Synthesis of nanorods and mixed shaped copper ferrite and their applications as liquefied petroleum gas sensor

Present paper reports the preparation and characterization of nanorods and mixed shaped (nanospheres/nanocubes) copper ferrite for liquefied petroleum gas (LPG) sensing at room temperature. The structural, surface morphological, optical, electrical as well as LPG sensing properties of the copper ferrite were investigated. Single phase spinel structure of the CuFe2O4 was confirmed by XRD data. The minimum crystallite size of copper ferrite was found 25 nm. The stoichiometry was confirmed by elemental analysis and it revealed the presence of oxygen, iron and copper elements with 21.91, 12.39 and 65.70 atomic weight percentages in copper ferrite nanorods. The band gap of copper ferrite was 3.09 and 2.81 eV, respectively for nanospheres/nanocubes and nanorods. The sensing films were made by using screen printing technology and investigated with the exposure of LPG. Our results show that the mixed shaped CuFe2O4 had an improved sensing performance over that of the CuFe2O4 nanorods, of which a possible sensing mechanism related to a surface reaction process was discussed. Sensor based on mixed shaped copper ferrite is 92% reproducible after one month. The role of PEG in the synthesis for obtaining nanospheres/nanocubes has also been demonstrated.