Accelerating Electrochemical Water Oxidation Activity by Tailoring Morphology and Electronic Structure of Nickel Organic Framework Nanoarrays with a Fe Etching Effect

Abstract

Fe-mediated nickel organic framework nanoarrays (NiFe-MOFs NAs) on carbon cloth were successfully constructed from ultrathin nanosheets via an etching effect. This strategy also combined the dissolution and coordination effect of acidic ligand (2,6-naphthalenedicarboxylic acid, NDC) to a self-sacrificial template of Ni(OH) 2 NAs. Benefiting from the strong Fe etching effect, dense and thick brick-like Ni-NDC nanoplates were tailored into loose and ultrathin NiFe-NDC nanosheets with abundant squamous nanostructures, which were still tightly attached to carbon cloth. As a consequence, more coordinatively unsaturated metal sites (CUMSs) that served as active centers were exposed to accelerate oxygen production. Meanwhile, the electronic structure of active Ni centers was modulated by the incorporation of Fe atoms. The charge density redistribution between Ni and Fe ultimately optimized the energy barrier of the adsorption/desorption of oxygenated intermediates, promoting the kinetics for water oxidation.

Engineering Internal and External Low-Coordination Atoms in Nickel–Organic Framework Nanoarrays to Promote the Electrochemical Oxygen Evolution Reaction

“…Recently, we have successfully synthesized a series of Ni-MOF NAs through the utilization of Ni(OH) 2 NAs on carbon cloth as a sacrificial template with a solid-state conversion. This approach effectively harnesses the dissolution and coordination effects of acidic ligands such as 2,5-dihydroxyterephthalic acid (DHTP), 27 2,6-naphthalenedicarboxylic acid (NDC), 28 and 1,1′-ferrocenedicarboxylic acid (FcDA). 29 Initially confined within insoluble Ni(OH) 2 NAs, the Ni ions are gradually released and coordinate with adjacent organic ligands to assemble diverse structures and morphologies of the Ni-MOF NAs.…”

Regulating the Electronic Structure of Ni Sites in Ni(OH)2 by Ce Doping and Cu(OH)2 Coupling to Boost 5-Hydroxymethylfurfural Oxidation Performance

“…Currently, to boost the performance of catalysts, many strategies, such as increasing the specific surface area, enhancing the conductivity, doping with heteroatoms, and combining with promoters, have been adopted. − By increasing the catalyst’s specific surface area, a substantial increment in the total count of exposed active sites may be achieved. Enhancing the conductivity can promote electron transfer kinetics.…”