Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Production on CdS/Cu₇S₄/g-C₃N₄ Ternary Heterostructures

Abstract

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