Synthesis and application of strontium-doped zinc ferrite nanomaterial in humidity sensing

Humidity sensors, being an important component of the Internet of Things (IoT) and artificial intelligence (AI), are currently used in noncontact sensing, electronic skin, respiratory analysis, etc. In this study, the sol-gel auto-combustion technique was used to prepare strontium-doped zinc ferrite (ZnFe₂O₄) nanomaterials. The synthesized materials have been characterized using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), energy dispersive X-ray (EDX), and field emission scanning electron microscopy (FESEM) techniques. The doping of strontium increases the lattice parameter and reduces the crystallite size. The synthesized nanoparticles were used to design a humidity sensor for the first time, and several humidity-sensing properties were investigated. The designed humidity sensor has a response and recovery times of 19 s and 81 s, respectively. It has low humidity hysteresis, excellent repeatability, and a minute ageing effect.

A comparison of the present study with previous reports suggests that the developed humidity sensor is promising in terms of recovery, response times, and material.