Porous Javelin-Like NiFe2O4 Nanorods as n-Propanol Sensor with Ultrahigh-Performance

The online detection of n-propanol concentration is required for health and safety issues in industry. Herein, through a morphology-inherited annealing treatment of Ni/Fe bimetallic metal-organic framework as the template, this paper reported the synthesis of porous javelin-like NiFe2O4 nanorods. As gas sensing material, the ferrite showed n-type gas-sensing behavior as its resistance decreased in reducing gas atmospheres, and exhibited excellent n-propanol sensing performance (the sensing response is 6.4 to 5 ppm) with ultralow detection limits (0.41 ppm) and ultrahigh gas sensitivity (1.13 ppm(-1)) toward n-propanol at relatively low working temperature (120 degrees C). Meanwhile, the sensor showed good selectivity to n-propanol as well as excellent cyclic and long-term stability. The unique morphology and porous structure of NiFe2O4 nanorods may be responsible for the excellent performance, which offer more reactive sites and accelerate the diffusion of n-propanol gas. This facile method of preparing porous metal oxides could be extended to fabricate other gas sensing materials applied to detect other target gases.