Self-generated FeSe2 and CoSe2 nanoparticles confined in N, S-doped porous carbon as efficient and stable electrocatalyst for oxygen evolution reaction. (20th March 2023) - Lei, Xiaofei
Highlights: Self-generated metal selenides confined in N, S-doped porous carbon is designed. Iron-PTS has multiple functions of oxidant, activator and Fe, S precursors. The electrocatalyst exhibits superior OER catalytic activity and good durability. Overall water splitting device based on this catalyst delivers low overpotential. Abstract: Transition metal selenides embedded into a nitrogen, sulfur co-doped carbon materials (TMS@NSC) are promising electrocatalysts to effectively address the sluggish kinetics of oxygen evolution reaction (OER). However, the OER catalytic activity of single metal TMS@NSC 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 TMS@NSC. 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 TMS@NSC catalysts for OER and other energy conversion applications. Graphical abstract: Image, graphical abstract