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.
Keywords: CdS/Cu7S4/g-C3N4; noble metal-free; photocatalytic hydrogen production; ternary heterostructures; visible light.