Rational Design of Core@shell Structured CoS<i><sub>x</sub></i>@Cu<sub>2</sub>MoS<sub>4</sub> Hybridized MoS<sub>2</sub>/N,S‐Codoped Graphene as Advanced Electrocatalyst for Water Splitting and Zn‐Air Battery
Dinh Chuong Nguyen, Duy Thanh Tran, Thi Luu Luyen Doan, Do Hwan Kim, Nam Hoon Kim, Joong Hee Lee
Abstract
Abstract A novel hybrid of small core@shell structured CoS x @Cu 2 MoS 4 uniformly hybridizing with a molybdenum dichalcogenide/N,S‐codoped graphene hetero‐network (CoS x @Cu 2 MoS 4 ‐MoS 2 /NSG) is prepared by a facile route. It shows excellent performance toward the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) in alkaline medium. The hybrid exhibits rapid kinetics for ORR with high electron transfer number of ≈3.97 and exciting durability superior to commercial Pt/C. It also demonstrates great potential with remarkable stability for HER and OER, requiring low overpotential of 118.1 and 351.4 mV, respectively, to reach a current density of 10 mA cm −2 . An electrolyzer based on CoS x @Cu 2 MoS 4 ‐MoS 2 /NSG produces low cell voltage of 1.60 V and long‐term stability, surpassing a device of Pt/C + RuO 2 /C. In addition, a Zn‐air battery using cathodic CoS x @Cu 2 MoS 4 ‐MoS 2 /NSG catalyst delivers a high cell voltage of ≈1.44 V and a power density of 40 mW cm −2 at 58 mA cm −2 , better than the state‐of‐the‐art Pt/C catalyst. These achievements are due to the rational combination of highly active core@shell CoS x @Cu 2 MoS 4 with large‐area and high‐porosity MoS 2 /NSG to produce unique physicochemical properties with multi‐integrated active centers and synergistic effects. The outperformances of such catalyst suggest an advanced candidate for multielectrocatalysis applications in metal‐air batteries and hydrogen production.