Nitrogen-doped carbon encapsulated polyhedral ZnSe@CoSe2 yolk-shell nanostructures for high-efficiency oxygen evolution reaction

Abstract

Designing non-noble metal oxygen evolution catalysts with outstanding catalytic activity is crucial for realizing cost-effective water splitting. In this paper, nitrogen-doped carbon-encapsulated polyhedral yolk-shell nanostructure bimetallic selenide (ZnSe@CoSe2/N-C) electrocatalyst was successfully prepared by high-temperature selenization strategy using ZIF-8 @ZIF-67 as the framework. The specially designed nitrogen-doped core-shell structure has the advantages of high specific surface area and rough porous surface, which can expose more active sites and facilitate the transfer of electrons and ions on the electrode surface. The high conductivity of ZnSe, CoSe2 nanoparticles and the synergistic effect of bimetal increase the electrochemical activity and electron mobility of the composite. ZnSe@CoSe2/N-C catalyst exhibits outstanding oxygen evolution reaction performance at 1.0 M KOH, which the overpotential is down to 170 mV at 10 mA cm−2. Furthermore, ZnSe@CoSe2/N-C also shows well durability and long-term stability (>113 h). This experiment might open a new path for fabrication of low-cost non-noble metal selenide electrocatalysts for oxygen evolution.