Fabrication and characterization of visible light-driven In2.77S4/In(OH)3 composite photocatalysts with excellent redox performance

The In 2.77 S 4 microspheres had been firstly fabricated by using polyethylene glycol (PEG) as the morphological modifier and then used to hybridize with In(OH) 3 nanocubes by a simply depositional method. The structure, optical properties, morphology, chemical compositions, and charge carrier behaviors of the as-prepared In 2.77 S 4 /In(OH) 3 composites were characterized, respectively. The methyl orange, tetracycline, rhodamine B, and Cr(VI) dilute solution were selected to evaluate their photocatalytic activities. Experimental results showed that In(OH) 3 nanocubes could improve the photocatalytic activity and recyclability of the In 2.77 S 4 microspheres under the visible light irradiation. With the usage of In(OH) 3 increased, the photocatalytic efficiency of the hybrids was firstly increased and then decreased. When the mass ratios of In 2.77 S 4 to In(OH) 3 were 6:2, it reached the maximum of 100% in 15 min for methyl orange, obviously higher than 67.4% of In 2.77 S 4 and 1.1% of In(OH) 3 . Meanwhile, it could also oxidize 85.6% of tetracycline in 20 min, 97.8% of rhodamine B in 7.5 min, and reduce 92.9% of Cr(VI) in 30 min under the visible light irradiation. Moreover, it could still degrade 91.7% of methyl orange solution after 3 cycles, which was much higher than 40.7% of In 2.77 S 4 microspheres. In addition, the possible mechanism of enhancing photocatalytic properties was proposed.