导电硅藻土粉体制备及性能研究

Preparation and Characterization of Composite Conductive Powders with Diatomite Matrix

采用化学共沉淀法制备硅藻土表面包覆锑掺杂二氧化锡导电粉体,并对制备工艺条件进行详细研究;采用X射线衍射、扫描电镜、透射电镜对样品进行表征,采用四探针仪测试样品导电性能。结果表明:最佳的制备工艺条件为:溶液温度40℃、反应时间1 h、pH为1、Sn4+与Sb3+的物质的量比为8∶1、包覆率为38%、700℃下煅烧1 h。硅藻土表面形成厚度为30 nm左右的金红石结构的均匀包覆层,样品体积电阻率最低可达18Ω.cm。

The superfine diatomite particles coated with n-type Sb-SnO2 was fabricated by coprecipitation method. The influences of reaction conditions on the final products were studied systematically. The samples were characterized by X-ray diffraction （XRD）, scanning electronic microscopy （SEM）, transmission electron microcopy （TEM）, energy dispersive X-ray spectrometry （EDS）. The process of preparation and technological parameters which affected the conductive behavior of the powders were studied respectively and the optimal process conditions were as follows： hydrolysis temperature was 40 ℃, reaction time was 1 h, pH value was 1, n（Sn^4＋） ： n （Sb^3＋）=8 ： 1 , the coating rate of SnO2 was 38%, the calcining temperature of coprecipitation products was 700 ℃. The results showed that the homogeneous coating of Sb-SnO2 rutile crystals in thickness of 30 nm was formed on the surface of diatomite particles. The powder volume resistivity could be less than 18 Ω ·cm.