Noble metal-free 0D-1D CoOx/Mn0.3Cd0.7S nanocomposites for efficient visible-light hydrogen production

Abstract

Here, a series of MnxCd1-xS sosoloid composite photocatalysts with visible-light activity were first prepared by a solvothermal process. The element ratio of Cd2+ to Mn2+ was optimized to be Mn0.3Cd0.7S in MnxCd1-xS sosoloid on account of its photocatalytic activity for H2 evolution from H2O in response to visible light excitation. And on this basis, the CoOx nanopariticles were loaded on the surface of Mn0.3Cd0.7S sosoloid composite to obtain a binary p-n heterojunction of CoOx/Mn0.3Cd0.7S composite through a facile impregnation process and a high temperature sintering procedure. Benefitting from the synergistic effect of the built-in electric field, binary p-n heterojunction structure, and rearrange of the Fermi level equilibrium, the as-synthesized CoOx/Mn0.3Cd0.7S composite presents a highly enhanced photocatalytic activity for hydrogen production from H2O in response to visible light excitation, which is demonstrated to be 53.4 and 4.0 times higher than that of the primitive CdS and Mn0.3Cd0.7S, respectively. Furthermore, after 4 times circles of photocatalytic H2 production tests, the CoOx/Mn0.3Cd0.7S composite still keeps 92.0 % of the original photocatalytic activity. Considering its reasonable photochemistry stability and excellent photocatalytic activity for hydrogen evolution from H2O under with visible light excitation, the as-synthesized CoOx/Mn0.3Cd0.7S composite has potential applications in solar hydrogen production areas.