Pure Titania Research Articles

Enhancing dye-sensitized solar cells efficiency through organic dyes-sensitized holmium-doped TiO2/SnO2 nanocomposites blended with P3HT

The pursuit of sustainable energy solutions has spurred innovation in photovoltaic technology, with dye-sensitized solar cells (DSSCs) emerging as promising contenders. This study presents a novel approach leveraging holmium-doped TiO2/SnO2 nanocomposites sensitized with organic dyes, Arsenazo-III, carminic acid, and dithizone, blended with poly (3-hexylthiophene) (P3HT). Through meticulous characterization and analysis, key parameters including short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and overall percent efficiency (%) were scrutinized to evaluate photovoltaic performance comprehensively. Absorption spectra analysis facilitated the calculation of band gaps, revealing a significant reduction from 3.10 eV in pure Titania (TiO2) nanoparticles to 2.72 eV upon doping with Holmium and coupling with SnO2. Notably, Arsenazo-III dye-sensitized holmium-doped TiO2/SnO2 nanocomposites exhibited highest power conversion efficiency, achieving a promising efficiency of 2.10 %, which marked a significant improvement over the reference device (0.82 %). This improvement is attributed to the synergistic effects of holmium dopant incorporation and SnO2 interaction, enhancing light responsiveness. The findings not only validate the efficacy of nanohybrid assemblies but also contribute valuable insights to solar cell technology advancement.

Hybrid magnetic nanocomposite NiFe2O4/TiO2 for Photocatalytic dye degradation and green hydrogen (H2) generation

The present paper focuses on designing and developing nanocomposites to modify their properties to increase the ability to generate hydrogen and degrade photocatalytic dyes. A nanocomposite of nickel ferrite (NiFe2O4)/Titanium dioxide (TiO2) was formulated using the sol-gel self-ignition method. X-ray diffraction (XRD) tool was adopted to analyze the structural behavior of pure nickel ferrite (NiFe2O4), pure titanium dioxide (TiO2), and nanocomposite of NiFe2O4/TiO2. XRD pattern of NiFe2O4 and TiO2 shows a monophasic nature whereas the XRD pattern of nanocomposites shows mixed phases of NiFe2O4 and TiO2. FTIR spectra confirm the formation of NiFe2O4, TiO2, and their composites with absorption bands near 400 cm-1 and 600 cm-1, 1500 cm-1. Raman spectra unveiled the presence of five active Raman modes in the case of NiFe2O4 whereas three active Raman modes are seen in TiO2. Field emission scanning electron microscopy (FE-SEM) images exposed the dense structure with spherical cluster-like morphology in the case of NiFe2O4. Energy-dispersive X-ray spectroscopy (EDX) analysis confirms the presence of all the desired elements of NiFe2O4, TiO2, and their composites in stoichiometric proportions. BET analysis of nickel ferrite NPs suggests a large surface area of the order of 31.54 m2/gm in comparison with TiO2 (19.23 m2/gm). The optical characterization was made through the UV-visible spectroscopic technique. TiO2 shows a maximum band gap of the order of 3.02 eV while NiFe2O4 shows a low band gap of the order of 1.74 eV. A typical M-H curve with saturation magnetization of the order of 27.54 emu/gm was observed for pure NiFe2O4. No magnetic properties were observed for TiO2 as it is a semiconductor. Enhancement in magnetic properties is observed with increases in NiFe2O4 content in a composite of NiFe2O4/TiO2. The photocatalytic activities were examined by degrading Methylene Blue (MB) dye under sunlight for pure nickel ferrite (NiFe2O4), pure titanium dioxide (TiO2), and a nanocomposite of NiFe2O4/TiO2. Photocatalytic hydrogen production reactions were carried out in a methanol/water solution under visible light. Consequently, the best configuration of the photocatalyst was determined as 25% wt% NiFe2O4/ TiO2 which had shown the maximum hydrogen (H2) production rate as 146.3 μmol/g/h after 8 h owing to its reduced bandgap energy and delayed e- / h+ recombination.

Ixora Coccinea Extract for Biosynthesis of Titanium Dioxide Nanoparticles: A Precursor for Organic Electronics

This study explores the synthesis, characterization, and evaluation of titanium dioxide nanoparticles (TiO2NPs) as a precursor for the electron transport layer in organic electronics. Traditional physical and chemical synthesis methods are not environmentally friendly or economical, due to the use of toxic chemicals and high energy. However, biosynthesis offers a low-cost, eco-friendly alternative. The synthesized NPs were characterized using various techniques, including X-ray diffraction technique, transmission electron microscopy, scanning electron microscopy, Fourier Transform Infra-red microscopy, electron dispersive X-ray, and UV-visible spectroscopy with a four-point probe equipped with Keithley2400 source meter. Results showed high crystallinity and a band gap energy of 4.02 eV. Electrical properties show sheet resistance, resistivity and conductivity as 67.22 x 106 Ω, 1.71 x 106 Ωm-1 and 0.585 x-6 Sm-1 respectively which were promising, with better photovoltaic characteristics than pure titanium dioxide. These properties suggest potential applications as an electron transport layer for solar cell technology.

Preparation of Titanium Dioxide (TiO<sub>2</sub>) from Waste of Polymetallic Ore Processing <i>via</i> Sulfurization Treatment

Various experimental conditions were applied to extract titanium oxide from the waste of polymetallic ore. X-ray diffraction (XRD) analysis confirms that the waste of polymetallic ore contains including various minerals such as almandine (Fe,Mg,Ca)3Al2Si3O12, brownmillerite (FeAlO3(CaO)2), quartz (SiO2), magnetite (Fe3O4). Using H2SO4 acid with a concentration of 93% in the S/L mass ratio of 1:1.5 at 140 °C is suggested as an optimum reaction condition. Its hydrolysis subsequently leads to the formation of the titanyl sulfate (TiOSO4), and relatively pure titanium oxide is obtained through precipitation and calcination at 600 °C. The observed band gap value of 3.2 eV for the obtained TiO2 corresponds to the typical band gap value of anatase-type TiO2. We calculated the crystallite size of extracted anatase-type titanium oxide according to the Debye-Scherrer equation it was determined to be 96.35 nm. Fully reflecting X-ray fluorescence (XRF) determined that the purity of extracted TiO2 is 93.18%. This report presents a newly developed process that enables the production of relatively high-purity TiO2 (93.18%) from the waste of polymetallic ore (TiO2 5.39%) by a simple sulfurization process.

Amorphous-Crystalline Interface Induced Internal Electric Fields for Electrochromic Smart Window.

Balancing optical modulation and response time is crucial for achieving high coloration efficiency in electrochromic materials. Here, internal electric fields are introduced to titanium dioxide nanosheets by constructing abundant amorphous-crystalline interfaces, ensuring large optical modulation while reducing response time and therefore improving coloration efficiency. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) reveals the presence of numerous amorphous-crystalline phase boundaries in titanium dioxide nanosheets. Kelvin probe force microscopy (KPFM) exhibits an intense surface potential distribution, demonstrating the presence of internal electric fields. Density functional theory (DFT) calculations confirm that the amorphous-crystalline heterointerfaces can generate internal electric fields and reduce diffusion barriers of lithium ions. As a result, the amorphous-crystalline titanium dioxide nanosheets exhibit better coloration efficiency (35.1cm2C-1) than pure amorphous and crystalline titanium dioxide nanosheets.

Tweaking the structural, micro–structural, optical and dielectric properties of anatase titanium dioxide via doping of nitrogen ions

The pure nanostructured anatase titanium dioxide (TiO2) and subsequent nitrogen–doped derivatives (TiO2–xNx; where, x = 0.005, 0.01, 0.05) were synthesized by sol–gel auto–combustion technique. XRD analysis confirms the formation of pure anatase phase of TiO2 up to doping of 1 mol% (x = 0.01) of nitrogen having tetragonal structure with space group of I41/amd whereas an additional monoclinic phase of TiO2–B was observed at 5 mol% of nitrogen doping in TiO2. This sample has smallest crystallite size of ∼4.7 ± 0.2 nm corresponding to TiO2–B phase and ∼12.0 ± 0.1 nm corresponding to anatase phase. XRD also reveals that the crystallite size of all other samples having pure anatase phase ranges between ∼8.7 ± 0.1 nm & 13.9 ± 0.1 nm. The crystalline phase revealed from XRD of all samples was further supported by the Raman analysis. The direct optical band gap of pure TiO2 (∼3.4 eV) was reduced non–monotonically after nitrogen doping in the ranges from ∼2.8 eV (TiO1.95N0.05) to ∼2.0 eV (TiO1.99N0.01). FTIR spectra confirm the metal oxide bond formation, surface adsorption of water molecules and presence of residual hydroxyl group in all crystalline samples. HRTEM analysis validates the coexistence of secondary phase of TiO2–B along with anatase phase of TiO2 in studied highest doped sample (TiO1.95N0.05) including its broader particle size distribution as compared to pure TiO2. The electrical studies reveal that the highest values of dielectric constant and ac conductivity can be realized for pure TiO2 and at 1 mol% (x = 0.01) of nitrogen doping, among all the studied nitrogen doped samples.

Platelet interaction and performance of antibacterial bioinspired nanostructures passivated with human plasma

The ever-increasing ageing of the world population is demanding superior orthopedic devices. Issues such as implant infection, poor osseointegration, or chronic inflammation remain problematic to the lifespan and long-term efficacy of implants. Fabrication of materials with bioinspired nanostructures is one emerging antibacterial strategy to prevent implant infection, however their interactions with blood components, and whether they retain their bactericidal properties in an environment displaying a complex protein corona, remains largely unexplored. In the present study, titanium alloy, commercially pure and plasma-sprayed titania were hydrothermally etched, passivated with human native plasma to develop a protein corona, and then incubated with either Staphylococcus aureus, Pseudomonas aeruginosa or human platelets. Surface analysis was first used to characterize the topography, chemical composition or crystallinity of each material. Fluorescence staining and SEM were performed to evaluate the nanostructure bactericidal properties, as well as to study platelet attachment and morphology. Composition of platelet supernatant was studied using ELISA and flow cytometry. Overall, our study showed that the bioinspired nanostructured surfaces displayed both impressive antibacterial properties in a complex environment, and a superior blood biocompatibility profile in terms of platelet activation (particularly for titanium alloy). Additionally, the amount of pro-inflammatory cytokines released by platelets was found to be no different to that found in native plasma (background levels) and, in some cases, presented a more pro-healing profile with an increased secretion of factors such as TGF-β, PDGF-BB or BMP-2. The nanostructured surfaces performed equally, or better, than hydroxyapatite-coated titanium which is one of the current gold standards in orthopedics. Although further in vivo studies are required to validate these results, such bioinspired nanostructured surfaces certainly show promise to be safely applied to medical device surfaces used in orthopedics and other areas.

Properties study of pure titanium oxide and cadmium doped thin films using chemical spray pyrolysis method and their effect on solar cell

Properties study of pure titanium oxide and cadmium doped thin films using chemical spray pyrolysis method and their effect on solar cell

Influence of Ag doping on structural, morphological, and optical characteristics of sol-gel spin-coated TiO2 thin films

Pure and Ag-doped Titanium dioxide (TiO2) thin films have been synthesized via the sol-gel spin coating method, and their structural, morphological, and optical properties have been investigated. X-ray diffraction analysis verifies that the polycrystalline anatase TiO2 phase is retained up to 2 % Ag doping. However, lattice expansion and grain refinement down to 25.345 nm are observed with increasing Ag content. Scanning electron microscopy (SEM) reveals the formation of large, isolated TiO2 aggregates separated by drying-induced cracks across the film surface. Optical studies show the undoped TiO2 films demonstrate excellent visible transparency (>75 % transmittance) that slightly decreases upon Ag doping, though it remains suitably high for device applications. Meanwhile, optical absorption and defect states improve with more Ag incorporation, narrowing the TiO2 bandgap from 3.83 eV (undoped) to 3.51 eV (2 % Ag-doping) due to the incorporation of Ag-induced electronic states just below the conduction band minimum. The capability to control optical and structural properties through Ag doping highlights the potential of these TiO2 films suitably tailored for photovoltaic devices or self-cleaning coatings.

Influence of Water Vapor on the Oxidation of Pure Titanium

Titanium and titanium alloys are extensively used in the aerospace, automotive, and medical industries due to their high chemical and mechanical stability. In a previous study, the influence of water vapor on the growth of the oxide scale and the formation of the oxygen diffusion zone (ODZ) for Ti-6Al-4V was investigated using a 6-zone furnace. To elucidate the effect of water vapor on the oxide scale growth and ODZ, without the effect of alloying elements on diffusion, a systematic comparative study at 500, 600, and 700 °C for up to 500 h was carried out on pure Ti. Inert marker experiments showed that outward scale growth and diffusion of Ti4+ were promoted by water vapor. Additionally, the extent of oxygen enrichment in the subsurface zone (ODZ) as a function of temperature and time was determined for pure Ti by nanoindentation profiles and compared with results obtained for Ti-6Al-4V. The thickness of the ODZ increased with increasing temperature and time for dry air and humid air. The diffusion of oxygen ions within pure Ti and Ti-6Al-4V was not significantly affected by the presence of water vapor in the oxidizing environment. The effect of water vapor on the oxide scale spallation was found to be less critical for pure Ti when compared to Ti-6Al-4V.

Band structure study of pure and doped anatase titanium dioxide (TiO2) using first-principle-calculations: role of atomic mass of transition metal elements (TME) on band gap reduction

Band structure study of pure and doped anatase titanium dioxide (TiO2) using first-principle-calculations: role of atomic mass of transition metal elements (TME) on band gap reduction

Characterization of graphene–TiO2-deposited semi-organic solar cell

High energy supply is critical, particularly in developing countries, to maintain lifestyles as the world's population and technological-economic metropolis grow. Solar photovoltaic cells have been used as an alternative to generate renewable, sustainable, and green energy for the past two decades. In general, the materials employed in the photoanode part are critical to manufacturing high-efficiency solar cells with 14–18% efficiency. A simple and successful method has been discovered for creating a film composed of graphene sheets and 99.8% pure anatase titanium oxide (TiO2) nanoparticles. After sensitization, the films were tested as photoelectrodes for dye-sensitized solar cells. The experimental results show that using an optimized graphene material considerably improves the power conversion efficiency of the cells, resulting in a 45% increase in short-circuit current density ( JSC). This study uses capsician as a bonding agent to enhance the current density of a graphene–TiO2 based semi-organic solar cell. The mechanical and electrical properties of the cell are investigated using a scanning electron microscope, energy dispersive X-ray, and Corescan.

Characterization of Gold-Enhanced Titania: Boosting Cell Proliferation and Combating Bacterial Infestation.

In this study an approach was made to efficaciously synthesize gold enhanced titania nanorods by electrospinning. This study aims to address effects of gold enhanced titania nanorods on muscle precursor cells. Additionally, implant related microbial infections are prime cause of various disastrous diseases. So, there is predictable demand for synthesis of novel materials with multifunctional adaptability. Herein, gold nanoparticles were attached on titania nanorods and described using many sophisticated procedures such as XRD, SEM, EDX and TEM. Antimicrobial studies were probed against Gram-negative Escherichia coli. C2C12 cell lines were exposed to various doses of as-prepared gold enhanced titania nanorods in order to test in vitro cytotoxicity and proliferation. Cell sustainability was assessed through Cell Counting Kit-8 assay at regular intervals. A phase-contrast microscope was used to examine morphology of exposed C2C12 cells and confocal laser scanning microscope was used to quantify cell viability. The findings indicate that titania nanorods enhanced with gold exhibit superior antimicrobial efficacy compared to pure titania. Furthermore, newly synthesized gold-enhanced titania nanorods illustrate that cell viability follows a time and concentration dependent pattern. Consequently, our study provides optimistic findings indicating that titania nanorods adorned with gold hold significant potential as foundational resource for developing forthcoming antimicrobial materials, suitable for applications both in medical and biomedical fields. This work also demonstrates that in addition to being extremely biocompatible, titania nanorods with gold embellishments may be used in a range of tissue engineering applications in very near future.

Analysis of the Inhomogeneous Growth of Sputtered Black TiO2 Thin Films.

Black titanium dioxide (B-TiO2) is a highly active photoelectrochemical material compared to pure titanium dioxide due to its increased light absorption properties. Recently, we presented the deposition of thin-film B-TiO2 using an asymmetric bipolar reactive magnetron sputter process. The resulting samples exhibit excellent photoelectrochemical properties, which can be fine-tuned by varying the process parameters. In this article, results of morphological, electrical, and photoelectrochemical measurements are discussed to better understand the surprisingly high electrochemical activity of the films. In order to study the influence of the dynamic process on film formation, we use static sputtering with a fixed substrate covering the entire chamber area in front of the two targets. This allows the material composition of the sputtered film to be analyzed depending on its relative position to the targets. The results lead to the conclusion that the asymmetric bipolar sputtering mainly produces two phases, a transparent, nonconductive crystalline phase and a black, conductive amorphous phase. As a consequence, the dynamically sputtered samples are multilayers of these two materials. We discuss that the significantly better electrical and photoelectrochemical properties emerge from the inhomogeneous nature of the laminates, like also found in core-shell nanoparticles of B-TiO2.

High responsivity UV detector based on TiO2-rGO nanocomposite material

The influence of reduced graphene oxide and the optoelectronic characterictics of a nanocomposites based on rGO and TiO2 were studied. Surface morphology and Raman spectra of nanocomposite materials indicate the presence of initial components. It has been illustrated that during hydrothermal synthesis further reduction of rGO occurs, i.e. the variety of oxygen-containing groups decreases. Studies of current-voltage characteristics have displayed the availability of rGO in the nanocomposite leads to an increase in the photo induced current to more than 40 µA. Next, the photoresponsivity of the samples was determined, which is three orders of value higher than pure titanium dioxide for nano-composite material. And the detectivity also increased 9 times. This parameter allows you to identify the performance of the device. In this regard, the UV detector based on nanocomposite has a higher performance. Studies also show a decrease in reaction time to light irradiation. When irradiated, the nanocomposite material reacts to light three orders of magnitude faster than TiO2.

Chemically reduced silver nanoparticles: preparation and applications

By virtue of their unique physiochemical properties, silver nanoparticles (AgNPs) have attracted enormous research interest for versatile applications. It is critical to study the effect of the microstructure – for example, the shape and the size of AgNPs – on their performance. Herein, AgNPs with varying shapes and sizes were synthesized by varying the manner that the reducing agent sodium borohydride (NaBH4) was added (i.e. multistep and one-step reduction methods) and then were studied for photocatalysis of dyes and electrocatalytic oxidation of glucose. The results showed that triangular AgNPs, spherical AgNPs or a mixture of triangular- and spherical-shaped AgNPs was obtained from the multistep reduction method, whereas only spherical-shaped AgNPs were yielded from the one-step reduction method. The sizes could be manipulated by changing the concentrations of the reagents or the reaction temperature. The triangular-shaped and smaller-sized AgNPs were more effective for photocatalysis of dyes, and the degradation percentage of methylene blue was enhanced to 95% for the silver (Ag)–titanium dioxide (TiO2) complex from 50% for pure titanium dioxide. Moreover, the spherical-shaped AgNPs with a smaller size could effectively detect glucose at a very low concentration of 5–10 mM with an excellent glucose tolerance.

Controlling TiO2 photocatalytic behaviour via perhydropolysilazane-derived SiO2 ultrathin shell.

This study addresses the inherent photocatalytic activity of pure titanium dioxide (TiO2), which limits its application as an industrial pigment. To mitigate this issue, a core-shell structure was employed, where TiO2 cores were encapsulated within SiO2 shells. Perhydropolysilazane (PHPS) was introduced as a superior SiO2 precursor over tetraethylorthosilicate (TEOS), resulting in thinner and more uniform SiO2 shells. Utilizing TiO2's photocatalytic properties, hydroxyl radicals facilitated the conversion of PHPS into SiO2via native Si-H bonds, eliminating the need for additional reducing agents. The formation of PHPS-derived TiO2@SiO2 core-shell nanoparticles demonstrated inherent self-limiting behaviour, ensuring uniform shell thickness regardless of PHPS concentration, simplifying the process for large-scale industrial applications compared to TEOS, which demands precise parameter control. Photocatalytic evaluations highlighted significant passivation of TiO2 photocatalytic activity by PHPS-derived TiO2@SiO2 core-shell particles and TiO2/SiO2 thin films. Specifically, TiO2@PHPS nanoparticles achieved 89-96% passivation compared to 30% with TiO2@TEOS, while TiO2/PHPS films degraded only 12% of Eosin B versus 80% with TiO2 films. Moreover, both PHPS-derived nanoparticles and films maintained TiO2's inherent high whiteness and high-refractive-index optical properties, underscoring their suitability for applications in white paint production, cosmetics, and high-refractive-index coatings.

Granular titanium dioxide and silicon‐doped titanium dioxide as reusable photocatalysts for dye removal

AbstractIn this study, photocatalytic oxidation of methylene blue (MB) and malachite green (MG) dyes was investigated using granular pure titanium dioxide and silicon‐doped granular titanium dioxide as photocatalysts. Both catalysts were used repeatedly throughout the photocatalytic oxidation experiments. The effect of initial dye and catalyst concentration on photocatalytic oxidation was investigated. The photocatalytic oxidation followed first‐order kinetics for both catalysts. The efficiency of photocatalytic oxidation increased with the increasing catalyst concentration and decreased with the increasing dye concentration. In a 60‐min reaction using granular titanium dioxide, removal efficiencies of MB and MG at 20 g/100 mL catalyst loading and 10 mg/L initial concentration were 83% and 93.3%, respectively. In a 60‐min reaction using granular silicon‐doped titanium dioxide, the removal efficiencies of MB and MG at 5 g/100 mL catalyst loading and 10 mg/L initial concentration were 90.2% and 91.6%, respectively.

Hard x-ray photoelectron spectroscopy reference spectra of Ti and TiO2 with Cr Kα excitation

Hard x-ray photoelectron spectroscopy using monochromatic Cr Kα radiation (5414.8 eV) has been used to acquire XPS and Auger data on pure titanium and titanium dioxide samples. Survey data, extended range high-resolution scans of all observed photoelectron peaks, and high-resolution scans of Auger lines are presented herein.

Soft-templated mesostructured TiO2 - SiO2 composites with high thermal stability

To overcome the drawbacks of pure mesostructured titania and in particular the low thermal stability, in this study we have investigated in detail the effect of Si4+ addition on the properties of mesostructured TiO2 prepared by combining the sol-gel process and the surfactant templating mechanism. Obtained materials have also been tested for the photodegradation of methyl orange, used as a model dye.From the SAXS and the manometry nitrogen adsorption-desorption analyses, it can be concluded that the presence of Si4+ delays the collapse of the mesopores network. Compared to the bare mesostructured TiO2, the XRD and Raman results show that the anatase and the rutile phases appear at higher temperature. The higher the Si4+ content, the higher the amorphous-anatase and rutile anatase-phase transition temperatures. The delay in the crystallization also allows the detection of the TiO2-β phase, which is an anatase phase with oxygen vacancies. These phenomena have been attributed to the « glass effect ». In that case, amorphous SiO2, which is formed during the synthesis, surrounds the titania particles and inhibits their growth, when the heating temperature is increased. By this way, the thermal stability of the mesostructured titania containing Si4+ is enhanced.Photocatalytic experiments highlight the importance of the presence of the anatase phase for the discoloration efficiency of the dye solution. Indeed, the increase of Si4+ leads to a clear decrease of the photodegradation efficiency.