Ti-C Bond Research Articles

Adsorption behavior of Cl2 on TiC0.89O0.11(001) surface based on the first principle calculation

Based on the first-principles ab initio calculation method of density functional theory (DFT), the adsorption models of Cl2 molecules on both the TiC0.89O0.11(001) intact surface and the carbon vacancy surface were established, followed by calculations and analysis of the adsorption structures, adsorption energy, differential charge density, and density of states (DOS). The results demonstrate that the adsorption process of Cl2 molecules on the TiC0.89O0.11(001) surface involves chemical adsorption, with a higher likelihood of dissociation into Cl atoms during adsorption. These dissociated Cl atoms can potentially interact with surface Ti and/or C atoms to form Ti-Cl bonds, C-Cl bonds, Ti-Cl-C bonds, and Ti-Cl-Ti bonds. Simultaneously, the stability of the adsorbed structure is influenced by both the bonding conditions between Cl atoms and surface atoms and the position of Cl atom adsorption (e.g., whether it is located above the vacancy C). Following adsorption, there is a weakening in the bonding strength of Ti-C or Ti-O bonds on the TiC0.89O0.11(001) surface. During the adsorption process, Cl atoms can either act as electron donors or acceptors. When the Ti-Cl bond structure is formed, Cl atoms function as electron acceptors; however, when the C-Cl bond structure is established, Cl atoms predominantly act as electron donors. Surface Ti atoms act as electron donors while surface C and O atoms function as electron acceptors. Additionally, the presence of surface carbon vacancy enhances the interaction between Cl and Ti atoms, weakens the interaction between Cl and C atoms, and attenuates the interaction between C, O, and Ti atoms in the structure. And it can augment the electron acquisition by Cl2 molecules upon adsorption, reduce the adsorption energy, and promote greater stability in the adsorption structure. All the effects contribute to facilitating TiCl4 formation.

Micropatterning MXene/TiO2 Nanocomposite Ink for Gas Sensing

This work describes the preparation, characterization and micropatterning of MXene (Ti3C2/TiO2) nanocomposite inks. The MXene nanopowder was oxidized to Ti3C2/TiO2 nanocomposite powder by stirring in air for 3 hours using air aging method. The Ti3C2/TiO2 nanocomposite powder was then dispersed into Dimethyl Sulfoxide (DMSO) solvent, and the Ti3C2/TiO2 ink was prepared by using 1% mass fraction of Polyvinylpyrrolidone (PVP) solution as dispersant. The two-dimensional layered nanostructure of MXene and the characteristic peaks of TiO2 were observed by Raman and XRD results. SEM and TEM results show the layered structure of MXene nanoparticles as well as TiO2 nanoparticles with a diameter of about 2 nm on a single layer of MXene. FTIR results confirms that Ti-O bonds and Ti-C bonds indicating that part of Ti3C2 was oxidized to TiO2. The results of Brunauer Emmett Teller (BET) test on Ti3C2/TiO2 nanocomposite ink show that the specific surface area of the ink is 10.7194 m²/g and the maximum adsorption of N2 is 32.039cm3/g. Thermogravimetric analysis (TGA) indicate that Ti3C2/TiO2 exhibited excellent thermal stability, with a mass loss of only 15% at 800°C. In order to achieve the optimal printing effect, plasma surface treatment was carried out on the gold-plated silicon wafers, Polyethylene terephthalate (PET), and glass substrates, which decreases the contact angle of the ink on these substrates. The printing of Ti3C2/TiO2 nanocomposite ink on the substrate using the atomized printing technique with a mask plate enables printing of straight lines with a line width of 5µm. Film thickness can be controlled by adjusting the distance between the printhead and the substrate, as well as the pressure of the atomized printing jet.

From Coordination to Noncoordination: Syntheses and Substitution Lability Studies of Titanium Triflato Complexes.

A new concept for obtaining cationic complexes with triflate counteranions from coordinating triflato ligands was developed. Various routes are leading to titanium(IV) and titanium(III) triflato complexes efficiently. The reactions of pentafulvene titanium complexes with either triflic acid or silver triflate give the corresponding titanium(IV) triflato complexes in excellent yields. Hydrolysis of the titanium(IV) bistriflato complexes leads to cationic aqua complexes via displacement of the triflato ligand, which consequently acts as a noncoordinating anion. A functionalized titanium(IV) monotriflato complex was synthesized by insertion of a nitrile into the Ti-C bond and the triflato ligand was displaced by an NHC. While the titanium(IV) complexes are mostly inert toward substrates, the donor-free titanium(III) triflato complex is a strong Lewis acid and forms various adducts with monodentate Lewis bases. The titanium(III) complex was oxidized by reaction with TEMPO, resulting in a diamagnetic titanium(IV) complex. The reaction with bidentate ligands results in cationic titanium(III) complexes due to displacement of the triflato ligand by the bidentate ligands. Treatment with acetone leads to an aldol reaction of two acetone molecules and the formation of a cationic diacetone alcohol complex.

Effects of impurities on stability of TiC, TaC and ZrC particles in tungsten

Titanium carbide (TiC), tantalum carbide (TaC) and zirconium carbide (ZrC) in form of particles are widely added in W to improve its mechanical and anti-irradiation properties. However, TiC, TaC and ZrC particles are decomposed to Ti-C-O, Ta-C-O and Zr-C-O in W, respectively. To understand the micro-mechanisms, we carry out systematical simulations and find that the presence of impurities such as O, N, and P has great influence on the bond length and bond strength of Ti-C, Ta-C and Zr-C in W. The bond lengths of Ti-C, Ta-C and Zr-C are generally increased when O meets Ti-C, Ta-C and Zr-C. The bond strength of O to Ti-C, Ta-C and Zr-C is much larger than that of C to Ti-O, Ta-O and Zr-O. In contrast, N has little effect on the Ti-C bond, but has great influence on the Ta-C bond. P significantly increases Ta-C bond length, while its influence on Zr-C bond is negligible. The kinetics calculations elucidate that the diffusion barriers of C away from TiO are significantly increased by about 1 eV. It is very difficult for C to escape from TiO and ZrO, and it is also extremely difficult for O to escape from TiC, TaC and ZrC. This may be the reason why Ti-C-O, Ta-C-O, and Zr-C-O particles are found in W when TiC TaC and ZrC compounds are dispersed in W.

Enhancement mechanism of ultrasonic vibration on interface bonding strength in laser joining of polymer to ceramic

The current challenge in laser joining polymer and ceramic heterogeneous structures lies in their relatively low mechanical strength, primarily attributed to weak interface bonding. To address this issue, this paper proposes the application of ultrasonic vibration during the laser joining process of PET with both Si3N4 and Ti-coated Si3N4 sheets to enhance the interface bonding strength. Investigating the mechanisms underlying the enhancement of interface bonding strength due to ultrasonic vibration is crucial for improving the overall mechanical strength of the joints. It is found that the physical wetting thermodynamic conditions and chemical bond thermodynamic conditions for laser joining of PET to ceramics were the surface tension of ceramics higher than that of the molten PET and the variation in the Gibbs function less than −24.3 kcal/mol, respectively. Experimental results demonstrated that the bonding interface between Si3N4 sheet and PET exhibits only physical and mechanical bonding, with no evidence of new chemical bonds. However, XPS analysis detected new TiC bonds at the bonding interface of Ti-coated Si3N4 and PET. Furthermore, experimental results substantiated that ultrasonic vibration could improve the spreading wetting of PET melt on the Si3N4 surface, resulting in a 17 % increase in the bonded area of the weld seam. Additionally, ultrasonic vibration enhanced the molten PET filling into the blind hole structure on the Si3N4 surface, resulting in an approximately 73 % increase in the filling depth of the blind holes. Lastly, ultrasonic vibration facilitated the chemical reaction between the molten PET and Ti atoms, resulting in an approximately 57 % increase in the thickness of the interface containing TiC bonds. It is evident that ultrasonic vibration can bolster the interfacial bonding strength of PET/Si3N4 and PET/Ti-coated Si3N4 in laser joining. Moreover, in comparison to physical bonding, its more pronounced impact on mechanical and chemical bonding is noteworthy.

Existence state of Ti in diamond-like carbon coatings and its effects on hybrid structure and residual stress: Molecular dynamics simulations

In this study, the modified embedded atom method potential function is selected via the LAMMPS platform and OVITO interface software to describe the interatomic interaction potential, which is used to simulate the existence states of doped Ti in Ti-doped diamond-like coatings as well as their effect on the hybrid structure, hardness, and residual stress of the coatings. The results indicate that Ti atoms preferentially combine with C atoms to form Ti–C bonds, thus rendering it difficult to form metallic Ti clusters. The formation of Ti-C bond clusters with high extent of ordering (nanoc-TiC) in the coating is related to the density (or sp3C fraction) of the coating; the higher the density, the higher is the critical content of Ti (CV-Ti) required to form nanoc-TiC. When the density of the coating ranges from 2.4 to 3.6 g/cm3, the CV-Ti is 2–6 at.%. When the Ti content in the coating is less than CV-Ti, Ti atoms existed only in amorphous Ti–C clusters, which is not conducive to the stability of the sp3C phase and significantly reduces the residual stress and hardness of the coating. When the CV-Ti is exceeded, nanoc-TiC formed and grew until the hybrid C–C bonds in the coating disappeared completely, thus increasing the residual stress of the coating.

INFLUENCE OF BIAS VOLTAGE ON THE STRUCTURE AND MECHANICAL PROPERTIES OF Ti-Nb-C FILMS DEPOSITED BY DC DUAL MAGNETRON SPUTTERING

The films of the Ti-Nb-C system were deposited by direct current (DC) magnetron co-sputtering of composite Ti+Nb, and graphite targets onto Si substrates to which negative substrate bias in the range of -50÷-200 V was applied during film deposition. The microstructure, chemical bonds, and mechanical properties of films were comparatively investigated. The X-ray diffraction (XRD) analysis revealed that the peaks of the XRD spectra of the film obtained by co-spattering of the composite Ti+Nb and graphite targets are located in the intermediate region between the corresponding peaks of the Ti-C and Nb-C films. The X-ray photoelectron spectroscopy (XPS) showed that the Ti-C and Nb-C bonds prevail in the deposited Ti-Nb-C films. It was suggested that the Ti-Nb-C films are nanocomposite and consist of the crystallites of Ti<sub>1-x</sub>Nb<sub>x</sub>C<sub>y</sub> solid solutions surrounded by amorphous carbon-based matrix. The Knoop hardness of the Ti-Nb-C film is highest (37.5 GPa) in the film deposited at -50 V substrate bias. The average friction coefficient determined before film delamination was the lowest (0.12) in that Ti-Nb-C film.

Ti-inducing sp2 nanocrystallites into amorphous carbon film for low-friction

We reported a low-friction performance of Ti-doped a-C film, which is Ti-inducing sp2 nanocrystallites embedded in a-C structure. Mechanical and tribological tests showed that Ti-inducing sp2 nanocrystallites softened the film hardness from 22.5 to 18.8 GPa and lowered the friction coefficient from 0.15 to 0.05. Friction interface characterization indicated that abundant sp2 nanocrystallites lay down on the contact surfaces. The low-friction was attributed to the interaction between sp2 C layers, which originated from original Ti-inducing and new Ti-promoting sp2 nanocrystallites. The Ti-promoting effect was speculated that Ti atoms with Ti-C bond reacted with O atoms to form TiO bond (TiO2), then some released C atoms turned to sp2 nanocrystallites at the friction interface.

Surface regulation of Si composite anode via synergistic coupling and Ti[sbnd]C bond for stable cycling lithium-ion battery

Silicon holds bright promise as the anode material for next-generation lithium-ion batteries (LIBs). Unfortunately, it is limited by enormous volume expansion and fast capacity fading in long-cycling or large current density. Here, we propose an in-situ assembling path to form a stable Si nanocomposite by introducing bicontinuous TiO2-C layer and graphene nano-sheets, and further enhance the stability for long-term LIBs. The enhanced synergistic coupling of graphene and bicontinuous TiO2-C layer and introduced TiC bond effectively improve long-cycling structural stability of Si nanocomposite for promising LIBs anode material. This anode material exhibits high capacity, long-term cycling and high-rate performance. Especially, it showed the high reversible capacities of 2147.6 mA h g−1 at 0.5 A g−1 after 800 cycles and 1328.2 mA h g−1 at 2 A g−1 after 500 cycles, which is much better than that of TiO2-C@Si and nano Si anodes. Moreover, the full cell including this composite anode and commercial LiFePO4 cathode exhibits a high capacity retention after 100 cycles. Our work demonstrates that this surface functionalization strategy can enhance synergistic coupling and introduce TiC bond to regulate the stability of Si nanocomposite as long-cycling LIBs anode.

Coordination-Induced Radical Generation: Selective Hydrogen Atom Abstraction via Controlled Ti-C σ-Bond Homolysis.

A method for the generation of transient alkyl radicals via homolytic Ti-C bond cleavage was developed by employing a tailor-made organotitanium half-cage complex. In contrast to established metal-mediated radical initiation protocols via thermal or photochemical M-C σ-bond homolysis, radical formation is triggered solely by coordination of a solvent molecule (thf) to a titanium(IV) center. During the reaction, the nonstabilized alkyl radical is formed along with a persistent titanium(III) metalloradical, thus taming the former transient radical (persistent radical effect). Radical coupling and hydrogen atom abstraction (HAT) reactions have been explored not only experimentally but also computationally and by means of kinetic analysis. Exploiting these findings led to the development of selective HAT transformations, for example, with 9,10-dihydroanthracene. Deuterium labeling studies using selectively deuterated alkyls and 9,10-dihydroanthracene-d4 confirmed a radical pathway, which was underpinned by developing a radical-radical cross-coupling reaction for transferring the alkyl radical to a stable Sn-centered radical. To set the stage for an application in organic synthesis, a 5-endo-trig radical cyclization based on our methodology was established, and a dihydroxylated sesquiterpene was thus prepared in high diastereomeric excess.

Adhesive and tensile properties of diamond(001)/TiC(111) interfaces: A first-principles investigation

Since a nanometer-thick carbide layer will be indispensably produced on diamond to ensure wettability with metallic parts, the interfacial properties of diamond/carbide directly affect the service performance of diamond devices. Herein, first-principles calculations were performed to investigate the interfacial properties and tensile responses of diamond(001)/TiC(111) interfaces. Taking into account Ti- and C-termination of TiC(111), and interfacial stacking of hollow- and top-site, four interface models were established. The results showed that Ti-termination could only be stacked by hollow-site. The analysis of energy and electronic structure suggested that hollow-site or C-termination favored to produce a more stable interface, attributing to stronger interfacial C-C covalent bonds and even the additional ionic attraction from Ti atoms, which enhanced the bonding strength significantly. Furthermore, the tensile simulations indicated cleavage always ignited from Ti-C bonds, of which along the interface for Ti-termination and within the TiC for C-termination. Growing C-terminated TiC could greatly improve interfacial stability, but at the expense of mechanical strength. This owed to the homogenization of C-termination by diamond surface. The results provided an atomic insight to characterize the structure and bonding of diamond/TiC interfaces, laying the foundation for developing high-performance diamond devices.

The Coordination of Titanium Ions and the Electrocrystallization Mechanism in Molten Chloride-Fluoride Salts

In electrochemical process, electrolyte composition is one of the key factors that determine the electrochemical behavior of elements. In this work, the nucleation mechanism and deposition process of titanium ions after the introduction of fluoride ions into molten salt were analyzed in detail by electrochemical technology, and the coordination behavior between fluorine ions and titanium was explored by molecular dynamics simulation, revealing the relationship between the electrocrystallization mechanism of titanium and its coordination properties. It can be found that the electrocrystallization mechanism of titanium ions is related to its coordination structure. Under our experimental conditions, the Ti-Cl bond in the system was gradually replaced by the Ti-F bond. This will lead to the change of charge transfer and ion diffusion of titanium ions, which will have an important effect on the electrocrystallization processes. This work has an important guiding significance for further study on the influence of different molten salt systems on the electrocrystallization mechanism of molten salt electrolytic titanium.

Density Functional Theory Calculations for Multiple Conformers Explaining the Regio- and Stereoselectivity of Ti-Catalyzed Hydroaminoalkylation Reactions.

Hybrid Density Functional Theory (DFT) calculations for multiple conformers of the insertion reactions of a methylenecyclopropane into the Ti-C bond of two differently α-substituted titanaaziridines explain the experimentally observed differences in regioselectivity between catalytic hydroaminoalkylation reactions of methylenecyclopropanes with α-phenyl-substituted secondary amines and corresponding stoichiometric reactions of a methylenecyclopropane with titanaaziridines, which can only be achieved with α-unsubstituted titanaaziridines. In addition, the lack of reactivity of α-phenyl-substituted titanaaziridines as well as the diastereoselectivity of the catalytic and stoichiometric reactions can be understood.

The formation potential of disinfection by-products of Ti3C2Tx MXene

Owing to the outstanding properties, including non-toxicity, large surface area, bactericidal ability, and versatile surface chemistry, Ti3C2Tx MXene-based adsorbents and membranes have been widely explored in drinking water and wastewater treatment. At the same time, with the rapid increase in MXene applications, it is inevitable that MXene will find its way into water and wastewater treatment systems. It is therefore imperative to assess its potential for disinfection by-products (DBPs) formation and physicochemical transformation by chlorination. This study demonstrated that Ti3C2Tx Mxene has a high formation potential of DBPs including trichloromethane (TCM), dichloroacetonitrile (DCAN) and dichloroacetic acid (DCAA) during the chlorination and chloramination procedures. Few-layered Ti3C2Tx with a larger specific surface area produced more DBPs. The concentrations of TCM and DCAN increased monotonically with the prolongation of chlorine contact time, while the amount of DCAA tended to be stable after 10 h of chlorination. Moreover, the effects of chlorine dose were also considered to better understand the pattern of DBPs formation by Ti3C2Tx MXene. The possible mechanism of DBPs formation was deduced by analyzing the results of FTIR, Raman and XPS before and after chlorination. The DBPs were primarily formed with the destruction of TiC bond by chlorine with the concurrent formation of TiO2. The findings of this research add to the understanding of the potential for DBPs formation from carbon-containing nanomaterials in water treatment systems and shed light on the environmental potential risk of MXene.

Pressureless manufacturing of high purity Ti3AlC2 MAX phase material: Synthesis and characterisation

The reported study involves the synthesis of high purity layered ternary carbide Ti3AlC2 MAX phase material by mixing the TiH2, Al and TiC powders in a planetary ball mill followed by two step pressureless sintering in flowing Argon (Ar) atmosphere. XRD and Raman analysis confirms the presence of Ti3AlC2 phase without impurities of Al2O3 and TiC. The morphology studies using SEM confirms the lamellar structure of Ti3AlC2 and EDS measurements shows atomic percentage of Ti, Al and C are in compliance with the XRD phase analysis. X-ray Photoelectron spectroscopy investigations confirm the Ti–C bond. Core level XPS data of Al2p peak show a negative shift indicating electrostatic bonding of Al in Ti3AlC2. Ti2p and C1s core level spectra show the bonding of Mn+1Xn i.e TiC bond. TG-DSC results revealed approximately 7% increase in weight. Ti3AlC2 phase follows an endothermic pattern and does not undergo decomposition upto 1400 °C in vacuum environment. From XRD analysis at different temperatures, it was seen that Al2O3 and TiCx peaks started to form along with Ti3AlC2 at 1000 °C because of selective oxidation of Al into Al2O3. Thus, this study provides a beneficial approach to synthesis of high-purity Ti3AlC2 materials and understanding the thermal behaviour of Ti3AlC2 for high temperature applications.

Electronic, Tensile, and Sliding Characteristics of the C/Ti Interface: A First-Principles Study.

In this paper, according to the C(111) surface and Ti(112̅0) surface relative positions, three stacking interface models were constructed by the first-principles method, and they were defined as 1st-C(111)/Ti(112̅0), 2nd-C(111)/Ti(112̅0), and 4th-C(111)/Ti(112̅0), respectively. After calculation, the work of interfacial adhesion of the 1st-C(111)/Ti(112̅0), 2nd-C(111)/Ti(112̅0), and 4th-C(111)/Ti(112̅0) interface models is found to be 9.689, 10.246, and 9.714 J/m2, respectively, and their interface energies are observed to be 1.064, 0.507, and 1.039 J/m2, respectively. Moreover, the electronic characteristics of C(111)/Ti(112̅0) interfaces are dominated by polar covalent bonds, supplemented by certain metallicity. When the strain reaches 13, 15, and 12%, respectively, the maximum tensile stress values of 1st-C(111)/Ti(112̅0), 2nd-C(111)/Ti(112̅0), and 4th-C(111)/Ti(112̅0) interface models are observed to be 16.207, 19.183, and 17.393 GPa, respectively. After all C(111)/Ti(112̅0) interfaces fracture under tension, the Ti atoms of the Ti(112̅0) surface are transferred to the C(111) surface, indicating that the strength of Ti-C bonds at the interface is higher than the strength of Ti-Ti bonds inside the Ti(112̅0) surface. The maximum value of the sliding potential energy surface is 1.709 J/m2; the maximum value of the potential energy curve is 0.445 J/m2; and the ideal shear strength of the C(111)/Ti(112̅0) interface is 0.386 GPa. In summary, the interfacial adhesion property of the 2nd-C(111)/Ti(112̅0) interface is better than those of 1st-C(111)/Ti(112̅0) and 4th-C(111)/Ti(112̅0) interfaces.

Role of titanium and organic precursors in molecular layer deposition of "titanicone" hybrid materials.

The development of hybrid inorganic-organic films with well-controlled properties is important for many applications. Molecular layer deposition (MLD) allows the deposition of these hybrid films using sequential, self-limiting reactions, similar to atomic layer deposition (ALD). In this paper, we use first principles density functional theory (DFT) to investigate the growth mechanism of titanium-containing hybrid organic-inorganic MLD films, known as "titanicones". We investigate in detail the chemistry between the most common Ti precursors, namely titanium tetrachloride (TiCl4) and tetrakis(dimethylamido)titanium (Ti(DMA)4), and ethylene glycol (EG) and glycerol (GL) as the organic precursors. We analyse the impact of the substrate on the initial MLD reactions in titanicone film growth using three different surface models: anatase TiO2, rutile TiO2 and Al2O3. Calculated energetics show that while TiCl4 is reactive towards the anatase and rutile TiO2 surfaces, it is not reactive towards the Al2O3 surface. Ti(DMA)4 is reactive towards all surfaces. This is attributed to the stronger Ti-Cl bonds in TiCl4 compared to Ti-N bonds in Ti(DMA)4. Ti(DMA)4 also shows high reactivity to the organics compared to TiCl4. Double reactions of EG and GL with the TiCl3 species from TiCl4 and TiDMA species from Ti(DMA)4 are also explored to better understand the origin of the different thicknesses of EG-titanicone and GL-titanicone films observed in experimental work. We find that EG and GL coupled with TiCl4 can orient in a flat lying configuration on anatase while on rutile, the preferred orientation is upright. When combined with Ti(DMA)4, EG and GL prefer the flat lying configuration on all surfaces. This work shows that the choice of the surface and the metallic precursor has a major impact on the behaviour of organic species. DFT findings provide motivation to develop a low temperature rutile TiO2/titanicone film suggesting that the desired film growth could be achieved.

Ti–Cl bonds decorated Ti2NT x MXene towards high-performance lithium-ion batteries

Transition metal carbides or nitrides, collectively known as MXenes, are burgeoning two-dimensional materials for energy conversion and storage. The surface chemistry of MXenes could be specially tuned by the modified surface terminations, which directly influences their physicochemical properties. However, the in-depth study and understanding of the specific microstructure and the influence on the electrochemical performance of these terminations remain lacking. Herein, we present an accordion layered Ti2NT x MXene with –Cl and –O terminations obtained from copper chloride molten salt etching at a relatively low temperature. X-ray absorption fine structure and x-ray photoelectron spectroscopy analyses reveal the formation of Ti–Cl and Ti–O bonds on the surface of Ti2NT x MXene. Density functional theory calculations further suggest that the surface terminations tend to be replaced by –O terminations after Ti–Cl decoration, which implies promising lithium-ion storage performance due to the high lithium affinity of –O terminations. As a result, the Ti2NT x MXene based electrode delivers a high reversible capacity (303.4 mAh g−1 at 100 mA g−1), stable cycling capability (1200 cycles without capacity attenuation), and fast Li+ storage (52% capacity retention at 32 C). This work provides a new vision for MXene surface chemistry and an effective avenue to prepare high-performance nitride electrodes, expanding the diversity and controllability of the MXenes family.

Concomitant abatement of ciprofloxacin, sulfamethoxazole and cefadroxil in synthetic wastewater using hybrid photoelectrochemical ozonation driven on TiO2 containing C, N and P species

Ciprofloxacin (CIP), sulfamethoxazole (SMX) and cefadroxil (CFX) are herein degraded in synthetic wastewater (SWW) composed of 20 mg L−1 of each pharmaceutical compound, Na2SO4, MgSO4 and biodegradable organic matter. Photoelectrocatalytic ozonation (PECO) is used to generate multiple routes of oxidizing agents (i.e. ●OH), attacking the recalcitrant pollutants, and compared against individual oxidation processes: ozonation (O3), photolysis (PH) and photoelectrocatalysis (PEC). A TiO2 electrode with N, P and C incorporated in its structure (CNP-TiNST) is synthesized throughout two subsequent anodization methods: a first electrolyte made up of ethylene glycol and ethylenediamine as C and N sources, and a second electrolyte containing phosphoric acid to introduce P. The synthesized electrode presents a significant absorption in the visible light region, according to the Diffuse Reflectance Spectroscopy (DRS) analysis, obtaining two band gaps with values of 1.62 and 2.79 eV, which are considerably reduced in the pristine TiO2 phase. X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) evaluations indicate the formation of mostly anatase phase and heterogeneous short nanostructures, respectively. XPS study reveals Ti-O, Ti-C and Ti-N bonds, confirming its successful incorporation into the photoanode. A photo-current density of 0.35 mA cm−2 is reached by the photoelectrode under Xe lamp irradiation while applying 1 V of potential vs Ag/AgCl. Contaminant removals in all systems are monitored by UV-Vis spectroscopy, High-Performance Liquid Chromatography (HPLC) and Total Organic Carbon (TOC). The highest degree of contaminant removal in SWW occurs with the PECO process (80% according to HPLC analysis), decreasing TOC by 43% in SWW; and 98% TOC removal of these pollutants in distilled water, after 240 min of treatment. A germination toxicity test is performed on Lettuce Sativa, where 100% germination is achieved in the seeds grown in the treated SWW using PECO.

Density functional theory studies on molecular geometry, spectroscopy, HOMO-LUMO and reactivity descriptors of titanium(IV) and oxidozirconium(IV) complexes of phenylacetohydroxamic acid.

The molecular geometry of new titanium(IV) and oxidozirconium(IV) phenylacetohydroxamate complexes [TiCl2 (L1)2 ] (I) and [ZrO(L1)2 ] (II) (where L1=Potassium phenylacetohydroxamate=C6 H5 CH2 CONHOK) computed by B3LYP/6-311++G(d,p) method has shown these to be distorted octahedral and square pyramidal, respectively. A comparison of computed characteristic bond lengths (CO, CN, and NO) of complexes with that of free ligand has shown chelation through carbonyl and hydroxamic oxygen atoms (O, O coordination). The TiO/ZrO bond lengths in complexes are suggestive of weak coordination through (carbonyl CO) and strong covalent (hydroxamic NO) bonding of the ligand. The magnitude of ClTiCl bond angle involving two chloride atoms is suggestive of cis-conformation at titanium metal in (I). The thermodynamic parameters Gibbs free energy, enthalpy, entropy, nuclear internal energy, constant volume heat capacity, and internal energy of ligand and complexes have been computed. From the energies of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), the global reactivity descriptors such as ionization potential (IP), electron affinity (EA), chemical potential (μ), hardness (η), softness (S), electronegativity (χ), electrophilicity index (ω), and dipole moment have been calculated. The computed vibrational frequencies, 1 H and 13 C NMR spectra have substantiated the molecular structure of complexes. The thermal behavior of complexes has been studied by thermogravimetric techniques (TGA, DTG, and DTA) in N2 atmosphere has shown complexes are thermally stable.