High performance gas sensing based on nano rods of nickel ferrite fabricated by a facile solvothermal route

Nanorods, nanocubes and nanospheres of Nickel Ferrite were synthesized by the solvothermal route by using different ratios of water and ethylene glycol. The surface morphology of the nanorods, nanospheres and nanocubes was studied by Transmission Electron Microscope and their diameter was ∼40 nm, ∼50 nm and ∼80 nm respectively. The role of the solvent in controlling the shape of the particles was investigated. The sensitivity of the particles to LPG, Ethanol, Methane and Carbon Monoxide gas was investigated at different operating temperatures (100 °C-250 °C). The nanorods exhibit significantly high response towards liquid petroleum gas (LPG) in comparison to other gases. The maximum sensitivity of the nanorods for 200 ppm concentration of LPG was 0.687 at 200 °C. Nanorods also showed a remarkable response and recovery time of 114 s and 18 s. All the samples were also found to be reversible type sensors which makes them all the more suitable for applications. Hence these nanorods of Nickel Ferrite are expected to be useful in industrial applications as a potential LPG sensor. Porosity and specific surface area of the samples were studied to relate the change in sensitivity from sample to sample with the change in morphology. All the samples were found to be highly selective towards LPG. The sensing mechanism was also discussed in details.