▎ 摘　　要

Low-concentration dye pollutants are difficult to manage completely and have posed a great threat to the environment. Among the various strategies, the Fenton reaction is an efficient approach for dye degradation in the presence of high-efficiency catalysts. In this article, we reported the application of Fe3O4-modified ultrasmall graphene oxide (Fe3O4/usGO) as a heterogeneous catalyst for the Fenton-like degradation of ppm-level dye pollutants (e.g., methylene blue, MB). Fe3O4/usGO was synthesized via the in situ coprecipitation of Fe3O4 nanoparticles on usGO. The as-prepared Fe3O4/usGO has excellent catalytic capacity and can effectively purify low-concentration MB wastewater. According to dynamic and thermodynamic analysis, this Fenton-like degradation process follows the first-order reaction kinetic model, and the reaction activation energy is calculated as 67.23 kJ/mol. In this strategy, we have obtained nearly 100% degradation rate of MB by using a very low dosage of catalyst (2.92 mg/L). Considering its simple preparation and high performance, Fe3O4/usGO holds great promise for dye pollutant purification.