Crystal-surface-regulated SnO2 sensors for specific detection of n-butanol and simple differentiation for isomers and homologs

In this work, SnO 2 was prepared by hydrothermal method and annealed at 550 °C. Through XRD characterization and BET measurement, it can be found that the addition of NH 4 F can guide the growth of the (110) crystal plane and the increase of the specific surface of SnO 2 . The results showed that the response of SnO 2 to n-butanol was increased from 190.46 to 354.11 after NH 4 F modification, and the detection limit was 2.82 ppb. The calculation of DFT adsorption energy provides direct and valid evidence for this. To further test whether the sensor can effectively distinguish for the homologs and isomers of n-butanol, the reciprocal of the lowest resistance is substituted for the magnitude of the response value in the response recovery curve. Moreover, the electron effect and steric hindrance effect can be reasonably explained for the response value of the target molecule.