Synthesis of novel CoxMo1-xS-Cd0.5Zn0.5S composites with significantly improved photocatalytic hydrogen evolution performance under visible-light illumination

Recently, MoS2 incorporates with Co2+ (or Ni2+) was found to increase the photocatalytic performance of semiconducting materials more effectively. In this study, novel CoxMo1-xS was effectively deposited on the surface of Zn0.5Cd0.5S semiconductors as an efficient promotor using in-situ hydrothermal process. The as-prepared CoxMo1-xS-Zn0.5Cd0.5S composites are examined by the following techniques: XRD, TEM, DRS, XPS, PL and TRPL. The photocatalytic hydrogen evolution performance under visible illumination over Zn0.5Cd0.5S is remarkably increased by adding cheap CoxMo1-xS as promotor. The CoxMo1-xS-Zn0.5Cd0.5S hybrid specimen with 10% molar amount illustrates the best catalytic performance with a homologous hydrogen generation rate of 188.65 μmol h−1, which is estimated to be 14.5 folds than that of unmodified Zn0.5Cd0.5S specimen in the presence of visible light. The apparent quantum yield of Co0.3Mo0.7Zn0.5Cd0.5S sample is determined to be 16.72% at monochromatic light of 420 nm. The experimental outcomes indicate that the synergistic action between CoxMo1-xS and Zn0.5Cd0.5S obviously promotes transfer of photo-induced charge carriers in the hybrid sample. A reasonable catalytic mechanism for the increased photocatalytic performance of CoxMo1-xS promotor was presented and authenticated by TRPL measure, which would present a new notion for the design of ideal semiconductors with plummy photocatalytic capability.