COMPARATIVE STUDY OF PHOTOCATALYTIC HYDROGEN EVOLUTION ON G-C3N4 DECORATED WITH NIS AND NIS2 CO-CATALYSTS VIA ION EXCHANGE PRECIPITATION METHOD

NiS and NiS 2 co-catalysts were decorated on the surface of g-C 3 N 4 through ion exchange reaction by precipitation method. Synthesized double systems were investigated using XRD, FT-IR, SEM, TEM, and TEM elemental mapping. XRD and FT-IR analyses showed the presence of g-C3N4 in the composition of g-C 3 N 4 /NiS and g-C 3 N 4 /NiS 2 , however the presence of nickel sulfides was not identified. SEM analysis showed that double systems have heterogeneous systems, the stacked flat sheets with wrinkles and an irregular shape morphology and rough surface, where the presence of irregular shape pores is visible. TEM proved the presence of irregularly shaped layers of g-C 3 N 4 , and TEM elemental mapping showed the presence of nitrogen, carbon, sulfur, and nickel. The ability of the photocatalytic hydrogen evolution by prepared samples revealed, that g-C 3 N 4 /NiS 2 manifests the highest hydrogen evolution rate in comparison with g-C 3 N 4 /NiS and g-C 3 N 4 . Thus, the highest evolution rate of hydrogen was reached by g-C 3 N 4 /NiS 2 on the 3 rd hour of the visible light irradiation and was equal to 56.79 μmolh -1 g -1 .