Ultralong needle-like N-doped Co(OH)F on carbon fiber paper with abundant oxygen vacancies as an efficient oxygen evolution reaction catalyst

Abstract

The 3D needle-like N-doped Co(OH)F on carbon fiber paper rich in oxygen vacancies synthesized by hydrothermal method has an efficient oxygen evolution performance.

Development of Co(OH)xF2−x Nanosheets for Acetone Gas Sensor Applications: Material Characterization and Sensor Performance Evaluation

“…Nevertheless, a close look into the image discloses that there are many areas (some marked with yellow circles) showing some shortrange ordering. Analysis on such short-range ordering areas indicates that the plane spacings are close to those of Co(OH)F, as shown in Figure 4e [19]. These results confirm that the synthesized nanosheets are amorphous Co(OH)xF2−x with some short-range ordering.…”

“…It should be noted that incorporated F, with a high electronegativity, could enhance the Lewis acidity of the material, which could facilitate the adsorption of gas molecules [15,16,19]. For the present study, the main reactions occurring at the surface of the Co(OH) x F 2−x nanosheets can be expressed as shown below [1,44,45].…”

“…Nonetheless, such a doping method has a limitation in obtaining a fluorine concentration high enough for a significant sensitivity improvement. Recently, cobalt fluoride hydroxide (Co(OH) x F 2−x ), a material including F anions as one of its main elements, came into the spotlight for being applied to catalysts for water oxidation, hydrogen production, and overall water splitting, taking full advantage of the high catalytic activity of F anions in the materials [9,[17][18][19]. Nevertheless, a challenge to employ this material for gas sensor applications is its poor thermal stability: it could easily transform into Co 3 O 4 via fluorine evaporation during a high temperature process such as the aging process (200~450 • C) which is usually required for sensor fabrication [20].…”

Three-dimensional hierarchical Co(OH)F nanosheet arrays decorated by single-atom Ru for boosting oxygen evolution reaction

“…For instance, three-dimensional (3D) Co(OH)F microspheres exhibited an overpotential of 313 mV for the OER to deliver the current density of 10 mA cm −2 [23]. The carbon fiber papersupported ultralong needle-like N-doped Co(OH)F could achieve the OER current density of 10 mA cm −2 at a potential of 1.54 V (vs. reversible hydrogen electrode (RHE)) in 1.0 mol L −1 KOH [24]. To achieve large catalytic current density as well as avoid the aggregation of Co-based materials resulting from the strong magnetism [21], in-situ growth of catalyst nanoarrays on conductive substrates would be a promising and facile approach [25].…”

Facile synthesis of nickel–copper hollow spheres as efficient bifunctional electrocatalysts for overall water splitting

“…While platinum group metals (PGMs) such as Pt-, Ir-, and Ru-based materials are considered to be the state-of-the-art catalysts for the HER and the OER because of their high catalytic efficiency, their high cost and rareness severely hinder their wide application in water-splitting systems. [5][6][7][8] To address this issue, much effort has been made to develop earth-abundant, economic alternatives for efficient electrolytic water splitting, [9][10][11][12] and in particular the alloys and compounds containing first-row transition metals (e.g. Ni, Fe, and Co) have attracted tremendous interest owing to their earth abundance and remarkable HER and OER performances.…”