New TiO2/WO3 films were produced by the layer-by-layer (LbL) technique and successfully applied as self-cleaning photocatalytic surfaces. The films were deposited on fluorine doped tin oxide (FTO) glass substrates from the respective metal oxide nanoparticles obtained by the sol-gel method. Thirty alternative immersions in pH = 2 TiO2 and pH = 10 WO3 sols resulted in ca. 400 nm thick films that exhibited a W(VI)/Ti(IV) molar ratio of 0.5, as determined by X-ray photoelectron spectroscopy. Scanning electron microscopy, along with atomic force images, showed that the resulting layers are constituted by aggregates of very small nanoparticles (<20 nm) and exhibited nanoporous and homogeneous morphology. The electronic and optical properties of the films were investigated by UV-vis spectrophotometry and ultraviolet photoelectron spectroscopy. The films behave as nanoscale heterojunctions, and the presence of WO3 nanoparticles caused a decrease in the optical band gap of the bilayers compared to that of pure LbL TiO2 films. The TiO2/WO3 thin films exhibited high hydrophilicity, which is enhanced after exposition to UV light, and they can efficiently oxidize gaseous acetaldehyde under UV(A) irradiation. Photonic efficiencies of ξ = 1.5% were determined for films constituted by 30 TiO2/WO3 bilayers in the presence of 1 ppm of acetaldehyde, which are ∼2 times higher than those observed for pure LbL TiO2 films. Therefore, these films can act as efficient and cost-effective layers for self-cleaning, antifogging applications.

All-inorganic layer-by-layer TiO2–Nb2O5 films were applied as underlayers in DSCs, leading to an expressive improvement on the conversion efficiency.

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A B S T R A C TRegular sized nanostructures of indium oxide (In 2 O 3 ) were homogeneously grown using a facile route, i.e. a microwave-hydrothermal method combined with rapid thermal treatment in a microwave oven. The presence of Er 3+ doping plays an important role in controlling the formation of cubic (bcc) and rhombohedral (rh) In 2 O 3 phases. The samples presented broad photoluminescent emission bands in the green-orange region, which were attributed to the recombination of electrons at oxygen vacancies. The photocatalytic activities of pure bcc-In 2 O 3 and a bcc-rh-In 2 O 3 mixture towards the UVA degradation of methylene blue (MB) were also evaluated. The results showed that Er +3 doped In 2 O 3 exhibited the highest photocatalytic activity with a photonic efficiency three times higher than the pure oxide. The improved performance was attributed to the higher surface area, the greater concentration of electron traps due the presence of the dopant and the possible formation of heterojunctions between the cubic and rhombohedral phases.

The factors that control the photocatalytic activity of TiO2/WO3 systems are unraveled.

Gd 3+-doped ZnO nanoparticles with different Gd 3+ concentrations were synthesized by an eco-friendly microwave hydrothermal method. X-ray diffraction measurements confirm that the prepared nanoplates exhibit hexagonal wurtzite structure. Gd 3+ doping induces lattice expansion of ZnO due to the larger ionic radius of rare earth Gd 3+ in relation to Zn 2+ ions. Rietveld refinement, Raman and Photoluminescence (PL) spectra confirm that Gd 3+ ions were successfully inserted into ZnO lattice. The 2.0 mol% Gd 3+ doped sample exhibits an increased photoluminescence intensity in comparison to that for the undoped ZnO, which is attributed to the enhance in the defect concentration due to Gd 3+ doping. The photocatalytic activities of the samples were also evaluated towards UV-A induced degradation of methylene blue in aqueous solution. The highest photocatalytic activity was observed for 1.0 mol% Gd 3+-doped ZnO nanoparticles (73% for methylene blue degradation within 150 min under UV-Vis irradiation). The particles size, agglomeration degree and the electronic effects due to the Gd 3+ dopping seems to be the main parameters that affect the photocatalytic activity of Gd 3+-doped ZnO nanoparticles.

Background and objective: Studies have shown that the rate of propofol infusion may influence the predicted propofol concentration at the effect site (Es). The aim of this study was to evaluate the Es predicted by the Marsh pharmacokinetic model (ke0 0.26 min −1 ) in loss of consciousness during fast or slow induction. Method: The study included 28 patients randomly divided into two equal groups. In slow induction group (S), target-controlled infusion (TCI) of propofol with plasma, Marsh pharmacokinetic model (ke0 0.26 min −1 ) with target concentration (Tc) at 2.0-g mL −1 were administered. When the predicted propofol concentration at the effect site (Es) reached half of Es value, Es was increased to previous Es + 1 g mL −1 , successively, until loss of consciousness. In rapid induction group (R), patients were induced with TCI of propofol with plasma (6.0 g mL −1 ) at effect site, and waited until loss of consciousness.Results: In rapid induction group, Tc for loss of consciousness was significantly lower compared to slow induction group (1.67 ± 0.76 and 2.50 ± 0.56 g mL −1 , respectively, p = 0.004). Conclusion: The predicted propofol concentration at the effect site for loss of consciousness is different for rapid induction and slow induction, even with the same pharmacokinetic model of propofol and the same balance constant between plasma and effect site.Estudo comparativo entre indução rápida e lenta de propofol em infusão alvo-controlada: concentração de propofol prevista no local de ação. Ensaio clínico aleatório Resumo Justificativa e objetivo: Estudos mostraram que a taxa de infusão de propofol pode influenciar na concentração prevista de propofol no local de ação (Ce). O objetivo deste estudo foi avaliar a Ce prevista pelo modelo farmacocinético de Marsh (ke0 0,26 min −1 ) na perda da consciência durante indução rápida ou lenta. Método: Participaram deste estudo 28 pacientes, divididos aleatoriamente em dois grupos iguais. No grupo indução lenta (L), foram induzidos com propofol em infusão alvo-controlada (IAC) plasmática, modelo farmacocinético de Marsh (ke0 0,26 min −1 ), com concentração alvo (Ca) em 2,0 g.ml −1 . Quando a concentração de propofol prevista no local de ação (Ce) atingia metade do valor da Ca, aumentava-se a Ca para Ca anterior + 1 g.ml −1 . Assim sucessivamente até o momento da perda da consciência do paciente. No grupo indução rápida (R), os pacientes foram induzidos com propofol em IAC plasmática com Ca em 6,0 g.ml −1 e aguardava-se a perda da consciência do paciente. Resultados: No grupo indução rápida, a Ce na perda da consciência foi significativamente mais baixa em relação ao grupo de indução lenta (1,67 ± 0,76 e 2,50 ± 0,56 g.ml −1 , respectivamente, p = 0,004). Conclusão: A concentração prevista de propofol no local de ação durante a perda da consciência é diferente numa indução rápida e numa indução lenta, até com o mesmo modelo farmacocinético de propofol e a mesma constante de equilíbrio entre o plasma e o local de ação.

All inorganic layer-by-layer (LbL) thin films composed by TiO2 nanoparticles and [Al(OH)4]− anions (TiO 2 /AlO x ) as well as Al2O3 and Nb2O5 nanoparticles (Al 2 O 3 /Nb 2 O 5 ) have been deposited to fluorine-doped tin-oxide coated glass (FTO) surfaces and applied as blocking layers in dye-sensitized solar cells (DSCs). Structural and morphological characterization of the LbL films by different techniques reveal that in TiO 2 /AlO x assembly, aluminate anions undergo condensation reactions on the TiO2 surface leading to the formation of highly homogeneous films with unique optical properties. After 25 depositions transmittance losses below 10% in relation to the bare FTO substrate are observed. Electrochemical impedance spectroscopy shows that TiO 2 /AlO x layers impose an effective barrier for the charge recombination at FTO/electrolyte interface with an electron exchange time constant 50-fold higher than that for bare FTO. As a result, an improvement of 85% in the overall conversion efficiency of DSCs was observed with the employment of TiO2/AlOx blocking layers. Al 2 O 3 /Nb 2 O 5 LbL films can also work as blocking layers in DSCs but not as efficient, which is associated with the poor homogeneity of the film and its capacitive behavior. The production of cost-effective blocking layers with a low light scattering in the visible region is an important feature toward the application of DSC in other Building-integrated photovoltaic applications.