Improvement of gas sensing performance for tin dioxide sensor through construction of nanostructures.

Rational design of tin dioxide (SnO2) nanomaterials with superior architectures and outstanding physicochemical capabilities is highly desirable for gas sensors. Here, three SnO2 nanostructures with different morphologies, particles, core-shell spheres and facet-exposed crystals, are developed and further applied to track amounts of volatile organic compounds (VOCs). Porous SnO2 core-in-hollow-shell sphere-based sensors exhibited enhanced sensing properties, especially a higher sensitivity than SnO2 particles. The monocrystalline SnO2 single-crystal-based sensor, which has dominant exposed (1 1 0) and (2 2 1) facets, also showed a superior sensing performance, especially faster response/recovery speed than the SnO2 particle-based sensor. The enhanced gas-sensing properties are mainly ascribed to the structural sensitization, and these results further confirm that the SnO2 core-shell structure and exposed single crystal exposed with high energy can provide more numerous active sites for gas molecule adsorption than that of SnO2 particles.