Fabrication of selective gas sensors using Fe3O4 nanoparticles decorated with CuO

Abstract

Metal-oxide nanoparticles are regarded as favorable candidates for different device applications including gas sensors. Decoration of nanoparticles with smaller ones of different types enables taking advantage of the physical and chemical characteristics of both core and decorate nanoparticles. Fe3O4 nanoparticles decorated with CuO are produced in this work by a coprecipitation method and investigated for their application for H2S gas sensor devices. The average size of Fe3O4 nanoparticles is 33.33∓5.55nm while the average grain size of the CuO nanoparticles is 9.72∓1.39nm. Gas sensors are fabricated by depositing dispersed nanoparticles on substrates with pre-printed interdigitated electrodes. Impedance spectroscopy is utilized to investigate the electrical characteristics of fabricated devices, where their activation energy is evaluated to 0.386±0.076eV. The fabricated sensors are found to be selective to H2S and sensitive to low concentrations, as low as 1.0 ppm, with minimum response time of 1.0 min. The produced sensors indicate potential for field applications due to their various features that include simplified and practical fabrication procedure, low power needs, high sensitivity, reasonable response time, and magnetic properties of nanoparticles that facilitate their recycling.