不同形貌纳米α-Fe₂O₃及其杂化薄膜的制备与气敏性研究

【作者】 李强；

【导师】 霍丽华；

【作者基本信息】 黑龙江大学 ， 无机化学， 2004， 硕士

【摘要】 本论文采用强迫水解法制备了三种不同形貌的α-Fe₂O₃水溶胶，通过对反应条件(Fe³⁺浓度、酸度、反应温度、反应时间等)的控制获得了不同形貌（椭球形、球形、准立方体形）和粒径的α-Fe₂O₃，并利用浸渍—提拉法制备了α-Fe₂O₃纳米粒子薄膜。测试了三种形貌α-Fe₂O₃薄膜对醇类气体的灵敏度，研究了粒子形貌对薄膜气敏性能的影响。采用分时取样的方法，对FeCl₃的水解过程进行了跟踪测试，研究了准立方体形α-Fe₂O₃的形成机理。 采用旋转涂膜技术制备了两种取代的酞菁铜旋涂膜，通过原子力显微镜对薄膜的表面形貌进行了表征，发现异丙氧基酞菁铜薄膜有明显的畴结构区域，而苯氧基酞菁铜分子为长条针状，没有出现畴状结构。同时，对薄膜材料进行了气敏性测试，结果表明，取代基团较大的苯氧基酞菁铜有更好的气敏性能。 选择分布均匀、致密的异丙氧基酞菁铜与气敏性能较好的准立方体和球形α-Fe₂O₃进行杂化，成功制备了无机—有机的交替型旋涂膜，对其表面形貌和紫外光谱进行了研究，通过结构的变化探讨了酞菁铜分子对杂化薄膜气敏性能的影响，发现杂化薄膜对甲醇和乙醇气体有较好的敏感性。 利用LB技术制各了异丙氧基酞菁铜LB膜和酞菁铜包埋球形α-Fe₂O₃纳米粒子的杂化LB薄膜，对其AFM、紫外和红外光谱的研究表明，利用LB技术可以实现酞菁与α-Fe₂O₃纳米粒子的有序组装，而且杂化薄膜对醇类气体的灵敏度有较大幅度提高，如对浓度为5ppm正丙醇的灵敏度为3.85，因此，杂化薄膜可以作为室温下醇类气体传感器进行开发研究。更多还原

【Abstract】 The preparation of three different shapes a-Fe2O3 nano-particles by means of force hydrolyzation was discussed in this paper. By controlling the experimental conditions (Fe3+ concentration, acidity, reaction time, reaction temperature etc.), the particles with different shapes (ellipsoidal, pseudocubic, sphere) were obtained. The thin films were fabricated by dip-coating technique. The gas-sensing properties of a-Fe2O3 thin films with different shape to alcohols were investigated. The formation mechanism of pseudocubic a-Fe2O3 nanoparticles was discussed.The thin films of two kinds of copper phthalocyanines were prepared by spin-coating technique. The surface morphology of the thin films was characterized by AFM. Obvious nano-domains were observed on the surface of the isopropoxyphthalocyanine thin film, while acicular crystals were found on the surface of the phenoxylphthalocyanine film. The gas-sensing properties of those films were studied. It showed that the phenoxylphthalocyanine thin films exhibited higher gas sensitivity to the alcohols than the other one.The organic/inorganic alternating composite films were further fabricated by spin-coating technique, using isopropoxyphthalocyanine and a-Fe2O3 (with pseudocubic or sphere shape) as the staring materials. The films were characterized by AFM and UV-Vis spectra, respectively. The effect of the phthalocyanine molecules on the gas sensing property of the composite film was discussed by considering the structural changes in the composite films. The results indicated that the composite films exhibited much improved gas sensing performance.The phthalocyanine and its a-Fe2O3 embedded nano-particulate LB filmswere prepared by Langmuir-Blodgett (LB) technique. The films were characterized by AFM, UV-Vis and FT-IR spectra. The results indicated that the embedded LB films were composed of a-Fe2O3 nanoparticles and isopropoxyphthalocyanine molecules. The gas sensitivity of such prepared composite LB films was greatly improved. The film could detect 5ppm of propyl alcohol at room temperature. The composite films could be considered as gas-sensors for alcohols.更多还原