Preparation and characterization of silica/carbon nanocomposites for a thermoelectric application

In this work, the silica/carbon nanocomposites are firstly fabricated by combining the cold-pressing methods and the sintering treatment, and then the thermal conductivity, the Seebeck coefficient and the electrical conductivity are experimentally studied. Results turn out that the thermal conductivity firstly decreases then rise with the increase of the sintering temperature, and there is an optimal sintering temperature for getting a low thermal conductivity. The decrease of the thermal conductivity is due to the enlarged porosity caused by a higher sintering temperature, while the rise arrives from the improved crystal degree of silica nanoparticles. Results also turn out that the Seebeck coefficient and the electrical conductivity of the silica/carbon nanocomposite are almost same to that of a common carbon material. This work is expected to supply some information for developing new thermoelectric nanocomposites. (paper)