Mesoporous SnO<sub>2</sub> by Nanocasting Route Using Various Silica Templates for Gas Sensing Application

Mesoporous SnO 2 was successfully synthesized via nanocasting route using various silica matrices likely KIT-6, SBA-15 and SBA-16 as hard templates. The chemical and structural properties of these materials were characterized by means of XRD, N 2 adsorption-desorption and TEM analyses. All replica products exhibited well-defined mesoporous structures and large surface areas as well as highly crystalline frameworks. Sensors were fabricated from the as-prepared mesoporous SnO 2 replicas and used to test the response to 1000 ppm of ethanol vapour at different operating temperatures. The results showed that the mesoporous SnO 2 sensors nanocasted from KIT-6, SBA-15 and SBA-16 silica templates exhibits excellent gas response as compared to a bulk SnO 2 material, suggesting the potential application of the sensor for detecting ethanol vapour. Maximum sensitivity (~ 18.7) was reached at 300 °C using mesoporous SnO 2 sensor nanocasted from KIT-6 silica. It can be explained by the large surface area and well-defined mesostructure of SnO 2(KIT-6) , which lead to highly effective surface interaction between the ethanol molecules and the surface active sites.