V(III)-Doped Nickel Oxide-Based Nanocatalysts for Electrochemical Water Splitting: Influence of Phase, Composition, and Doping on the Electrocatalytic Activity

Boehm, Daniel; Beetz, Michael; Kutz, Christopher; Zhang, Siyuan; Scheu, Christina; Bein, Thomas und Fattakhova-Rohlfing, Dina (2020): V(III)-Doped Nickel Oxide-Based Nanocatalysts for Electrochemical Water Splitting: Influence of Phase, Composition, and Doping on the Electrocatalytic Activity. In: Chemistry of Materials, Bd. 32, Nr. 24: S. 10394-10406

Abstract

Doped nickel oxide-based compounds are attracting great interest as very efficient and abundant catalysts and were thoroughly investigated as battery materials in the past. However, there is still no clear understanding of the influence of dopants on the complex dynamic character of their chemically and potentially driven transformations. We have developed a synthesis procedure enabling the controlled formation of nanosized nickel hydroxide and nickel oxide polymorphs substituted with vanadium(III) [V(III)] ions and further investigated their structure-activity correlation for electrochemical water oxidation. This work therefore primarily focuses on an in-depth structural characterization of the homogeneously doped nanosized alpha- and beta-Ni(OH)(2) polymorphs. It could be shown that concentrations of 10 at. % V(III) and higher can effectively inhibit a spontaneous phase transformation known as chemical aging of the turbostratic alpha-phase to the more crystalline beta-Ni(OH)(2) phase in neutral aqueous media. The Fe-impurity-biased electrocatalytic activity determined for alpha-/beta-Ni1-xVx(OH)(2) showed only a minor increase of 10% oxygen evolution reaction (OER) activity for an 1 at. % doped nonaged sample resembling the alpha-phase, while a 5 at. % V(III)-doped sample chemically aged over 24 h led to a doubled OER activity versus the undoped reference which transformed into beta-Ni(OH)(2) over that period of time.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Fakultätsübergreifende Einrichtungen: Center for NanoScience (CENS)
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie ; 500 Naturwissenschaften und Mathematik > 500 Naturwissenschaften
• ISSN: 0897-4756
• Sprache: Englisch