Humidity Sensing Properties of Hierarchical Fe Doped SnO2 Nanocoral-Like Structures

Present technical paper investigates the humidity sensing properties of Fe doped SnO2 nanocoral (FSNC)-like structures which were achieved by hydrothermal synthesis. The structural properties of FSNC samples were characterized using field emission scanning electron microscopy (Hitachi S–4800), energy-dispersive x-ray spectroscopy and x-ray diffraction (Rigaku Miniflex). FSNC with rod-, spherical-, and rod-shaped tentacles have been achieved using autoclave reactors of size 100 ml, 250 ml and 500 ml, respectively. The average crystallite size of FSNC with rod-, spherical-, and rod-shaped tentacles have been found to be ~ 6.51 nm, 7.26 nm and 4.93 nm, respectively. The sensing properties of the FSNC sensors have been established in a humidity chamber for a range of 20–80% relative humidity. The response/recovery time of sensors for FSNC with rod-, spherical-, and rod-shaped tentacles have been found to be 18/32 s, 25/40 s, and 20/30 s, respectively. The highest sensitivity has been achieved for FSNC with rod-shaped tentacles. The humidity sensing properties of FSNC sensors, such as response/recovery time, stability, hysteresis, and sensitivity have been investigated in detail.