AgI-ZnO纳米复合粉体的制备及催化性能

Preparation and Catalytic Properties of AgI-ZnO Nanocomposites

采用沉淀法制备AgI-ZnO复合纳米粉体,用差示扫描量热仪研究前躯体的热分解历程,借助X射线衍射仪、X射线光电子能谱仪及透射电子显微镜研究不同AgI掺量对产物组成及形貌和尺寸的影响,进一步将差热分析和电子自旋共振检测相结合,探讨不同AgI掺量对高氯酸铵(ammoniumperchlorate,AP)催化性能的影响。结果表明:AgI-ZnO复合纳米粉体在350℃左右煅烧1 h,所制得目标产物粒径约为53 nm且分布均匀。AP催化过程研究表明:与纯纳米ZnO相比,AgI掺杂到ZnO中,其非共格晶界所营造的缺陷效应使复合纳米粉体的氧空位浓度提高,催化作用增强;AgI摩尔掺量为0.3%时,催化效果最强,可使AP的高温分解峰由433℃直接降低到301℃。

AgI-ZnO nano composites were prepared by the precipitation method,and the thermal decomposition process of precursor was investigated by the thermogravimetry-differential scanning calorimetry.Composition and morphology of products were analyzed by the X-ray diffraction,X-ray photoelectron spectroscopy and transmission electron microscopy.Effects of different doping ratios on pow-ders＇ catalytic property were investigated via the differential thermal analysis and electron spin-resonance spectroscopy.Results indicate that products with a uniform size of about 53 nm are obtained after calcining precursor at 350 ℃ for 1 h.Study of the catalytic process for ammonium perchlorate（AP） suggests that compared with pure ZnO,oxygen vacancy concentration in AgI-ZnO increases because of defect effects created by the non-coherent phase boundary and that catalysis activity is also improved.Composite with 0.3%（mole frac-tion） AgI doping has the best catalytic effect and decomposition temperature of the AP decreases significantly from 433 ℃ to 301 ℃.