Low-temperature molten salt synthesis and catalytic mechanism of CoS2/NC as an advanced bifunctional electrocatalyst

The development of productive and sustainable bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) plays an important role in the commercial evolution of metal-air batteries. In this paper, a low-temperature molten salt template method was adopted to synthesize the composite of CoS2 and nitrogen-doped carbon (CoS2/NC) without the protection of inert gas. The structural characterization studies show that the specific surface area (SSA) and crystal growth kinetics are increased and effectively improved, respectively, by the composite of CoS2 and NC. The as-synthesized CoS2/NC composite demonstrates outstanding bifunctional catalytic activity in alkaline electrolytes and exhibits a half-wave potential (E-1/2) of 0.854 V (vs. RHE) and an overpotential of only 220 mV for the OER at a current density of 10 mA cm(-2) (& eta;(10)). Simultaneously, CoS2/NC also exhibits excellent electrochemical stability. Additionally, density functional theory (DFT) calculations have manifested that the synergistic effect of CoS2 and NC results in a remarkable enhancement in the bifunctional catalytic performance of the composite materials. This study offers a new pathway and theoretical guidance for the fabrication of efficient bifunctional electrocatalysts.

Automated summary

The paper introduces a low-temperature molten salt template method to synthesize a composite of CoS2 and nitrogen-doped carbon (CoS2/NC). The as-synthesized CoS2/NC composite demonstrates outstanding bifunctional catalytic activity in alkaline electrolytes.