Atomic layer deposition of Ti-Nb-O thin films onto electrospun fibers for fibrous and tubular catalyst support structures

Abstract

Here, the authors report on the preparation of core–shell carbon-ceramic fibrous as well as ceramic tubular catalyst supports utilizing electrospinning and atomic layer deposition (ALD). In this paper, ALD of Ti-Nb-O thin films using TiCl4, Nb(OEt)5, and H2O as precursors is demonstrated. According to the time-of-flight-elastic recoil detection analysis and Rutherford backscattering spectrometry, carbon and hydrogen impurities were relatively low, but depend on the pulsing ratio of the precursors. Optimized ALD process was used for coating of sacrificial electrospun polyvinyl alcohol (PVA) template fibers to yield tubular Ti-Nb-O structures after thermal or solution based PVA removal. Another approach utilized 200–400 nm thick carbon fibers prepared by electrospinning from polyacrylonitrile and subsequent thermal treatment.