Construction and performance of CdS/MoO2@Mo2C-MXene photocatalyst for H2 production
Sen Jin, Huijuan Jing, Libo Wang, Qianku Hu, Aiguo Zhou
Abstract
Abstract Nowadays, photocatalytic technologies are regarded as promising strategies to solve energy problems, and various photocatalysts have been synthesized and explored. In this paper, a novel CdS/MoO 2 @Mo 2 C-MXene photocatalyst for H 2 production was constructed by a two-step hydrothermal method, where MoO 2 @Mo 2 C-MXene acted as a binary co-catalyst. In the first hydrothermal step, MoO 2 crystals with an egged shape grew on the surface of two-dimensional (2D) Mo 2 C MXene via an oxidation process in HCl aqueous solution. In the second hydrothermal step, CdS nanorods were uniformly assembled on the surface of MoO 2 @Mo 2 C-MXene in ethylenediamine with an inorganic cadmium source and organic sulfur source. The CdS/MoO 2 @Mo 2 C-MXene composite with MoO 2 @Mo 2 C-MXene of 5 wt% exhibits an ultrahigh visible-light photocatalytic H 2 production activity of 22,672 µmol/(g·h), which is ∼21% higher than that of CdS/Mo 2 C-MXene. In the CdS/MoO 2 @Mo 2 C-MXene composite, the MoO 2 with metallic nature separates CdS and Mo 2 C MXene, which acts as an electron-transport bridge between CdS and Mo 2 C MXene to accelerate the photoinduced electron transferring. Moreover, the energy band structure of CdS was changed by MoO 2 @Mo 2 C-MXene to suppress the recombination of photogenerated carriers. This novel compound delivers upgraded photocatalytic H 2 evolution performance and a new pathway of preparing the low-cost photocatalyst to solve energy problems in the future.