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Energías de reorganización para la transferencia interfacial de electrones acoplados a un catalizador de oxidación de

Matthew Kessinger¹, Alexander V Soudackov², Jenny Schneider¹

¹Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina27599, United States.

Journal of the American Chemical Society

|October 31, 2022

Resumen

Este estudio cuantifica las energías de reorganización para la transferencia interfacial de electrones (ET) y la ET acoplada a protones (PCET) en la catálisis de oxidación de agua. Los hallazgos revelan una ventaja cinética para la oxidación solar del agua a un pH alto, lo que demuestra la teoría de Marcus-Gerischer

Área de la Ciencia:

Fotocatálisis
Química inorgánica
Química Física

Sus antecedentes:

La oxidación eficiente del agua solar requiere comprender la cinética de la transferencia interfacial de electrones (ET) y la ET acoplada a protones (PCET).
La teoría de Marcus-Gerischer es crucial para analizar las energías de reorganización en las reacciones ET.
La extensión de esta teoría al PCET es vital para optimizar los procesos catalíticos.

Objetivo del estudio:

Determinar las energías de reorganización (λ) para el ET interfacial y el PCET desde el óxido de indio y estaño (ITO) hasta un catalizador de oxidación de agua.
Investigar la influencia del pH en la cinética de estas reacciones interfaciales.
Para validar la extensión de la teoría de Marcus-Gerischer al PCET.

Principales métodos:

Análisis cinético de las reacciones interfaciales ET y PCET bajo irradiación de luz visible.
Aplicación de la teoría de Marcus-Gerischer a los datos experimentales para extraer energías de reorganización.
Modelado computacional para elucidar las contribuciones de energía de reorganización de la esfera interna.

Principales resultados:

Se determinaron las energías de reorganización: λ = 0,40 ± 0,02 eV para ET y λ = 0,90 ± 0,02 eV para PCET.
Las constantes de velocidad para PCET disminuyeron con el aumento del pH, a diferencia de ET.
Se confirmó computacionalmente una mayor energía de reorganización de la esfera interna para el PCET.

Conclusiones:

La teoría de Marcus-Gerischer puede extenderse de manera confiable al PCET, proporcionando información sobre los mecanismos de reacción.
La oxidación del agua solar se favorece cinéticamente a un pH alto debido a la reducción de la PCET competidora.
Comprender las energías de reorganización es clave para diseñar fotocatalizadores eficientes.

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