Visual observation of hydrogen bubble generation from monodisperse CoP QDs on ultrafine g-C3N4 fiber under visible light irradiation

Abstract

Solar-driven hydrogen evolution reaction (HER) via water splitting is an attractive technology to address the growing demand for clean fuels. g-C₃N₄ is a promising candidate among photocatalysts, but it is plagued by its puny HER activity and miserly quantum efficiency. Tremendous efforts have been made to enhance g-C₃N₄ performance on HER; however, it is still far below the expectations in industrial production. Herein, we report a monodisperse CoP QDs-modified ultrafine g-C₃N₄ fiber (CoP/CNF) via in situ electrostatic adsorption deposition followed by low-temperature phosphatization treatment. The CoP/CNF showed an HER activity of 2.42 mmol h⁻¹ under visible light, 34.9 times higher than that of Pt/CNF, in which hydrogen bubbles evolution was observed with an apparent quantum efficiency of 59.9% at 420 nm. This benchmark HER activity was mainly because the CoP QDs could significantly suppress photoinduced charge recombination and improve the heterointerface HER rate. This work provides a useful strategy for designing highly active catalysts for solar-to-hydrogen fuel conversion.