Rational Lattice Engineering of Spinel CoxRh3-xO4 Solid Solution Expediting Oxygen Evolution Reaction
- 주제(키워드) Acid−base reaction , Density functional theory (DFT) simulation , Oxygen evolution reaction (OER) , Spinel Co<sub>x</sub>Rh<sub>3−x</sub>O<sub>4</sub>
- 등재 SCIE, SCOPUS
- 발행기관 American Chemical Society
- 발행년도 2023
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000213538
- 본문언어 영어
- Published As https://doi.org/10.1021/acssuschemeng.3c04304
초록/요약
Electrochemical water splitting holds great promise as a viable method to produce a sustainable hydrogen fuel. Spinel crystal structure (AB2O4) is regarded as a promising electrocatalyst for the anodic oxygen evolution reaction (OER) of water electrolysis. Fine-tuning of metal cations’ composition at the tetrahedral (A) and octahedral (B) sites within the well-defined spinel structure plays a critical role in determining the electroactivities for electrochemical reactions, including the OER. Herein, we report the rational incorporation of rhodium ions into the B sites of the spinel lattice of Co3O4 to form the CoxRh3-xO4 solid solution via an ecofriendly acid-base reaction between metal (Co, Rh) chlorides and NaOH in an aqueous solution, followed by the thermal annealing process. Among the CoxRh3-xO4 series, Co1.47Rh1.53O4 nanoparticles represented superior OER catalytic performances in alkaline conditions, verified by the lowest onset potential, small Tafel slope, and excellent long-term stability. The combination of experimental data with theoretical simulations suggests that the moderate d-band center (ϵd) energy levels are responsible for the enhanced activity by tuning the adsorption and desorption strengths of oxygen-containing intermediates, such as *OH, *O, and *OOH species. Our findings introduce a straightforward and environmentally friendly synthetic methodology for a single phase of spinel Co1.47Rh1.53O4 nanoparticles, resulting in a rational lattice structure that can be applied as an effective OER catalyst electrode. © 2023 American Chemical Society
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