Polyvinylpyrrolidone and chitosan-doped lanthanum oxide nanostructures used as anti-bacterial agents and nano-catalyst

In the current study, various compositions (1:1, 1:2, and 1:3) of polyvinylpyrrolidone (PVP) and chitosan (CS) doped in a fixed amount of La₂O₃ via co-precipitation technique was prepared to investigate their catalytic and antibacterial activities. The structural properties were confirmed using X-ray diffraction and selected area electron diffraction, which revealed the hexagonal structure and increased crystallinity with doping. The dominant functional groups were determined by Fourier transform infrared spectroscopy. The UV–Vis spectroscopy revealed bathochromic shift led to a reduction in bandgap width (4.3–3.7 eV) upon doping. The morphology of prepared samples was examined using the field emission scanning electron microscope and high-resolution transmission electron microscope display nano-flower (NFs) like topology. Furthermore, the PVP/CS-La₂O₃ NFs exhibit excellent catalytic activity in terms of their ability to degrade toxic methylene blue (MB) dye in different mediums (neutral, basic, acidic). The doped La₂O₃ samples have shown outstanding antibacterial characteristics against S. aureus with an inhibition zone of 6.25 mm and E. coli with an inhibition zone of 2.95 mm at a high dose level. This study suggests that PVP/CS-La₂O₃ nano-flower can be utilized as an excellent agent to treat bacterial infectious diseases in addition to its use as a nano-catalyst for wastewater treatment.