SnO2 Nanostructure with Well-Engineered Crystal Facets by Zn Doping for Chemical Sensing Applications

Crystal facet engineering has attracted considerable interests in the surface gas-solid chemical reaction such as the application in gas sensing due to the unique properties derived by different atom arrangements, bond energies, and charge densities. Herein, various hierarchical SnO2 nanostructures with different exposed facets including (110) facets exposed irregular decahedrons and (101) facets exposed nanorods and nanocones were successfully synthesized by different Zn doping via a hydrothermal process. We found that the difference in the exposed facets was induced by low Zn-doping energy of (101) facets compared with that of the (110) facets. Experimental and density functional theory calculation results confirmed that the Zn doping in the (101) surface of SnO2 nanostructure could facilitate the generation of ionosorbed oxygen species and optimize the electronic structure. When applied to detecting triethylamine (TEA), the SnO2 nanostructure with exposed well-engineered (101) facets exhibited an excellent sensitivity toward TEA with the detection limit of 50 ppb at low working temperature (70 degrees C). This work not only posed a new pathway to enhance facet-related properties of metal oxides semiconductors but also developed the various applications in detecting and catalyzing harmful gases in the environment.