Short stick-shaped MnS/Mn0·5Cd0·5S grown in situ on CuSe nanosheets for efficient photocatalytic hydrogen evolution

The development of efficient and stable photocatalysts is very important for photocatalytic hydrogen evolution. In this work, a series of CuSe/MnS/Mn0.5Cd0.5S composites with high hydrogen evolution performance were synthesized by a simple hydrothermal method. The synthesized products were characterized by X-ray diffraction, Scanning electron microscopy, Transmission electron microscopy, Mapping, X-ray photoelectron spectroscopy, UV-Vis diffuse reflection spectroscopy, Mott-Schottky, Transient photocurrent response, Electrochemical impedance spectroscopy, and Photoluminescence spectroscopy. The obtained products showed efficient photo -catalytic hydrogen evolution efficiency in Na2S-Na2SO3 solution under 300 W Xe lamp (? > 420 nm), with the highest photocatalytic hydrogen evolution efficiency reaching 24.7 mmol g(-1) h(-1), which was 4.1 times higher than pure MnS/Mn0.5C0.5S (5.99 mmol h(-1) g(-1)) and 6.3 times higher than pure CdS (3.59 mmol h(-1) g(-1)). A possible mechanism of photocatalytic hydrogen production was proposed. The addition of CuSe effectively en-hances the photogenerated electron-hole separation efficiency and reduces the electron-hole pair complexation rate of CuSe/MnS/Mn0.5C0.5S composites. This work provides an effective way to improve the photocatalytic activity of Mn0.5Cd0.5S using transition metal selenide cocatalysts.