Visible light degradation of textile effluent using nanostructured TiO2/Ag/CuO photocatalysts

In this work the systematic study of the Au/TiO 2 and Ag/TiO 2 nanocomposites was evaluated. Aeroxide P25 preparation was taken as a titania precusor. Composites were obtained using different wet chemistry techniques: impregnation by previously prepared nanoparticles(NPs) sols, in-situ reduction by sodium borohydride, sodium citrate and UV irradiation. The varying of the synthesis method due to the reduction rate differences results in the different interaction between metal NPs and titanium dioxide, and hence different metal/TiO 2 contacts were observed. All the obtained samples were analyzed by XRD, TRS, SEM with EDX and TEM with EDX. According to the statistical analysis of the TEM images the correlation between the metal NPs rate formation and their anisotropy was shown, which may allow us to consider the anisotropy as a descriptor of the contact quality. Combining the results of the optical spectroscopy with the NPs TEM statistical analysis, we confirmed the correlation between observable anisotropy and the contact quality. Finally, the effect of the synthesis method on the photocatalytic activity (PCA) of nanocomposites was shown. Since the work functions of Au and Ag differ, the opposite effects on PCA are expected. Thus, in the case of the Au/TiO 2 nanocomposites, the positive effect associated with NPs anisotropy on the PCA was demonstrated. Alternatively, in the case of the Ag/TiO 2 nanocomposites the PCA evolution was detected only in the case of small NPs formation.

Section: Introductionmentioning

confidence: 99%

The microstructure effect on the Au/TiO2 and Ag/TiO2 nanocomposites photocatalytic activity

Козлов¹,

Лебедев²,

Polyakov³

et al. 2018

“…Conversely, titanium oxide with small defect concentration is the most promising photocatalyst. The modification of its properties by preparing composites with metal particles and semiconductors indeed leads to the growth of photocatalytic activity [38,39].…”

Section: They Can Be Attributed To D-d Transitions Of Timentioning

confidence: 99%

Optical properties and photocatalytic activity of nanocrystalline TiO2 doped by 3d-metal ions

Kolesnik¹,

Лебедев²,

Гаршев³

2018

The influence of impurities on optical and photocatalytic properties was studied in a series of nanocrystalline TiO 2 with similar coherent scattering region sizes, phase compositions, surface areas and lattice parameters doped by Fe, Cr, Mn and V ions. Doping leads to an increase of absorption in the visible part of the spectrum due to the formation of additional levels in the band gap. In the case of Fe and Cr ions, d-d transitions are observed, whereas in the case of Mn and V ions, an additional band is associated with the transition from impurity level to Ec. The presence of impurities effectively suppresses photocatalytic activity in the methyl orange decoloration reaction.

“…The modern level of nanotechnology development allows for the design of new polyfunctional materials possessing unique physicochemical properties that find wide application in the manufacturing of sensors [1,2], catalysts [3,4] hybrid functional coatings [5,6] and biomedical products [7]. At that, nanocrystalline cerium dioxide is considered to be one of the most promising materials for biomedical purposes [8][9][10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Cytotoxicity analysis of gadolinium doped cerium oxide nanoparticles on human mesenchymal stem cells

Попов¹,

Savintseva²,

Mysina³

et al. 2018

A complex analysis of cytotoxicity was performed for a nanodispersed sol of cerium dioxide doped with gadolinium (Ce 0.8 Gd 0.2 O 2−x) using a culture of mesenchymal stem cells. The absence of cyto-and genotoxicity over a wide range of concentrations (10 −5-10 −9 M) was demonstrated. At that, the highest concentration of Ce 0.8 Gd 0.2 O 2−x nanoparticles (10 −4 M) was found to slightly reduce the activity of intracellular dehydrogenase, yet not leading to the development of apoptosis and further cell death. The obtained results confirm a high degree of Ce 0.8 Gd 0.2 O 2−x nanoparticle biocompatibility, which opens prospects for their safe application as a contrasting agent in the magnetic resonance tomography.