Abstract:
measuring the zone of inhibition, i.e., 5.5±0.3 against S. aureus and 5.8±0.1 for E. coli, the
highest zone of inhibition than lignin, ZnO, and Cr@ZnO. Among all the synthesized
composites, L@CrZnO showed the best antibacterial activity. Additionally, a potential
mechanism for the MB and bactericidal breakdown using L@CrZnO NPs has been
proposed. Furthermore, tests were conducted on the effectiveness of degradation of
methylene blue (MB) concerning changes in several experimental parameters, such as dose
of L@CrZnO nanoparticles (0.005–0.025 g/mL), reaction time (30–75 min) and
temperature (25-40 oC). Using the Box-Behnken design expert, the aforementioned factors
were enhanced and their impact on the degrading process efficiency was assessed.
Moreover, the application of RSM to enhance photocatalytic removal of MB from the
wastewater through the utilization of L@CrZnO as nano-catalyst is examined. Initially, the
RSM method will be discussed along with the second-order design experiments that are
more commonly used with it. After that, a description of the nano-photocatalyst's removal
mechanisms will be followed. Lastly, a representation of the use of RSM experimental
designs in modeling and photocatalytic removal optimization procedures will be given.
The ANOVA results showed a significant regression between experimental and predicted
values of MB degradation, validating the developed quadratic model, with a 94%
confidence level. Thus, L@CrZnO nanoparticles possess great practical usefulness and
work well as effective photocatalyst for MB removal. The significant increase in
antibacterial and photocatalytic activity of produced L@CrZnO NPs may be related to a
reduction in their energy bandgap and the inhibition of electron-hole (e-h) pair
recombination brought on by the introduction of extra energy levels that are below ZnO
and Cr@ZnO NP's conduction band. Good photocatalytic persistence was demonstrated
by the L@CrZnO NPs even after five consecutive cycles.
