Core-shell structured ZnCo/NC@MoS2 electrocatalysts for tunable hydrogen evolution reaction

The electrocatalysts with high activity and low cost are essential for hydrogen evolution reaction (HER). Herein, we report an approach to prepare hierarchical core-shell structures ZnxCo1-x/NC@MoS2. The Zn/Co ratio affects the particle sizes of ZnxCo1-x/NC polyhedra and the distribution of Co nanoparticles, resulting in the change of the amount of exposed active sites and further afforded tunable HER activities. Notably, the hybrids exhibit significantly superior catalytic activities to pristine MoS2. The optimal catalyst displays an extraordinary HER performance in acid media with a low overpotential of 130 mV at 10 mA cm (2) and high durability. The remarkable HER properties mainly originate from the fantastic structural characteristics such as abundant exposure of MoS2 edge-sites, uniform distribution of Co-N-x species, as well as the porousness and high conductivity of supports. This research provides a promising strategy to develop inexpensive and highly-efficient HER electrocatalysts derived from metal-organic frameworks and MoS2. (c) 2019 Elsevier Ltd. All rights reserved.