Interfacial Atom‐Substitution Engineered Transition‐Metal Hydroxide Nanofibers with High‐Valence Fe for Efficient Electrochemical Water Oxidation

Abstract

Developing low‐cost electrocatalysts for efficient and robust oxygen evolution reaction (OER) is the key for scalable water electrolysis, for instance, NiFe‐based materials. Decorating NiFe catalysts with other transition metals offers a new path to boost their catalytic activities but often suffers from the low controllability of the electronic structures of the NiFe catalytic centers. Here, we report an interfacial atom‐substitution strategy to synthesize an electrocatalytic oxygen‐evolving NiFeV nanofiber to boost the activity of NiFe centers. The electronic structure analyses suggest that the NiFeV nanofiber exhibits abundant high‐valence Fe via a charge transfer from Fe to V. The NiFeV nanofiber supported on a carbon cloth shows a low overpotential of 181 mV at 10 mA cm−2, along with long‐term stability (>20 h) at 100 mA cm−2. The reported substitutional growth strategy offers an effective and new pathway for the design of efficient and durable non‐noble metal‐based OER catalysts.

Synthesis of NiFe-layered double hydroxides using triethanolamine-complexed precursors as oxygen evolution reaction catalysts: effects of Fe valence

“…17–19 Hence, numerous strategies have been developed to further optimize the electrocatalytic performance of NiFe-LDH, including morphology modulation, anion exchange or intercalation, heteroatom doping or substitution, and defect engineering. 20–25 Liu et al synthesized oxygen vacancy-rich hierarchical NiFe-LDH microtubes assembled using two-dimensional nanosheets via a template-assisted strategy as a way to increase the number of catalytically active sites. 26 Wu et al reported a surface strategy to manipulate the coordinatively unsaturated metal sites of NiFe-LDH to enhance the OER activity of the catalyst by using an optimized amount of ammonium fluoride (NH 4 F) as a metal-complexing agent.…”

Electronically Conductive, Multifunctional Polymer Binder for Highly Active, Stable, and Abundant Composite Electrodes for Oxygen Evolution

“…Solar and wind energy are diffuse and intermittent. Efficient, high-capacity and output- storage methods are needed to transition to carbon-zero energy production. , Electrochemical water splitting to form hydrogen and oxygen is a promising approach. , Unfortunately, the electrooxidation of water to oxygen, called the oxygen evolution reaction (OER), is slow, and it remains a significant challenge to develop low-cost, stable OER electrodes with low overpotentials and loadings at high current densities. , Further, electrode preparations must be straightforward and utilize abundant starting materials for widespread, large-scale utilization …”

“…5,6 Further, electrode preparations must be straightforward and utilize abundant starting materials for widespread, large-scale utilization. 7 Nonprecious metal OER electrocatalysts help fulfill these requirements. The reported systems are typically more active in base.…”