Indium element- induced oxygen vacancies and polycrystalline structure enabled SnO2 nanofibers for highly sensitive detection of NOx

High response and high selectivity of SnO2-based NOX sensors play a major role in industry and biology. However, there are still some disadvantages such as high production cost, low response and high detection limit. Therefore, a simple electrospinning method is reported for the preparation of In-doped SnO2 nanofibers (InSnO2 NFs) for high response and selectivity to NOX in this paper. The results showed that In doping not only changed the morphology of the nanofibers but also improved the gas response to NOX (Rg/Ra = 737.8 under 100 ppm). The gas-sensing mechanism of In-SnO2 NFs to NOX was researched by XPS, O-2-TPD and H-2-TPR tests. The results showed that the excellent sensing performance was due to the polycrystalline structure consist of nanoparticles which provided multiple active centers for sensing reactions, and the In dopant increased the carrier concentration, adsorbed oxygen and oxygen vacancy. Therefore, In-SnO2 NFs has a good application value in sensing materials.

Automated summary

In-doped SnO2 nanofibers were prepared by electrospinning method and showed high response and selectivity to NOX. The gas-sensing mechanism was investigated and it was found that the polycrystalline structure and In dopant played important roles in the excellent sensing performance.