Anatase Phase Of TiO2 Research Articles

Facile synthesis of Ni0.5Zn0.5Fe2O4/MXene composite powders for high-performance asymmetric supercapacitors

Ni0.5Zn0.5Fe2O4/Ti3C2Tx MXene composite powders were prepared by solution combustion synthesis method. The various amounts of Ti3C2Tx MXene sheets were dispersed in the precursor solution containing the metal nitrates as oxidant and glycine as fuel in water solvent. The effects of Ti3C2Tx MXene contents (25, 50, 75 wt%) on the structural, microstructural, and electrochemical properties were studied by various characterization methods. The Ni0.5Zn0.5Fe2O4 particles covered the Ti3C2Tx MXene sheets at the lower contents. However, the Ti3C2Tx MXene was delaminated to the rutile and anatase TiO2 phases without losing the sheetlike morphology at its higher contents. The Ni0.5Zn0.5Fe2O4 and Ti3C2Tx MXene had the specific capacity of 598 and 680C g−1, respectively, which was enhanced to 1614C g−1 at 1 Ag−1 for the Ni0.5Zn0.5Fe2O4–25 wt%Ti3C2Tx MXene. The hybrid capacitor made of the Ni0.5Zn0.5Fe2O4–25 wt% MXene composite powders as positive electrode and activated carbon as negative electrode showed the energy density of 53 Whkg−1 at the power density of 1335 Wkg−1 by applying a current density of 1 Ag−1.

Enhanced Photocatalytic activities of TiO2 through Metal chalcogenides based Nanocomposites (ZnS/TiO2) for Methylene Blue degradation

We report the photocatalytic activity of ZnS/TiO2 nanocomposite synthesized through a one‐step hydrothermal method. The effect of ZnS concentration on the phase and morphology of coupled materials was investigated. X-ray diffraction (XRD) confirms the phase purity and formation of the tetragonal structure of anatase phase TiO2. From the UV-Visible spectra, it is found that the increase in ZnS concentration enhances the absorption towards higher wavelength. The surface morphology as revealed by Transmission electron microscope (TEM) shows the formation of the mesoporous structure of TiO2. The presence of ZnS deposited on the mesoporous structure of TiO2 was further confirmed through elemental (EDX) analysis. The surface area of ZST1 is found to be 236.23 m2/g as measured by Brunauer Emmett-Teller (BET) analysis. The addition of ZnS prevents the aggregation of TiO2 and promotes the carrier transfer efficiency, high electron mobility and thus enhancing the photocatalytic activity. The highest degradation efficiency was found to be 93 % of methylene blue (MB) solution after 60 minutes under visible light irradiation.

Influence of copper and iron transition metals in the photocatalytic activity of titanium dioxide microspheres

This work proposes the combined sol–gel/solvothermal synthesis method to prepare Cu-doped TiO2 and Fe-doped TiO2 microstructures, and further study their photocatalytic activity in the degradation of Eriochrome Black T (EBT) at neutral conditions using a simulated sunlight source. TiO2:at%M (at%=0.25, 0.5, and 1.0; M = Cu or Fe) catalysts were characterized by X-ray diffractometry, Scanning electron microscopy, Diffuse reflectance UV–Vis spectroscopy, Raman spectroscopy, and Brunauer-Emmett-Teller surface area analysis. All synthesized catalysts showed TiO2 anatase phase with spherical morphology and average particle size of 4 to 8 μm. Transition metal doping did not modify the TiO2 anatase phase. TiO2:at%M catalysts exhibited lower bandgap energies than pure TiO2. TiO2:0.5at%Fe showed the lowest bandgap energy (2.87 eV). TiO2 catalysts with a transition metal content of 0.25at% showed a higher surface area compared to the rest of dopant concentrations. The inclusion of the metallic elements in the TiO2 structure enhances the photocatalytic efficiency of the TiO2 anatase under visible light. TiO2:0.25at%Cu showed the highest EBT degradation yields of 90% color removal, 61% total organic carbon (TOC) reduction, and 87% chemical oxygen demand decrease at 180 min. TiO2:0.25at%Cu and TiO2:0.50at%Fe microspheres retained good degradation efficiency for color and TOC removals even after being reused for three cycles.

Chitosan – TiO2 Nanocomposite Films for Efficient Decolourisation of Sulphur Black Dye under Dark Conditions

ABSTRACT Sulphur dyes are a class of dyes known for their low cost and excellent fastness to light and wash. But, excess amounts of unused dyes, electrolytes and sulphide contents were found to cause serious hazards to health and environment. This work reports the synthesis of cost-effective, non-toxic, environment-friendly chitosan (CS) and chitosan-TiO2 (5 wt% (CST-5), 10 wt% (CST-10) and 15 wt% (CST-15)) polymer nanocomposite films by the facile solution casting method. CS and CST polymer nanocomposite films were tested for the decolourisation of sulphur black dye. The structural analysis of the synthesised films using X-ray Diffraction (XRD) displayed the semi-crystalline peaks of chitosan and the anatase phase of TiO2 with tetragonal-bcc structure. The morphological analysis using Atomic Force Microscopy (AFM) revealed that TiO2 had dispersed uniformly into the polymer matrix. UV–Vis DRS and PL revealed the wide indirect band gap energy and charge transfer characteristics, respectively, of the polymer nanocomposite films. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) studies revealed the various bonds, functional groups and elemental properties of CS and TiO2-loaded CS films. Sulphur black dye decolourisation studies conducted under dark conditions at room temperature and atmospheric pressure revealed that CST-5 nanocomposite film exhibited an excellent decolourisation efficiency of 87.6% within 12 min of contact with the sulphur black dye solution. This swift and enhanced decolourisation was due to the synergistic effects of adsorption by chitosan and catalytic wet air oxidation (CWAO) by the catalyst TiO2. These nanocomposite films are potential materials for the treatment of wastewater and decolourisation of various toxic dyes.

Breaking Boundaries in LED Technology: Exploring the Revolutionary Diode Characteristics of Screen Printed (TiO2)1−x (CuO)x Thick Films

A thick TiO2-CuO composite film is deposited on a Si substrate by a low-cost screen printing method. Both anatase and CuO-doped TiO2 are characterized for diode applications. X-ray Diffraction (XRD) confirms that the composite film exists as an anatase phase of TiO2 and a monoclinic phase of CuO with a maximum diffraction of (101) plane. SEM images depict the less severe agglomeration of particles for the doped TiO2 as compared to the anatase TiO2. The UV–visible spectra reveal a direct band gap shift of 3.35 eV (pure TiO2) to 3.26 eV (doped TiO2). From the PL study, the blue shaded emission is perfectly derived for anatase TiO2 while the color is seen to change to the white zone supporting TiO2-CuO composite formation as depicted by the CIE diagram. The diode parameters such as ideality factor (n) and barrier height (Φb) are calculated with the help of I–V characteristics. This only reported novel effort on screen-printed TiO2-CuO thick film may help in manufacturing possible LEDs for optoelectronic applications.

Fabrication of ordered layered SnO2/TiO2 heterostructures and their photocatalytic performance for methyl blue degradation.

The rapid growth in population and industrialization has given rise to serious environmental issues, especially the water pollution. Photocatalysis with the assist of semiconductor photocatalysts has been considered as an advanced oxidation technique for degrading a variety of pollutants under solar irradiation. In this work, we have fabricated SnO2-TiO2 heterostructures with different ordered layers of SnO2 and TiO2 via the sol-gel dip-coating technique and utilized in photocatalysis for degradation of methyl blue dye under UV irradiation. The influence of the layer's position on SnO2 and TiO2 properties is investigated via the various techniques. The grazing incidence X-ray diffraction (GIXRD) analysis reveals that the as-prepared films exhibit pure anatase TiO2 and kesterite SnO2 phases. The 2SnO2/2TiO2 heterostructure exhibit the maximum crystallite size and smallest deviation from the ideal structure. Scanning electron microscopy cross-section images manifest good adhesion of the layers to each other and to the substrate. Fourier transform infrared spectroscopy reveals the characteristic vibration modes of SnO2 and TiO2 phases. UV-visible spectroscopy measurements indicate that all films exhibit high transparency (T = 80%) and the SnO2 film reveals a direct band gap of 3.6eV, while the TiO2 film exhibits an indirect band gap of 2.9eV. The optimal 2SnO2/2TiO2 heterostructure film revealed best photocatalytic degradation performance and the reaction rate constant for methylene blue solution under UV irradiation. This work will trigger the development of highly efficient heterostructure photocatalysts for environmental remediation.

Green Synthesized TiO2-SnO2 Nanocomposite for the Photocatalytic Degradation of Methylene Blue Dye

Abstract: TiO2-SnO2 nanocomposite was prepared by green synthesis method with the help of the Allium sativum extract obtained from garlic cloves. The green synthesized TiO2-SnO2 nanocomposite was characterized by XRD, SEM, EDS, Raman, ATR-FTIR, and UV-Visible spectroscopy. The XRD pattern reveals the polycrystalline nature of the synthesized nanocomposite and indicates the simultaneous presence of anatase and rutile phases of TiO2, along with SnO2. The calculated average crystallite size is 11.79 nm. The SEM images give the concept of surface morphologies of the synthesized nanocomposite. EDS spectrum detects the presence of Ti, Sn, and O in the synthesized nanocomposite material. The Raman spectrum confirms the chemical compositions. ATR-FTIR spectrum shows the presence of organic components of garlic as functional groups in the synthesized nanocomposite. The Tauc plot obtained from the UV-Visible spectral data displays the direct and indirect band gap values of 3.97 and 3.25 eV, respectively. Moreover, the present study investigates the effect of the synthesized nanocomposite’s concentration on the photocatalytic degradation of methylene blue (MB) dye. The aqueous suspension of TiO2-SnO2 nanocomposite photocatalyst with a concentration of 1.5 mg/mL exhibits maximum photocatalytic activity. Keywords: Green synthesis, TiO2-SnO2 nanocomposite, Allium sativum extract, Photocatalytic activity, Methylene blue.

Solvothermally Synthesized Hierarchical Aggregates of Anatase TiO2 Nanoribbons/Nanosheets and Their Photocatalytic–Photocurrent Activities

Hierarchical aggregates of anatase TiO2 nanoribbons/nanosheets (TiO2-NR) and anatase TiO2 nanoparticles (TiO2-NP) were produced through a one-step solvothermal reaction using acetic acid or ethanol and titanium isopropoxide as solvothermal reaction systems. The crystalline structure, crystalline phase, and morphologies of synthesized materials were characterized using several techniques. According to our findings, both TiO2-NR and TiO2-NP were found to have polycrystalline structures, with pure anatase phases. TiO2-NR has a three-dimensional hierarchical structure made up of aggregates of TiO2 nanoribbons/nanosheets, while TiO2-NP has a nanoparticulate structure. The photocatalytic and photocurrent activities for TiO2-NR and TiO2-NP were investigated and compared with the widely used commercial TiO2 (P25), which consists of anatase/rutile TiO2 nanoparticles, as a reference material. Our findings showed that TiO2-NR has higher photocatalytic and photocurrent performance than TiO2-NP, which are both, in turn, higher than those of P25. Our developed solvothermal method was shown to produce a pure anatase TiO2 phase for both synthesized structures, without using any surfactants or any other assisted templates. This developed solvothermal approach, and its anatase TiO2 nanostructure output, has promising potential for a wide range of energy harvesting applications, such as water pollution treatment and solar cells.

Solar-driven photodegradation of synthetic dyes by ternary of titanium oxide-copper oxide-chitosan catalyst

The ternary titanium oxide (TiO2), copper oxide (CuO), and chitosan (TiO2/CuO/Chitosan) photocatalyst (composites) for the photodegradation of synthetic methyl orange (MO) were developed by entrapping copper ions and nanosized TiO2 into chitosan thin films at room temperature. TiO2 Degussa P25 was incorporated with CuO and Chitosan (CS) solution using an ex-situ synthesis method before being immobilized onto glass plates via a dip-coating technique. This study is the first time approach for a combination of a composite comprising two metal oxides to suppress the electron-hole recombination, thus enhancing their catalytic and adsorptive properties. The morphology and surface interactions of the TiO2/CuO/Chitosan composite were determined using techniques such as XRD, FTIR, RAMAN, and SEM-EDX, respectively. The results show the anatase phase and homogenous spherical features of TiO2. The TiO2/CuO/Chitosan composites (0.5 gL-1) exhibited excellent activity for the photodegradation of MO under solar irradiation (λ > 400 nm) at different pH. The decolorization efficiency increased according to pH 9 < pH 7 < pH 6 < pH 3 with the highest degradation efficiency of 85.29% at 1 ppm MO solution, reaching two times greater than the pristine TiO2 nanoparticles (56.55%). Complete degradation of MO was attained at 240 min of solar irradiation with pH 3 using the optimum TiO2/CuO/Chitosan composites of 1:4:1 composition (5 cycles of dip coating) and the photodegradation rate constant is 0.0073 min−1. The physic-chemical study has established the structure, crystalline phase, surface contact, and stability of the catalyst. The photocatalytic improvement under visible irradiation is attributed to band-gap reduction and suspension of electron-hole recombination of the ternary catalyst system. The results of this study offer guidelines for the design of a new synthetic strategy.for the preparation of an efficient photocatalyst for the selective oxidation of synthetic azo dyes compounds.

Green synthesis, antioxidant and anticancer activities of TiO2 nanoparticles using aqueous extract of Tulbhagia violacea

In this study, titanium oxide nanoparticles represented as TiO2(1), TiO2(2), and TiO2(3) were prepared using different volumes (10, 20, and 40 mL, respectively) of aqueous leaf extract of Tulbhagia violacea. The physicochemical characteristics of these materials were established using X-ray diffraction (XRD), ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy. The obtained XRD pattern confirmed the formation of the anatase TiO2 phase in all the prepared materials irrespective of the volume of extracts used. Nevertheless, TiO2(2) nanoparticles obtained using 20 mL of plant extract showed the highest crystallinity. The maximum absorption wavelength found in the region between 260 and 267 nm in the UV–vis spectroscopy study suggested a quantum size effect. All synthesized TiO2 nanoparticles appeared to possess varying shapes and sizes, mostly dominated by rectangular shapes that were irregularly distributed across the materials. The material was found to be highly agglomerated due to the high calcination temperature. The antioxidant assay showed weak to moderate activity relative to the standard ascorbic acid. Also, compared to 5-Fluorouracil, all the nanoparticles exhibited moderate cytotoxicity against HEK 293 and HeLa cell lines. The TiO2 (1) showed the best specificity towards the cancer cell line with IC50 values of 29.73 and 34.27 µg/mL for both HeLa and HEK 293 cell lines, respectively. This suggests its potential as a promising candidate in applications where it is important to protect healthy cells.

Growth and characterization of screen printed TiO2–CuO thick films for optoelectronic applications

We herein report, the deposition of pure and CuO doped TiO2 thick films on glass slides by a cost effective screen printing process, which were then sintered to obtain desired stochiometric composition. Different analytical approaches were used to reveal the precise structural, morphological, optical and electrical characteristics information of pure TiO2 and TiO2–CuO thick films. X-ray diffraction (XRD) patterns exhibit the formation anatase phase of TiO2 and monoclinic phase of CuO. Raman spectra show four TiO2 anatase phase modes only in 100–800 cm−1 region. Infrared (IR) transmittance spectra of these samples recorded in 4000–400 cm−1 region also showed weak, very weak and medium intensity stretching and bending modes of O–Ti–O and Ti–O–Ti bond groups of TiO2 only in 700–400 cm−1 region which further supported the formation of TiO2 anatase phase only. Scanning electron microscopy (SEM) images indicate porous surfaces morphology, irregular shaped as well as size polygonal and spherical shaped particles with tendency to form aggregates along with the EDS analysis that confirms proper composition of the films. The optical band gap energies were derived from diffused reflectance spectroscopy and photoluminescence (PL) spectra. They showed a red shift in peak positions which caused reduction in band gap energy. The CIE diagram clearly depicted blue-green and white emissions. I–V characteristics has been used for calculation of the diode parameters such as ideality factor (n) and barrier height (Φb). The extracted results such as band gap, particle size and electrical parameters suggest that the TiO2–CuO thick films can be used in photovoltaic applications.

Correlating the Nonlinear Roughening and Optical Properties of Anatase Thin Films—A Fractal Geometric Approach

AbstractThe anatase phase of TiO2 is highly suitable for photocatalytic application consequently, prerequisite an unpretentious scale‐independent understanding of its roughening‐facilitated surface topography dynamics. Herein, the nonlinear roughening in anatase thin films and its correlation with the nonlinear trend of optical properties in the framework of fractal geometry are investigated. The self‐affine nature of analyzed surfaces is confirmed from the autocorrelation function. The dynamic scaling exponents indicate the existence of Kardar–Parisi–Zhang scaling in surface growth. In addition, the trend of generalized Hurst exponent and mass exponent indicates insignificant multifractal characteristics in the analyzed surfaces. Moreover, fractal analysis explains and aids to description of roughening trend from stereometric and Minkowski functionals analysis. Furthermore, the significance of fractal dimension for probing the surface roughening is validated from the principal component analysis. Consequently, variation in optical bandgap and linear refractive index are investigated in regards to the fractal dimension and root mean‐squared surface slope and regression equations are proposed for tuning of bandgap.

Multi‐Phase Sputtered TiO2‐Induced Current–Voltage Distortion in Sb2Se3 Solar Cells

AbstractDespite the recent success of CdS/Sb2Se3 heterojunction devices, cadmium toxicity, parasitic absorption from the relatively narrow CdS band gap (2.4 eV) and multiple reports of inter‐diffusion at the interface forming Cd(S,Se) and Sb2(S,Se)3 phases, present significant limitations to this device architecture. Among the options for alternative partner layers in antimony chalcogenide solar cells, the wide band gap, non‐toxic titanium dioxide (TiO2) has demonstrated the most promise. It is generally accepted that the anatase phase of the polymorphic TiO2 is preferred, although there is currently an absence of analysis with regard to phase influence on device performance. This work reports approaches to distinguish between TiO2 phases using both surface and bulk characterization methods. A device fabricated with a radio frequency (RF) magnetron sputtered rutile‐TiO2 window layer (FTO/TiO2/Sb2Se3/P3HT/Au) achieved an efficiency of 6.88% and near‐record short–circuit current density (Jsc) of 32.44 mA cm−2, which is comparable to established solution based TiO2 fabrication methods that produced a highly anatase‐TiO2 partner layer and a 6.91% efficiency device. The sputtered method introduces reproducibility challenges via the enhancement of interfacial charge barriers in multi‐phase TiO2 films with a rutile surface and anatase bulk. This is shown to introduce severe S‐shaped current–voltage (J–V) distortion and a drastic fill–factor (FF) reduction in these devices.

Tailoring Black TiO2 Thin Films: Insights from Hollow Cathode Hydrogen Plasma Treatment Duration

In this study, we report the use of a radiofrequency plasma-assisted chemical vapor deposition (RF-CVD) system with a hollow cathode geometry to hydrogenate anatase TiO2 thin films. The goal was to create black TiO2 films with improved light absorption capabilities. The initial TiO2 was developed through magnetron sputtering, and this study specifically investigated the impact of hollow cathode hydrogen plasma (HCHP) treatment duration on the crucial characteristics of the resulting black TiO2 films. The HCHP treatment effectively created in-bandgap states in the TiO2 structure, leading to enhanced light absorption and improved conductivity. Morphological analysis showed a 24% surface area increase after 15 min of treatment. Wettability and surface energy results displayed nonlinear behavior, highlighting the influence of morphology on hydrophilicity improvement. The anatase TiO2 phase remained consistent, as confirmed by diffractograms. Raman analysis revealed structural alterations and induced lattice defects. Treated samples exhibited outstanding photodegradation performance, removing over 45% of methylene blue dye compared to ~25% by the pristine TiO2 film. The study emphasized the significant impact of 15-min hydrogenation on the HCHP treatment. The research provided valuable insights into the role of hydrogenation time using the HCHP treatment route on anatase TiO2 thin films and demonstrated the potential of the produced black TiO2 thin films for photocatalytic applications.

Photocatalytic and photovoltaic applications of green synthesized titanium oxide (TiO2) nanoparticles by Calotropis gigantea extract

Titanium di oxide (TiO2) nanoparticles were prepared by green synthesis method using leaves, seeds, and flower solvent extract of Calotropis gigantean medicinal plant. The X-ray diffraction (XRD) analysis of the prepared TiO2 nanoparticles shows tetragonal structure of anatase phase TiO2. The quantum confinement of the TiO2 particles by the inclusion of active biomolecules was confirmed by optical studies. The polycrystalline nature of the prepared nanoparticles was confirmed by XRD and SAED analysis. The particle size reduction and increase of band gap energy are noted with Calotropis gigantean leaf assisted TiO2, while it increases with flower and seed assisted TiO2. The prepared nanoparticles exhibit the size dependent photocatalytic activity and solar cell fabrication. Calotropis gigantean leaf assisted TiO2 NPs had the highest photocatalytic activity, completely degrading methylene blue in 60 min with an 96 % of degradation, due to a low recombination rate of photo-generated electrons and holes. The prepared Calotropis gigantean plant assisted TiO2 nanoparticles boosted the concentration of OH• and O2• radicals in the solution, which is beneficial for enhancing the photodegradation rate of organic compounds. Plant derivative based TiO2 nanoparticles are the best candidates due to simplicity and cost-effectiveness leading to economical and operational advantages in the large-scale synthesis of nanoparticles.

Direct sunlight photodegradation of congo red in aqueous solution by TiO2/rGO binary system: Experimental and DFT study

Photolysis was employed to produce titanium dioxide (TiO2) with exposed (001) facets, which were then modified by incorporating reduce graphene oxide (rGO) sheets at (1, 3 and 5) wt.%.The chemical composition, optical properties, morphology, and electrochemical behavior of both the pure and composite nanomaterials were analyzed. The X-ray diffraction (XRD) and Raman spectroscopy techniques confirmed the formation of the anatase phase of TiO2 in the samples. The Debye Scherrer method was utilized to estimate the size of the particles. It was observed that the particle size decreased as the concentration of rGO increased; at 5 wt% rGO, the size was 11 nm. The morphology of the rGO/TiO2 nanocomposite was analyzed with transmission electron microscopy (TEM) which showed that TiO2 nanoparticles were dispersed on the surface of the rGO sheets. The analysis of the X-ray photoelectron spectrum (XPS) revealed that bonding of TiO2 with rGO occurred through the formation of Ti-C and Ti-O-C bonds. The results obtained from the diffuse reflectance spectroscopy (DRS) showed a decrease in band gap upon an increase in rGO concentration. Moreover, confirmation was obtained regarding the reduction of recombination carriers through the photoluminescence (PL) spectrum. The results indicated that the prepared nanocomposite had a high number of oxygen vacancies. The photodegradation mechanism of congo red dye under sunlight was studied by Liquid chromatography–mass spectrometry (LC-Mass) and scavenger effect. The photodegradation of congo red dye (CR) utilizing TiO2, both pure and incorporated with rGO, was observed under normal conditions in the presence of sunlight. The study revealed that the optimal condition for achieving maximum photodegradation of CR dye was pH = 7, 100 min, 50 ppm initial CR dye concentration and 10 mg of catalyst dosage. The photodegradation data illustrated that 5 wt% rGO doped TiO2 exhibits higher efficiency than other 3; 1 wt% rGO and pure TiO2. Finally, the improving breakdown of CR dye using direct sunlight showed high efficiency without leaving behind any secondary intermediates.

Green Synthesis by Microwave Irradiation of TiO2 Using Cinnamomum verum and the Application in Photocatalysis

The extraction process of bioactives from the aqueous extract of cinnamon (Cinnamomum verum) was optimized using the Design Expert 11 program and analysis of variance (ANOVA) by considering the following parameters: cinnamon weight (g), power (W), and time (s) of microwave irradiation. The optimal conditions are cinnamon weight of 4.5 grams, time of 600 seconds, and power of 150 watts of microwave irradiation. With Cinnamomum verum extract under optimal conditions and titanium (IV) tetrachloride as a precursor, TiO2 nanostructures were synthesized using the sol-gel method assisted by microwave irradiation in the crystallization stage with a power and irradiation time of 150 W and 600 sec, respectively. Similarly, a sample without extract was synthesized under the same conditions. The following techniques characterized the materials: X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-vis diffuse reflectance, Raman spectrometry, and high-resolution transmission electron microscopy (HRTEM). It was feasible to obtain nanocrystalline solids of TiO2 anatase phase with and without cinnamon extract; the particle size and the crystallinity were influenced by the bioactive agents during the synthesis (aqueous extract of Cinnamomum verum) and the synthesis method (microwave irradiation); a smaller crystal size, a smaller particle size, a higher crystalline order, and a lower band gap were achieved for the material synthesized with cinnamon extract compared to the material synthesized without extract and other methods. The synthesized materials were evaluated in the photodegradation of methyl orange (as a model of photodegradation), employing as reference parameters the commercial TiO2 brand Sigma-Aldrich phase anatase and the photolysis of the system. The amount of dye adsorbed in the tested materials was quantified, finding an equilibrium time of 15 min, where the TiO2 synthesized with Cinnamomum verum extract was the material that most adsorbed methyl orange at 7.5%. In the case of photodegradation, the TiO2 synthesized with cinnamon extract apparently promoted the total mineralization of methyl orange in 40 minutes of reaction, making it the best material of those evaluated in the photodegradation. In all cases, the degradation models were adjusted to a first-order kinetic model, where it was confirmed that the highest reaction rate corresponded to TiO2 synthesized with Cinnamomum verum.

Cerium Ion-Incorporated Titanium Metal Implants of Enhanced Bioactivity for Biomedical Applications.

The enhancement in the performance of metallic bone implants based on commercially pure titanium (CP-Ti) by incorporation of cerium (Ce) ions onto the surface was evaluated. The incorporation of Ce ions onto the CP-Ti surface was carried out by a simple two-step chemical treatment method, where an initial NaOH treatment and then a subsequent treatment with different molar concentrations of ceric nitrate solution followed by heat treatment at 600 °C were carried out. The modified surfaces were observed using field emission scanning electron microscopy (FE-SEM), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), X-ray photoelectron spectroscopy (XPS), the laser Raman spectroscopic technique, high-resolution transmission electron microscopy (HR-TEM), and atomic force microscopy (AFM). The formation of a nanonetwork structure by the initial NaOH treatment and the replacement of Na ions with Ce ions along with different phases of TiO2 was evident from the surface characterization results. The transition of rutile TiO2 to anatase TiO2 in the modified surface is evident from the Raman spectra with respect to the treatment of higher to lower concentrations of ceric nitrate solution. The presence of two different oxidation states of Ce (Ce3+ and Ce4+) and improvement in the surface wettability were also distinct in the modified samples. Thus, the incorporated Ce ions over the nanostructured titania network showed low cytotoxicity, good cell adhesion, and enhanced extracellular mineralization on MG-63 cells with better protein adsorption in BSA medium. Taken together, the thus-improved nanostructured surface morphology with the anatase TiO2 phase and distinct extracellular mineralization in the Ce-incorporated Ti metal with good biocompatibility make it a promising candidate for bone implant applications.

Precursor concentration-dependent structural, optical and electrical properties of titanium dioxide nanostructures

Titanium dioxide (TiO2) is a widely used material in many industries due to its unique properties, such as high refractive index, high chemical stability, and excellent photocatalytic as well as antimicrobial activity. The anatase phase of TiO2 is particularly important because it exhibits the highest photocatalytic activity among all TiO2 phases. The anatase phase TiO2 nanostructures are synthesized by the Sol-Gel route at a fixed calcination temperature of 600 °C and varying precursor concentrations i.e. the number of moles of TTIP and its influence on the structural, optical and electrical properties is investigated. The most prominent peak in XRD spectra is (101) which corresponds to anatase TiO2 with average crystallite size ranging from 20 nm to 37 nm at a TTIP concentration varying from 6.75 mmol to 16.9 mmol. With the increase of precursor concentration, the dislocation density decreases gradually. The SEM micrograph reveals the formation of nanosheets at lower concentrations and both nanosheets and nanoparticles at higher concentrations. From the UV–visible spectroscopy and four probe resistivity measurements, the energy band gaps and resistivity of the nanostructures are found to decrease with the increase of concentration. For making the theoretical prediction of our experimental results, the DFT was employed to simulate and calculate the structural and electronic properties of the synthesized materials which revealed the indirect band-gap of 1.94 eV for the anatase phase. The XRD spectra generated from the simulated anatase phase also matched the experimental XRD data.

Growth of TiO2–CdO coated films: A brief study for optoelectronic applications

Current work reports the deposition of pure and TiO2 doped CdO printed films on glass substrate via cost-effective screen-printing method and then sintered at 550 °C for 10 min. The pure TiO2, CdO and TiO2–CdO coated films were used to investigate the structural, morphological and opto-electrical properties by different analytical techniques. X-ray diffraction pattern of polycrystalline doped analogue confirms the existence of TiO2 anatase phase and cubic phase of CdO with a maximum diffraction of (101) plane. Surface morphology is derived from scanning electron microscopy finding out porous images along with EDS results to confirm the desired composition. The spectra of UV–Vis diffused reflectance spectroscopy and photoluminescence absorbance peaks show a red shift due to change in reflectance. IR transmittance spectra recorded in 4000-400 cm−1 region exhibits the stretching modes of O–Ti–O and Cd–O groups present in these samples. The current vs. voltage (IV) characteristics and direct current conductivity measurement shows p-n junction diode behaviour. All the parameters were calculated and described in-depth, including structural, optical and electrical properties. The obtained results suggest that TiO2–CdO thick film could be used in optoelectronic applications due to the shift in optical radiation absorption to visible region, reduction in recombination rate of charge carriers and increase in electrical conductivity.