【Purposes】 Electrochemical synthesis of hydrogen peroxide (H2O2) in situ coupled Fenton-like technology has broad application prospects in the treatment of black-odorous waterbodies. However, the development of low-cost, high-performance oxygen reduction cathode electrocatalysts in neutral media has become a key obstacle to the commercial implementation of this technology. 【Methods】 To address this problem, a graphite felt(GF)-supported NiOOH electrocatalyst (x-NiOOH/GF) was prepared by a simple and effective hydrothermal method, and the effects of nickel nitrate addition on the morphology and electrochemical performance of the catalysts during the hydrothermal process were discussed. 【Findings】 The experimental results show that: The surface of 3.5-NiOOH/GF carbon fiber is covered with a layer of ordered sheet-like structure. Under neutral conditions, it exhibits high electrochemical activity, nearly 100% H2O2 selectivity, and excellent stability in oxygen reduction reaction (ORR). Finally, 3.5-NiOOH/GF effectively degrades rhodamine B by electro-Fenton process, indicating its potential to treat black-odorous waterbodies.