| 초록 |
Two-dimensional (2D) metal oxides have widely studied in various applications due to their intriguing properties, such as super high surface-to-volume ratio, ultra-thin thickness, high ratio of mesopores and small grain size. However, 2D nanostructures have the tendency to restack, so they can induce the decrease of accessible surface area and low ratio of macropores. In this work, crumpled SnO2 nanosheets (NSs), crumpled ZnO NSs, and crumpled SnO2 and ZnO NSs composite were synthesized using graphene oxide (GO) as a template, to take advantages and get over disadvantages of 2D nanostructures for highly effective gas sensor, i.e., - (i) high surface-to-volume ratio (ii) complete electron depletion and (iii) effective gas diffusion. First of all, GO/metal ion composites were synthesized by dissolving metal precursor and GO in absolute ethanol to allow bonding between GO and the metal ions. And then, the crumpled GO/metal oxide composites were fabricated by spray pyrolysis. After calcination of them at 450 ℃ for 1 h, GO were thermally decomposed to form crumpled metal oxide NSs. The gas sensing performances were proceeded to VOCs (volatile organic compounds) gas species, e.g., CH3COCH3, NO, C7H8, C2H6O, HCHO, H2S and NO2. The sensing test results demonstrated that crumpled metal oxide NSs can effectively detect VOCs species with high speed of response and recovery from exhaled breath. This work suggests the facile and effective synthesis method of crumpled holey metal oxide NSs templated by the GO for enhanced gas sensors. |
