Effect Of TiCl Research Articles

Effect of TiCl4‐based TiO2 compact and blocking layers on efficiency of dye‐sensitized solar cells

The effect of the number and arrangement of TiO2‐based photoanode layers on the efficiency of dye‐sensitized solar cells (DSSCs) was investigated. Compact, mesoporous, and blocking layers of TiO2 were prepared to form monolayer, bilayer, and trilayer photoanodes. Compact and blocking TiO2 layers were prepared using dip‐coating technique, whereas the doctor‐blade method was employed to prepare TiO2 paste layers using nanoparticles prepared by the sol–gel method. The crystalline structure of photoanodes was characterized by X‐ray diffraction (XRD) measurements and their morphology and thickness were characterized by the scanning electron microscopy (SEM) technique. The photovoltaic performance of constructed DSSC devices was investigated and the optimum arrangement was identified and explained in terms of dye loading enhancement and recombination reduction at the fluorine‐doped tin oxide (FTO)/electrolyte interface.

Mechano-chemical Synthesis of NaAlH4: Optimization of Reaction Conditions

NaAlH 4 was mechano-chemically synthesized with high energy ball-milling method. The effect of synthesis conditions such as milling time, H 2 pressure, chloride catalysts, and solvents was investigated to enhance the synthesis of NaAlH 4 . Among the chloride catalysts, TiCl 4 showed the highest H 2 pressure decrease which means the highest NaH conversion to NaAlH 4 . Furthermore, when the NaAlH 4 was synthesized with THF solvent, it exhibited the higher H 2 pressure decrease than that of sample prepared without THF solvent. This is mainly due to the synergy effect of TiCl 4 catalyst and THF solvent.

Effects of TiCl<SUB>4</SUB> Post-Treatment on the Efficiency of Dye-Sensitized Solar Cells

The effects of compact TiO2 overlayers, deposited on TiO2 photoelectrodes through the hydrolysis of TiCl4, on the overall performance of dye-sensitized solar cells (DSSCs) were investigated. A thermal treatment at high-enough temperature was required for a more effective and higher dye-loading of the compact TiO2 overlayers. This led to improvements in the crystallinity and porosity of the layer, which contributed to higher power conversion efficiencies (PCE) of DSSCs compared with the electrodes prepared at relatively lower temperatures. Moreover, the existence of an additional secondary overlayer led to an increase in the net PCE of the cells by increasing the amount of dye-loading, even though this layer itself, in the absence of a first overlayer formed under high thermal treatment, did not enhance cell efficiency, because of the higher charge transport resistance over the layers and an increase in surface states.

The Effect of TiCl<sub>4</sub> and Chitosan Concentration on the Coating of TiO<sub>2</sub> on Iron Foam Substrate by Self-Assembled Monolayer Method

Iron foam is a type of material having potential to be used as water or air filter andimplant material. One of the limitations of this material is its high reactivity on corrosion. In thepresent research TiO2 coating on iron foam substrate has been developed by self-assembledmonolayer method. Focus is given on the effect of TiCl4 and chitosan concentration on thecharacteristic of the developed TiO2 layer. Precursor was prepared with HCl concentration of 0.5; 1;1.5 M and chitosan solution concentration of 1% ; 2% ; 4% (w/v). Scanning Electron Microscopy(SEM) and Energy Dispersive Spectroscopy (EDS) characterizations show that TiO2 particles areformed on the iron foam surfaces. It was observed that with the higher TiCl4 concentration moreTiO2 particles obtained on substrate surfaces. On the other hand, SEM results also show the averageTiO2 particles size at around 1 micrometer and in tetragonal shape. It was observed that with thehigher chitosan concentration, the particles shape tend to have tetragonal stucture, while at lowerchitosan concentration (1%), agglomeration of TiO2 particles were observed.

Effects of TiCl4 Treatment of Nanoporous TiO2 Films on Morphology, Light Harvesting, and Charge-Carrier Dynamics in Dye-Sensitized Solar Cells

We report on the effects of treating TiO2 nanocrystalline films with different concentrations of TiCl4 (5–500 mM) on the film morphology, charge-carrier dynamics, and performance of dye-sensitized solar cells. Transport and recombination in the TiCl4-treated films were studied by frequency-resolved modulated photocurrent/photovoltage spectroscopies. These studies showed that, at a low TiCl4 concentration (5 mM), the electron diffusion coefficient in the annealed film increased. At intermediate TiCl4 concentrations (15–50 mM), the surface area of the films increased, resulting in an increase of light harvesting and overall power conversion efficiency. At a high TiCl4 concentration (500 mM), light scattering in the film in the long wavelength region of the visible spectrum was enhanced, but the averaged pore size of the film became narrower, resulting in slower transport and loss of cell performance.

Effect of TiCl4 Concentration and Acidity on Size and Phase of TiO2 Nanopowders Prepared by Non-Hydrolytic Sol-Gel Method

TiO2nanopowders were synthesized by non-hydrolytic sol−gel method. Effects of TiCl4concentration and acidity on the properties of TiO2nanopowders were investigated. The results showed that the average grain size of TiO2decreased with the increasing of TiCl4concentration. H+can inhibit the growth of TiO2particles and Cl-is conducive to the formation of rutile phase. When 2.06M HCl was used as the reaction solution, TiO2microspheres with diameter 2μm was obtained, and TiO2microspheres was composed of anatase and rutile phase.

Ti-Doped LiAlH4 for Hydrogen Storage: Synthesis, Catalyst Loading and Cycling Performance

The direct synthesis of LiAlH(4) from commercially available LiH and Al powders in the presence of TiCl(3) and Me(2)O has been achieved for the first time. The effects of TiCl(3) loadings (Ti/Al = 0, 0.01, 0.05, 0.2, 0.5, 1.0 and 2.0%) and various other additives (TiCl(3)/Al(2)O(3), metallic Ti, Nb(2)O(5), and NbCl(5)) on the formation and stability of LiAlH(4) have been systematically investigated. The yield of LiAlH(4) initially increases, and then decreases, with increasing TiCl(3) loadings. LiH + Al → LiAlH(4) yields above 95% were obtained when the molar ratios of Ti/Al were 0.05 and 0.2%. In the presence of a very tiny amount of TiCl(3) (Ti/Al = 0.01%), LiAlH(4) is still generated, but the yield is lower. In the complete absence of TiCl(3), LiAlH(4) does not form. Addition of metallic Ti, Nb(2)O(5), and NbCl(5) to commercial LiH and Al does not result in the formation of LiAlH(4). Preliminary tests show that TiCl(3)-doped LiAlH(4) can be cycled, making it a suitable candidate for hydrogen storage.

Effect of TiCl 4 treatment on the photoelectrochemical properties of LaTiO 2N electrodes for water splitting under visible light

A lanthanum titanium oxynitride (LaTiO 2N) electrode was studied as a visible-light driven photoelectrode for water splitting. The electrode was prepared by casting a LaTiO 2N powder on a fluorine-doped tin oxide glass substrate, followed by calcination under dinitrogen. The as-prepared electrode exhibited an anodic photocurrent based on water oxidation under visible-light irradiation ( λ > 420 nm) in an electrolyte (Na 2SO 4) solution. This current was increased by post-treatment with titanium(IV) chloride (TiCl 4) solution. Scanning electron microscopy and X-ray photoelectron spectroscopy revealed that the titanium species introduced by the post-treatment were titanium oxide, and that they were embedded within LaTiO 2N particles. Resistance measurements of LaTiO 2N electrodes suggested that the increase in the electrode photocurrent after TiCl 4 treatment was due to the improvement of inter-particle electron transfer in the LaTiO 2N thin film.

The effect of TiCl 3 on the microstructure of donor-doped boron-added Ti-excess BaTiO 3

The effect of TiCl 3 and 0.5, 1.0, 2.0 mol% B 2O 3 addition on the microstructure and on the densification of Ti-excess BaTiO 3 were investigated. Sb 2O 3 was used as a donor dopant in boron containing compositions. The Ti-excess, platelet-type Ba 2Ti 5O 12 or Ba 4Ti 12O 27 phases were detected in undoped and Ti-excess formulations and compositions doped with 0.5 mol% B 2O 3, which were sintered below the eutectic temperature. Suppression of these platelet-type grains occurred in the formulations containing more than 0.5 mol% B 2O 3. Donor doping by Sb 2O 3 was very effective for promoting twin formation due to the increased concentration of the Ti 3+ ions. Sudden grain growth occurred at the 2 mol% B 2O 3 addition level, with the loss of twin lamellae within the structure. The addition of 0.2 mol% excess TiO 2 in liquid form (TiCl 3) to the 0.5 mol% B 2O 3 containing sample, reduced the size and the number of polygonal grains and had a marked effect on the twin formation due to the homogeneous distribution of the excess Ti ions in the composition. The effects of adding the grain boundary modifier B 2O 3 (before and after the calcination step) on the microstructure and on the positive temperature coefficient of resistivity (PTCR) of Sb 2O 3 donor-doped Ti-excess barium titanate (BT) were also investigated; PTCR effects up to 5.0 orders of magnitude were obtained.

A new class of Ti–Si–C–N coatings obtained by chemical vapor deposition — part II: low-temperature process

A new class of the Ti–Si–C–N coatings obtained by chemical vapor deposition with TiCl 4, SiCl 4, C 2H 2, H 2 and N 2 as reactants have been further examined in this study. The effects of deposition temperatures have been explored in the range of 700–1100°C. The resulting deposits have a non-stoichiometric TiC structure as a (Ti,Si)(C,N) solid solution. Large, dense, well-crystallized, and faceted crystals with a hardness value of ∼10 GPa can be obtained at deposition temperature as low as 800°C. The Si content is barely detectable in the coatings deposited at 800°C, but increases as the deposition temperatures increase from 800 to 1100°C. Coatings of a hardness value of 27.5 GPa are obtained for a coating deposited at 1100°C. Furthermore, the effects of TiCl 4 and SiCl 4 flows at a deposition temperature of 800°C have also been studied. The data for growth rate and composition can be best described by the absorption/surface coverage behavior and the relatively low reactivity of SiCl 4 at low temperatures. Finally, the effects of H 2 and N 2 at deposition temperature of 800°C have been studied. Deposits form at higher H 2 input and improve when sufficient N 2 is also added.

Competition between gas phase and surface oxidation of TiCl 4 during synthesis of TiO 2 particles

The effect of TiCl 4 surface reaction on the size of product TiO 2 particles is quantitatively investigated over a wide range of process conditions (temperature and reactant concentration) that are typically employed in industrial and research facilities. A model for titania aerosol dynamics is developed accounting for the simultaneous gas phase and particle phase (surface) oxidation rate of TiCl 4. Using this model, the implications of these two chemical pathways on the size of product titania particles are elucidated. It is shown, for the first time, that TiCl 4 oxidation on the surface of freshly formed titania particles is most important at high TiCl 4 concentrations. A design diagram is presented mapping the significance of surface and gas-phase oxidation of TiCl 4 in terms of process temperature and initial TiCl 4 mole fraction. The model predictions are compared with experimental results and conflicting interpretations of the mechanism of titania formation by TiCl 4 oxidation in the literature are reconciled. This model can be used to investigate the significance of surface growth in gas-phase synthesis of fumed silica as well as other ceramic and metallic particles.

Propene polymerization with Mg(OC2H5)2‐supported TiCl4 catalyst, 2. Effects of TiCl4 treatment

Etude de l'influence du traitement par TiCl 4 du catalyseur Mg(OEt) 2 /C 6 H 5 COCl sur son aire superficielle, son activite catalytique et son isospecificite dans la polymerisation du propene. Les resultats montrent que des traitements repetes par TiCl 4 transforment completement Mg(OEt) 2 en MgCl 2 et que le catalyseur supporte obtenu a une efficacite comparable a celle du catalyseur supporte sur MgCl 2 usuel

NMR and raman spectroscopic study of complex formation between TiCl 4 and N-methylated lactams with 11- and 13-membered rings

Complex formation between N-methylated lactams (L) with 11- and 13-membered rings which in the liquid state assume both the cis and the trans structures of the amide bond, and TiCl 4, (M) in 1,1,2,2-tetrachloroethane and CDCl 3 solutions has been studied by analysis of 1H and 13C-NMR and Raman spectra. The composition and structure of the complexes as well as the effect of TiCl 4, on the cis— trans isomerization equilibrium have been determined. As for the lower cis lactams, it was found that at molar ratios [L]:[M] > 2, the lactams with the 11- and 13-membered rings form complexes of composition ML 2. The free energies of activation for the exchange processes in these systems were estimated from the temperature dependence of 1H-NMR spectra and it was found that the barrier to rotation about the amide bond is increased by complex formation.