Reduced graphene oxide (rGO) with metal sulfides is an efficient photocatalyst for treating textile effluent. Herein, a hydrothermal technique was used to synthesize transition metal sulfide with rGO nanocomposite. Under 120 min of sunlight exposure, the cerium-nickel sulfide/rGO nanocomposite (Ce2S3-NiS2/rGO) photodegraded the methyl orange (MO) dye with an efficiency of 89.1% which is significantly higher than that of bare nickel sulfide (NiS2) and cerium sulfide (Ce2S3) photocatalysts. Moreover, another model pollutant dye bromophenol blue (BP) was treated under the same experimental condition, and it has achieved about 84.2% degradation efficiency. The combination of NiS2 and Ce2S3 improves the separation efficiency of photogenerated carriers, resulting in improved photocatalytic activity. In addition, ternary metal sulfide with rGO increases pollutant adsorption and electron–hole photogenerated pairs. Therefore, the mechanism of photocatalytic Ce2S3-NiS2/rGO is investigated in detail. This research could pave the way for the development of capable and adaptable Ce2S3-NiS2/rGO photocatalysts for environmental remediation. Graphical Abstract: [Figure not available: see fulltext.]. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.