Synthesis and characterization of NiO nanoparticles prepared via plasma jet method

Nanomaterials have attracted significant attention due to their broad range of applications, particularly in electronics, catalysis, energy storage, and environmental remediation. The synthesis method plays a crucial role in determining the structural, morphological, and optical properties of these materials. In this work, nickel oxide (NiO) nanoparticles were synthesized using a plasma jet method, which offers advantages in terms of simplicity, environmental friendliness, and scalability. The purity of the synthesized NiO nanoparticles was confirmed through X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analysis. XRD analysis revealed characteristic peaks at 2θ = 37.2°, 43.3°, 62.9°, and 75.4°, which correspond to the (111), (200), (220), and (311) planes, respectively—a fingerprint of the cubic face-centered crystal structure of NiO. The average crystallite size calculated from the XRD data using the Scherrer equation was approximately 14.02 nm. Atomic force microscopy (AFM) provided surface topology data, from which the average particle size was estimated to be 72.65 nm, indicating some degree of agglomeration or grain stacking. Additionally, field emission scanning electron microscopy (FESEM) images confirmed the spherical morphology and good dispersion of the nanoparticles, with particle sizes ranging from 19.33 to 38.21 nm. Optical properties were investigated via UV-Vis spectroscopy, and the optical band gap energy (Eg) was calculated using a Tauc plot. The estimated band gap for the NiO nanoparticles was 4.05 eV, highlighting their potential for use in optoelectronic and photocatalytic applications.