Synthesis of mesoporous SnO2 nanomaterials with selective gas-sensing properties

Using SBA-15/KIT-5/KIT-6 as the hard templates, the mesoporous SnO2 nanomaterials with different structures were synthesized by nanocasting. X-ray diffraction, transmission electron microscopy, and nitrogen adsorption isotherms were used to testify their structure characteristics. These mesoporous SnO2 nanomaterials showed high specific surface areas (57–96 m2 g−1) and pore volume (0.17–0.27 cm3 g−1). The nanopore of these templates makes the nanosize particle of the final mesoporous SnO2 nanomaterials (4–9 nm) at last. The sensing properties of acetone, ethyl alcohol and methyl alcohol were investigated. The response of SnO2-15, SnO2-5, and SnO2-6 are 17.0, 19.5, and 16.1, respectively as the concentration of ethyl alcohol on 200 ppm. The sensitivity of SnO2-5 is 28.2 as the concentration of acetone was increased to 200 ppm. With the large surface area, high pore volume, and nanosized particles (close to 2 L = 6 nm of SnO2), the SnO2-5 show four fold enhancement in sensitivity compared to commercial SnO2 powder and low detection limit (even at 200 ppb). The surface area and particle size play a significant party in the gas response. With the large surface area and smallest particle size, SnO2-5 shows the highest sensitivity of all. These mesoporous nanomaterials show well potential application on the gas response.