Self-generated FeSe2 and CoSe2 nanoparticles confined in N, S-doped porous carbon as efficient and stable electrocatalyst for oxygen evolution reaction

Transition metal selenides embedded into a nitrogen, sulfur co-doped carbon materials ([email protected]) are promising electrocatalysts to effectively address the sluggish kinetics of oxygen evolution reaction (OER). However, the OER catalytic activity of single metal [email protected] is still limited by insufficient active sites. Hence, FeSe2 and CoSe2 nanoparticles self-generated and confined in N, S-doped porous carbon (FeSe2/CoSe2@NSC) catalyst has been synthesized by in-situ polymerization and the subsequent low temperature selenization strategy, aiming to increase the active sites of [email protected] The hybridized FeSe2/CoSe2@NSC catalyst has excellent OER catalytic activity and good durability in alkaline media, which only requiring an overpotential as low as 278 mV to drive a current density of 10 mA cm−2, outperforming most recently reported selenide catalysts and commercial RuO2 catalysts. The high catalytic activity of FeSe2/CoSe2@NSC catalyst is attributed to the rapid electron transfer between FeSe2 and CoSe2 in the unique N, S-doped graphene nanosheets, which effectively inhibits the aggregation of nanoparticles, fully exposes the active sites and provides pathway for oxygen release during the OER process. Moreover, the overall water splitting device assembled with FeSe2/CoSe2@NSC catalyst showed low overpotential of 1.57 V. This study provides a feasible strategy for the design of high active and stable [email protected] catalysts for OER and other energy conversion applications.