Carbon nitride (C₃N₃) decorated with non-noble metal Ni₂P Co-catalyst based nanocomposites for photocatalytic water splitting

Carbon nitrides based 2D materials have been recently explored as visible light harvesting photocatalysts due to their unique optoelectronic properties. However, these materials require strategies to improve their photoconversion efficiencies by improving the separation of photoexcited charge carriers and minimizing their recombination. Here in this paper, we report the synthesis of 2D carbon nitride with formula C₃N₃ decorated with non-noble metal nickel phosphide (Ni₂P) co-catalyst-based nanocomposites (Ni₂P/C₃N₃) for the enhanced photoelectrochemical water splitting. The ratio of Ni₂P co-catalyst was varied from 1%, 2% and 3% in the nanocomposites. Under similar set of experimental conditions, the 2% Ni₂P co-catalyst loaded photocatalyst (2% Ni₂P/C₃N₃) showed significant enhancement in the photocurrent (43 µA/cm²) in comparison to the pristine C₃N₃ (23 µA/cm²) under 1 sun light irradiation. In addition, the 2% Ni₂P/C₃N₃ photocatalyst exhibited enhanced H₂ production rate (148 μmol h⁻¹ g⁻¹) than pure C₃N₃ (60 μmol h⁻¹ g⁻¹). In addition, the 2% Ni₂P/C₃N₃ nanocomposites demonstrated higher photostability. The H₂ production rate was almost the same after eight cycles conducted within 65 h of time. Moreover, Ni₂P/C₃N₃ nanocomposites are low cost, naturally abundant and environmentally friendly.