Spatial charge separation of one-dimensional Ni2P-Cd0.9Zn0.1S/g-C3N4 heterostructure for high-quantum-yield photocatalytic hydrogen production

Constructing heterostructured photocatalysts to facilitate spatial charge separation is deemed to be central to improving photocatalytic hydrogen production. Herein, we reported the synthesis of Ni2P-Cd0.9Zn0.1S/graphitic carbon nitride (g-C3N4) heterostructure for photocatalytic hydrogen production under visible-light irradiation. It was revealed that the ternary photocatalysts exhibited a one-dimensional morphology. Ni2P nanoparticles and a layer of g-C3N4 were tightly deposited on the surface of Cd0.9Zn0.1S nanorods. The optimal hydrogen evolution rate over Ni2P-Cd0.9Zn0.1S/g-C3N4 was similar to 2100 mu mol h(-1) mg(-1), corresponding to an apparent quantum yield as high as 73.2% at 420nm. Meanwhile, the g-C3N4 layer could effectively collect the photo-induced holes from Cd0.9Zn0.1S, which substantially alleviated the photocorrosion of metal sulfide and led to an excellent stability for 90 h. A detail analysis of the action mechanism by photoluminescence, surface photovoltage, and electrochemical measurements revealed that the dramatically improved photocatalytic activity should be ascribed to highly efficient spatial separation of photo-induced charge carriers, as well as accelerated surface reaction by Ni2P cocatalysts. It is believed that the present work supplies an effective way to obtain non-precious heterostructured photocatalytic system for high-quantum-yield and stable hydrogen production. (C) 2017 Elsevier B.V. All rights reserved.