Alkali metal-mediated interfacial charge redistribution toward near-optimal water oxidation. Issue 40 (27th September 2022)

• Record Type: Journal Article
• Authors: Kim, Ungsoo; Lee, Sangjin; Oh, Nam Khen; Seo, Jihyung; Cha, Ji Hoo; Lee, Junghyun; Lee, Seong-hun; Shin, Tae Joo; Baik, Jeong Min; Han, Young-Kyu; Park, Hyesung
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 40(2022)
• Page Start: 21512
• Page End: 21522
• Publication Date: 2022-09-27
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2ta04736e
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Maximized water oxidation kinetics was realized by employing an alkali metal-mediated interfacial charge redistribution. Abstract : The optimal oxidation state and electronic structure of active sites in an electrocatalyst are critical factors for maximizing water-oxidation kinetics. To this end, we developed a heterostructured electrocatalyst for oxygen evolution reaction (OER) comprising La0.5 Sr0.5 CoO3− δ and Li2 MoO4 (LSC/LMO) with optimized oxidation states for active metal sites using an alkali metal mediator. The LSC/LMO system exhibited excellent OER performance (overpotential: 1.45 V at 10 mA cm −2 ) and operational durability (chronoamperometric and cyclic voltammetry stabilities of 200 h at 1.52 V and 5000 cycles). The experimental and computational analyses revealed that lithium atoms accumulated at the LSC/LMO interface exhibit a mediating function toward optimizing the oxidation state and electronic structure of OER active metal elements (cobalt and molybdenum), minimizing the free energy barrier of the rate-determining step in OER. This study provides a new insight for boosting sluggish OER kinetics in water oxidation through in situ oxidation state modulation for heterostructured electrocatalysts.