Sustainable synthesis of low-cost nitrogen-doped-carbon coated Co3W3C@g-C3N4 composite photocatalyst for efficient hydrogen evolution

Abstract

The availability of low-cost noble-metal-free photocatalyst is vital for sustainable and large-scale hydrogen production. Herein, N-doped-carbon coated Co3W3C nanocrystallines (NC-Co3W3C), a novel cocatalyst, are anchored onto g-C3N4, forming a (NC-Co3W3C@g-C3N4) composite photocatalyst for application in photocatalytic hydrogen evolution reaction (HER). Under visible light irradiation, NC-Co3W3C@g-C3N4 photocatalyst shows a remarkable photocatalytic HER rate of 1332 μmol h−1 g−1, achieving 148 times higher than pristine g-C3N4 photocatalyst and 89.22% as high as Pt/g-C3N4 photocatalyst (the expensive noble-metal-based catalyst). The mechanism investigation via systematic experimental and theoretical analysis (Density Functional Theory (DFT) calculation) suggests that the high photocatalytic efficiency could be attributed to boosted light absorption and accelerated HER kinetic that is resulted from the enhanced conducitity, reinforced stability, and the suitable H adsorption free energy introduced by the cocatalyst. This work suggests the construction of highly efficient catalyst for photocatalytic hydrogen evolution is chemically and economically viable for the green hydrogen economy.