Metal oxide nanoparticles
(MO-NPs) are presently an area of intense
scientific research, attributable to their wide variety of potential
applications in biomedical, optical, and electronic fields. MO-NPs
such as zinc oxide nanoparticles (ZnO-NPs) and others have a very
high surface-area-to-volume ratio and are excellent catalysts. MO-NPs
could also cause unexpected effects in living cells because their
sizes are similar to important biological molecules, or parts of them,
or because they could pass through barriers that block the passage
of larger particles. However, undoped MO-NPs like ZnO-NPs are chemically
pure, have a higher optical bandgap energy, exhibit electron–hole
recombination, lack visible light absorption, and have poor antibacterial
activities. To overcome these drawbacks and further outspread the
use of ZnO-NPs in nanomedicine, doping seems to represent a promising
solution. In this paper, the effects of temperature and sulfur doping
concentration on the bandgap energy of ZnO nanoparticles are investigated.
Characterizations of the synthesized ZnO-NPs using zinc acetate dihydrate
as a precursor by a sol–gel method were done by using X-ray
diffraction, ultraviolet–visible spectroscopy, and Fourier
transform infrared spectroscopy. A comparative study was carried out
to investigate the antibacterial activity of ZnO nanoparticles prepared
at different temperatures and different concentrations of sulfur-doped
ZnO nanoparticles against
Staphylococcus aureus
bacteria.
Experimental results showed that the bandgap energy decreased from
3.34 to 3.27 eV and from 3.06 to 2.98 eV with increasing temperature
and doping concentration. The antibacterial activity of doped ZnO
nanoparticles was also tested and was found to be much better than
that of bare ZnO nanoparticles.
The preparation of flexible electrode, including working electrode (WE) and counter electrode (CE), for dye-sensitized solar cells (DSSCs) utilizing metal oxides using environmentally friendly sustainable TEMPO-oxidized cellulose nanofibers (TOCNFs) is reported in this work. A new type of flexible electrode for the DSSCs, which were made of cellulose nanofiber composites with nickel hydroxide [CNF/Ni(OH) 2 ] substrate films and cellulose nanofiber composites with polypyrrole (CNF/PPY). Nickel hydroxide, Ni(OH) 2 , has been prepared hydrothermally in the presence of TOCNFs, [TOCNF@Ni(OH) 2 ]. Similarly, the conductive polymer substrate has also been prepared from a composite consisting of TOCNF and PPY, TOCNF@ PPY film, by means of polymerization for the CE. Overall, the prepared electrodes both WE from CNF/Ni(OH) 2 substrates and CE from the TOCNF@PPY substrate film were revealed as the novelty of this work and which no one has introduced previously. Although NiO nanoparticles (NPs) coated on the Ni(OH) 2 /TOCNF electrode also produced a good power conversion efficiency, PCE (0.75%); nevertheless, the NiO NP treatment with carbon dots boosted the efficiency up to 1.3%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.