Heterostructure CoS<sub>2</sub>/MoS<sub>2</sub> Nanosheets as a Dual-Active Electrocatalyst for the Oxygen Evolution Reaction
Yang Li, Qixuan Du, Jian Cui, Hongwei Yang, Hua Qian
Abstract
Cost-effective and earth-abundant oxygen evolution reaction (OER) electrocatalysts are an incredible research hotspot in numerous energy storage and conversion technology fields. Herein, CoS 2 /MoS 2 nanosheets supported by carbon cloth as a dual-active CC@CoS 2 /MoS 2 heterostructure electrocatalyst is prepared through a simple solvothermal method. The catalyst demonstrates admirable OER performance in 1 M KOH solution with a low overpotential of 243 mV at a current density of 10 mA cm –2 and a minor Tafel slope of 109 mV dec –1, displaying honorable stability after 1000 cyclic voltammetry (CV) cycles and long-term robustness over 60 h. Theoretical calculations further ascertain that the rate-determining step of the electrocatalytic course of the CC@CoS 2 /MoS 2 heterostructure is the conversion *O + OH – → *OOH + e – with a lower energy barrier of 1.49 eV due to the heterojunction established by CoS 2 and MoS 2, which can promote the OER performance of electrocatalysts. The actual identification of the catalytic mechanism in the heterostructure is conducive to the improvement of electrocatalysis applications in the OER.