Environmental conversion of As(III) to less toxic As(V) is a critical step for the arsenic pollution remediation. In the present study, MoS2 ultrathin nanosheets modified carbon felt electrode is fabricated by a facile hydrothermal method and employed as the two-electron oxygen reduction reaction (ORR) cathode for the As(III) oxidation in alkaline media. Due to the rich Mo-O bonds at MoS2 ultrathin nanosheets, the two-electron ORR catalytic property, electrical conductivity and hydrophilic behavior are significantly enhanced. Besides, As(III) can be efficiently conversed via adsorption-oxidation scheme on the modified layer, and there is good stability on the MoS2 modified electrode during the electrooxidation process. This MoS2 modified carbon felt can be presented as a cost-effective cathode for the electroperoxidation process and provided further understanding for the environmental remediation in alkaline media. (C) 2017 Elsevier Ltd. All rights reserved.