Robust and efficient photocatalytic hydrogen generation of ReS2/CdS and mechanistic study by on-line mass spectrometry and in situ infrared spectroscopy

Photocatalytic hydrogen evolution is an attractive technology to address the increasing energy crisis. The development of advanced photocatalysts presents an attractive but challenging issue. For the first time, we anchored inorganic ReS2 via a facial hydrothermal route as co-catalyst to CdS nanorods for highly efficient H-2 evolution. CdS/ReS2 composite photocatalyst containing 1 wt% of ReS2 co-catalyst exhibits the highest photocatalytic H-2 evolution rates of 24.36 and 137.5 mmol h(-1) g(-1) using Na2S-Na2SO3 and lactic acid as sacrificial reagents, respectively, corresponding to 127 and 8.8 fold enhancements, respectively, compared with bare CdS. The photocatalytic enhancement mechanism was elucidated by experimental means and theoretical calculations. The source of hydrogen and the fate of the sacrifice reagents were studied by in situ Fourier transform infrared (FT-IR) spectroscopy and on-line mass spectrometry. Our results showed that ReS2 is a promising co-catalyst to achieve high photocatalytic hydrogen production from water under visible light irradiation.