Strengthening reactive metal–support interaction to stabilize Ni species on the nitrogen vacancies of g-C3N4 for boosting photocatalytic H2 production

Abstract

A noble-metal-free Ni species-modified graphitic carbon nitride (CN) photocatalyst (DCN–Ni) is fabricated by stabilizing Ni species on the nitrogen vacancies of g-C₃N₄. The experimental observation expresses that the nitrogen vacancies in g-C₃N₄ arouse an obvious electron-deficient effect, which significantly promotes the metal–support interaction by interface bonding states. This strong metal–support interaction builds a conducive highway (Ni–C bonding states) for electrons to transfer from DCN to the Ni species, which contributes to the high separation and transportation efficiency of charge carriers. As a result, the outstanding H₂-evolution activity over DCN–Ni₂ reaches up to about 1.75 times higher than that of Pt/g-C₃N₄ under visible light. The structure characteristic reveals that the strong metal–support interaction not only stabilizes the Ni species on the electron-deficient g-C₃N₄via interface bonding states, but also allows the Ni species to optimize the electronic structures of g-C₃N₄ for a highly efficient photocatalytic H₂ evolution reaction. This work supplies a reliable guideline for designing and constructing a low-cost, highly efficient, and durable cocatalyst acting on g-C₃N₄, opening a new channel and possibility for energy and environment-related applications.