Incorporation Of Ti Research Articles

Optimization of dendritic TS-1/Silica micro–mesoporous composites for efficient hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene

A novel composite material (TD) composed of TS-1 microcrystalline and dendritic mesoporous silica nanospheres (DMSNs) was successfully prepared. The TD composite material had open pore structure and large specific surface area, which was conducive to the mass transfer of reactants and products. The Ti element in TS-1 could be used as an electron assistant, and the spillover d-electrons were conducive to the improvement of the sulfidation and dispersion of MoS2, thereby forming more type II MoS2 active phases. The incorporation of Ti could bring more Brønsted (B) and Lewis (L) acid, which was conducive to the hydrogenation pathway (HYD) selectivity (41.2%) of dibenzothiophene (DBT) hydrodesulfurization (HDS) and isomerization (ISO) route selectivity (21.9%) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) HDS, thus improve the HDS activity of DBT and 4,6-DMDBT. NiMo/TD-70 (Aging temperature = 70 °C) had the best HDS activities of DBT (99.0%) and 4,6-DMDBT (93.7%) due to its large open pore structure, good acidity, suitable metal-support interaction (MSI) and perfect dispersion of the metallic active sites.

Dry Reforming of Methane over 5%Ni/Ce1-xTixO2 Catalysts Obtained via Synthesis in Supercritical Isopropanol.

A series of 5%Ni/Ce1-xTixO2 catalysts was prepared with nickel impregnation of mixed Ce-Ti oxides obtained via synthesis in supercritical isopropanol. All oxides have a cubic fluorite phase structure. Ti is incorporated into the fluorite structure. Small amounts of impurities of TiO2 or mixed Ce-Ti oxides appear with Ti introduction. Supported Ni is presented as the NiO or NiTiO3 perovskite phase. Ti introduction increases total samples reducibility and results in stronger interaction of supported Ni with the oxide support. The fraction of rapidly replaced oxygen and the average tracer diffusion coefficient also increase. The number of metallic nickel sites decreased with increasing Ti content. All catalysts except Ni-CeTi0.45 demonstrate close activity in tests of dry reforming of methane. The lower activity of Ni-CeTi0.45 can be connected to Ni decoration with species of the oxide support. The incorporation of Ti prevents detachment of Ni particles from the surface and their sintering during dry reforming of methane.

Crystallization Behavior of Highly Defective MSE-Type Zeolite, Incorporation of Ti into the Framework, and Its Hydrophobic–Hydrophilic Nature Controlled by Post-Synthesis Modifications

Crystallization Behavior of Highly Defective MSE-Type Zeolite, Incorporation of Ti into the Framework, and Its Hydrophobic–Hydrophilic Nature Controlled by Post-Synthesis Modifications

Investigation on the catalysis performance of metal-doped zeolites on ring-opening acidolysis reaction

Metal-incorporated zeolites as heterogeneous Lewis acid were applied in the ring-opening acidolysis of ethylene oxide with acrylic acid to prepare 2-hydroxyethyl acrylate (HEA). The catalysis characteristics, including Lewis acid strength and internal mass transfer resistance, were systematically investigated to facilitate the rational design of zeolite catalysts. Through modifying the Lewis acid strength of zeolites via different metals (Sn, Zr and Ti) incorporation and the internal mass transfer resistance of zeolites from the particle size, pore diameter or pore structure, it was found that the increased Lewis acidity can accelerate both the main and side reactions, resulting in the high activity but low selectivity of zeolite catalysts; the enhanced internal diffusion was the key to limiting subsequent cascade alcoholysis side reactions as well as the decline of catalytic performance. Based on these findings, Zr-containing zeolites featured with moderate Lewis acidity and uniform intracrystalline mesoporosity were designed and prepared, presenting excellent catalysis and recycling performance. These results demonstrated the great potential of the developed zeolite catalysts for the green synthesis of HEA as well as the similar ring-opening acidolysis of epoxides.

Selective Styrene Oxidation Catalyzed by Phosphate Modified Mesoporous Titanium Silicate

Selective oxidation of organics over an efficient heterogeneous catalyst under mild liquid phase conditions is a very demanding chemical reaction. Herein, we first report the modification of the surface of mesoporous silica MCM-41 material by phosphate for the efficient incorporation of Ti(IV) in the silica framework to obtain highly ordered 2D hexagonal mesoporous material STP-1. STP-1 has been synthesized by using tetraethyl orthosilicate, triethyl phosphate, and titanium isopropoxide as Si, P, and Ti precursors, respectively, in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) under hydrothermal conditions. The observed specific surface area and pore volume of STP-1 were 878 m2g−1 and 0.75 ccg−1, respectively. Mesoporous STP-1 has been thoroughly characterized by XRD, FT-IR, Raman spectroscopy, SEM, and TEM analyses. Titanium incorporation (Ti/Si = 0.006) was confirmed from the EDX analysis. This mesoporous STP-1 was used as a heterogeneous catalyst for the selective oxidation of styrene into benzaldehye in the presence of dilute aqueous H2O2 as an oxidizing agent. Various reaction parameters such as the reaction time, the reaction temperature, and the styrene/H2O2 molar ratio were systematically studied in this article. Under optimized reaction conditions, the selectivity of benzaldehyde could reach up to 93.8% from styrene over STP-1. Further, the importance of both titanium and phosphate in the synthesis of STP-1 for selective styrene oxidation was examined by comparing the catalytic result with only a phosphate-modified mesoporous silica material, and it suggests that both titanium and phosphate synergistically play an important role in the high selectivity of benzaldehyde in the liquid phase oxidation of styrene.

Tribological performance and failure mechanism of Ti:WS2/P201 hybrid lubrication system under atomic oxygen irradiation

Ti:WS2 films with duplex-layer structure were deposited by magnetron sputtering. The mechanical properties and tribological performance of Ti:WS2 film were improved after Ti incorporation. Ti:WS2/P201 hybrid system constructed by combination of Ti:WS2 film and P201 oil displays a synergistic lubricating effect, significantly prolonging lubricating lifetime compared to the single film. It is attributed to the effectively repairing function in some wear areas owing to the debris acted as an additive in oil. However, the AO irradiation can decrease the tribological performance of Ti:WS2/P201 hybrid system to different extent, depending on dose of irradiation. The high-dose AO irradiation rapidly deteriorates the tribological properties of the hybrid system, dramatically shortening the lubricating lifetime. It is found that the AO irradiated oil caused the severe tribo-oxidation reaction with the increase of sliding distance, resulting in forming numerous W oxides and carbide. Finally, failure mechanism of Ti:WS2/P201 hybrid system under AO irradiation were revealed.

Mechanisms and conditions of Ti and Cr incorporation in mantle phlogopite: the results of atomistic simulation

Modeling of eight mechanisms for the incorporation of Ti4+ and Cr3+ impurity components into phlogopite was carried out by a semi-empirical method using the GULP (General Utility Lattice Program) software. The calculation of thermodynamic mixing properties in the range of 1–7 GPa and 373–1573 K and the analysis of the structure geometry for the simulated solid solutions provided the following energy-preferred schemes of isomorphic substitution: VI(Mg2+) + 2IV(Si4+) = VI(Ti4+) + 2IV(Al3+) and VI(Mg2+) + 2IV(Al3+) = VI(□) + 2IV(Ti4+), VI(Mg2+) + IV(Si4+) = VI(Cr3+) + IV(Al3+), and 3VI(Mg2+) = VI(Al3+) + VI(Cr3+) + VI(□). It is shown the scheme 2VI(Mg2+) = VI(Ti4+) + VI(□) illustrating entrance of Ti with the formation of a vacancy is realized in the case of microconcentrations of Ti only. Accumulation of high-Ti contents associates with the formation of a vacancy in the octahedral site. This provides incorporation of Ti via the schemes VI(Mg2+) + 2IV(Al3+) = VI(□) + 2IV(Ti4+) and (Mg, Fe2+) + 2OH− = Ti4+ + 2O2− only. It is shown that incorporation of high-Cr concentrations (> 5.5 wt % Cr2O3) is accompanied by an increase in the number of vacancies in the octahedral site with an increase in the proportion of the dioctahedral component K(Al, Cr, □)2AlSi3O10(OH)2.

The eruption interface between carbonatitic dykes and diatremes – The Gross Brukkaros volcanic field Namibia

Carbonatites exist as intrusive and extrusive rocks, with the former dominating the rock record. The geochemical link between intrusive and extrusive equivalents and the processes during eruption of carbonatite melt are essentially unknown. This contribution aims at providing new insights into the transition from intrusive to extrusive carbonatites with special emphasis on the trace element budget. The Gross Brukkaros natural laboratory in central Namibia was chosen to study the interface between fine-grained dolomite‑carbonatite dykes and associated diatremes. Whole rock geochemistry combined with micro-scale petrography via BSE imaging and microXRF mapping provide evidence that the carbonatite dykes contain significant amounts of silica and aluminium, which is inherited from crustal xenoliths by resorption and leaching. At the transition from carbonatite dyke to diatreme, the CO2 component (likely together with most of the other volatiles e.g. Cl, H2O, F, S) of the carbonatitic brine-melt vaporised and was released into the atmosphere. During this process the Si, Ca, Mg and Fe transported together with a high amount of trace elements became precipitated from a resulting primarily magmatic fluid as a mixture of cryptocrystalline quartz (quartz I) and aegirine-augite (plus minor magnetite) with frequently occurring microcrystalline quartz I grains. This mineral assemblage forms the matrix in the diatreme breccia and precipitated by rapid temperature drop in the course of decompression from the hydrothermal fluid. In the post-eruption stage the influx of meteoric waters (into the system), which mixed with the remaining magmatic fluid, caused precipitation of a second quartz generation (quartz II; euhedral grains), which is depleted in trace elements. All measured trace elements show significantly higher contents in quartz I compared to quartz II (with exception of Li). The application of the TitaniQ geothermometer indicates that Ti incorporation in quartz is kinetically controlled for quartz I. During quartz II formation the system thermodynamically equilibrates and ends up with realistic precipitation temperatures of 290–350 °C. Therefore, this study shed light on the trace element behaviour at the interface between feeder dykes and diatreme roots of a strongly contaminated carbonatite melt.

Enhanced corrosion resistance, antibacterial and biological properties of sol-gel derived Ti-rGO-HAp nanocomposites

In the present work, pure Hydroxyapatite (HAp), Titanium-Hydroxyapatite (Ti-HAp), reduced Graphene oxide-Hydroxyapatite (rGO-HAp), and Titanium-reduced Graphene Oxide-Hydroxyapatite (Ti-rGO-HAp) nanocomposites were successfully synthesized using sol-gel technique. They are fabricated as films on 316 L stainless steel plate. The impact of the incorporation of Ti and rGO on properties (structural, optical, morphological, corrosion, antibacterial, and biocompatibility) of the HAp nanopowders are investigated. The hexagonal structure of the nanocomposites was observed through XRD spectrographs. The average crystallite size of the synthesized nanocomposites varies from 37 to 51 nm. The crystallite size was reduced due to the incorporation of Ti ions on the HAp surface. The surface morphology and chemical compositions of as-prepared samples are investigated using a scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX), respectively. The antimicrobial activity and biocompatibility observations of the pure HAp and Ti-rGO-HAp nanocomposites demonstrated that titanium-added HAp nanocomposites exhibit more toxic in opposition to all bacterial strains and have no toxicity against live tissues. The incorporation of Ti and rGO ions increase polarization resistance with a decrease in current density from 8.7 to 3.0 A, which is observed in the corrosion tests of the manufactured films in the stimulated body fluid (SBF). The corrosion resistance efficiency, zone inhibition layer and improved biocompatibility show that the novel (Ti–rGO-HAp) nanocomposites are the potential candidate for biomedical applications-.

Lithium, Phosphorus, and rare earth elements in magmatic garnets from granitic Pegmatites: Coupled substitution and petrogenetic implications

The general chemical formula of garnet can be expressed as X3Y2(ZO4)3 where X, Y, and Z represent dodecahedral, octahedral, and tetrahedral sites, respectively. Lithium, phosphorus, and rare earth elements (including yttrium) in garnets from the Luanzhuang-Guanpo and Ziyugou (ZYG) pegmatite fields in the East Qinling orogen and the Kalu’an (KLA) Li pegmatites in the Chinese Altay orogen have been investigated both at a mineral scale and in the context of pegmatite types to identify the substitution mechanisms for these elements. Our results show that Y + REE or P can enter the garnet lattice through coupled substitution with Li (+Na) that can compensate the charge differences due to Y + REE in the X-site or P in the Z-site of the garnet. Two substitutions, namely [X(Li,Na)+1X(Y,REE)3+1(R2+)–2] and [X(Li,Na)1ZP1XR2+-1ZSi-1], are likely the most important and can account for incorporation of the majority of Y + REE, P, and Li + Na in pegmatite garnets. Whichever substitution becomes predominant in garnets is strongly dependent on the bulk chemistry of pegmatite-forming melts. Consequently, the first substitution dominates in garnets from NYF (niobium-yttrium-fluorine) pegmatites and mixed-type pegmatites with NYF affinity whereas the other one dominates in garnets from relatively P-rich LCT (lithium-cesium-tantalum) and barren pegmatites. Incorporation of Sc and Ti in garnet may also need Li + Na, although Sc and Ti are not as much as Y and REE in pegmatite garnet. The zonings of Y, REE, and Sc in garnet are mainly controlled by the composition of pegmatite-forming melt and consumption of these elements due to the growth of garnet itself and other minerals enriched in Y + REE (e.g., xenotime, fergusonite, monazite, etc.) or Sc (e.g., biotite). Additionally, our results, combined with the data in the literature, show that garnets from NYF pegmatites and mixed-type pegmatites with NYF affinity commonly contain elevated Y (up to ∼ 20000 ppm), REE (up to ∼ 20000 ppm), and Sc (up to ∼ 2400 ppm) but low P (<100 ppm) compared to those from LCT and barren pegmatites. Nevertheless, individual garnets with low concentrations of Y, REE, Sc, and P can occur in any types of pegmatites. Therefore, the coupled substitution between Li + Na and Y + REE or P along with zonings and concentrations of Y, REE, and Sc in garnet should be investigated on a regular basis to interpret pegmatite petrogenesis.

Homeostatic Solid Solution in Layered Transition-Metal Oxide Cathodes of Sodium-Ion Batteries.

Two-phase transformation reaction is ubiquitous in solid-state electrochemistry; however, it usually involves inferior structure rearrangement upon extraction and insertion of large-sized Na+, thus leading to severe local strain, cracks, and capacity decay in sodium-ion batteries (SIBs). Here, a homeostatic solid solution reaction is reported in the layered cathode material P'2-Na0.653Ni0.081Mn0.799Ti0.120O2 during sodiation and desodiation. It is induced by the synergistic incorporation of Ni and Ti for the reinforced O(2p)-Mn(3d-eg*) hybridization, which leads to mitigated Jahn-Teller distortion of MnO6 octahedra, contracted transition-metal oxide slabs, and enlarged Na layer spacings. The thermodynamically favorable solid solution pathway rewards the SIBs with excellent cycling stability (87.2% capacity retention after 500 cycles) and rate performance (100.5 mA h g-1 at 2500 mA g-1). The demonstrated reaction pathway will open a new avenue for rational designing of cathode materials for SIBs and beyond.

Structure and mechanical properties of MAO coatings formed on aluminum-coated titanium alloy

ABSTRACT Application of titanium alloys is restricted due to their low hardness and poor wear resistance. Duplex surface treatment consisting of depositing of Al coating by arc ion plating (AIP) plus micro-arc oxidation (MAO) was carried out on Ti6Al4V alloy to improve its tribological performance. Ceramic coating mainly composed of α-Al2O3, γ-Al2O3 and mullite was fabricated on the aluminum-coated titanium alloy after the MAO treatment, and its thickness, compactness and hardness increased with the MAO time before the titanium alloy was oxidized. After the substrate titanium alloy was locally oxidized due to oxygen anions inward migration, a thin transition layer containing titanium oxides and aluminum titanate formed and incorporation of Ti in the alumina coating occurred. Occurrence of the strong eruptible discharges at these positions was facilitated probably due to the large difference in permittivity of the alumina and the titanium oxides, which led to the formation of penetrating cracks in the MAO coating. The hardness and compactness of the ceramic coating decreased. Tensile test results showed bonding strength of MAO ceramic coating/aluminum layer/titanium alloy substrate system was more than 40 MPa, and the maximum value could reach around 68 MPa. The bonding strength of the ceramic coating/titanium alloy substrate system decreased to around 34 MPa due to the weak bonding between the alumina ceramic coating and the titanium alloy substrate. Tribological test results show wear resistance of titanium alloy was greatly improved due to the fabrication of hard alumina ceramic coating on titanium alloy.

Tuning the sensing selectivity of mesoporous hierarchical Ti-doped Co3O4 to toluene and xylene via controlling the oxygen defects

Vast efforts have been made to develop high-performance gas sensing materials for the detection of harmful volatile organic compounds (VOCs) like toluene and xylene. However, it is challenging to selectively detect toluene and xylene simultaneously. Herein, the hierarchical Ti-doped cobalt layered hydroxides miscrospheres were synthesized first and sintered at high temperature consequently to prepare hierarchical Ti-doped Co3O4 miscrospheres. The incorporation of Ti into the lattice of Co3O4 decreased the crystal sizes and crystallinity, resulting in higher specific surface area and more oxygen defects. Interestingly, the 3 at.% Ti-doped Co3O4 miscrospheres sintered at 450 °C exhibited the highest response of 64.9 to 50 ppm of xylene at 210 °C, while the 1 at.% Ti-doped Co3O4 miscrospheres calcined at 500 °C displayed the highest response of 57.2 to 50 ppm of toluene at 240 °C, which were about 11.8 and 7.8 times higher in comparison with pristine Co3O4. The different selectivity of Ti-doped Co3O4 to toluene and xylene arises from the different amounts of oxygen vacancies and defect oxygen ions. The obtained Ti-doped Co3O4 microspheres also showed the merits of good selectivity, repeatability and long-term stability, indicating the promising applications of Ti-doped Co3O4 miscrospheres in the detection of toluene and xylene.

The importance of type of Ti-based additives on the PEO process and properties of Al2O3-TiO2 coating

Al2O3-TiO2 coatings were obtained from a silicate-based electrolyte using pulsed bipolar current by PEO process. Nano-particle titania (NP-TiO2) and potassium titanyl oxalate (PTO) were used as Ti-based additive sources in the PEO electrolytic solution, separately. The coatings were characterized using scanning electron microscope, energy dispersive spectroscopy, and an X-ray diffractometer. The mechanical properties of the coatings were investigated using nanoindentation and ball-on-disk tests. SEM results showed that the PTO developed a more compact inner layer besides the increase of coating thickness. However, NP-TiO2 created an inner layer with less thickness but with higher compactness, without any effect on the outer layer morphology. XRD and Raman spectroscopy analyses showed that the NP-TiO2 had inert incorporation into the alumina. However, TiO2 produced by PTO had reactive incorporation into alumina and made a polymeric titanium oxide structure on the coating with doped rutile and anatase phases. Nanoindentation and tribology analyses approved that the Ti incorporation through PTO provides appropriate mechanical properties owing to the more compact and thicker inner layer. The mechanism of PTO performance in the PEO process was discussed regarding its effect on coating characteristics.

Cyclic oxidation behavior of selected commercial NiCr-alloys for engine exhaust valves in wet air environment between 800 and 950 °C

The impact of water vapor on the cyclic oxidation behavior of four commercial Ni-based superalloys (N80A, N90, R41 and H282) was investigated between 800 and 950 °C. Oxidation- and volatilization-induced Cr loss accelerated the transition from protective and adherent oxide formation (Cr2O3) to mixed oxides that significantly spalled at 950 °C for H282 and R41. The accelerated oxidation, Cr depletion, and spallation susceptibility for R41 and to a lesser extent for H282 compared to N80A and N90 was related to the higher fraction of γ’, which led to increased Ti incorporation into the Cr2O3 scale in the presence of water vapor.

Enhanced formation of nanometric titanium cones by incorporation of titanium, tungsten and/or iron in a helium ion beam

Surface patterning of bio-compatible titanium (Ti) shows a growing interest in the medical field. The engineering of material surfaces can achieve bactericidal properties and osteointegration improvements in order to develop medical implants. Spikes-like surface morphologies have already demonstrated the development of promising bactericidal properties. A barely new method to produce nanometric-sized cones on titanium consists of helium (He) ion irradiation using low energies (≈100eV) and temperatures comprised between 0.25<T/Tm<0.5 (with Tm being the melting temperature of the material). Ti, iron (Fe) and/or tungsten (W) were incorporated in a He beam, and their amounts were quantified using X-ray Photoelectron Spectroscopy (XPS). The He ion energy was varied from 70 and 120eV, the surface temperatures from 571 to 651K for fluences approximately equal to 1024m−2. After irradiation, the surface morphology was characterized using Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB). This study demonstrated the capability for irradiated Ti surfaces to form cones with tunable density, aspect ratio, and heights with the incorporation of Ti, Fe and/or W in a He ion. Additionally, the growth rate of the cones was enhanced by about 30 times in comparison to pure He irradiation as a function of the chosen materials introduced in the He beam.

Understanding electrocatalytic activity of titanium and samarium doped ceria as anode material for solid oxide fuel cells

• Titanium and samarium stabilized ceria (Ce 0.73 Ti 0.07 Sm 0.2 O 2-δ (STDC)) prepared by urea combustion method. • Proposed anode material shows nearly 4 times enhancement in surface area. • H 2 -TPR results indicates incorporation of Ti in Sm stabilized ceria promotes low temperature reduction. In the present work, titanium and samarium doped ceria (Ce 0.73 Ti 0.07 Sm 0.2 O 2-δ , (STDC)) is evaluated as potential anode material for intermediate temperature solid oxide fuel cells (IT-SOFCs). The anode and electrolyte (Ce 0.8 Sm 0.2 O 2-δ, (SDC20)) materials are synthesized using urea combustion method. The desired phase formed is confirmed by powder X-ray diffraction (XRD). The textural study is performed using Brunauer–Emmett–Teller method. STDC shows nearly 4 times enhancement in surface area and higher mesopores compared with SDC20. The effect of titanium on chemical environment of cerium is investigated using X-ray Photoelectron Spectroscopy. Both + 3 and + 4 valence states of cerium exist, which indicate high oxygen non-stoichiometry present in the synthesized samples. The morphological features are investigated using Scanning Electron Microscopy/High-Resolution Transmission Electron Microscopy. Electrolyte supported cell is fabricated using cold-pressing and spin coating of electrode and co-firing of cell. Fuel cell tests with 5 % H 2 (95 % N 2 ) as a fuel demonstrate Ce 0.73 Ti 0.07 Sm 0.2 O 2-δ -NiO as a potential anode material for IT-SOFCs.

Tailoring the corrosion and tribological performance of Ti-modified MoS2-based films in simulated seawater

Film protection has become a crucial means to improve the corrosion and wear performance of key components in aggressive environment. In this study, the feasibility of using MoS2-based modified films in artificial seawater (3.5% NaCl solution) was evaluated by co-deposition of Ti to produce Ti–MoS2 composite and Ti/MoS2 multilayer films. The microstructure, wettability, mechanical, tribological and corrosion behavior of the Ti-modified MoS2-based films was contrasted to pure MoS2 film. The results show that the incorporation of Ti not only improves densification, but also promotes a transformation from a columnar to an amorphous film structure, leading to the improvement of mechanical properties of Ti–MoS2 composite film and Ti/MoS2 multilayer film. The friction coefficient curves of all of the three MoS2-based film in 3.5 wt% NaCl solution show stable values during the sliding process. The advantage of the preferential (002) growth orientation, improved mechanical properties and reduced hydrophobicity for both of the Ti-modified MoS2 films caused the decreased friction coefficient and wear rate in NaCl solution. The electrochemical results before and after friction show that the ranking of corrosion resistance is Ti/MoS2 multilayer > Ti–MoS2 composite film > pure MoS2 film, which is attributed to the compact microstructure and the presence of surface passive films.

Optical and structural characteristics of pulsed DC magnetron sputtered Ce1−xTixOy coatings

This contribution investigates the impact of adding transition metal of Ti to CeOy samples at various concentrations referring to 0, 15.84, 24.46, 34.46, 36.23, 38.46, 45.38% and pure TiOy, correspondingly. The samples were fabricated by the magnetron sputtering technique. X-ray diffraction (XRD) configurations demonstrate the presence of α-Ce2O3 and Ce2O3 phases with increased Ti contents in the systems. X-ray photoelectron spectroscopy (XPS) experimentation confirms the purity of the S1-sample (CeO2) and the purity of the S8-sample (TiO2). Further XPS analysis reveals that Ti incorporation in the doped systems functions as a reducing agent because of the existence of α-Ce2O3 and Ce2O3 phases. Moreover, based on UV–vis spectroscopy results, the studied samples exhibit indirect optical energy band-gaps reduced from 2.6 to 2.35 eV with the increase of Ti concentrations of 0–45.38% in (S1-S7), respectively. In reference to bandgap 2.35 eV, a slight rise in band gaps was detected for S3 sample. However, an observable increase in the band gap of 2.9 eV occurred for S8 (pure TiO2). Optical analysis of the calculated energy loss parameters demonstrates that all the studied samples reveal small amounts of energy loss. Our results suggest that the improved optical properties of Ti-doped CeOy films could serve for various optical applications.

Oxygen hyper stoichiometric trimetallic titanium doped magnesium ferrite: Structural and photocatalytic studies

Oxygen hyper stoichiometric titanium doped magnesium ferrite, Mg 1-x Ti x Fe 2 O 4+δ (x = 0–1.0) nanoparticles (NPs) were synthesized using sol-gel method. XRD analysis revealed a decrease in the lattice parameter from 8.9 to 8.3 Å and confirmed the incorporation of Ti 4+ , a smaller ionic radius dopant. Presence of M-O vibrational bands at tetrahedral and octahedral sites were authenticated by FT-IR analysis. The observed reduction in saturation magnetization values from 23.3 emug −1 to 18.3 emug −1 was ascribed to the doping of non-magnetic Ti 4+ ions in MgFe 2 O 4 NPs. BET studies corroborated the mesoporous nature of the NPs and doped ferrite NPs displayed larger surface area (53.0–73.0 m 2 g -1 ) as compared to pristine ferrite NPs (32.8–39.0 m 2 g -1 ). Optical studies displayed red shift in the absorption edge of the Ti 4+ doped MgFe 2 O 4 NPs in contrast to pristine NPs. Oxygen hyper stoichiometry in the doped ferrite NPs was determined experimentally. Photoluminescence emission spectra exhibited reduction in the emission intensity in case of Ti 4+ doped NPs which supported their higher light capturing potential. Among synthesized doped ferrite NPs Mg 0.5 Ti 0.5 Fe 2 O 4.5 NPs exhibited maximum (98%) photodegradation capacity for rhodamine B. The • O 2 − and • OH were the main reactive species in the photodegradation. The present studies have clearly shown the potential of tuning the composition of oxygen hyper stoichiometric ferrite Mg 0.5 Ti 0.5 Fe 2 O 4.5 for the removal of toxic organic contaminants from water.