Tween20 surfactant effect on the electrocatalytic performance of porous carbon micro-spheres supported MnO2

Abstract

This study is concerned with the electrocatalytic evolution of oxygen at polyoxyethylene sorbitan monolaurate (Tween20) modified porous carbon micro-spheres (PCS) supported MnO₂ catalyst in 0.1 M KOH solution. The Super P (SP) was used to improve the electrical conductivity of the catalyst. The electrochemical measurements revealed a significant enhancement of the electrocatalytic activity of the MnO₂/PCS towards the oxygen evolution reaction (OER) upon the Tween20 modification. The onset potentials of the OER at the Tween20 modified MnO₂/PCS particles electrode are more negative by about 0.162 V compared with the bare (i.e. unmodified) MnO₂/PCS electrode. Tween20 is absorbed on the surface of MnO₂/PCS and covers the entire surface of the MnO₂/PCS particles homogeneously. The Tween20 plays a vital role as a catalytic mediator, which facilitates the ion transfer during the water oxidation into molecular oxygen and thus the OER is accomplished at less positive potentials.