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.