The Fabrication Of One-dimensional ZnO Nanorod/Nanotube Array Coating For Solid Phase Micro-extraction

One-dimensional(1D) ZnO nanostructures are a kind of good gas adsorptionmaterial due to its high surface to volume ratio and porous property，which can beadopted as coating material for solid phase microextraction (SPME). In this paper, thehydrothermal sythesis of ZnO nanorod array was carried out by using the aqueoussolution of zinc acetate (ZnAc) and methenamine (HMT) in reaction kettle, and thenthe core of ZnO nanorods was selectively etched in NH3·H2O solution, resulting in theformation of ZnO nanotube array. The as-prepared ZnO nanorod/nanotube array asadsorptive coating fibers were first applied in the field of SPME for extraction ofVOCs. The extraction capability of the ZnO nanorod array coating was studied indetail. The thesis consists of four chapters.In chapter1, the general introduction, which included historical perspective ofZnO nanomaterial, the principle of SPME, as well as the preparation method andinfluence factors of SPME, was described in detail. Furthermore, the aim andsignificance of this thesis were also briefly presented.In chapter2, ZnO nanorod array was synthesised on the surface of the fusedsilica fiber by hydrothermal method. And then it was first used for SPME. Theextraction and adsorption conditions were optimized in details. The result showed thatthe coating had high extraction capacity toward the volatile organic compounds(VOCs) by using BTEX as standards. In addition, the coating also exhibited goodextraction selectivity to1-propanethiol.In chapter3, a new method for preparation of ZnO nanotubes array on SiO2substrate by hydrothermal reaction were described. Then, the obtained ZnO nanotubearray fibers were used as headspace solid-phase microextraction (HSSPME) forextracting BTEX from water coupled to gas chromatography-mass spectrometry(GC-MS). The influence factors and growth mechanism of the formation of ZnOnanotubes array were investigated in detail. The proposed ZnO nanotube array fibersshowed good extraction properties for head sampling BTEX in water. In chapter4, the prepared ZnO nanotubes array coating was used for head spaceextracting the volatile components from green onion coupled to GC-MS technology.Four compounds were identified, including methyl mercaptan,1-propanethiol,di-n-prophl disulfide and disulfide, methyl propyl. Among them methyl mercaptanwas first identified in this work.