Origin of Enhanced Oxygen Evolution Reaction Activity and Stability of Nitrogen and Cerium Co-doped CoS2 Electrocatalyst
Electrochemical water splitting is a promising technology to enable a sustainable energy supply; however, it remains a formidable challenge to find efficient and stable electrocatalysts. Particularly, oxygen evolution, the half-reaction at the anode, imposes serious overpotential penalties due to its sluggish kinetics. The continued rational design and optimization of OER catalysts via different strategies such as chemical substitution motivate an understanding of the way that catalytic properties can be finely tuned. Here, we show a facile synthetic approach involving a Ce(NO3)3 precursor to yield nitrogen and cerium co-doped CoS2 electrocatalyst. Remarkably, it requires overpotentials of only 190 mV to reach current densities of 10 mA/cm2 and performs long-term stability for 120 h. More importantly, a suite of advanced characterizations and theoretical calculations reveal complementary roles of the dual dopants which stabilize the intermediates as a result of the formation of two higher oxidation state metal active centers and maintain the surface structure. This work correlates electronic structure and heteroatom doping, providing insights into electrochemical activities and stability and guiding the rational design of efficient electrocatalysts.
- This article is part of the themed collection: Journal of Materials Chemistry A HOT Papers