Decorating spherical In₂O₃ nanoparticles onto ZnO nanosheets for outstanding gas-sensing performances

The presence and detection of hazardous environmental gases at deficient concentrations are essential to protect human beings from intensive gas exposures. Therefore, the development of high-response gas sensors is vital to overcome these overwhelming issues. The spherical In₂O₃ nanoparticles are successfully decorated onto ZnO nanosheets in ZnO@In₂O₃ (ZIO) nanocomposites via a simple co-precipitation method. The as-prepared nanocomposites are exposed to gas-sensing applications. The fabricated gas sensors exhibit high sensing response and selectivity towards NO₂ gas than other gases, tested at various working temperatures and different range of gas concentrations. The gas-sensing property of ZnO nanosheets and ZIO nanocomposites has been investigated, which reveals that 10 wt% ZIO nanocomposites shows the outstanding response of 68 at 70 ppm (1.88% higher than pristine ZnO NSs), possesses fast response/recovery time (43, 65 s) respectively, and demonstrates excellent stability and repeatability. A plausible nanostructure formation and gas-sensing mechanism are also discussed in detail. The fabricated sensors are considered potential applicants in the development of the NO₂-based gas sensor industry.