P1GS.4 - Correlation between the NO2 gas sensing properties and surface area of ZnO nanofibers, hyerarchical and thin films structures
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- P-1 - Gas Sensors
- C. Cantalini, V. Paolucci, S. Emamjomeh - University of L'Aquila, L'Aquila (Italy), U. Anselmi-Tamburini - University of Pavia, Pavia (Italy), J. Tulliani - Politecnico di Torino, Torino (Italy)
- 527 - 528
Aim of this work is to assess relationships between sub-ppm NO2 gas relative response (RR= Rg/Ra) and absolute surface area evolution of: ZnO nanofibers (ZnO-NF), nanofiber-nanowire brush like ZnO (ZnO-NB) and ZnO thin film (ZnO-TN). In a first step ZnO-NFs mats with two different amounts of fibers (LD-ZnO, HD-ZnO, i.e. low and high fiber density), have been initially characterized both as respect to their absolute surface area and to NO2 gas response (20ppb – 1ppm). In a second step, the same previously prepared LD-ZnO and HD-ZnO fibers, have been subjected to hydrothermal growth of side branches ZnO nanorods to yield brush like hierarchical structures (ZnO-NB) with enhanced surface area. ZnO-TN were prepared by sol-gel spin coating. A linear relationship between RRs and absolute surface area of all the prepared samples was found. The bigger the absolute surface area the higher the RRs, the lower the detection limit (down to 20 ppb) respectively. Traditional porous structures like thin films show better RRs as respect to 1D hierarachical structures but slower response times.