Enhanced electrocatalytic activity of POM-derived CoMoS/FCP heterostructures for overall water splitting in alkaline media

Abstract

For the development of green energy and environmental protection, water splitting is an effective method to achieve high-efficiency H2 production as a clean and pollution-free energy source. However, the kinetics of the reaction are limited as a severe reaction. Thus, it is essential to find an economical and robust bifunctional electrocatalyst to boost the hydrogen evolution reaction (HER) and oxygen evolution reaction reactions (OER). In this work, we designed a bifunctional catalyst, CoMoS/FCP, by using the polyoxometalate (POM) Co2Mo10 as a precursor on carbon paper. The catalyst exhibits excellent performance under alkaline conditions (1 M KOH). The overpotential for the HER at 10 mA·cm−2 is 225 mV, and the overpotential of OER at 20 mA/cm2 is 215 mV. We also prepared an assembled two-electrode electrolyzer in alkaline condition. The electrolyzer has a quite low cell voltage of 1.67 V at a current density of 10 mA·cm−2. Moreover, even after 12 h of durability tests, the current density is only slight diminished. In addition, the electrolyzer operates stably under high current density (100 mA/cm2) at a cell voltage of 1.85 V. This work provides excellent potential for low energy consumption H2 production with the CoMoS/FCP catalyst.