Microwave-assisted polyol synthesis of mesoporous Ta doped mixed TiO2/SnO2: Application for CO2 capture

Abstract

Tantalum-decorated mixed oxides (Ti0.5Sn0.5O2) was successfully synthesized, using a microwave-assisted polyol process (MAP) and triethylene glycol as a solvent, in a much shorter time than conventional heating. The newly-synthesized nanocomposites materials were used to make resistive semiconductor gas sensors to detect CO2. The powders were investigated using X-ray diffractometry, transmission electron microscopy and N2 physisorption. The X-ray diffraction patterns of the samples confirm that TiO2 is in the anatase phase and SnO2 and Ti0.5Sn0.5O2 are in the cassiterite phase. The TEM images showed uniform isotropic morphologies with average sizes close to 10 nm. The optimized sensor, based on TiO2/SnO2/Ta showed promising performances towards CO2 capture, ensuring a high response and fast dynamics at an operating temperature of 20 °C. The CO2 adsorption capacity was also remarkably increased from 0.58 mmol g−1 for TiO2 alone to 0.90 mmol g−1 for the Ti0.5Sn0.5O2. This work brings insights into a new way of limiting atmospheric pollution using mixed-oxide nanoparticles.