Sn-doping induced oxygen vacancies on the surface of the In2O3 nanofibers and their promoting effect on sensitive NO2 detection at low temperature

Herein, Sn-doped In2O3 nanofibers (Sn-In2O3 NFs) were successfully synthesized via an electrospinning and carbon template-induced doping method. Interestingly, abundant oxygen vacancies were simultaneously introduced on the surface of the Sn-In2O3 NFs through Sn doping, and the amount of oxygen vacancies was proportional to Sn doping contents. Gas-sensing test results indicate that the sensor based on the Sn-In2O3 NFs exhibited excellent gas sensing response toward NO2 as compared with the pure In2O3 NFs. The highest response value of the Sn-In2O3 NFs reached 44.6 to 1 ppm of NO2 at 90 degrees C, which was 3.4 times higher than that of pure In2O3 NFs. The superior NO2 sensing properties were demonstrated to be highly related to the oxygen vacancies on the surface of nanofibers, which could not only enhance the electronic conductivity but also provide active sites for the adsorption of gas molecules. This work might give a deep comprehension about the role of oxygen vacancies in influencing the sensing performance of gas sensors.