Highly sensitive acetone gas sensor based on porous ZnFe2O4 nanospheres

Porous ZnFe2O4 spherical structures built from nanoparticles were successfully synthesized by annealing the precursor, which was synthesized via a simple template-free solvothermal route with ethanol/ethylene glycol (EG) binary solvents. Various techniques were employed for the characterization of the structure and morphology of as-obtained products. The results revealed that the samples were composed of large amounts of porous ZnFe2O4 nanospheres with an average diameter around 230 nm, which were constructed by plenty of nano-sized primary particles. Moreover, gas sensor based on the as-prepared samples was fabricated and its sensing performances were investigated. It was revealed that the as-fabricated sensor device exhibited excellent selectivity toward acetone at the operating temperature 200 °C and had a response of about 12–30 ppm acetone, which was about 2.5 times higher than that of sensor based on ZnFe2O4 nanoparticles. The enhancement in gas sensing properties of porous ZnFe2O4 nanospheres was attributed to their unique structures.