Hierarchically porous nanoarchitecture constructed by ultrathin CoSe_(2)embedded Fe-CoO nanosheets as robust electrocatalyst for water oxidation

The sluggish kinetics and high cost of the noble-metal based electrocatalyst for oxygen evolution reaction(OER)still seriously limits the efficiencies of water splitting.Herein,for the first time,we rationally design a porous hierarchical nanoarchitecture,constructed by ultrathin CoSe_(2)embedded Fe-CoO nanosheets(CoSe_(2)@Fe-CoO),which is synthesized via self-assembly hydrolysis driven in-situ synergetic selenization of Fe/Co/O/Se precursor followed by Ostwald ripening.As an OER catalyst,the porous CoSe_(2)@Fe-CoO hybrid with abundant CoOOH electroactive sites delivers a small Tafel of 56.2 m V/dec with very low onset overpotential of 280 m V@10 m A/cm~2and excellent long-term physicochemical stability till 62h without obvious decay,which outperforms well-established benchmark electrocatalysts(RuO_(2)).The boosted OER performance of CoSe_(2)@Fe-CoO nanosheets is mainly attributed to its iron-doping effect,porous nanoarchitecture,and multicomponent synergetic/interfacial effect between ultrathin cobalt(II)oxide and conductive cobalt selenide(CoSe_(2))nanoframework.This work presents a facile construction strategy to find a nonprecious hybrid OER electrocatalyst with excellent performance and long-term stability.