Figure 10.

(a) Responses of In₂O₃ nanofiber-based sensors to 50 ppm formaldehyde as a function of operating temperature and the temperature of calcination (t = 3 h, T_c = 400–800 °C). Reprinted with permission from [171]. Copyright 2016 Elsevier. (b) Conductivity response to NH₃ (5–25 ppm) at room temperature for four types of gas sensors based on In₂O₃ nanostructures: 1—broken In₂O₃ hollow nanofiber; 2—regular In₂O₃ hollow nanofiber; 3—In₂O₃ nanofiber; 4—In₂O₃ nanoparticles. Adapted with permission from [140]. Copyrights 2007 Wiley.