The structural phase change of copper ferrite and its gas-sensing properties

Abstract

The article presents the synthesis, characterization, and gas-sensing studies of $${{\mathrm{Cu}}_{1-x}{M}_{\text{x}}\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$$ , where M = Ni, Zn, and x = 0, 0.35. The study aims to obtain a stable and sensitive material suitable for gas sensing by the thermal decomposition method. X-ray diffraction analysis revealed the structural phase transition of copper ferrite due to doping. The systems cation distribution was evaluated by the x-ray diffraction method and verified using the XPS technique. In addition, microscopic studies confirmed the reduction in particle size in doped samples. BET analysis validates nanoparticles of large specific surface area and pore size in nickel/zinc doped copper ferrites. Chemi-resistive sensors were fabricated and tested using carbon monoxide and methane gases. The gas sensing results towards carbon monoxide and methane demonstrated the promising effect of nickel or zinc in copper ferrite. The nickel doped sensor achieved a response enhancement of $$\sim 90 \%$$ and $$\sim 47\%,$$ respectively, against $$\sim 40\%$$ and $$\sim 24\%$$ recorded by pure copper ferrite sample on exposure to carbon monoxide gas and methane gases. The copper ferrite response against carbon monoxide enhances from $$\sim 40$$ to $$\sim 74\%$$ due to zinc doping. Compared to pure copper ferrite, the nickel doped sensor shows fast response and recovery time.