Efficient visible-light-induced hydrogen evolution from water splitting using a nanocrystalline nickel phosphide catalyst

Nanocrystalline nickel phosphide (Ni12P5) was successfully synthesized by a simple hydrothermal method via using NiCl2 and red phosphorus as raw materials. The crystal structure, morphology and surface chemical compositions of the as-prepared sample were characterized by X-ray diffraction, scanning electron microscope and X-ray photoelectron spectroscopy techniques, respectively. Its catalytic activity for the hydrogen evolution from water was investigated under visible light irradiation (lambda >= 420 nm) with fluorescein sodium as the photosensitizer and triethanolamine as the sacrificial electron donor, respectively. The results indicated that the Ni12P5 sample showed high catalytic activity (10 760 mmol h(-1) g(-1), TOF = 9.3 h(-1)) and good stability (15 h) in the present system. The electrochemical results revealed that Ni12P5 had a high cathodic current and small charge transfer resistance, which further suggested Ni12P5 indeed could efficiently catalyze the evolution of hydrogen.