Trimesic acid anchored electrocatalysts of bioinspired design: Unique static and dynamic compatibility enhanced water oxidation

Abstract

Abstract Layered double hydroxides (LDH) are successful candidates for electrocatalytic oxygen evolution reaction (OER). Unfortunately, their catalytic kinetics and long-term stability are far unsatisfactory comparing to rare metals in practice. Here we track the endurance of NiFe-LDH and uncover that the ablation of lamellar structure caused by metal dissolution is the immediate reason for the decreased stability. Inspired by amino acid residues in photosystem II, we report a strategy using trimesic acid anchor to achieve the subsize NiFe-LDH to drive with superior kinetics, activity and stability to the benchmark commercial catalysts. Fundamental investigations through operando spectroscopy and theoretical calculations reveal that the superaerophobic surface is beneficial for the immediate release of the generated O2 bubbles and maintaining its active structure as well. The coupling between metal and coordinated carboxylate by C‒O‒Fe bonds effectively prevent metal species from dissolving, which enhances the stabilization of electronic structure by the static coordination. In addition, the uncoordinated carboxylates formed by dynamic evolution on OER process act as proton ferries to accelerate the OER kinetics. This work offers a promising way to achieve breakthroughs in OER stability and dynamics performance by introducing functional ligand with static and dynamic compatibility.