposites with Pt cocatalyst for enhanced visible light photocatalytic performance

摘要： Visible light-driven photocatalytic hydrogen production has been deemed a potential means to solve the increasingly serious energy shortage problem. Herein, two dimensional (2D) Sr2Ta2O7/S-doped g-C3N4 nanocomposites that applied in photocatalytic water reduction were fabricated through thermal condensation of thiourea with hydrothermal-prepared Sr2Ta2O7. The resulted Sr2Ta2O7/S-doped g-C3N4 nanocomposite exhibited enhanced hydrogen evolution rate (11.36 μmol g?1 h?1) under visible light irradiation, which is about 3.5 times higher than that of pure S-doped g-C3N4. In light of the UV–vis diffuse reflectance spectroscopy, Mott-Schottky curve and photoluminescence spectra, the enhanced photocatalytic performance could be mainly attributed to the conduction band difference between Sr2Ta2O7 and S-doped g-C3N4. In addition, transient photoluminescence spectra, electrochemical impedance spectra and photocurrent responses proved that the presence of Pt cocatalyst also plays an important role in facilitates the transport of photoexcited electron-hole pairs, subsequently promoting the photocatalytic performance.