Encapsulating Fe2O3 Nanotubes into Carbon-Coated Co9S8 Nanocages Derived from a MOFs-Directed Strategy for Efficient Oxygen Evolution Reactions and Li-Ions Storage

The development of high-efficiency, robust, and available electrode materials for oxygen evolution reaction (OER) and lithium-ion batteries (LIBs) is critical for clean and sustainable energy system but remains challenging. Herein, a unique yolk-shell structure of Fe2O3 nanotube@hollow Co9S8 nanocage@C is rationally prepared. In a prearranged sequence, the fabrication of Fe2O3 nanotubes is followed by coating of zeolitic imidazolate framework (ZIF-67) layer, chemical etching of ZIF-67 by thioacetamide, and eventual annealing treatment. Benefiting from the hollow structures of Fe2O3 nanotubes and Co9S8 nanocages, the conductivity of carbon coating and the synergy effects between different components, the titled sample possesses abundant accessible active sites, favorable electron transfer rate, and exceptional reaction kinetics in the electrocatalysis. As a result, excellent electrocatalytic activity for alkaline OER is achieved, which delivers a low overpotential of 205 mV at the current density of 10 mA cm(-2) along with the Tafel slope of 55 mV dec(-1). Moreover, this material exhibits excellent high-rate capability and excellent cycle life when employed as anode material of LIBs. This work provides a novel approach for the design and the construction of multifunctional electrode materials for energy conversion and storage.Funding Agencies|Science and Technology Commission of Shanghai MunicipalityScience & Technology Commission of Shanghai Municipality (STCSM) [19ZR1418100]; Science and Technology Program of Shanghai [21010500300]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [22179080]; STINT Joint China-Sweden Mobility Project [CH2017-7243]; Swedish Government strategic faculty grant in material science (SFO, MATLIU) in Advanced Functional Materials (AFM) (VR) [5.1-2015-5959]; Shanghai Engineering Research Center of Intelligent Computing System [19DZ2252600]