Ferrite application as an electrochemical sensor: A review

Nano-ferrites are one of the extensively explored sensing materials for the detection and quantification of the evolution of toxic gases from industries, vehicle exhaust and biological wastes. It can be further utilized for the monitoring and regulation of environmental pollution. This review article reports the literature available on ferrite with single metal ion dopant, mixed ferrite materials (multi-ion doping), ferrite-based composites with another metal oxide, polymer and carbon material /ferrite-based core-shell structures. It is reported that the ferrite with a single metal ion dopant exhibits a better response for gas sensing than pure Fe3O4. Also, by doping the La ions in Mg-ferrite the sensitivity increases many times at lower operating temperature and similar is the case with Ce ion doping to Co-ferrite. Nanocomposite of PANI (Polyaniline) with Cu-ferrite reports higher response for NH3 gas at room temperature than pure Cu-ferrite and the selectivity of NiO/Ni-ferrite changes for HCHO than the pure Ni-ferrite. In general, ferrites possess characteristic porosity, physical and chemical absorption properties which are easily optimized by choosing appropriate synthesis routes and parameters like pH of the solution, temperature, sintering temperature, nature and concentration of doping/co-doping ions, nanocomposites and morphology. This paper consolidates the available literature over the last three decades on the development of ferrites as a gas sensing material.

Automated summary

Nano-ferrites are extensively researched sensing materials for detecting toxic gases and monitoring environmental pollution, with improved gas sensing performance achieved through various doping and composite materials.