In situ photodeposition of Cu and Ni(OH)2 dual cocatalyst: Synergistic effect on enhancing g-C3N4 photocatalytic H2 evolution

The hydrogen generated through photocatalytic technology is crucial for environmental resources and energy supply. The key to solving photocatalytic efficiency is the migration and compounding of photogenerated carriers. In this paper, Cu is chosen as an electron co-catalyst with good metallic properties to replace the expensive metal. Meanwhile, Ni(OH)2 unites with g-C3N4 to facilitate hole transfer as a hole co-catalyst. The data shows that the g-C3N4 photocatalyst using Cu and Ni(OH)2 as modified co-catalyst has the maximum hydrogen evolution efficiency (2037.3 μmol·g−1·h−1). Due to the Ni(OH)2 and Cu nanoparticles combined with g-C3N4 and their synergistic effect, the hydrogen evolution activity of the dual-loaded photocatalyst is higher than the sum of that of the single-loaded Cu-C3N4 (303.6 μmol·g−1·h−1) and Ni(OH)2-C3N4 (447.3 μmol·g−1·h−1). The photoluminescence spectra (PL) showed that Cu-Ni(OH)2-C3N4 possessed the lowest carrier recombination rate and the fastest carrier transfer rate, consistent with the hydrogen evolution performance results. Data from electrochemical workstations show that composite samples owned a lower electrochemical impedance. The above experiments indicate that the double-loaded synergistic catalytic g-C3N4 possesses a more vital photocatalytic driving force, which has implications for studying energy-catalytic conversion.