© 2021 Elsevier B.V.The development of innovative methods for the effective removal of toxic organic pollutants from wastewater is of paramount importance. Removal of organic pollutants from aqueous media by chemical reduction using low cost metal-based nanocatalysts and in the presence of sodium borohydride (NaBH4), as a reducing agent, has become a very valuable approach in recent years. We report the advanced catalytic property of copper (0) nanoparticles (Cu NPs) supported on sulfonated reduced graphene oxide (Cu@rGO-SO3H) for the catalytic reduction of thioflavine-T (ThT) dye in the presence of NaBH4, at moderate conditions. Cu@rGO-SO3H catalyst was synthesized by the impregnation-reduction method and diverse characterization techniques were applied to explain the structure and morphology. The results show that the Cu NPs are perfectly dispersed on the surface of the rGO-SO3H support surface (dmean = 6.9 ± 0.4 nm). The catalytic activity of the Cu@rGO-SO3H catalyst was tested in the reduction of ThT in water at 298 K in the presence of NaBH4 and the excellent activity of catalyst have been detected against ThT with 30.5 min−1 initial turn-over frequency (TOFinitial) value. Another important point is that the catalyst has good reusability performance (at 5th reuse 68%) for the catalytic reduction of ThT. Our catalytic studies were also carried out at various temperatures in order to calculate the Ea, ΔH≠ and ΔS≠.