镧铈混合掺杂氧化钛纳米粉体晶型转变的研究

采用溶胶-凝胶法,在不同的热处理温度下制备了稀土镧铈掺杂的不同晶型的TiO2纳米粉体。用X射线衍射仪,透射电子显微镜对所制备的TiO2纳米粉体进行表征,分析在不同热处理温度下制备的TiO2纳米粉体的晶粒尺寸及晶相组成,研究热处理温度对晶型转变的影响。研究表明:与未掺杂的TiO2晶型转变温度650℃相比较,稀土镧铈混合掺杂大大的抑制了TiO2锐钛矿向金红石晶相的转变,且在800℃煅烧温度以下,平均晶粒在15nm之内;当达到晶相转变温度时,晶粒突增到49nm。

The crystal transformation of La-Ce co-doped TiO2 nano-powder

Nano-TiO2 co-doped with La-Ce was synthesized by sol-gel method,and then annealed at varying temperatures to control their crystallinity,and characterized by various physical techniques(e.g.XRD,TEM).The mixed crystal composition and the size of the grain have been widely studied because they were greatly influenced by the annealing temperature.The results showed that the phase transformation was significantly inhibited by the mix-doped lanthanum and cerium compared to the TiO2 without rare earth.The average grain size was less than 15nm when the calcination temperature below 800℃,however,it suddenly increased to 49nm when the calcination temperature reached to the phase transition temperature.Consequently,these results indicated that control of crystal phase composition through anneal temperature was found to be a simple and effective way.