Controlled coating of antimony-doped tin oxide nanoparticles on kaolinite particles

Composite conductive powders of kaolin coated with antimony-doped tin oxide nanoparticles (Sb–SnO2/kaolin, SSK) were prepared by co-precipitation. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electronic microscopy (SEM), transmission electron microcopy (TEM), high-resolution TEM (HRTEM) and energy-dispersive X-ray spectrometry (EDS). Effects of pH value, hydrolysis temperature, kaolin content, content of doped antimony, calcination temperature and time on the resistivity of SSK were studied under the optimum experimental conditions, the resistivity was less than 10 Ω · cm. The rod-like kaolinite particles were coated with a layer of 35 nm thickness of well-crystallized, dense and uniform antimony-doped tin oxide (Sb–SnO2). A possible mechanism for coating of Sb–SnO2 nanoparticles on the surface of kaolin rods is proposed.