Iron-doped Cobalt Phosphide Nano-Electrocatalyst Derived from Metal-Organic Framework for Efficient Water Splitting
The development of hydrogen energy relies to a large extent on electrocatalysts that are highly-efficient and widely-sourced. Even if transition metal phosphides (TMPs) have made great achievement in reducing the overpotential of hydrogen evolution reaction (HER), improving oxygen evolution reaction (OER) performance which is relatively lagging in view of relatively large overpotentials and high kinetics energy barriers. Herein, we propose an extremely convenient and practical approach to prepare iron-doped cobalt phosphide nanoparticles (Fe-CoxP NPs) by one-step introducing iron element in the in-situ synthesis of metal-organic framework (ZIF-67) and then a phosphate treatment. The as-obtained Fe-CoxP shows excellent OER and acceptable HER activities. Especially, for OER, the optimized Fe-doped CoxP (Fe0.27Co0.73P) exhibits an ultra-low overpotential of 251 mV at a current density of 10 mA cm-2, a negligible electrocatalytic degradation after 3000 CV cycles, and time over 40 h-reliant current density stability. When working as cathode and anode electrodes in water splitting, the current density of 10 mA cm-2 can be achieved at a potential of 1.68 V. Our facile synthesis strategy and innovative ideas are undoubtedly beneficial to the design and construction of advanced water-splitting electrocatalysts.