Innovative spongy TiO2 layers for gas detection at low working temperature
Abstract The capillary distribution of reliable solutions for gas detections implies identifying high throughput and up-scalable approaches for the growth of porous active materials with high surface to volume ratio and high surface avaialability/reactivity. Thereby we implemented a competitive method to render thin (hundreds of nanometers) TiO 2 layers highly sensitive to gas species. This method is easily implementable in gas sensor devices with an additional ending step at room temperature without any temperature needed for reaction. It is based on the local oxidation of sputtered Ti atoms that land grazing on the sensor architecture (called gig-lox process). The process gives rise to a contaminant-free TiO 2 spongy structure consisting of rods separated by meso-pores arising from the grazing geometry; the rods, on their side, have an internal branched structure creating an interconnected network of nano-pores. The overall porosity amounts to ∼50% of the volume. For sensing, we exploited the double-scale porosity of the layer such that the meso-pores behave as highways for the gas species to enter the whole thickness and deeply imbue the network of nanopores. This enhances the probability of surface interaction. The overall TiO 2 structure accounts for more than one order of magnitude sensitivity exhibited by a 350nm-thick spongy layer to 44 ppm of ethanol at 250 °C. The sensitivity remains relatively high at 17 ppm of ethanol concentration. Moreover, the response of the material is independent of the ambient humidity with a response time as low as ∼10s. Demonstrating high performances in low-power consumption sensing devices using this innovative layer with scaled thickness integrated by a simple procedure represents an important step forward both in terms of materials saving and in terms of industrial benefits. Highlights Newly designed sputtering-based method, called gig-lox, allows growing spongy TiO 2 layers with high porosity. The material empowering is related to a double-scale porosity at the meso and nano-scale. Gig-lox growth renders thin TiO 2 layers highly sensitive to gas species. Gig-lox growth is done at room temperature and does not require additional processing steps. Gig-lox TiO 2 layers are easily implementable in any device architecture. Gig-lox method is in principle extendable to any metallic oxide. Graphical abstract [DISPLAY OMISSION]
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
원문복사신청을 하시면, 일부 해외 인쇄학술지의 경우 외국학술지지원센터(FRIC)에서
무료 원문복사 서비스를 제공합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 위의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.
- 이 논문과 함께 출판된 논문 + 더보기