resumo
A new atomic layer deposition (ALD) process was applied for the uniform coating of carbon nanotubes with a number of transition-metal oxide thin films (vanadium, titanium, and hafnium oxide). The presented approach is adapted from non-aqueous sol-gel chemistry and utilizes metal alkoxides and carboxylic acids as precursors. It allows the coating of the inner and outer surface of the tubes with a highly conformal film of controllable thickness and hence, the production of high surface area hybrid materials. The morphology and the chemical composition as well as the high purity of the films are evidenced through a combination of electron microscopic and electron-energy-loss spectrometric techniques. Furthermore, in order to highlight a possible application of the obtained hybrids, the electrical and sensing properties of resistive gas sensors based on hybrid vanadium oxide-coated carbon nanotubes (V2O4-CNTs) are reported and the effect of thermal treatment on the gas sensing properties is studied.
palavras-chave
SOL-GEL ROUTES; THIN-FILMS; NONAQUEOUS SYNTHESIS; VANADIUM-OXIDES; SENSORS; TEMPERATURE; OXYGEN; NO2; NANOCRYSTALS; ADSORPTION
categoria
Chemistry; Physics
autores
Willinger, MG; Neri, G; Bonavita, A; Micali, G; Rauwel, E; Herntrich, T; Pinna, N
nossos autores
Nicola Pinna
InvestigadorGrupos
agradecimentos
Dr Dangsheng Su and Rosa Arrigo from the Fritz Haber Institute of the Max Planck Society, Berlin, Germany, for supplying carbon nanotubes. Financial support from FCT project No (PTDC/CTM/65667/2006), DAAD-FCT/DREBM exchange project, FAME network of excellence, Marie Curie (MEIF-CT2006-041632) and WCU (World Class University) program through the Korea Science and Engineering Foundation funded by the Ministry of Education, Science and Technology (400-2008-0230) is acknowledged.