Photocatalytic hydrogen evolution performance of NiS cocatalyst modified LaFeO3/g-C3N4 heterojunctions
Abstract
NiS cocatalyst modified LaFeO3/g-C3N4 heterostructures were successfully prepared and their photocatalytic hydrogen evolution performance under visible light irradiation was presented. LaFeO3/g-C3N4/NiS composites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption desorption isotherms, UV-vis diffuse reflectance spectroscopy (DRS), transient photocurrent responses and electrochemical impedance spectroscopy (EIS). The results indicated that the LaFeO3/g-C3N4/NiS heterostructures had enhanced photocatalytic hydrogen evolution performance than pure g-C3N4, LaFeO3 and LaFeO3/g-C3N4. 5%-LaFeO3/g-C3N4/2%NiS exhibited the highest photocatalytic hydrogen evolution rate of 121 μmol g−1 h−1 under visible light, which was almost 60 times higher than the hydrogen evolution rate of 5%-LaFeO3/g-C3N4. The effective separation of photogenerated electron–hole pairs in the LaFeO3/g-C3N4 Z-scheme system with NiS as a cocatalyst enhanced the photocatalytic hydrogen evolution performance. This study provided a facile approach to prepare NiS modified LaFeO3/g-C3N4 heterostructures and to construct an effective photocatalytic system for hydrogen evolution under visible light irradiation.