▎ 摘　　要

NiS (nickel sulfide)-In2O3 (indium oxide) nanostructures and NiS-In2O3 decorated on graphene oxide (GO) were demonstrated by ultrasonic/hydrothermal method. The structural study demonstrates the preparation of bixbyite and hexagonal phase of In2O3 and NiS for all of the synthesized catalysts. The band gap of the synthesized catalyst was determined to be in the range of 2.30-3.00 eV. A morphological evaluation by field emission scanning electron microscopy of NiS-In2O3 decorated on graphene oxide shows support for the NiS-In2O3 on the graphene oxide layer. Different test parameters were performed to study the phase and morphology. The particle sizes of the In2O3, NiS-In2O3 and NiS-In2O3/GO nanocomposites were 56.0, 62.0 and 66.0 nm, respectively. The photocatalytic performance of NiS-In2O3/GO nanocomposites was examined for the degradation of methylene blue dye under a UV lamp. The prepared sample shows 98.25% photocatalytic degradation within 40 min and at pH 9. With the presence the NiS and GO, the photo-degradation capacities of In2O3 and NiS-In2O3 are improved owing to the low band gap being calculated in UV-vis DRS analysis. The high ratio of NiS causes the highest photocatalytic properties of NiS-In2O3 nanocomposites owing to the enhancement of charge separation efficiency and generation of hydroxyl radicals. This study presents a facile and low-cost method to prepare highly active NiS-In2O3/GO nanocomposites. The antibacterial data indicate the significant properties of NiS-In2O3/GO nanocomposites for this study.