Noble metal-free CoS2/g-C3N4 nanosheet composite photocatalysts for improved visible-light photocatalytic hydrogen production

Various of CoS2/g-C3N4 nanosheet composites were fabricated through supramolecular self-assembly and copolymerization approaches. This fabrication entailed the incorporation of CoS2 nanoparticles into ultra-thin layers of g-C3N4 nanosheets. Demonstrating a significant boost, these composites achieved a 28-fold increase in the photocatalytic H2 evolution from H2O with visible light response, without the aid of noble metal nanocrystalline co-catalysts. The enhanced CoS2/g-C3N4 composite sustained approximately 92.4 % of its initial photocatalytic activity after four repeated uses. The planar structure of g-C3N4 nanosheet amplifies its specific surface area, which improves access to catalytic sites and reduces the transport distance for photo-excited electrons and holes. Moreover, the close conjunction of CoS2 nanoparticles and g-C3N4 nanosheets establishes p-n heterojunctions, which promote swift charge separation and transfer at the material interface. Based on these characteristics, an initial model for the photocatalytic process has been proposed. With its remarkable photocatalytic performance and durability, the developed CoS2/g-C3N4 composite presents substantial potential for solar-driven H2 production.