Establishing Quantitative Understanding of Defect-Tuned Properties in Functional Oxides by an Electrochemically-Induced Gradient of Ionic Defect Concentration

ACS Applied Materials & Interfaces, Год журнала: 2025, Номер 17(9), С. 13342 - 13357

Опубликована: Фев. 22, 2025

Tuning the physical and chemical properties of functional oxides by controlling amount ionic point defects has been recognized as a new paradigm designing with tailored functionality. In order to enable precise tuning properties, it is important construct quantitative relationships between interest concentration defects, which are conventionally achieved synthesizing measuring large number samples varying defect concentration. Compared this conventional method, labor-intensive susceptible sample-to-sample variations, review focuses on high-throughput method that utilizes an electrochemically induced gradient in one single oxide sample. Combined spatially resolved characterizations, allows establishing property-defect relationship. This will present working principles case studies use based graded defects. Potentials future extensions also be discussed.

Язык: Английский

Quantifying Dynamic Changes of Oxygen Nonstoichiometry and Formation of Surface Phases of SrCoO_x Electrocatalysts by Operando Characterizations

ACS Nano, Год журнала: 2025, Номер unknown

Опубликована: Апрель 6, 2025

Perovskite electrocatalysts like strontium cobaltite (SrCoOx, denoted as SCO) experience dynamic changes in both surface and bulk during the oxygen evolution reaction (OER), rather than remaining static. This dynamic, electrochemically driven composition, structure, ionic defects (e.g., vacancies) can strongly impact OER activity stability. Yet, current lack of quantitative information on these processes impedes a precise predictive evaluation individual combined effect transformations. Here, using epitaxial SCO thin films model system, we demonstrate that is redox-active electrocatalyst undergoes phase transition via induced intercalation, well toward Co (oxy-)hydroxide. Specifically, applying suite operando ex situ characterization established reliable relationship between nonstoichiometry, optical density, conductivity function applied potentials. We further accurately quantify stoichiometry thickness formed secondary phase. Our work provides generalizable workflow toolbox for assessment transformations oxygen-deficient perovskite electrocatalysts.

Язык: Английский

Influence of graphene on enhancing supercapacitance characteristics of tungsten oxide based composite

Journal of Materials Science Materials in Electronics, Год журнала: 2024, Номер 36(1)

Опубликована: Дек. 26, 2024

Язык: Английский