A MOF derived bifunctional electrocatalyst Ni3ZnC0.7-Mo2C with enhanced performance for overall water splitting

Abstract

The efficiency and cost of electrocatalysts are critical factors restricting their application in water electrochemical decomposition. In recent years, transition metal carbides (TMCs) have been highlighted due to their unique characteristics for water splitting: good conductivity and stability. However, their electrochemical performance required further optimization. In this work, a distinct non-solvent method was utilized to achieve a Ni₃ZnC_0.7-Mo₂C/Ni foam (NF) catalyst, which exhibited a nanoflower structure with efficient exposed active sites. Moreover, the synergistic effect between the Mo and Ni species greatly affected its HER and OER performance. Ni₃ZnC_0.7-Mo₂C/NF showed excellent electrocatalytic performance with small overpotentials of 58 mV and 257 mV at 10 mA cm⁻² for the HER and OER, respectively. To our delight, the overall water splitting could be driven by only 1.56 V. This work not only demonstrates an excellent bifunctional electrocatalyst for overall water splitting but also provides another method for polymetallic carbide preparation and activity optimization.