Solvothermal synthesis of CZTS nano-structure based-electrospun PAN nanofibers impact on characterizations and antibacterial activity

Abstract

The study focused on the solvothermal approach to synthesize Cu₂ZnSnS₄ (CZTS) nanoparticles (NPs) with an average particle size of 50 nm. At the same time, the composite nanofibers were fabricated from PAN-CZTS using the electrospinning method. XRD analysis confirmed the formation of the kesterite CZTS phase, while the functional groups revealed the chemical properties of the as-prepared samples via FTIR analysis. The FESEM images of CZTS indicated the appearance of quasi-spherical and nanoworm shapes, also a uniform nanofiber from PAN and PAN-CZTS with average diameters, descending order from 145 to 127 nm. The EDXs showed the compositional elements for as prepared samples. The TEM image proved the inclusion of CZTS NPs within polymer matrix. The significant highest absorption of CZTS is exhibited in the Vis region at about 400 nm, while at 260 nm in the UV region for nanocomposites, which makes it suitable applications in optoelectronic. Additionally, the values of the indirect optical band gap ($E_{\mathrm{g\; indir}.}^{\mathrm{opt}})$ decreased from 3.6 to 2.6 eV using the Tauc model and confirmed by the imaginary dielectric constant ${(E}_g^{\epsilon i})$. The high real dielectric constant and low imaginary dielectric constant values displayed that the prepared films can be used in the manufacture of optical energy storage devices. Furthermore, the CZTS-encapsulated PAN nanofiber demonstrated notable antibacterial activity against four bacterial strains, with maximum inhibition zones (23 ± 1.25 mm) for Staphylococcus aureus. This makes it useful in the medical field.