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Intercambio de ligandos mediado por ácido y base en puntos cuánticos coloidales III-V de absorción de infrarrojo
Jari Leemans1,2, Kim C Dümbgen1,2, Matthias M Minjauw3
1Physics and Chemistry of Nanostructures, Ghent University, 9000 Gent, Belgium.
Journal of the American Chemical Society
|March 12, 2021
Resumen
Estudiamos la química de la superficie de los puntos cuánticos coloidales III-V basados en indio (QD) para aplicaciones infrarrojas. Comprender el intercambio de ligandos en estos QD es clave para desarrollar tintas infrarrojas imprimibles y recubrimientos conductores.
Área de la Ciencia:
- Ciencias de los materiales
- Nanotecnología
- Química de las superficies
Sus antecedentes:
- Los puntos cuánticos coloidales III-V basados en indio (QD) son materiales infrarrojos imprimibles prometedores.
- La comprensión limitada de su química superficial dificulta el desarrollo de tintas infrarrojas y recubrimientos conductores QD.
Objetivo del estudio:
- Investigar la terminación superficial y los mecanismos de intercambio de ligandos de los puntos cuánticos coloidales In ((As,P) (QD).
- Establecer un modelo general para la química superficial de los QD basados en In III-V sintetizados con haluros de indio.
Principales métodos:
- Síntesis de las QDs In ((As,P) activas por infrarrojos absorbidas a 1220 nm.
- Caracterización de la terminación de la superficie QD mediante análisis espectroscópico y químico.
- Simulaciones de la teoría funcional de la densidad (DFT) para modelar las energías de intercambio de ligandos.
Principales resultados:
- En ((As,P) los QD sintetizados con haluros de indio y aminopnictógenos muestran terminación superficial con oleilamina y cloruro.
- El intercambio de ligandos se produce a través de un mecanismo ácido/base, impulsado por la formación de sal de cloruro de alquilamonio.
- DFT confirma que la formación de sales puede impulsar el intercambio de ligandos incluso con ácidos orgánicos débiles como los alcanetiolos.
Conclusiones:
- La química superficial de los QD basados en In III-V implica una mezcla de ligandos de tipo L y tipo X.
- El intercambio de ligandos mediado por ácido/base es un mecanismo general aplicable a estos QD.
- Este entendimiento facilita el desarrollo de tintas infrarrojas imprimibles y recubrimientos conductores de QD.
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