2D-2D PhCN/WS2 exfoliated nanosheets for visible-light hydrogen production: A platinum-free Co-catalyst approach

Substituting fossil fuels with green energy sources such as H2 is one of the prime objectives of achieving a sustainable and carbon-neutral future. In this work, a noble-metal-free 2D-2D hybrid photocatalyst PhCN/WS2 is reported for application in hydrogen production under visible-light irradiation, where WS2 is utilized as an environmentally friendly co-catalyst. The synthesis and characterization of 2D Phenyl-modified carbon nitride (PhCN) and 2D WS2 via liquid-phase exfoliation are systematically investigated. The effectiveness of a solventmediated self-assembly is highlighted, and the effect of WS2 flake size on the photocatalytic activity of the hybrid is examined. The hybridization of exfoliated PhCN with two-dimensional (2D) WS2 demonstrates a 42-fold enhancement in hydrogen evolution compared to exfoliated PhCN alone under visible light. This improvement is attributed to the role of WS2 as an effective hydrogen evolution reaction (HER) co-catalyst. The utilization of larger WS2 nanoflakes proved to be ideal to establish fast charge carrier transportation networks.