Polycarbonate membrane assisted growth of pyramidal SnO2 particles

We demonstrate here the utility of polycarbonate membrane in preparing oxide particles of unusual shape and properties. Unlike the usual formation of nanowires or tubes using alumina templates, here, pyramidal shaped SnO₂ particles with a preferred orientation along the (2 1 1) direction have been prepared using polycarbonate membranes. Simple impregnation of SnO₂ sol into a polycarbonate membrane by sonication followed by calcination at 800 °C resulted in the formation of pyramidal shaped SnO₂ particles. Compared to the alumina membrane the recovery of the particles from polycarbonate membrane is very simple. The sensor fabricated using such particles without any catalyst addition exhibited 64% sensitivity towards 500 ppm butane at 500 °C with a recovery time of 27 s. This method could be used as a simple technique to prepare oxide particles of different size and shape for diverse applications.