Facile synthesis of Ni based metal-organic frameworks wrapped MnO2 nanowires with high performance toward electrochemical oxygen evolution reaction

Abstract

The transition metal oxides based catalysts have drawn great attention for their application in the electrolysis of water for renewable energy generation. Although manganese oxides were rarely used as oxygen evolution reaction (OER) catalysts, they were still considered as active and efficient OER catalysts due to the earth-abundant and low toxic nature of manganese. In this work, we proposed a facile method for the synthesis of high-performance electrochemical OER catalyst by magnetically stirring the mixture of 1,3,4-thiadiazole-2,5-dithiol (DMTD), Ni2+ and MnO2 nanowires (NWs) in ethanol at room temperature, noted as Ni/DMTD/MnO2. The Ni/DMTD complex and MnO2 NWs showed synergistically enhanced OER activity and excellent durability in alkaline solution. The introducing of MnO2 and the presence of Ni3+ after the oxidation of Ni2+ were the key factors which improve the OER performance. The potential at 10 mA cm-2 was 1.492 V (vs RHE) with a Tafel slope of 69.46 mV dec-1 in 1 M KOH aqueous solution, comparable to the state-of-art RuO2. The results indicated that MnO2 was found to have the capability to enhance not only the catalytic activity but also operation stability of Ni/DMTD/MnO2 towards OER.