Designing copper–nickel hybrid nanoparticles based resistive sensor for ammonia gas sensing

Designing advanced and cost-effective materials for ammonia gas sensing is concomitantly a challenging and crucial task. Herein, copper nickel (Cu–Ni) bimetallic hybrid nanoparticles were synthesized by the co-precipitation method for the application of ammonia gas detection. The synthesized nanoparticles (NPs) were characterized by employing UV–Visible spectroscopy which confirmed the band gap of 2.35 eV. FTIR analysis confirmed the stretching oscillation for hybrid Cu–Ni at 455 cm⁻¹. XRD effectively evaluated the overall crystallinity and particle size while SEM confirmed the spherical shaped particles of the Cu–Ni BNPs. For ammonia gas sensing, the synthesized NPs were deposited onto an interdigitated electrode through electrospinning, then, connected through an LCR meter for analysis of different electrical properties. There was a direct relationship between current and voltage depicting the metallic behavior of the Cu–Ni BNPs. The Cu–Ni BNPs based sensor showed excellent performance on low frequencies of 1 kHz and there was an increase in resistance which confirmed that the sensor was a resistive type. The Cu–Ni showed a maximum response of 27s with a 24s recovery. The as-prepared sensing device can be applied for potential use in ammonia detection quantitatively and qualitatively.