Colloidal synthesis of a heterostructured CuCo2S4/g-C3N4/In2S3 nanocomposite for photocatalytic hydrogen evolution

Abstract

The introduction of the hot injection approach in designing effective nanocomposites with heterostructures significantly enhances the photocatalytic performance by reinforcing their active sites and facilitating the directed transfer of photocarriers. Here, we present a rapid and easy fabrication process for the synthesis of CuCo₂S₄ and CuCo₂S₄/g-C₃N₄/In₂S₃ heterostructures by the colloidal hot injection method and employed them for photocatalytic H₂ generation under visible light irradiation. The as-prepared materials exhibit unique properties, specifically visible light absorption, suppressed recombination of photogenerated charge carriers, and sustainable H₂ production over prolonged exposure to light irradiation. The catalysts were characterized well to investigate the structural, photophysical and electronic properties. In the CuCo₂S₄/g-C₃N₄/In₂S₃ composite, CuCo₂S₄ and In₂S₃ nanoparticles are deposited on 2D g-C₃N₄. The post synthetically modified hybrid photocatalyst CuCo₂S₄/g-C₃N₄/In₂S₃ greatly influences the redox and e⁻–h⁺ separation process and exhibits an impressive rate of HER (∼11.66 mmol h⁻¹g⁻¹), suppressing the pristine CuCo₂S₄ (∼1.32 mmol h⁻¹g⁻¹). Because of the band gap energy and potential of the conduction band of the components, we proposed a type-I scheme of photocatalytic reaction. The experimental results indicate that the heterostructured materials exhibit remarkably high activity for hydrogen evolution. The DFT results demonstrate the role of g-C₃N₄ and In₂S₃ in improving the photocatalytic performance of the hybrid CuCo₂S₄ catalyst, which leads to superior catalytic behaviour. Furthermore, the increased photocatalytic activity of CuCo₂S₄/g-C₃N₄/In₂S₃ is ascribed to the synergistic interaction of CuCo₂S₄, In₂S₃ nanoparticles and g-C₃N₄, which form an electron transfer channel to harvest photo-generated electrons.