ZnO包覆TiO_2超微颗粒的制备及相转位研究

Preparation and phase transition kinetics of ZnO-coated ultrafine TiO_2 particles

采用Ti(SO4)2水解制得纳米级水合TiO2胶粒,并在其表面通过沉积碱式碳酸锌,制备得到ZnO包覆TiO2微粒。采用了SEM、TEM、EDS以及XRD等方法对所制备的粉体进行了表征。通过实验选择了合适的ZnO包覆含量,并对含ZnO摩尔分数为10%的包覆体进行了高温热处理,利用XRD等手段确定了粉体颗粒中锐钛以及金红石的含量,进而进行了相转位动力学研究,得到转化反应的活化能E为99 7kJ/mol,结合热处理过程以及包覆体结构,提出了可能的相转变机制。

Nanosize hydrous TiO2 precipitates were obtained from the thermal hydrolysis of titanium sulfate. After hydrolysis of titanium sulfate, the sample was coated with zinc carbonate hydroxide through deposition. The precursor was then calcinated to get ZnOcoated nano TiO2 particles. The prepared powders were characterized by SEM, TEM, XRD and EDS techniques. Appropriate amount of ZnO in the prepared powder sample was obtained through the experimental results. The rutile and anatase contents in the prepared ZnOcoated nano TiO2 particles were determined by XRD technique. Phase transformation of the sample containing 10 mol% ZnO from anatase to rutile was investigated, and its activation enthalpy was 997 kJ/mol, The possible mechanism of phase transition was given in terms of the structure of the prepared ZnOcoated nano TiO2 particles with annealed temperature.