One-step synthesis of heterojunction Cr2O3 nanoparticles decorated Bi2S3 nanorods with enhanced photocatalytic activity for mineralization of organic pollutants

Abstract

Herein, one-step synthesis of Cr2O3/Bi2S3 nanorods at various Cr2O3 contents (0.01–0.05%) is developed using a hydrothermal approach for degradation of two organic pollutants such as phenol and methylene blue (MB) under visible light irradiation. TEM observation showed that the Cr2O3 NPs around 5 nm at very small content decorated the surface of Bi2S3 nanorods. The photocatalytic performance of synthesized photocatalyst exhibited an effective photocatalytic efficiency of about 90% for Phenol and 80% for MB upon visible light exposure. The photocatalytic performance of 0.04% Cr2O3/Bi2S3 heterostructure was enhanced 2.66 and 2.25 times larger than bare Bi2S3 nanorods for degradation of MB and phenol, respectively. The temperature-programmed desorption ensures that Cr2O3/Bi2S3 heterostructure has more acidic active sites, which increased the OH radical absorption and then increased the photocatalytic efficiency. The electrochemical impedance spectroscopy (EIS), photoelectrochemical behavior and photoluminescence spectra were measured as evidence for the photocatalytic mechanism. The results indicated that the construction Cr2O3/Bi2S3 heterostructure has significantly suppressed the recombination rate of photoinduced carriers and consequently enhanced its photocatalytic efficiency. Additionally, the Cr2O3/Bi2S3 heterostructure revealed high recyclability, durability and stability for five cyclic runs without significant loss of the photocatalytic performance, making the synthesized photocatalyst promising for the remediation of wastewater under sunlight.