Fast One-Step Synthesis of Biocompatible ZnO/Au Nanocomposites with Hollow Doughnut-Like and Other Controlled Morphologies

Abstract

Hollow doughnut-like ZnO/Au nanocomposites have been synthesized through a fast one-step microwaveassisted hydrothermal route. The formation mechanism of the product is closely connected with the coordination and selective adsorption effect of trisodium citrate (TSC). Other different structures, such as ZnO nanorods/Au nanoparticles, ZnO nanodisks/Au nanoparticles, and ZnO nanospheres/Au nanoparticles have also been obtained in control experiments. The UV−vis and photoluminescence properties of the asprepared hollow structures with different Au concentrations showed tunable UV and visible emission intensity. The hollow ZnO/Au nanocomposites are photostable with a strong resonance Raman signal. The colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays showed that ZnO/Au nanomaterials have low biological cytotoxicity on human colon cancer cells (LOVO cells) at the concentration of 50 μg/mL. The as-prepared ZnO/Au nanocomposites with good biocompatibility may have potential applications in biomedicine and biosensors.

Viability of Au/CeO2–ZnO/Al2O3 Catalysts for Pure Hydrogen Production by the Water–Gas Shift Reaction

“…First, related to the doping agent, ZnO, which was not possible to detect by XRD analysis, appeared in the UV/Vis experiment. ZnO is a wideband‐gap semiconductor ( E g =3.37 eV) with a large excitation binding energy (60 meV) 15. The absorption peaked at 340 nm in the Zn/Al sample could be attributed to a well‐defined excitation band of ZnO in agreement with the absorption band observed for ZnO nanorods in Ref.…”

Hydrothermal Synthesis of (001) Facet Highly Exposed ZnO Plates: A New Insight into the Effect of Citrate

“…It can be concluded that the plates are highly (001) facet exposed, which is consistent with its highest intensity of (001) peak among three samples in Figure 1. As reported previously [24][25][26], the selective combination of citrate with (001) facet of ZnO resulted in the final (001) exposed structures, which was supported by the complexation between carboxyl and zinc atoms. In this experiment, ZnO-NC showed rod-like shape while ZnO-OS were plate-like (Figure 2a,c), confirming that citrates are effective for ZnO shape controlling.…”

Fabrication of lotus-like Au@TiO2 nanocomposites with enhanced gas-sensing properties

“…A previous study demonstrated that the crystallinity of Au seeds controlled the nucleation process [33,34]. Similarly, it is reasonable that the morphology of Au@TiO2 was controlled by the contents of Au in this study.…”