Synthesis of Au decorated SnO2 mesoporous spheres with enhanced gas sensing performance

Abstract

Au decorated mesoporous SnO₂ spheres with a size range of 400–700 nm have been synthesized for gas sensing. Specifically, the mesoporous SnO₂ spheres were fabricated through a solvothermal route followed by a thermal treatment process. The surface area of the mesoporous SnO₂ spheres is 78.2 m² g⁻¹ and the pore size is ca. 10 nm. After being decorated by Au, the Au nanoparticles with sizes of ca. 5 nm were deposited on the surface and the inner wall of pores. Gas sensing tests showed that the Au decorated SnO₂ mesoporous spheres exhibited superior gas sensing performances to CO and H₂ in terms of high sensitivity and fast response and recovery speed, mainly attributed to the facts that the SnO₂ mesoporous structure provides a high reaction surface area and abundant mesochannels for the probe gas and oxygen, and Au nanoparticles act as the catalyst to improve the reaction rate of the probe gas molecules with the oxygen ions.