Multistep assembly of Au-loaded SnO2 hollow multilayered nanosheets for high-performance CO detection

The designed preparation of pure and Au-loaded SnO2 hollow multilayered nanosheets for CO detection has been realized via a rational combination of different purposeful multi-step synthetic route. The synthetic step-dependent shape and structure evolution has been investigated and the formation mechanism for the unique hollow nanosheets is also discussed. The characterized results confirm that flowerlike SnO2 nanosheets with a polycrystalline rutile structure are assembled from hexagonal mesoporous and multilayered walls, which can further be subdivided into SnO2 nanoparticles as structural subunits. Furthermore, gas sensors based on the as-prepared pure and Au-loaded SnO2 have also been fabricated. The Au-loaded SnO2 hollow nanosheets show significantly lower working temperature, faster response recovery and improved selectivity to CO in comparison with that of pure SnO2. Besides structural merits including hollow and easily penetrated multilayered walls, which facilitate the transport rate and augment the adsorption quantity of gas molecule, the significant improvement of the sensing properties is also attributed to the catalytic effect of Au. (C) 2015 Elsevier B.V. All rights reserved.