Titanium Dioxide Nanomaterials Research Articles

Structural and photoelectrochemical dynamics of in-situ hydrogenated anatase TiO2 thin films grown by DC reactive magnetron sputtering

Hydrogenation has become one of the most used strategies to improve the photoactive properties of titanium dioxide nanomaterials, n-TiO2. To obtain more information about the hydrogenated process on anatase TiO2 thin films and the improvement of the photoactivity of this material, we report a study on the structural changes of hydrogenated anatase thin films produced by direct-current reactive magnetron sputtering. In the first stage of the hydrogenation process, the obtained polycrystalline anatase films present an increment of the {001} facet according to the amount of hydrogen used in the plasma reaction. At higher hydrogen concentrations, amorphous and rutile phases start to appear. The photoactivity of the hydrogenated anatase samples, H:TiO2, presents a redshift of the photoelectrochemical onset and an increase of the reactivity in the UV region. Both results were experimentally and theoretically related to the formation of the {001} facet and the TiH/TiOH bonds at the surface of the hydrogenated thin films.

Characterization of nanomaterials synthesized from Spirulina platensis extract and their potential antifungal activity.

Nowadays, fungal infections increase, and the demand of novel antifungal agents is constantly rising. In the present study, silver, titanium dioxide, cobalt (II) hydroxide and cobalt (II,III) oxide nanomaterials have been synthesized from Spirulina platensis extract. The synthesis mechanism has been studied using GCMS and FTIR thus confirming the involvement of secondary metabolites, mainly amines. The obtained products have been analysed using XRD, SEM, TGA and zeta potential techniques. The findings revealed average crystallite size of 15.22 nm with 9.72 nm for oval-shaped silver nanoparticles increasing to 26.01 nm and 24.86 nm after calcination and 4.81 nm for spherical-shaped titanium dioxide nanoparticles which decreased to 4.62 nm after calcination. Nanoflake shape has been observed for cobalt hydroxide nanomaterials and for cobalt (II, III) oxide with crystallite size of 3.52 nm and 13.28 nm, respectively. Silver nanoparticles showed the best thermal and water dispersion stability of all the prepared structures. Once subjected to three different Candida species (C. albicans, C. glabrata, and C. krusei) silver nanoparticles and cobalt (II) hydroxide nanomaterials showed strong antifungal activity at 50 μg/mL with minimum inhibitory concentration (MIC) values. After light exposition, MIC values for nanomaterials decreased (to 12.5 μg/mL) for C. krusei and increased (100 μg/mL) for C. albicans and C. glabrata.

Progressive thermal onset of modified hybrid nanoparticles for oscillating flow via modified fractional approach

The aim of this research is to develop a fractional supported thermal model for studying the features of modified hybrid nanofluid endorsed by uniformly accelerating plate. The novel impact of this work is observing the comparative thermal enhancement of water base fluid by utilizing four types of nanoparticles. The silver, copper, aluminum oxide and titanium oxide nanomaterials are utilized to present the comparative thermal aspect of modified hybrid nanofluid model. Moreover, the inclined direction of magnetic impact is treated. The second-grade nonlinear model is used to explore the base fluid properties. The fractional model is first attained into dimensionless form. The fractional computations with employing the Prabhakar fractional mathematical definitions are reported. The motivations for suggesting the Prabhakar algorithm are justified as this fractional algorithm contains modern definitions without any restriction of singularities. The verification of model is accomplished after simulating the comparison task with already performed studies. The physical dynamic and thermal enhancement of transportation phenomenon is performed for specific range of flow parameters like [Formula: see text] [Formula: see text] and [Formula: see text] Based on the computational model, it is concluded that the thermal transportation phenomenon is more impressive for water-based titanium oxide nanoparticles. The temperature profile rises due to factional parameter for both copper–water- and sliver — water-based hybrid nanofluid suspension.

Synthesis and application of titanium dioxide photocatalysisfor energy, decontamination and viral disinfection: a review.

Global pollution is calling for advanced methods to remove contaminants from water and wastewater, such as TiO2-assisted photocatalysis. The environmental applications of titanium dioxide have started after the initial TiO2 application for water splitting by Fujishima and Honda in 1972. TiO2 is now used for self-cleaning surfaces, air and water purification systems, microbial inactivation and selective organic conversion. The synthesis of titanium dioxide nanomaterials with high photocatalytic activity is actually a major challenge. Here we review titanium dioxide photocatalysis with focus on mechanims, synthesis, and applications. Synthetic methods include sol-gel, sonochemical, microwave, oxidation, deposition, hydro/solvothermal, and biological techniques. Applications comprise the production of energy, petroleum recovery, and the removal of microplastics, pharmaceuticals, metals, dyes, pesticides, and of viruses such as the severe acute respiratory syndrome coronavirus 2.

Titanium dioxide nanomaterials market is expected to reach a value of around $3.6 bn by 2032, up from $1.7 bn In 2022

Titanium dioxide nanomaterials market is expected to reach a value of around $3.6 bn by 2032, up from $1.7 bn In 2022

TiO2 Nanoparticles as Bifunctional Adsorbent/Photocatalyst for Degradation of Effluent from Local Dairy in Telangana

Contamination of precious life sources with industrial waste including dairy effluent is an increasing concern worldwide. Over the past few years, titanium dioxide nanoparticles have drawn worldwide attention as an efficient photocatalyst and adsorbent for wastewater treatment. The current study refers to the potential of nitrogen doped titanium dioxide nanoparticles as an adsorbent and photocatalyst to purify wastewater from the local dairy to meet the quality of wastewater discharged into public sewers. The Nitrogen doped titanium dioxide (TiO2) Nano Materials were prepared by sol-gel technique and calcined at various temperatures. Characterization techniques such as SEM, XRD and FTIR were performed and Zeta potential was estimated. Efficiency of degradation as applied to dairy effluent has been examined varying the parameters such as time of exposure and dose of nanoparticles along with solution pH variation monitored during study. A good reduction in COD of about 99 % was observed after treatment under visible light. It is observed that calcining temperature affects activity of TiO2 nano particles. Furthermore, statistical analysis that represent experimental response as a function of independent parameters as well as analyse the interaction between the parameters was successfully employed. The results showed that TiO2 nanoparticles can be employed as adsorbents for the treatment of dairy waste water. Keywords: Adsorbent, Chemical oxygen demand, Dairy effluent, Doping, nanoparticles, TiO2

Strong Resonant Light Absorption Band on Sub-Oxidized Metal Titanium Nanostructures

Nanopatterned or roughed metallic structures have received considerable attention due to the effective light absorption capability via optical effects of light confinement or photonic excitation of surface plasmon polaritons.1, 2, 3, 4, 5 However, individual metallic structures have limited light capture. To augment the solar light utilization, coupling of different absorption modes was developed within three-dimensional architectures.6, 7 Among these, the absorbers using dielectric-nanostructures interactions showed effective light harvesting, which exhibited enhanced photocatalysis and water splitting activities. Here, we present a solid visible light absorber made of proper sub-oxidation of metal Ti through a facial approach.First, surface nanostructures were prepared using a chemical etching process on cleaned metal Ti foils. Then, a thermal sub-oxidation was employed to diffuse oxygen into the sub-surface region of the metal Ti, forming titanium-oxides nanocomposites. The titanium-oxides are composed of titanium suboxides on the sub-surface of metal Ti nanostructures. The surface sharpness of nanostructures was checked by atomic force microscopy (AFM) and scanning electron microscopy (SEM) (Figure 1), showing favorable surface nanostructures. The nanostructures of quasi-prisms with sharp nano-curvatures allow light concentration in a more vigorous intensity. The affluent sharp edges of nanostructures could behave as “hot spots”. In Figure 2, the UV-vis absorption spectra of the as-prepared specimen disclose a strong resonant light absorption in the visible region with an almost four times enhancement. The resonant absorption band position and intensity are adjustable by controlling thermal diffusion parameters and surface structures.Our observation is quite distinctive from the absorption spectra of single phases, anatase or rutile phase TiO2, and the cases of mixed-phase TiO2-x nanoparticles. To our best knowledge, this is the first demonstration of uniquely strong resonant visible absorption band by sub-oxidized metal Ti nanostructures. The absorber is of particular interest in a wide range of extensive photo-responsive applications, such as optoelectronic devices, photovoltaics, and photocatalysis. The approach represents a new pathway to enable photonic absorption within nanostructures, not only for metal Ti but also for other related metallic structures. Acknowledgments: The authors acknowledge the research grants from EEA (European Economic Area)-Norway-Romania project# GRAFTID, RO-NO-2019-0616, EEA-Poland-NOR/POLNORCCS/PhotoRed/0007/2019-00, and the Research Council of Norway projects #314012 and #245963/F50.References Montoya JH, Seitz LC, Chakthranont P, Vojvodic A, Jaramillo TF, Norskov JK. Materials for solar fuels and chemicals. Nat Mater 16, 70-81 (2016).Chen X, Liu L, Huang F. Black titanium dioxide (TiO2) nanomaterials. Chem Soc Rev 44, 1861-1885 (2015).Robatjazi H, Zhao H, Swearer DF, Hogan NJ, Zhou L, Alabastri A, McClain MJ, Nordlander P, Halas NJ. Plasmon-induced selective carbon dioxide conversion on earth-abundant aluminum-cuprous oxide antenna-reactor nanoparticles. Nat Commun 8, 27 (2017).Atwater HA, Polman A. Plasmonics for improved photovoltaic devices. Nat Mater 9, 205-213 (2010).Maier SA, Brongersma ML, Kik PG, Meltzer S, Requicha AAG, Atwater HA. Plasmonics-a route to nanoscale optical devices. Adv Mater 13, 1501-1505 (2001).Shi X, Ueno K, Oshikiri T, Sun Q, Sasaki K, Misawa H. Enhanced water splitting under modal strong coupling conditions. Nat Nanotechnol 13, 953-958 (2018).Choi D, Shin CK, Yoon D, Chung DS, Jin YW, Lee LP. Plasmonic optical interference. Nano Lett 14, 3374-3381 (2014). Figure 1

The Diatom Peptide R5 Fabricates Two-Dimensional Titanium Dioxide Nanosheets.

Diatoms use peptides based on the protein silaffin to fabricate their silica cell walls. To the interest of material scientists, silaffin peptides can also produce titanium dioxide nanoparticles. Peptide-based synthesis could present an environmentally friendly route to the synthesis of titanium dioxide nanomaterials with potential applications in water splitting and for biocompatible materials design. Two-dimensional nanomaterials have exceptional surface-to-volume ratios and are particularly suited for these applications. We here demonstrate how the silaffin peptide R5 can precipitate free-standing and self-supported sheets of titanium dioxide at the air-water interface, which are stable over tens of micrometers.

Black titanium dioxide nanomaterials for photocatalytic removal of pollutants: A review

• Black TiO 2 nanomaterials exhibited superior performance in environmental pollutant removal. • Black TiO 2 synthesis, its basic properties, environmental contaminant removing mechanism were analyzed. • Resent development of black TiO 2 on photocatalytic removal of different kinds of environmental pollutants were summarized. • The stability and recoverability of black TiO 2 were firstly discussed. Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants. As a well-developed photocatalyst, titanium dioxide (TiO 2 ) still has limits in its wide bandgap and rapid recombination rate of photogenerated charge carriers. Recently, black TiO 2 appears as a strong candidate in the improvement of sunlight harvesting, because of its excellent absorption capacity and utilization of solar radiation. Despite extensive applications in both environmental and energy fields, the use of black TiO 2 as a photocatalyst in pollutant removal is ambiguous. The primary objective of the review is to comprehensively evaluate the applications of black TiO 2 in photocatalytic removal of contaminants, including conventional organic contaminants, emerging contaminants, microbes, and heavy metals. The basic properties, photocatalytic mechanism, and synthesis of black TiO 2 have been summarized and analyzed. Moreover, the stability and recoverability of black TiO 2 have also been discussed. Finally, the perspectives of the application of black TiO 2 in pollutant removal have been further discussed.

Preparation and photocatalytic application of terbium and sulfur co-doped titanium nanomaterials.

Titanium-based nanomaterials co-doped with terbium (Tb) and sulfur (S) were synthesized by sol-gel method via a facile step. Physicochemical properties of the resulting composites were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), X-ray photo-electron spectroscopy (XPS) and UV-Vis diffused reflectance spectroscopy (DRS). Methylene blue (MB) was used as a degradation target for evaluating the photocatalytic performance. The factors which influence the photocatalytic activity were investigated, including calcined temperatures and S doping amount. Tb, S (2 wt%) co-doped TiO2 composite calcined at 500°C exhibited the highest photocatalytic activity with a degradation rate of 72.4% in 3h. The reaction constant was 0.11529, 0.26025, 0.35038 and 0.41462h-1 for undoped TiO2, Tb-doped TiO2, S-doped TiO2 and Tb, S co-doped TiO2, respectively. Importantly, the synergistic effect of terbium and sulfur dopants was profoundly discussed. Furthermore, recycling tests and acute toxicity experiments were carried out to confirm the reusability and biosafety of Tb, S co-doped TiO2.

Nanosponges for Water Treatment: Progress and Challenges

Nanosponges have shown promising capabilities for efficient removal of organic/inorganic pollutants from water based on absorption/adsorption and disinfection processes. The application of nanosponges (especially cyclodextrin-based nanosponges) can be considered a cost-effective strategy with minimal energy and time requirements in comparison to other routinely deployed water treatment modalities. These polymers with unique physicochemical properties, architectures, and highly cross-linked three-dimensional networks need to be further explored for removing pollutants with simultaneous eliminations of microbial contaminants from wastewater. Additionally, the surface functionalization of these nanosponges utilizing magnetic, titanium dioxide, and silver nanomaterials can significantly improve their properties for water remediation purposes, although nanosponges altered with carbon nanotubes and metallic nanomaterials/nanocatalysts for water treatment appliances are barely explored. Notably, crucial factors such as adsorbent type/dosage, contact time, competing ions, adsorption isotherm models, kinetics, thermodynamics, and reaction/experimental conditions (e.g., molar ratios, temperature, and pH) are important aspects affecting the adsorption and removal of pollutants using nanosponges. Furthermore, the nanotoxicity and biosafety of these nanosponge-based systems utilized for water treatment should be comprehensively evaluated. Herein, recent advancements in the design and deployment of nanosponge-based systems for removing organic/inorganic pollutants from water and wastewater are deliberated with an emphasis on challenges and perspectives.

Ternary Biocidal-Photocatalytic-Upconverting Nanocomposites for Enhanced Antibacterial Activity

Active antibacterial food packaging represents one of the most rapidly developing techniques in the food industry. The ability to inhibit, inactivate, kill, or maintain a low level of microbials in food products or food packages is crucial to reducing global foodborne diseases. Notably, metallic silver (Ag) and semiconducting titanium dioxide (TiO2) nanomaterials as well as their nanocomposites have been widely studied for food packaging because of their intrinsic biocidal and photocatalytic properties, respectively. However, they have inherent limitations associated with potential nanotoxicity of Ag nanoparticles and the need for ultraviolet (UV) irradiation for wide-bandgap TiO2 nanomaterials to invoke photocatalytic oxidation of microbials. In this context, upconverting nanocrystals (UCNCs) convert near infrared photons into visible and UV photons that could excite TiO2 without the use of a UV source. Herein, we designed ternary multifunctional nanocomposites composed of plasmonic Ag, photocatalytic TiO2, and upconverting NaYF4@Yb:Tm NPs as highly efficient biocidal nanomaterials under ambient light. The incorporation of UCNCs into the nanocomposites is found to be the key to enhanced antibacterial performance. Compared to Ag NP and Ag/TiO2 nanocomposite counterparts, the ternary Ag/TiO2/NaYF4@Yb:Tm nanocomposites yield superior antibacterial performance against Escherichia coli under both ambient light and solar simulator irradiation with UV photons filtered, when either applied alone or mixed with cellulose nanofibrils and then processed into films. Such multicomponent nanocomposites have great potential for use in food packaging as they reduce the amount of potentially toxic Ag used and are able to function without UV.

Leaching of Titanium Dioxide Nanomaterials from Agricultural Soil Amended with Sewage Sludge Incineration Ash: Comparison of a Pilot Scale Simulation with Standard Laboratory Column Elution Experiments.

Nanoscale titanium dioxide (nTiO2 (Hombikat UV 100 WP)) was applied to sewage sludge that was incinerated in a large-scale waste treatment plant. The incineration ash produced was applied to soil as fertilizer at a realistic rate of 5% and investigated in pilot plant simulations regarding its leaching behavior for nTiO2. In parallel, the applied soil material was subject to standard column leaching (DIN 19528) in order to test the suitability of the standard to predict the leaching of nanoscale contaminants from treated soil material. Relative to the reference material (similar composition but without nTiO2 application before incineration) the test material had a total TiO2 concentration, increased by a factor of two or 3.8 g/kg, respectively. In contrast, the TiO2 concentration in the respective leachates of the simulation experiment differed by a factor of around 25 (maximum 91.24 mg), indicating that the added nTiO2 might be significantly mobilisable. Nanoparticle specific analysis of the leachates (spICP-MS) confirmed this finding. In the standard column elution experiment the released amount of TiO2 in the percolates between test and reference material differed by a factor of 4 to 6. This was also confirmed for the nTiO2 concentrations in the percolates. Results demonstrate that the standard column leaching, developed and validated for leaching prediction of dissolved contaminants, might be also capable to indicate increased mobility of nTiO2 in soil materials. However, experiments with further soils are needed to verify those findings.

Effect and Mechanism of Titanium Nanomaterials on Microbial Community Structure and Function in Sequencing Batch Reactor

Effect and Mechanism of Titanium Nanomaterials on Microbial Community Structure and Function in Sequencing Batch Reactor

Engineered titania nanomaterials in advanced clinical applications.

Significant advancement in the field of nanotechnology has raised the possibility of applying potent engineered biocompatible nanomaterials within biological systems for theranostic purposes. Titanium dioxide (titanium(IV) oxide/titania/TiO2) has garnered considerable attention as one of the most extensively studied metal oxides in clinical applications. Owing to the unique properties of titania, such as photocatalytic activity, excellent biocompatibility, corrosion resistance, and low toxicity, titania nanomaterials have revolutionized therapeutic approaches. Additionally, titania provides an exceptional choice for developing innovative medical devices and the integration of functional moieties that can modulate the biological responses. Thus, the current review aims to present a comprehensive and up-to-date overview of TiO2-based nanotherapeutics and the corresponding future challenges.

Surface- and Structural-Dependent Reactivity of Titanium Oxide Nanostructures with 2-Chloroethyl Ethyl Sulfide under Ambient Conditions.

Robust materials capable of heterogeneous reactivity are valuable for addressing toxic chemical clean up. Synthetic manipulations for generating titanium oxide nanomaterials have been utilized to alter both photochemical (1000 nm > λ > 400 nm) and chemical heterogeneous reactivity with 2-chloroethyl ethyl sulfide (2-CEES). Synthesizing TiO2 nanomaterials in the presence of long-chain alkylphosphonic acids enhanced the visible light-driven oxidation of the thioether sulfur of 2-CEES. Photooxidation reaction rates of 99 and 168 μmol/g/h (quantum yields of 5.07 × 10-4 and 8.58 × 10-4 molecules/photon, respectively) were observed for samples made with two different alkylphosphonic acids (C14H29PO3H2 and C9H19PO3H2, respectively). These observations are correlated with (i) generation of new surface defects/states (i.e., oxygen vacancies) as a result of TiO2 grafting by alkylphosphonic acid that may serve as reaction active sites, (ii) better light absorption by assemblies of nanorods and nanowires in comparison to individual nanorods, (iii) surface area differences, and (iv) the exclusion of OH groups due to the surface functionalization with alkylphosphonic acids via Ti-O-P bonds on the TiO2. Alternatively, nanowire-form H2Ti2O5·H2O was produced and found to be capable of highly efficient hydrolysis of the carbon-chlorine (C-Cl) bond of 2-CEES in the dark with a reaction rate of 279.2 μmol/g/h due to the high surface area and chemical nature of the titanate structure.

Investigation of the genotoxicity of digested titanium dioxide nanomaterials in human intestinal cells

The widespread use of titanium dioxide nanomaterials (TiO2 NMs) in food and consumer products such as toothpaste or food contact materials, suggests the relevance of human oral exposure to these nanomaterials (NMs) and raises the possibility of adverse effects in the gastrointestinal tract (GIT).We previously showed that the in vitro digestion of TiO2 NMs may increase their toxicity in intestinal cells. In this work, we analyzed the genotoxicity and the intracellular reactive oxygen species induction by physiologically relevant concentrations of three different TiO2 NMs (NM-102, NM-103 and NM-105) in Caco-2 and HT29-MTX-E12 intestinal cells, while considering the potential influence of the digestion process in the NMs’ physiochemical characteristics. The results evidenced a DNA-damaging effect dependent on the NM, more relevant for the rutile/anatase NM-105, possibly due to its lower hydrodynamic size in the cells medium. In addition, the results of the micronucleus assay suggest effects on chromosomal integrity, an indicator of cancer risk, in the HT29-MTX-E12 cells, for all the tested TiO2 NMs, especially after the in vitro digestion. This work supports the evidence for concerns on the use of TiO2 NMs as a food additive, recently reported by EFSA, and for their use in applications in consumer products that may drive human exposure through ingestion.

Cellular and Molecular Mechanisms of Toxicity of Ingested Titanium Dioxide Nanomaterials.

An exponential increase in products containing titanium dioxide nanomaterials (TiO2), in agriculture, food and feed industry, lead to increased oral exposure to these nanomaterials (NMs). Thus, the gastrointestinal tract (GIT) emerges as a possible route of exposure that may drive systemic exposure, if the intestinal barrier is surpassed. NMs have been suggested to produce adverse outcomes, such as genotoxic effects, that are associated with increased risk of cancer, leading to a concern for public health. However, to date, the differences in the physicochemical characteristics of the NMs studied and other variables in the test systems have generated contradictory results in the literature. Processes like human digestion may change the NMs characteristics, inducing unexpected toxic effects in the intestine. Using TiO2 as case-study, this chapter provides a review of the works addressing the interactions of NMs with biological systems in the context of intestinal tract and digestion processes, at cellular and molecular level. The knowledge gaps identified suggest that the incorporation of a simulated digestion process for in vitro studies has the potential to improve the model for elucidating key events elicited by these NMs, advancing the nanosafety studies towards the development of an adverse outcome pathway for intestinal effects.

Sustainable decoloration of polluted water through cellulosic TiO2 nano- crystalline material composite using sono synthesis

Titanium dioxide (TiO2) nanomaterials are noteworthy for their valuable photoactive properties and applications. Their cellulosic nano-particles could be used for the decoloration of polluted water since they are eco-friendly. Therefore, this study investigated the cellulose powder coated with a layer of nano-crystalline-titanium dioxide (TiO2) through the sonosynthesis process to minimize the hazardous of contaminated water containing reactive dyes. Powder X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Zeta Potential Spectroscopy were utilized to examine the subsequent composition. Decoloration of the compositions was perceived through Ultra Violet (UV) light at 30 min. It was observed that the composition simultaneously improved the quality (cleaning) of polluted water. It absorbed the reactive dye hastily in 2 min which is the fastest time reported up to now and transformed the polluted water quality into hygienic condition. Additionally, the cleaning efficiency of the polluted water was increased with the number of functional repeats. Thus, assisted in an eco-friendly remedy of wastewater and minimizing the pollution.

Photocatalytic and Superhydrophilic TiO2‐SiO2 Coatings on Marble for Self‐Cleaning Applications

AbstractThe application of photocatalytic and self‐cleaning titanium dioxide (TiO2) nanomaterials coating on the stone of architectural heritage (particularly on marble) can be used to preserve their aesthetic qualities. The present work describes the effect of dipping time on the wetting property of coatings and the effect of UV irradiation on the coating in terms of hydrophilicity. The suspension of TiO2‐SiO2 is prepared by adding 30–50 nm in size TiO2 particles in the sol–gel processed SiO2 solution. The water contact angle (WCA) decreases with increasing dipping time of piece of marble in TiO2 – SiO2 suspension. Also the hydrophilicity of coating increases with increasing UV illumination time. The 2D and 3D laser microscope analysis revealed surface structure and stable surface roughness of 1.0 µm. Such type of superhydrophilic TiO2 – SiO2 coating may be used to protect architectural heritage and buildings.