CoNi bimetallic alloy cocatalyst-modified g-C3N4 nanosheets for efficient photocatalytic hydrogen production

Non-precious and Earth-abundant cocatalysts have emerged as promising alternatives to precious metal catalysts for hydrogen generation from photocatalytic water splitting. In this work, CoNi/g-C3N4 photocatalyst composed of g-C3N4 nanosheets and CoNi alloyed nanoparticles was prepared by a simple solvothermal and chemical reduction method. Bimetallic CoNi alloy was found to accelerate charge transfer and inhibit electron and hole recombination, thereby enhancing the photocatalytic activity of CoNi/g-C3N4. Under optimal conditions, the hydrogen production rate of CoNi/g-C3N4 reached up to 354.4 μmol h−1 g−1 with visible light (λ > 420 nm) in triethanolamine aqueous solution; this value greatly exceeded that of g-C3N4 by a factor of 188 times. A mechanism explaining the excellent photocatalytic performance was proposed accordingly. These results suggest that g–C3N4–based photocatalysts have good potential for hydrogen generation.