Cytotoxicity, Antioxidant, Antibacterial, and Photocatalytic Activities of ZnO–CdS Powders

Abstract

In this work, ZnO–CdS composite powders synthesized by a simple chemical precipitation method were thoroughly characterized. The morphological, structural, compositional, photocatalytical, and biological properties of the prepared composites were investigated in comparison with those of the pristine components and correlated with the CdS concentration. ZnO–CdS composites contain flower-like structures, their size being tuned by the CdS amount added during the chemical synthesis. The photocatalytic activity of the composites was analyzed under UV irradiation using powders impregnated with methylene blue; the tests confirming that the presence of CdS along the ZnO in composites can improve the dye discoloration. The biological properties such as antioxidant capacity, antibacterial activity, and cytotoxicity of the ZnO, CdS, and ZnO–CdS composites were evaluated. Thus, the obtained composites presented medium antioxidant effect, biocidal activity against Escherichia coli, and no toxicity (at concentrations less than 0.05 mg/mL for composites with a low CdS amount) for human fibroblast cells. Based on these results, such composites can be used as photocatalytic and/or biocidal additives for photoactive coatings, paints, or epoxy floors, which in their turn can provide a cleaner and healthier environment.

Burdock-Derived Composites Based on Biogenic Gold, Silver Chloride and Zinc Oxide Particles as Green Multifunctional Platforms for Biomedical Applications and Environmental Protection

“…ZnO-containing particles presented an absorption peak located at the wavelengths: 372, 369, and 371 nm for the samples of ZnO, AuZnO, and AgClZnO, respectively. This peak is characteristic for ZnO nanoparticles as mentioned by various reports [ 25 , 41 , 42 , 43 , 44 ], highlighting that ZnO generally shows UV absorption bands at the λmax ranging from 355 to 380 nm. The bottom inset of Figure 1 displays the spectral signature of ZnO in the spectra of the ZnO-based particles.…”

“…The holes from the surface of AgClNPs can lead to the oxidation of Cl − ions to Cl 0 atoms. Furthermore, the holes react with the water molecules and create the ● OH radical and the electrons from the conduction band react with the absorbed O 2 and create the O 2 −● radical which are the active species used in the degradation of dyes [ 43 , 58 ]. Superoxide radical anions, ● OH radicals and Cl 0 atoms are strong oxidants for the degradation of RhB [ 59 , 60 ].…”

Prokaryotic and eukaryotic toxicity of halloysite decorated with photoactive nanoparticles

“…Cadmium sulfide remains one of the most efficient photocatalysts operating under the action of visible light and capable of generating superoxide O À 2 À Á and hydroxyl radicals ( OH). 72 Cadmium sulfide, a visible-light active photocatalyst with a band gap of 2.4 eV, is one of the most prominent semiconductor photocatalysts among the various sulfides. It has a good carrier transportation capacity, which can make photogenerated electrons and holes mobility timely and efficient, extending the life of the photogenerated carrier and leading to high photocatalytic activity.…”

“…Cadmium sulfide remains one of the most efficient photocatalysts operating under the action of visible light and capable of generating superoxide and hydroxyl radicals (˙OH). 72…”

Improved Bacteriostatic and Anticorrosion Effects of Polycaprolactone/Chitosan Coated Magnesium via Incorporation of Zinc Oxide

“…The outstanding antimicrobial activity of the PCL/CS/ZnO composite coating was due to the synergistic antimicrobial properties of CS and ZnO NPs. This result in the production of reactive oxygen species (ROS) like H 2 O 2 , where CS electrostatically binds to the bacterial cell wall while ZnO NPs interact with protein membrane, resulting in the intracellular released material and perforated cell membrane [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50].…”