Bimetallic PtNi alloy modified 2D g-C3N4 nanosheets as an efficient cocatalyst for enhancing photocatalytic hydrogen evolution.

Platinum-based alloy materials as effective cocatalysts in improving the performance of photocatalytic H 2 production have raised great interest. Herein, a facile strategy of chemical reduction is established to synthesize bimetallic PtNi nanoparticles on 2D g-C 3 N 4 nanosheets with excellent photocatalytic activity. The addition of PtNi nanoparticles can provide new H+ reduction sites and increase more active sites of the material. The synergistic effect between PtNi alloy nanoparticles and 2D g-C 3 N 4 nanosheets can regulate electronic structure, narrow the band, accelerate charge transfer efficiency and inhabit the recombination of photo-induced electron (e−) and hole pairs (h+), contributing to the improvement of hydrogen evolution activity. The optimal hydrogen evolution rate of Pt 0.6 Ni 0.4 /CN shows higher hydrogen evolution rate (9528 μmol·g−1·h−1), which is 13.1 times than that of pure g-C 3 N 4 nanosheets. Besides, a possible mechanism of photocatalytic hydrogen generation has been brought up according to a series of physical and chemical characterization. This work also provides a potential idea of developing cocatalysts integrating metal alloys with 2D g-C 3 N 4 nanosheets for promoting photocatalytic hydrogen evolution. The integration of bimetallic PtNi nanoparticles and g-CN can inhabit the recombination of photo-induced electron (e−) and hole pairs (h+), contributing to promoting hydrogen evolution activity. [Display omitted] • Pt x Ni 1-x /CN catalysts were synthesized by a facile method of chemical reduction. • The synergistic effect of PdNi alloy could accelerate charge transfer efficiency. • The Pt 0.6 Ni 0.4 /CN showed the highest H 2 generation activity. • A possible mechanism of photocatalytic hydrogen production was proposed. [ABSTRACT FROM AUTHOR]