Highly\nEfficient Visible-Light-Driven Photocatalytic Hydrogen Production\non CdS/Cu₇S₄/g‑C₃N₄ Ternary Heterostructures

Abstract

Hydrogen\nproduction through photocatalytic water splitting has attracted much\nattention because of its potential to solve the issues of environmental\npollution and energy shortage. In this work, CdS/Cu₇S₄/g-C₃N₄ ternary heterostructures are\nfabricated by ion exchange between CdS and Cu⁺ and subsequent\nultrasonication-assisted self-assembly of CdS/Cu₇S₄ and g-C₃N₄, which provide excellent\nvisible-light photocatalytic activity for hydrogen evolution without\nany noble metal cocatalyst. With the presence of p–n junction,\ntuned band gap alignments, and higher charge carrier density in the\nCdS/Cu₇S₄/g-C₃N₄ ternary\nheterostructures that can effectively promote the spatial separation\nand prolong the lifetime of photogenerated electrons, a high hydrogen\nevolution rate of 3570 μmol g^–1 h^–1, an apparent quantum yield of 4.4% at 420 nm, and remarkable recycling\nstability are achieved. We believe that the as-synthesized CdS/Cu₇S₄/g-C₃N₄ ternary heterostructures\ncan be promising noble metal-free catalysts for enhanced hydrogen\nproduction from photocatalytic water splitting.