化学共沉淀法制备镧掺杂纳米二氧化锡的研究

Study of La-doped nanosized SnO_2 by chemical co-precipitation

以SNCl4和La2O3为原料,采用化学共沉淀法制备掺杂La的纳米SnO2,并对其物相和粒度进行了分析.结果发现采用化学共沉淀法制备La掺杂SnO2粉末,焙烧温度在400～650℃时,其晶体结构保持SnO2的四方结构;750℃以上焙烧,得到La2Sn2O7和SnO2两相结构.La元素的掺杂明显抑制SnO2晶粒的长大,并且随含量的增加抑制SnO2长大的效果更明显.同时掺杂La元素使纳米SnO2晶粒的形成与长大对保温时间不敏感,在550℃焙烧1 h与8 h晶粒大小只相差1 nm左右.

La-doped nanosized SnO_2 powders were prepared by the chemical co-precipitation method using SnCl_4 and La_2O_3 as starting material,and the phase and size of La-doped nanosized SnO_2 were studied.Experimental results show that the calcination temperature can affect the production,when the calcination temperature is 400 to 650℃,the SnO_2 crystal has tetragonal lattice structure.Above 750℃,the particles become a two-phase mixture of SnO_2 and La_2Sn_2O_7 crystallites.La doping can efficiently prevent the growingup of nanosized SnO_2 crystallites,and higher doping concentration is more effective to prevent the growth of nano-particles.After La doping,the calcination time has little influence on crystallite size because the difference is smaller than(1 nm) at 550℃ from 1 to 8 h.