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Efectos del tamaño del racimo en la reacción de evolución del hidrógeno fotocatalítico

Florian F Schweinberger¹, Maximilian J Berr, Markus Döblinger

¹Chair of Physical Chemistry, Department of Chemistry and Catalysis Research Center, Technische Universität München , Lichtenbergstraße 4, 85748 Garching, Germany.

Journal of the American Chemical Society

|August 22, 2013

Resumen

El estudio sobre los nanorods de sulfuro de cadmio (CdS) encontró que el tamaño del racimo de platino (Pt) afecta la producción de hidrógeno (H2) durante la reducción de agua. El rendimiento máximo de H2 se produjo con grupos Pt de 46 átomos debido a las propiedades electrónicas que se alinean con el semiconductor.

Área de la Ciencia:

Ciencia de los materiales Ciencia de los materiales.
La fotocatálisis por fotocatálisis.
Nanotecnología La nanotecnología es la nanotecnología.

Sus antecedentes:

La división fotocatalítica del agua es un proceso clave para la energía renovable.
Las nanorodas de sulfuro de cadmio (CdS) son materiales semiconductores prometedores para la fotocatálisis.
El papel del tamaño del co-catalizador de metales nobles en la fotocatálisis no se entiende completamente.

Objetivo del estudio:

Para investigar el efecto del tamaño del racimo de platino (Pt) en la producción de hidrógeno (H2) durante la reducción fotocatalítica de agua utilizando nanorodos CdS.
Para dilucidar la relación entre las propiedades electrónicas del racimo Pt y la actividad fotocatalítica.
Proporcionar ideas para el diseño de sistemas fotocatalíticos eficientes.

Principales métodos:

Síntesis de los nanorodos de CdS.
Deposición de grupos de Pt de diferentes tamaños (por ejemplo, Pt46) en las nanorodas de CdS.
Experimentos fotocatalíticos de reducción de agua para medir la evolución del H2.
Análisis de las propiedades electrónicas, como el nivel más bajo de órbita molecular desocupada (LUMO), de los cúmulos de Pt.

Principales resultados:

Se observó una producción máxima de H2 para los nanorods CdS decorados con racimos de Pt46.
Se encontró una clara correlación entre el tamaño del racimo Pt y la actividad fotocatalítica.
La mayor actividad de Pt46 se atribuye a la alineación óptima de su nivel LUMO con los bordes de la banda CdS.

Conclusiones:

El tamaño del racimo Pt es un factor crítico que determina la eficiencia de la reducción de agua fotocatalítica en nanorods CdS.
Las propiedades electrónicas del co-catalizador, específicamente su nivel LUMO en relación con la estructura de la banda del semiconductor, rigen la velocidad de reacción.
Estos hallazgos ofrecen un marco para optimizar el diseño de cocatalizadores para varias reacciones fotocatalíticas, incluida la oxidación del agua y la reducción de CO2.

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