摘要
对比了氨水或NaOH共沉淀和尿素水解均相沉淀三种不同的制备方法，以及NaOH沉淀不同的老化条件下制备的SnO_2粉体材料的比表面以及烧结特性.实验结果表明，减慢成核速度及在母液中高温老化都有利于提高初始粒子的晶化程度和焙烧后样品的比表面.以NaOH共沉淀，在100 ℃下回流老化48 h制备的SnO_2具有最大的比表面和最好的烧结性能，在500、800和1000 ℃焙烧后比表面分别为94、75和53 m^2·g－1.初始粒子晶化程度的提高以及材料中硬团聚的减小是改善SnO_2烧结性能的主要原因.
Comparison of the influences of the preparation methods and reaction conditions to the properties of SnO2 powder, especially the specific surface area and the stability under high temperature calcination were performed. SnO2 prepared by precipitation method using NaOH solutions as the precipitating agent in the pH region of 10 and aged at 100 degreesC for 48 h had the highest BET surface area of 93.5 m(2) . g(-1) after calcination at 500 degreesC for 4 h. The materials maintained a surface area of 75.2 m(2) . g(-1) after 800 degreesC and 53.2 m(2) . g(-1) after 1000 degreesC calcination. The sample using NH3 . H2O as precipitation agent had the lowest BET surface area calcinied under the above three temperatures. It was shown that using NaOH as precipitation agent and digestion at high temperature was beneficial to maintain high surface area and good stability under high temperature. One of the reasons is that the digestion under high temperature reduced the water content in the hydrous tin oxide gel, so the initial structure of the particle was enhanced during the drying and calcining process. The other reason is that the crystallization of the initial particles was enhanced during the digestion and the defect on the surface was reduced also, so the sintering due to the surface diffusion was restrained. Further more, washing with ethanol reduced the formation of hardcore agglomeration between the particles, thus improved the stability of the particles under high temperature calcining process.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2001年第7期577-581,共5页
Acta Physico-Chimica Sinica
基金
国家重点基础研究发展规划项目(G2000077503)
国家自然科学基金资助项目(29803001)
