Curved molybdenum dichalcogenide embedding endowed hierarchical graphite oxide nanosheets with robust oxygen reduction electrocatalysis

Abstract

The curved structure and hierarchical structure are two effective strategies to improve the efficiency of electrocatalysis. Herein, hierarchical nitrogen-doped curved MoS2 embedded in graphite oxide nanosheets (MoS2-NGO) were developed via a flexible hydrothermal process and followed by nitrogen doping aiming to improve the oxygen reduction reaction (ORR) electrocatalytic activity. For the prepared MoS2-NGO, the curved MoS2 with tailored electronic structure can strengthen the mechanical strength of GO nanosheets, promoting the formation of robust hierarchical GO nanosheets, which can accelerate electron/mass transmission for beneficial ORR electrocatalytic process. The optimal MoS2-NGO-10, with a close to four electron reaction pathway, showed sharply enhanced catalytic capability for ORR compared to most reported MoS2 catalysts. As a cathode catalyst, a homemade MoS2-NGO-10-driven zinc air battery (ZAB) delivered a high peak power density of 150 mW cm−2 as well as robust catalytic durability when compared to commercial Pt/C-driven ZAB. This work highlighted the significance of monolithic structure comprising of curved MoS2 and hierarchical GO nanosheets on enhancing the overall electrocatalytic performance for ZAB and other energy conversion systems.