Facilitating Reconstruction of the Heterointerface Electronic Structure by the Enriched Oxygen Vacancy for the Oxygen Evolution Reaction

Abstract

Exploring high-performance non-precious metal-based electrocatalysts for the sluggish oxygen evolution reaction (OER) process is fundamentally significant for the development of multifarious renewable energy conversion and storage systems. Oxygen vacancy (Vo) engineering is an effective leverage to boost the intrinsic activity of OER, but the underlying catalytic mechanism remains anfractuous. Herein, we realize the construction of oxygen vacancy-enriched porous NiO/ln2O3 nanofibers (designated as Vo–NiO/ln2O3@NFs hereafter) via a facile fabrication strategy for efficient oxygen evolution electrocatalysis. Theoretical calculations and experimental results uncover that, compared with the no-plasma engraving component, the presence of abundant oxygen vacancies in the Vo–NiO/ln2O3@NFs is conducive to modulating the electronic configuration of the catalyst, altering the adsorption of intermediates to reduce the OER overpotential and promote O* formation, upshifting the d band center of metal centers near the Fermi level (E f), and also increasing the electrical conductivity and enhancing the OER reaction kinetics simultaneously. In situ Raman spectra proclaim that the oxygen vacancy can render the NiO/ln2O3 more easily reconstructible on the surface during the OER course. Therefore, the as-obtained Vo–NiO/ln2O3@NFs demonstrated distinguished OER activity, with an overpotential of only 230 mV at 10 mA cm–2 and excellent stability in alkaline medium, surmounting the majority of the previously reported representative non-noble metal-based candidates. The fundamental insights gained from this work can pave a new path for the electronic structure modulation of efficient, inexpensive OER catalysts via Vo engineering.

Molecular Mechanisms of Oxygen Evolution Reactions for Artificial Photosynthesis

“…Abundant Vo modulated the electronic configuration of the catalyst for altering the adsorption of intermediates to reduce the OER overpotential and promote *O formation, upshifting the d band center of metal centers near the Fermi level, and also increasing the electrical conductivity and enhancing the OER reaction kinetics simultaneously. In situ Raman spectra suggested that the Vo can render the NiO/ln 2 O 3 more easily reconstructible on the surface during the OER course [201].…”

Molecular Mechanisms of Oxygen Evolution Reactions for Artificial Photosynthesis

“…Abundant Vo modulated the electronic configuration of the catalyst for altering the adsorption of intermediates to reduce the OER overpotential and promote O* formation, upshifting the d band center of metal centers near the Fermi level, and also increasing the electrical conductivity and enhancing the OER reaction kinetics simultaneously. In situ Raman spectra suggested that the Vo can render the NiO/ln2O3 more easily reconstructible on the surface during the OER course [201].…”

Tailoring the electronic environment of MoSe2via cation metal doping for the enhanced alkaline hydrogen evolution reaction

“…1–3 Differentiation from existing hydrogen production approaches, the electrochemical hydrogen evolution reaction (HER), which can be powered by intermittent renewable electricity, is considered an effective and facile targeted approach for generating high-purity green hydrogen, and therefore has drawn considerable attention recently. 4–6 Compared with acidic and neutral solutions, the alkaline electrocatalytic HER is more attractive as it takes advantage of its lower corrosiveness to equipment and materials. In addition, the HER pathway in alkaline media works under an additional Volmer step (M + H 2 O + e − → M–H ads + OH − ) for water dissociation in advance of the Heyrovsky (M–H ads + H 2 O + e − → M + H 2 + OH − ) or Tafel (2M–H ads → 2M + H 2 ) step, which leads to the sluggish water adsorption/dissociation process during HER.…”