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 photocatalytic hydrogen evolution efficiency in Na2S–Na2SO3 solution under 300 W Xe lamp (λ ＞ 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 enhances 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.