MOF derived multi-metal oxides anchored N, P-doped carbon matrix as efficient and durable electrocatalyst for oxygen evolution reaction

Abstract

Because the oxygen evolution reaction (OER) process is a rate-determining step for water splitting, it is extremely significant to rationally design and explore highly efficient and durable as well as the low-cost OER electrocatalyst to promote electrocatalytic water splitting. Based on this consideration, herein, for the first time, multi-metal oxides MoO2/Co2Mo3O8/Fe2Mo3O8 (MCF) compactly anchored N, P-doped carbon matrix (CNT and amorphous carbon derived from cobalt hexacyanoferrate) (MCF/NPCCNT) is fabricated by simply pyrolyzing composite precursor consisted of phosphomolybdic acid, cobalt hexacyanoferrate and CNT under the nitrogen atmospheres. The as-prepared MCF/NPCCNT-40 hybrid catalyst delivers a high OER electrochemical activity with a smaller overpotential of 292 mV at the current density of 10 mA cm−2 and a lower Tafel slope of 45.9 mV dec-1, as well as favorable cycle stability in 1.0 M KOH solution, markedly improving the charge transfer efficiency in catalytic processes and preventing the corrosion of the metallic compounds. In addition, the MCF/NPCCNT-40 hybrid catalyst exhibits large mass density of 323.2 A g−1 at a fixed potential of 1.7 V, which is the highest mass activity towards OER process compared to the other reference samples. The design idea and synthetic strategy of this work can be expanded to design and fabricate other novel, highly effective and low-cost multi-metal oxide anchored N, P-doped carbon matrix based electrocatalysts with greatly improved OER performance.