P2GS.16 - Size Effects on Sensing Properties of ZnO Nanoparticles for Detection of Isoprene

17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
P-2 - Gas Sensors
Y. Park, R. Yoo, S. Park, J. Lee, H. Jung, W. Lee - Department of Materials Science and Engineering, Yonsei University, Seoul (Republic of Korea)
798 - 799


The sensing properties of ZnO particles have been investigated for the detection of VOCs (Volatile Organic Compounds), in particular, isoprene (C5H8). According to previous studies, size reduction of ZnO particles was used as one of the methods for maximizing the reactivity. Thus, we compared the reactivity of the ZnO particles, classified by average particle sizes, ~5 (so-called quantum dots (QDs)) and ~25 nm (so-called nanoparticles (NPs)), for the detection of isoprene. Evidently, from the X-ray diffraction characterizations, the ZnO particles were successfully synthesized by a wet-chemical synthesis method. According to the XPS and BET results, larger number of oxygen vacancies and specific surface area were observed in the ZnO QDs compared to the NPs. The maximum response to 1 ppm isoprene was ~33 at 400 °C for the QDs and ~5 at 500 °C for the NPs. The higher sensing response and lower optimal working temperature of the ZnO QDs can be attributed to the comparably active adsorption sites and enhanced kinetics of the surface reaction from the size effect. Furthermore, the sensing response of ZnO QDs to 1 ppm isoprene is superior to previously reported isoprene sensors that are based on semiconducting metal oxides.