Fluorination of ZIF-67 framework templated Prussian blue analogue nano-box for efficient electrochemical oxygen evolution reaction

Abstract

Efficient oxygen evolution nano-catalyst is significant for hydrogen generation in the water-splitting reaction. Herein, we demonstrate that fluorination of ZIF-67 Framework templated Prussian blue analogue hollow nano-box is highly efficient for the oxygen evolution reaction (OER). The structure and morphology observation shows the degree of structural transformation and morphology are influenced by the fluorination temperature, and the catalytic ability for OER is correspondingly correlated to these characters. The product obtained at the annealed temperature of 250 °C exhibits the highest catalytic performance for OER with an overpotential of 243 mV (No IR correction) to offer 10 mA cm−2 when loaded on the inert glass carbon electrode, which is much better than that of the commercial IrO2 catalysts. High catalytic stability and kinetics are also found for the OER. Moreover, it has the highest intrinsic activity as demonstrated by the specific activity and turnover frequency indicating the intrinsic advantages of fluorination and hollow nano-box structure. This study enriches the application of Prussian blue analogue based hollow materials for OER by facile fluorination at low temperatures.