Significantly enhanced photocatalytic hydrogen production performance of MoS2/CNTs/CdS with carbon nanotubes as the charge mediators

Abstract

Photocatalysis technology can efficiently produce hydrogen, which is essential for the sustainable development of clean energy. Herein, molybdenum sulfide/carbon nanotubes/cadmium sulfide (MoS2/CNTs/CdS) ternary composites are designed as catalysts to obtain an efficient photocatalytic hydrogen production system. In particular, the in-situ growth of CdS on the surface of MoS2/CNTs improves the dispersion of CdS nanoparticles, reduces the size of CdS particles, and increases the active site of photocatalytic reaction. A built-in electric field is formed between the interface between CdS and MoS2, which causes photogenerated electrons in conduction band (CB) of CdS and photogenerated holes in valence band (VB) of MoS2 to move in Z-type conduction mechanism. The excellent charge-conducting ability of CNTs reduces the recombination of photogenerated electrons and holes in CdS, further improving the hydrogen production efficiency and the stability of photocatalytic performance. Experiments showed that MoS2/CNTs/CdS (15%) have the highest hydrogen production rate (101.18 mmol h−1 g−1), which was 253 times higher than that of pure CdS. This study is expected to provide new ideas for the design and preparation of ternary hybrid photocatalysts for hydrogen production by photolysis of water.