摘要
通过XRD、SEM和动态光散射粒度测定仪(DLS)研究了胶溶及水热晶化过程中纳米TiO2晶粒聚集行为及形貌．实验结果表明,在胶溶无定形沉淀过程中所形成的大小为10-15nm的锐钛矿(A)型胶粒或金红石(R)型胶粒(初级粒子)易定向聚集成更大的、具有(30-50)nm×(80-100)nm的次级晶粒．含有次级晶粒的溶胶前驱液在水热晶化过程中,次级晶粒发生崩裂并生长成结晶度更高的大小约为10-30nm球形(A型)和大小约为20-60nm棒状(R型)纳米TiO2．
During the process of peptization and hydrothermal crystallization, the aggregation behavior and the resulting morphology of nanocrystalline titania （TiO2） were studied by X-ray diffraction （XRD）, scanning electron microscope （SEM）, and dynamic light scattering （DLS） techniques. The results show that during peptization process the mixture of rutile-type and anatase-type primary particles with 10-15nm in diameter formed by peptizing the precipitated amorphous titania are transformed into rod-like secondary crystalline grains with sizes of （30-50）nm×（80-100）nm through an oriented aggregation mechanism, which obey a crystal face-matching rule. In the process of hydrothermal crystallization under 180℃, however, the rod-like secondary crystalline grains are first broken into nanoparticles with diameter in the range of 10-15nm （namely the same sizes as those of the primary particles）, and the formed nanoparticles then grow in hydrothermal solution. The finally resulting particles with the sizes of 10-30nm （spherical anatase） and 20-60nm （rod-like rutile） are found to have a higher crystallization degree than the primary particles formed in the process of peptization.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第1期59-64,共6页
Journal of Inorganic Materials
基金
教育部新世纪优秀人才支持计划(NCET-04-0557)
关键词
二氧化钛
聚集结晶
胶溶
水热晶化
titania
aggregation crystallization
peptization
hydrothermal crystallization
