Explore the properties and photocatalytic performance of iron-doped g-C3N4 nanosheets decorated with Ni2P

Abstract The splitting of water into hydrogen is a promising and sustainable approach for solar-to-chemical energy conversion process. To replace the role of noble-metal co-catalysts, earth-abundant and environmentally friendly materials nickel phosphide was introduced into hydrogen evolution system. In this work, a highly efficient and robust heterogeneous photocatalytic hydrogen evolution system was established for the first time by using In situ phosphating nickel ions on the iron-doped graphite carbon nitride. Among all the photocatalysts employed, the 5 wt% Ni2P/0.5-Fe3+ doped g-C3N4 nanosheets (weight ratio) composite shows the highest H2 evolution rate of 397 μmol h−1 g−1 under visible light irradiation, which is 71 times higher than that of bulk g-C3N4. The photocatalyst also shows excellent stability with a hydrogen evolution rate of 1891 μmol h−1 g−1 for the first 5 h under visible light irradiation. Based on detailed analyses of characterizations, the enhanced photocatalytic performance can be directly ascribed to the presence of Ni2P co-catalyst, which could promote the charge transfer both in the photocatalyst and photocatalyst/solution interface. Meanwhile, the synergistic effect of the iron ion and nickel phosphide has good absorption ability of visible light and can reduce the recombination of electrons and holes within the catalyst. This work may provide a novel co-catalyst for the rational design of g-C3N4-based photocatalyst.