Interface reinforced 2D/2D heterostructure of Cu-Co oxides/FeCo hydroxides as monolithic multifunctional catalysts for rechargeable/flexible zinc-air batteries and self-powered water splitting

Elaborate engineering of heterostructure and composition to regulate the electroactivities remains a pronounced challenge. Herein, a self-supported 2D/2D heterostructure monolith is constructed by interlinked FeCo-hydroxides nanosheets tightly interlacing with aligned Cu0.76Co2.24O4 nanoplates. Due to the well-defined hierarchical nanoarrays and desirable interfacial coupling, the monolithic catalyst can guarantee the rapid charge transfer and mass transport pathways for accelerated surface kinetics, leading to manifestly improved electroactivities and stability toward trifunctional catalysis. Both experimental and theoretical calculations unravel the enriched multimetal active sites for intermediates adsorption and the synergistic interplay of the heterostructure to achieve enhanced catalytic efficiency. Consequently, the heterostructure catalyst contributes to high-performance rechargeable/flexible all-solid-stated Zn-air batteries and water electrolyzer with an ultralow potential of 1.51 V. Moreover, self-powered water splitting system driven by flexible Zn-air batteries delivers a high H2 generation rate. This cost-effective heterostructure monolith could open an intriguing avenue for advancing all-in-one films toward portable energy conversion/storage.