Boosting the photocatalytic activity of ZnO-NPs through the incorporation of C-dot and preparation of nanocomposite materials.

Due to their applications in cosmetology, medicine, antibacterial and other fields, zinc oxide nanoparticles (ZnO-NPs) are among the nanoscale materials experiencing exponential growth. In contrast, pure ZnO-NPs have been reported to have a very large energy bandgap, a large exaction binding energy, electron-hole recombination, no visible light absorption, and poor photocatalytic activities, which limit their potential uses. ZnO-NPs can be further extended through the incorporation of trace amounts of carbon materials to engulf these problems. We investigate the photocatalytic degradation of methylene blue (MB) dye with pure ZnO-NPs infused with a limited amount of carbon dot (C-dot) materials. Consequently, adding 10% C-dot to ZnO-NPs reduced their energy bandgap from 3.1 to 2.8 eV and significantly increased their photocatalytic activity. MB was almost completely degraded (98.4%) after 60 min when 50 mg of C-dot-incorporated ZnO-NPs were added. By comparison, the nanocomposite's photocatalytic activity exceeded that of pure ZnO-NPs by more than 50%. A surface charge and stability improvement are responsible for the extraordinary photocatalytic improvement. As far as we know, this is the best-ever photocatalytic improvement achieved by incorporating a trace amount of C-dot material into pure ZnO-NPs.

Synthesis of Nickel Oxide Nanoparticles and Copper-Doped Nickel Oxide Nanocomposites Using Phytolacca dodecandra L'Herit Leaf Extract and Evaluation of Its Antioxidant and Photocatalytic Activities.

Nanotechnology research is emerging as cutting-edge technology, and nanoparticles (NPs) and nanocomposites (NCs) have played a significant role in the bioremediation and treatment of polluted water by organic and nonorganic materials. Nanoparticles produced by plant extracts are more stable and biocompatible in comparison with those produced by physical and chemical methods. This research focuses on the synthesis of NiO NPs and Cu-NiO NCs using Phytolacca dodecandra L'Herit (P.d) leaf extract and evaluation of their antioxidant and photocatalytic activities. Cu-NiO NCs were synthesized using 50 mL of 0.1 M nickel(II) nitrate hexahydrate, 10 mL of 0.1 M copper(II) nitrate trihydrate, and 20 mL of leaf extract. The synthesized nanoparticles were characterized by UV-vis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analyses to study the energy band gap, average crystallite size, functional groups, and morphology of the samples, respectively. The UV-vis analysis showed a red shift after copper doping, indicating a decrease in the optical band gap values. FT-IR characterization confirms the presence of various functional groups in samples. Crystallite sizes of the formed particles were obtained to be 14.18 and 16.10 nm from the XRD data for NiO NPs and Cu-NiO NCs, respectively. SEM showed the crystallinity of particles with a cubic structure. The photocatalytic degradation of methylene blue (MB) was found to be 78.3 and 97.8% by NiO NPs and Cu-NiO NCs, respectively. In the antioxidant test, NiO NPs and Cu-NiO NCs prevented the oxidation of 50% of the H2O2 molecules at a concentration of 363.96 and 350.29 µg/mL, respectively. Finally, the synthesized samples showed good photocatalytic and antioxidant activities.