Graphdiyne (G-Cnh2n-2) Based Co3s4 Anchoring and Edge-Covalently Modification Coupled with Carbon-Defects G-C3n4 for Photocatalytic Hydrogen Production

Abstract

Graphdiyne (GDY), as a novel two-dimension carbon allotrope material composed of sp- and sp2-hybrid carbon network, has been widely explored since it was synthesized for the first time by Li’s group in 2010. In this research, we developed a synthesis scheme of Co3S4-anchored graphdiyne/carbon defects g-C3N4 (DCN) nano-hybrids for efficient photocatalytic hydrogen evolution. This system has a fantastic 0D-2D/2D structure and the porous interconnected framework favors multivariate collaborative catalysis, greatly promoting the mass transfer performance between them, and enhancing the light absorption and the density of active sites. Most of all, as a charge transfer station, the edge-covalently modified GDY provides shortcuts for the dual-induction of electrons and holes. Charge kinetic analysis indicated that the electron transfer rate of the system reached 9.27 × 109 s-1, and the ultra-fast interfacial transfer greatly promoted the charge separation. In addition, photoelectrochemical technology proved that the multiplex nanoreactor has lower carrier recombination rate and smaller hydrogen evolution overpotential. Under 5W LED light (λ>420 nm), the dye-sensitized optimized hydrogen generation rate is 2075.67 μmol g-1 h-1, which is 77.2 times that of bare DCN. This work is expected to a new design concept for the construction of multiple and efficient synergistic nanocomposites, opening up new opportunities and possibilities for photocatalysis application.

Keywords: g-C3N4, graphdiyne, Photocatalysis, hydrogen evolution