Biosynthesis of La/NiO Nanoparticles: Study of Photocatalytic Degradation of Anionic and Cationic Dye, and Their Antibacterial Activity

Semiconductor photocatalytic degradation of industrial dyes and bacterial growth inhibition using nanosemiconductor materials are beneficial for contaminants removal and biomedical applications. Metal oxide semiconductor nanoparticle production has attracted a lot of interest in recent years since the materials are inexpensive, easy to make, and environmentally benign. The overall objective of this study is to create novel La/NiO nanoparticles. The nanoparticle's phase structure, bandgap, electron–hole recombination rate, vibrational modes, morphology, elemental investigation, stability, oxidation state, pore size distribution, and electron distribution were studied using XRD, TGA, DTA, DRS UV–Vis spectroscopy, Tauc's plot, FTIR, Raman, SEM, EDAX, elemental mapping, TEM, zeta potential, XPS, and BET analyses. The XRD analysis showed high crystallinity for NiO and reduced crystal size for La/NiO. The results of the zeta potential demonstrated the remarkable stability of the La/NiO. TEM results exhibited a morphology that resembled spheres. Using XPS analysis, the oxidation state and nature of environment of the elements were identified. The BET surface area of La/NiO were equal to 22.5 m2/g. The photocatalytic degradation of congo red (anionic), and emerald green dye (cationic) was investigated over La/NiO. The results showed 94% degradation of congo red and emerald green dyes under UV light (365 nm) within 180 min. The degradation followed pseudo-first-order kinetics. The antibacterial activity of La/ NiO nanoparticles on various bacterial strains was examined using the agar well diffusion technique. The results revealed higher antibacterial activity for Pseudomonas putida (zone of inhibition equal to 30 mm in diameter) than others. So, the La/NiO degrading approach was demonstrated to be an outstanding and low-cost degrading technique in unaffected textile dye effluent and has effective antibacterial activity for other bacterial strains.