Combining Heterojunction Engineering with Surface Cocatalyst Modification To Synergistically Enhance the Photocatalytic Hydrogen Evolution Performance of Cadmium Sulfide Nanorods

Abstract

Photocatalytic decomposition of water to hydrogen is an energy conversion process just like photosynthesis. Herein, for the first time, CoP-modified CdS/g-C3N4 composite nanorods were synthesized on the basis of the concept of combining heterojunction engineering with cocatalyst modification. The obtained CoP-CdS/g-C3N4 composites exhibit excellent photocatalytic activity and good photostability when applied as a photocatalyst for water reduction. The H2 production rate reaches up to 23 536 μmol g–1 h–1, which was about 14 times higher than that of pure CdS. Furthermore, the stability of the composite was obviously improved. The outstanding performance of the CoP-CdS/g-C3N4 composites can be attributed to the following reasons: (1) Intimate contact between CdS and g-C3N4 can effectively promote the electron–hole pair spacial separation. (2) The introduction of CoP as cocatalyst on the CdS/g-C3N4 nanorods can further extract photogenerated electrons from CdS/g-C3N4 and lower the overpotential of H+ reduction.