Overall Water Splitting by Bio-Modification of Fe₃O₄ with Co–Ni Complexes

Abstract

For years hydrogen has attracted much interest as a substitute for fossil fuels, but the high cost of green hydrogen production has led to a small share of the daily energy consumed. Various electrocatalysts have been designed and reported to facilitate water splitting. In this study, by using polyphenols extracts from Camellia sinensis plant and folic acid along with magnetic cores, we designed and synthesized a novel electrocatalyst with a high capacity for water splitting reactions. The catalyst was characterized using transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric techniques. The catalyst exhibited high performance for overall water splitting. The overpotential of 245 and 346 mV (for 100 mA cm–2) with a Tafel slopes of 39 and 86 mV dec–1 were obtained for the oxygen evolution reaction (OER) and for the hydrogen evolution reaction (HER), respectively. The faradic efficiency for both OER and HER was calculated as being close to 100%.