CdS supported on ZIF-67-derived Co-N-C as efficient nano polyhedron photocatalysts for visible light induced hydrogen production

Abstract

Hydrogen energy is vital important for solving pollution of environment and energy shortage. Hydrogen production via solar energy and semiconductor photo-splitting water is one of the most environmentally friendly strategies at present. In this work, Co-N-C, a non-noble metal-based ZIF-67 derivative, was employed as a co-catalyst to achieve an in situ growth of spherical CdS via simple one-step hydrothermal. Due to the large specific surface area of Co-N-C, the agglomeration of CdS is avoided and the photocorrosion phenomenon is weakened. Under irradiation of visible light, the hydrogen generation activity of Co-N-C/CdS was achieved 905 μmol g−1 h−1. It is 6 times that of pure CdS with excellent stability. At the contact interface of the Co-N-C and CdS, the transfer and the separation of photoinduced carriers had been enhanced by a great many of channels. DFT calculation further showed that Co nanoclusters, as the active sites of hydrogen production, significantly enhanced photocatalytic hydrogen evolution activity. Therefore, Co-N-C not only acts as electron acceptor, but also serves as support of highly dispersed CdS to promote the stability of system during photocatalytic hydrogen generation. This work demonstrates the advantages of CdS binding MOF derivatives to construct composite photocatalysts with enhanced dispersibility and hydrogen production activity.