摘要
采用NaOH/十二烷基苯磺酸钠(DBS)/甲苯/水和NaOH/十六烷基三甲基溴化铵(CTAB)/三氯甲烷/正丙醇/水2种微乳液体系制备了γ-Fe_2O_3纳米粉体,并对其气敏性能进行了研究和讨论。用FT-IR、XRD和TEM测试技术对纳米粉体进行了结构表征。结果表明,选用DBS和CTAB作为表面活性剂,在W/O分别为10．77和10．56的条件下均可获得粒径为4～5 nm的球形γ-Fe_2O_3纳米颗粒。由于获得的γ-Fe_2O_3纳米颗粒表面均有残余的表面活性剂存在,导致产物颗粒之间不易团聚,粒径较小。由2种微乳液体系制备的γ-Fe_2O_3纳米粉体制作的气敏元件,对体积分数为0．1％的乙醇的灵敏度分别为12．5和23．8,并测得元件DBS的响应-恢复时间分别为20和30s;元件CTAB的响应．恢复时间分别为15和47 s。元件的灵敏度与所测气体的浓度呈线性关系。
γ-Fe2O3 nanopowders were synthesized from the two microemulsion solutions, such as NaOH/ DBS/C6H5CH3/H2O and NaOH/CTAB/CHCl3/CH3CH2CH2OH/H2O, and their gas sensing properties were studied. The products were characterized by means of FT-IR, XRD and TEM. The results indicate that spherical γ-Fe2O3 nanoparticles with a particle size of about 4 - 5 nm can be obtained from the two microemulsion solutions, when DBS and CTAB were used as surfactant and the ratios of W/O were 10. 77 and 10. 56, respectively. The small particle size can be attributed to the remanant surfactants adsorbed on γ-Fe2O3 nanoparticles which prevent the aggregation of γ-Fe2O3 nanoparticles. The sensors, made from γ-Fe2O3 nanopowders obtained from the two microemulsion solutions, have high sensitivities of 12. 5 for DBS and 23.8 for CTAB to 0.1% ethanol, as well as show short response-recovery time to 0. 1% ethanol, that is, 20 and 30 s for DBS and 15 and 47 s for CTAB, respectively. Both of them can meet the requirements of practical applications and are promising ethanol sensors due to their sensitivities and good linear relations to the concentration.
出处
《应用化学》
CAS
CSCD
北大核心
2007年第2期148-151,共4页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金(20271028)
