Coupling Plant Polyphenol Coordination Assembly with Co(OH)2 to Enhance Electrocatalytic Performance towards Oxygen Evolution Reaction

Abstract

The oxygen evolution reaction (OER) is kinetically sluggish due to the limitation of the four-electron transfer pathway, so it is imperative to explore advanced catalysts with a superior structure and catalytic output under facile synthetic conditions. In the present work, an easily accessible strategy was proposed to implement the plant-polyphenol-involved coordination assembly on Co(OH)2 nanosheets. A TA-Fe (TA = tannic acid) coordination assembly growing on Co(OH)2 resulted in the heterostructure of Co(OH)2@TA-Fe as an electrocatalyst for OER. It could significantly decrease the overpotential to 297 mV at a current density of 10 mA cm−2. The heterostructure Co(OH)2@TA-Fe also possessed favorable reaction kinetics with a low Tafel slope of 64.8 mV dec−1 and facilitated a charge-transfer ability. The enhanced electrocatalytic performance was further unraveled to be related to the confined growth of the coordination assembly on Co(OH)2 to expose more active sites, the modulated surface properties and their synergistic effect. This study demonstrated a simple and feasible strategy to utilize inexpensive biomass-derived substances as novel modifiers to enhance the performance of energy-conversion electrocatalysis.

Mapping current high-entropy materials for water electrolysis: from noble metal to transition metal

“…It means that simultaneously using excellent electrocatalysts for OER and HER can achieve high-efficiency hydrogen production through water splitting. 23–28 Currently, precious metals such as platinum, ruthenium and iridium are ideal catalysts to effectively reduce the overpotential for either HER or OER. 29–33 In recent years, many research scholars have been exploring efficient materials to catalyze HER and OER to improve the efficiency of hydrogen preparation.…”