Mixture Of Anatase Research Articles

Deposition of Titanium Dioxide Particles on Kanthal Coils by Direct Heating Technique for Photodegradation of Methylene Blue Solution

Organic dyes are extensively used in textile and batik industry. Dispose of untreated dye effluent into water system is hazardous to human and environment. Advanced oxidation process (AOPs) based on heterogeneous TiO2 photocatalyst is proven for effluent treatment. Immobilization of TiO2 photocatalyst on supporting substrate is one of the research focuses to realize its application in industry to minimize the loss of TiO2 photocatalyst over time during effluent treatment. Many synthesis techniques have been used to grow TiO2 photocatalyst on supporting substrates. However, these synthesis techniques are either time- or cost-consuming. In this work, a novel direct heating (DH) technique has been developed for the first time to deposit TiO2 particles on kanthal coils. The optimum deposition of TiO2 particles was achieved in 15 min using 60 W. The TiO2 particles contained mixture of anatase (82.7%) and brookite (17.3%), with an average particle size of 167.36±15.37 nm. The surface coverage of TiO2 particles on kanthal wire was good, with minimum agglomeration. The TiO2 particles deposited on kanthal coils recorded 43.7% of photodegradation efficiency in methylene blue removal under UV light.

Positive and Negative Impacts of Interfacial Hydrogen Bonds on Photocatalytic Hydrogen Evolution.

Understanding the behavior of water molecules at solid-liquid interfaces is crucial for various applications such as photocatalytic water splitting, a key technology for sustainable fuel production and chemical transformations. Despite extensive studies conducted in the past, the impact of the microscopic structure of interfacial water molecules on photocatalytic reactivity has not been directly examined. In this study, using real-time mass spectrometry and Fourier-transform infrared spectroscopy, we demonstrated the crucial role of hydrogen bond (H-bond) networks on the photocatalytic hydrogen evolution in thickness-controlled water adsorption layers on various TiO2 photocatalysts. Under controlled water vapor environments with relative humidity (RH) below 70%, we observed a monotonic increase in the H2 formation rate with increasing RH, indicating that reactive water molecules were present not only in the first adsorbed layer but also in several overlying layers. In contrast, at RH > 70%, when more than three water layers covered the catalyst surface, the H2 formation rate turned to decrease dramatically because of the structural rearrangement and hardening of the interfacial H-bond network induced during further water adsorption. This unique many-body effect of interfacial water was consistently observed for various TiO2 particles with different crystalline structures, including brookite, anatase, and a mixture of anatase and rutile. Our results demonstrated that depositing several water layers in a water vapor environment with RH ∼ 70% is optimal for photocatalytic hydrogen evolution rather than liquid-phase reaction conditions in aqueous solutions. This study provides molecular-level insights into designing interfacial water conditions to enhance photocatalytic performance.

Antibacterial Activity of Visible Light Responsive‐Silver‐Nanoparticle/Titania Composite Thin Films with Unprecedently Higher Amounts of Silver

AbstractTo study the antibacterial efficacy of metallic Ag nanoparticle/titania (Ag‐NP)/TiO2 composite thin films against Escherichia coli (ATCC 25922), COMP‐Agn with various amounts of Ag (10 mol% ≤ n ≤ 80 mol%) are fabricated on a quartz glass substrate at 600 °C using the molecular precursor method. The films are characterized by X‐ray diffraction, X‐ray photoelectron, scanning electron microscopy, transmission electron microscopy, photoluminescence, and UVvis techniques. The analysis reveals that the films are composed of metallic Ag‐NPs embedded in a mixture of anatase and rutile matrix, with a volumetric fraction of Ag ranging from 0.18 to 0.68. The antibacterial activity of the TiO2 thin film and COMP‐Agn are determined by disk diffusion and viable cell count methods. Neither pure TiO2 nor pure Ag films exhibit any discernible antibacterial under dark and visible light. The antibacterial of Ag content in composite films is observed to persist for a maximum increase of 70%. The model is proposed on the basis of photoexcited electron transfer from Ag NPs to the TiO2 conduction band of COMP‐Agn, which clarifies the main factors affecting the photoresponse and the excellent response to visible light via surface plasmon resonance.

Doping of photoactive TiO2 films by DC plasma electrolytic oxidation: Effect of transition metals

Several beneficial features maintain TiO2 in the top list of viable materials for photocatalytic purposes. However, its relatively large band-gap (3.0–3.2 eV) still hampers practical applications under sunlight. This work explores Direct Current (DC) Plasma Electrolytic Oxidation (PEO) of titanium as a fast, easily-scalable and single-step tool to synthesise doped TiO2 photoanodes with controlled morphology, crystalline structure and thickness. Zn-, Cu- and Fe-doped crystalline TiO2 films were obtained in H2SO4 aqueous solutions containing ZnSO4, CuSO4 and FeSO4 precursors, respectively. As-prepared TiO2 films showed a porous and homogeneous sponge-like surface morphology, typical of PEO-produced oxides, and a crystalline phase structure consisting of a mixture of anatase and rutile phases. The anatase content varied in the 54–100 % range and correspondingly the band-gap energy was in the 2.85–3.07 eV range. Doped oxides prepared with a low concentration of the metal precursors showed monochromatic incident-photon-to-current-efficiency (IPCE) values exceeding those obtained with pristine TiO2 by up to 24 %, best performing in the order Zn- > Cu- > Fe-doped TiO2. Photocurrent under polychromatic UV-Vis irradiation showed an analogous trend and the estimated efficiency of solar-light harvesting was in the 0.3–4 % range, with Zn- ≈ Cu- > Fe-doped TiO2. Although the superior performance of the PEO-prepared metal-doped TiO2 could not be fully confirmed by photoelectrocatalytic oxidation tests of organics, the present investigation showed the viability of DC PEO for the synthesis of metal-doped TiO2 photoanodes.

Exploring the Impact of Potential, Ammonium Fluoride Concentration, and Anodization Time on the Structure, Surface Characteristics, and Corrosion Resistance of Nanotubular Titanium Oxide Coatings on Biomedical Alloy Ti-6Al-4V ELI

The current research delves into assessing the impact of applied potential, ammonium fluoride concentration, and anodization duration on the structural, phase compositional, microhardness, and surface roughness attributes of nanotubular titanium oxide coatings on anodized Ti-6Al-4V ELI. A meticulous experimental design was executed to systematically investigate the varied effects of these factors. Scanning electron microscopy (SEM) unveiled the presence of well-defined titania nanotubes on the surfaces of the anodized specimens. X-ray diffraction (XRD) analysis discerned the composition of the nanotubular oxide layer, revealing the presence of both anatase and a mixture of anatase and rutile phases contingent upon the anodization parameters. Notably, surface microhardness, surface roughness, and corrosion resistance manifested noticeable variations in response to alterations in applied voltage, NH4F concentration, and anodization duration within the designated experimental ranges.

Effect of Heating Power on The Synthesis of Titanium Dioxide Particles by Direct Heating Method for Photodegradation of Methylene Blue Solution

Dyes are extensively used in the textile industry. Untreated dye-containing wastewater is hazardous to humans and the environment. Advanced oxidation processes (AOPs) based on heterogeneous TiO2photocatalyst is a technology that has been proven successful for effluent treatment. Nevertheless, use of TiO2 photocatalyst in particles form could result in loss of TiO2 photocatalyst over time during effluent treatment. Immobilization of TiO2 photocatalyst on substrates could address this problem. In this study, a method called direct heating (DH) was devised to deposit TiO2 particles on kanthal wires to prevent the particles from being washed away during effluent treatment. This method has low equipment cost and short synthesis duration when compared to others. The TiO2 particles synthesized at 50 W in 15 min gave the best photodegradation efficiency, which was 36.3 % under 90 mins of UV light irradiation. It contained a mixture of anatase (22.5 %) and brookite (77.5 %), with an average particle size of 139.34 ± 15.89 nm. The TiO2 particles had high surface coverage on kanthal wire with little agglomeration. The current work presents a captivating and low-cost setup, providing easy control over synthesis conditions and scaling potential for immobilizing TiO2 particles on the kanthal wires.

Influence of electrical polarization on thrombogenicity of titania nanotubes

AbstractThe development of hemocompatible biomaterials with antithrombogenic surface coatings remains a challenge in cardiovascular applications. There is interest in negatively charged surfaces that inhibit thrombus formation through electrostatic repulsion between the biomaterial surface and negatively charged platelets. Hence, the present study investigated the influence of electrical polarization on the thrombogenicity of titania nanotubes (TNT), which are promising candidates for inhibiting thrombogenicity via surface modification. TNTs were formed on commercially pure titanium plate by the electrochemical anodization technique using platinum as a counter electrode at 60 V for 24 h with two kinds of electrolytes (hydrofluoric acid diluted with dimethyl sulfoxide [D‐TNT] or ethylene glycol [E‐TNT]) followed by an annealing at 540°C for 3 h in air. Both TNTs were mixture of anatase and rutile, and the D‐TNT had a diameter of 108.76 ± 2.55 nm and the E‐TNT, 53.833 ± 2.42 nm. The TNTs were electrically polarized at 100 V of DC field and 400°C for 1 h. Water contact angle measurements showed that the non‐polarized (0‐) TNT surface was hydrophilic whereas the positively (P‐) or negatively (N‐) polarized TNT surfaces showed high‐hydrophilicity. Antithrombogenicity was evaluated using the thrombus coverage area ratio (TCAR) after soaking the TNTs in bovine whole blood. The TCARs for 0‐polarized E‐ and D‐TNTs were 5.30 ± 4.34% and 36.3 ± 5.8% and for P‐polarized E‐TNT and D‐TNT were 1.50 ± 0.77% and 2.76 ± 1.07%, whereas no thrombus formation (0 ± 0%) for N‐polarized E‐TNT and very few thrombus formation (0.12 ± 0.22%) for N‐polarized D‐TNT. The electrostatic repulsion between the N‐polarized E‐TNTs and platelets completely inhibits thrombus formation, which cannot be achieved by the nanomorphology and high‐hydrophilicity of other TNTs. Hence, N‐TNTs formed by electrical polarization are potential candidates for cardiovascular devices, such as artificial heart valves with long‐term hemocompatibility.

Dehydration and reduction reactions favored under medium pressure and temperature assisted by photocatalysis

The impact of UV irradiation on the catalytic transformation of dihydroxyacetone molecule (DHA) has been investigated under inert atmosphere, medium pressure (5 Bars) and temperature (<=120°C) in presence of commercial anatase TiO2 samples (UV100 and A100), rutile TiO2 (R100) and mixture of anatase and rutile phase (P90). In absence of light, the main products formed are pyruvaldehyde and lactic acid whatever the temperature playing only a role on kinetic. Under UV irradiation, we highlighted their decomposition and the formation of new compounds, hydroxyacetone (HydA) in high concentration and acrylic acid (AcrAc) together with H2, CO2 and acetaldehyde in gas phase and new condensation products. The higher the number of photons emitted, the greater the HydA and AcrAc formation highlighting the importance of light and especially of the (e-, h+) pairs generated by photocatalysis. Actually, whereas the formation of HydA and AcrAc is similar in presence of all TiO2 samples containing anatase phase, these compounds are formed in low concentration in presence of TiO2 rutile. Mechanisms of the formation of hydA and AcrAc under photocatalysis assisted by pressure and temperature were discussed considering the formation of H+ and reducing agent made possible thanks to simultaneous oxidation reaction occurring via h+ and or OH°

Fenton-mediated solar-driven photocatalysis of industrial dye effluent with polyaniline impregnated with activated TiO2-Nps

Various integrated technologies have been investigated for the remediation of heavily polluted industrial dye effluent. Also, more than 70 % of these dyes are known to be solely azo dyes used in the textile industry with 5–30 % presence in the effluent as loose dye molecules which are recalcitrant to treatment. These challenges led to the investigation of energy-efficient processes (solar) and the fabrication of high-performance nano-photocatalysts for proficient photocatalysis of dye effluent while mediating the process with Fenton reagents. The study fabricated nanopolymeric catalyst composites (P-AKT) via novel in situ coupling and impregnation of the polyaniline (PANI) with surface-activated TiO2 NPs. This fabrication is aimed at developing a high-performance catalyst with rapid and proficient photocatalytic activities to photons from sunlight irradiation. The photocatalytic process was mediated using a novel Fenton reagent to enhance the generation of radical species for dye degradation. Various instrumental characterization methods were used to study the structural, molecular, elemental, functional and optoelectronic properties of the fabricated nanocomposite photocatalysts. The result reveals functional groups aiding dye-catalyst bonding and morphological interaction reveal a surface-activated tetragonal crystalline mixture of anatase and rutile from TiO2−Nps embedded in the macromolecular chain of PANI. It also reveals the optimal conditions of 20 mg dosage, 10 mg/L initial concentration with substantial effectiveness at pH of 5 and 7. However, the most efficient photocatalyst recorded was P-AKT-2 % and P-AKT-3 % having 95 % and 94 % efficiencies at 90 min of solar irradiation. The photocatalyst equally demonstrated its capacity for effluent treatability up to 4 cycles of use.

Interface-confined intermediate phase in TiO2 enables efficient photocatalysis

As a prototypical photocatalyst, TiO[Formula: see text] has been extensively studied. An interesting yet puzzling experimental fact was that P25-a mixture of anatase and rutile TiO[Formula: see text]-outperforms the individual phases; the origin of this mysterious fact, however, remains elusive. Employing rigorous first-principles calculations, here we uncover a metastable intermediate structure (MIS), which is formed due to confinement at the anatase/rutile interface. The MIS has a high conduction-band minimum level and thus substantially enhances the overpotential of the hydrogen evolution reaction. Also, the corresponding band alignment at the interface leads to efficient separation of electrons and holes. The interfacial confinement additionally creates a wide distribution of the band gap in the vicinity of the interface, which in turn improves optical absorption. These factors all contribute to the enhanced photocatalytic efficiency in P25. Our insights provide a rationale to the puzzling superior photocatalytic performance of P25 and enable a strategy to achieve highly efficient photocatalysis via interface engineering.

Elucidating the effect of TiO2 nanoparticles on mung bean rhizobia via in vitro assay: Influence on growth, morphology, and plant growth promoting traits.

Titanium dioxide nanoparticles (TiO2 NPs) are among the most commonly used nanomaterials and are most likely to end up in soil. Therefore, it is pertinent to study the interaction of TiO2 NPs with soil microorganisms. The present in vitro broth study evaluates the impacts of low-dose treatments (0, 1.0, 5.0, 10.0, 20.0, and 40.0 mg L-1 ) of TiO2 NPs on cell viability, morphology, and plant growth promoting (PGP) traits of rhizobia isolated from mung bean root nodule. Two types of TiO2 NPs, that is, mixture of anatase and rutile, and anatase alone were used in the study. These TiO2 NPs were supplemented in broth along with a multifunctional isolate (Bradyrhizobium sp.) and two reference cultures. The exposure of TiO2 (anatase+rutile) NPs at low concentrations (less than 20.0 mg L-1 ) enhanced the cell growth, and total soluble protein content, besides improving the phosphate solubilization, Indole-3-acetic acid (IAA) production, siderophore, and gibberellic acid production. The TiO2 (anatase) NPs enhancedexopolysaccharide (EPS) production by the test rhizobial cultures. The radical scavenging assay was performed to reveal the mode of action of the nano-TiO2 particles. The study revealed higher reactive oxygen species (ROS) generation by the TiO2 (anatase) NPs as compared with TiO2 (anatase+rutile) NPs. Exposure to TiO2 NPs also altered the morphology of rhizobial cells. The findings suggest that TiO2 NPs could act as promoters of PGP traits of PGP bacteria when applied at appropriate lower doses.

Exploiting Laser‐Induced Oxidation Phase Diagrams for Multifunctional Titania Thin Films

AbstractLocal laser‐induced oxidation is an extremely valuable technique to perform high‐throughput optimization across multidimensional parameter sets. In this work, a versatile method is presented for the synthesis of titanium dioxide (TiO2) thin‐films with varying crystalline structures through the use of localized, visible, continuous‐wave laser‐processing. By controlling the laser intensity and the exposure time, the conversion of amorphous titanium disulfide (a‐TiS2) precursor films into distinct phases of TiO2 is achieved and a laser‐induced oxidation phase diagram is constructed with the resulting material phases, including anatase, rutile, and black TiO2. By utilizing the dependence of phase formation on the rate and duration of laser energy input, mixtures of anatase and rutile phases are fabricated with controlled spatial arrangements. Photocatalytic properties of the synthesized films are evaluated using the degradation of nitrogen oxide (NOx) gas under UV illumination and an organic dye under white‐light illumination, revealing that mixtures of anatase and rutile phases demonstrate superior photocatalytic activity. The laser‐induced oxidation method highlighted showcases a strategy for precisely tailored phase composition for directly tunable properties, paving the way for in‐depth studies into structure‐property relationships in photocatalysis and other applications of metal oxide films.

Synergistic Effect of Combined Polymorphs Anatase-Rutile Nano-Modified Lightweight Concrete on Photocatalytic Reduction of NOx, Self-Cleaning Performance, and Antimicrobial Properties

Anatase, one of the polymorphs of titanium dioxide (TiO2), has become the most widely used semiconductor for photocatalytic materials due to its chemical and physical properties. However, researchers have been studying the use of alternative materials (e.g., ZnO, N-doped, and C-doped TiO2) to improve the photocatalytic activity of cementitious materials. In this paper, we propose a modification of lightweight concrete by introducing mixed phases of titanium dioxide—anatase and rutile—to enhance its photocatalytic performance. The efficiency of NOx degradation of nano TiO2-modified concrete, its self-cleaning performance, and its antimicrobial properties were studied. The photocatalytic activity of lightweight concrete without TiO2 and concrete with the addition of anatase, rutile, and anatase-rutile was compared. The results show that modifying the samples by adding a mixture of anatase and rutile (2.5 wt % A + 2.5 wt % R) significantly improved the photocatalytic performance of lightweight concrete.

Crystalline Structure, Morphology, and Adherence of Thick TiO2 Films Grown on 304 and 316L Stainless Steels by Atomic Layer Deposition

Titanium dioxide (TiO2) thin films are widely used in transparent optoelectronic devices due to their excellent properties, as well as in photocatalysis, cosmetics, and many other biomedical applications. In this work, TiO2 thin films were deposited onto AISI 304 and AISI 316L stainless steel substrates by atomic layer deposition, followed by comparative evaluation of the mixture of anatase and rutile phase by X-ray diffraction, Raman maps, morphology by SEM-FEG-AFM, and adhesion of the films on the two substrates, aiming to evaluate the scratch resistance. Raman spectroscopy mapping and X-ray diffraction with Rietveld refinement showed that the films were composed of anatase and rutile phases, in different percentages. Scratch testing using a diamond tip on the TiO2 film was employed to evaluate the film adherence and to determine the friction coefficient, with the results showing satisfactory adherence of the films on both substrates.

Effect of anodization time on the morphological, structural, electrochemical, and photocatalytic properties of anodic TiO2 NTs

Titanium dioxide nanotubes (TiO2 NTs) were prepared by electrochemical anodizing of a pure titanium foil in glycerol-distilled water containing ammonium fluoride. The diameters and tube length of TiO2 NTs are controlled by tailoring of the anodization time. Synthesized NTs have been characterized by using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, and electrochemical impedance spectroscopy (EIS). The results revealed that the internal diameters of NTs can be adjusted from 30 to 130 nm. The length of NTs became longer progressively to reach a maximum of about 3.32 μm after 90 min. XPS analysis shows that the oxidation state of titanium is +4, which confirms the formation of TiO2. XRD and Raman spectroscopy revealed that the TiO2 NTs are composed of a mixture of anatase and rutile phases. The Mott-Schottky analysis showed that the TiO2 nanotubes are consistent with an n-type semiconductor. The photocatalytic performances of TiO2 NTs were tested by degradation of methylene blue (MB) in aqueous solution. The results revealed that the length of the NTs has an important effect on photocatalytic efficiency. The TiO2 NTs with 2.55 μm of length exhibited excellent photocatalytic efficiency of about 79.69% with a kinetic rat 0.0051 min−1. Increasing solution pH from 3 to 12 increases the degradation efficiency from 31.6 to 93.1%.

Ultrasound assisted synthesis of Fe‐TiO2 and Ce‐TiO2 catalysts and subsequent application for photocatalytic, sonocatalytic, and sonophotocatalytic decolorization of basic Victoria blue dye

AbstractSynthesis of Fe‐TiO2 and Ce‐TiO2 catalysts using conventional, and ultrasound assisted (US) homogeneous coprecipitation method has been investigated. Effects of ultrasonic irradiation time and ultrasonic power on catalyst synthesis were studied and it was elucidated that best conditions were 140 W and 60 min, respectively. Characterization using FE‐SEM revealed spherical particles with the size range from 36.4 to 49.4 nm whereas XRD analysis affirmed a mixture of anatase, rutile, and brookite TiO2 phase with crystallite size ranging from 4.18 to 12.99 nm. BET analysis revealed highest specific surface area (211.59 m2/g) for the sonochemically synthesized Ce‐TiO2. The process intensification benefits demonstrated in catalyst synthesis were better crystallinity, lower particle size, and higher surface area. The application of catalyst efficacy was tested for photocatalytic, sonocatalytic, and sonophotocatalytic oxidation where maximum decolorization as 71.97% was obtained for sonochemically synthesized Ce‐TiO2 applied in the sonophotocatalytic approach. Studies related to regeneration, stability, and leaching of Ce and Ti ion from the sonochemically synthesized Ce‐TiO2 catalyst were also performed. It was observed that the catalyst can be regenerated easily and there were no structural changes in the catalyst after regeneration with negligible leaching of the ions from the catalyst into the solution. Overall, an improved process for catalyst synthesis with intensified decolorization application was demonstrated based on the use of ultrasound.

Early osseointegration of micro-arc oxidation coated titanium alloy implants containing Ag: a histomorphometric study

BackgroundThis study aimed to evaluate bone response to micro-arc oxidation coated titanium alloy implants containing Ag.Methods144 titanium alloy implants were prepared by machine grinding and divided into three treatment groups as following, SLA group: sand-blasting and acid-etched coating; MAO group: micro-arc oxidation without Ag coating; MAO + Ag group: micro-arc oxidation containing Ag coating. Surface characterization of three kind of implants were observed by X-ray diffraction, energy dispersive X-ray spectrometer, scanning electron microscopy, High Resolution Transmission Electron Microscope and roughness analysis. The implants were inserted into dog femurs. 4, 8 and 12 weeks after operation, the bone response to the implant to the bone was evaluated by push-out experiment, histological and fluorescent labeling analysis.ResultsMAO + Ag group consisted of a mixture of anatase and rutile. Ag was found in the form of Ag2O on the surface. The surface morphology of MAO + Ag group seemed more like a circular crater with upheaved edges and holes than the other two groups. The surface roughness of MAO and MAO + Ag groups were higher than SLA group, but no statistical difference between MAO and MAO + Ag groups. The contact angles in MAO + Ag group was smallest and the surface free energy was the highest among three groups. The maximum push-out strength of MAO and MAO + Ag groups were higher than SLA group at all time point, the value of MAO + Ag group was higher than MAO group at 4 and 8 weeks. Scanning electron microscopy examination for the surface and cross-section of the bone segments and fluorescent labeling analysis showed that the ability of bone formation and osseointegration in MAO + Ag group was higher than that of the other two groups.ConclusionThe micro-arc oxidation combination with Ag coating is an excellent surface modification technique to posse porous surface structure and hydrophilicity on the titanium alloy implants surface and exhibits desirable ability of osseointegration.

Facile synthesis of N-doped biphasic TiO2 nanoparticles with enhanced visible light-driven photocatalytic performance

Undoped and N-doped TiO2 anatase/brookite mixed-phase nanoparticles were synthesized via a facile sol-gel method using urea as a nitrogen source. Surprisingly, nitrogen played a dual role in doping and controlling the anatase and brookite phases in the nanoparticles. The as-synthesized photocatalysts were characterized by powder X-ray diffraction (PXRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis and UV–vis diffuse reflectance spectroscopy (DRS). PXRD results revealed that TiO2 nanoparticles consisted of a mixture of anatase and brookite crystalline phases where the anatase phase increased with increasing urea concentration (1–60 wt. %), and the pure anatase phase was found at a urea concentration of ≥15 wt. %. N-doped anatase/brookite mixed-phase (brookite ̴ 20 wt. %) nanoparticles exhibited superior photocatalytic activity over others in degrading rhodamine-B (RhB) under simulated visible light irradiation, and its photocatalytic performance was comparable to that of Degussa P25. The enhanced photodegradation activity was credited to biphasic composition, narrower bandgap energy, and stronger light absorption in the visible region.

Fe (III) doped TiO2 nanoparticles prepared by high energy ball milling as booster for non-enzymatic, mediator-free and sensitive electrochemical sensor

In this paper, pure and Fe (III) doped TiO2 nanoparticles were prepared in order to fabricate a nano sensor for electrochemical sensing of paracetamol. TiO2 nanoparticles as anatase phase were synthesized using a solvothermal method and doped with Fe (III) by mechanochemical planetary ball mill method. For structural and chemical characterization of the as-synthesized nanoparticles, techniques such as X-ray diffraction (XRD), energy dispersive X-ray (EDX), and transmission electron microscopy (TEM) were employed. XRD proved that the nanoparticles, after doping, consist of a mixture of anatase and brookite phases. The performance of the modified electrode was characterized with cyclic voltammetry, differential pulse-voltammetry techniques. The.Fe (III)TiO2/GCE modified electrode represents excellent electrocatalytic activity for paracetamol detection in phosphate buffer (pH = 7) solution, with a considerable enhancing of the peak current and decrease of overvoltage in comparison with the bare GCE. It poses a low limit of detection (LOD) and a good linear relationship. The nano sensor showed good sensitivity, selectivity, stability, reproducibility, and fast response. Furthermore, to demonstrate the rapid and convenient determination of paracetamol in pharmaceutical samples, this sensor has been successfully utilized in analyzing real samples, and satisfactory results have been achieved. The response of the nano sensor was linear over the paracetamol concentration range of 1.50–10.2 μM and 10.2–62 μM. The limit of detection (LOD) was calculated to be 0.52 μM (S/N = 3).

Preparation and characterization of TiO2 photocatalytic composites supported by blast furnace slag fibres for wastewater degradation

The carrier selection for photocatalytic materials is critical for photocatalytic degradation technology. In this study, blast furnace slag fibre (BFSF) prepared using metallurgical waste was employed as a carrier for TiO2. The photocatalytic activity of the resulting TiO2/BFSF composite and its influencing factors during the sol-gel process was systematically investigated via TG-DTA, XRD, SEM-EDS, BET, UV–Vis absorption spectroscopy, degradation of methylene blue (MB) experiments, and mass loss technology. The results showed that the crystal phase of TiO2 transformed from pure anatase to a mixture of anatase and rutile and then to pure rutile as the calcination temperature increased from 350 °C to 800 °C. When the number of TiO2 loading cycles increased from 1 to 6, the TiO2 film changed from thin to thick and from uneven to uniform, until cracking and spalling finally occurred. When the number of TiO2 loading cycles and calcination temperatures increased, the photocatalytic activity increased and then decreased. After loading TiO2 sol four times and calcining at 450 °C for 2.5 h, a uniform and dense anatase TiO2 film was observed to be wrapped on the BFSF, achieving the highest photocatalytic activity and a maximum degradation ratio of 95.3%. The TiO2/BFSF composite showed excellent reusability. After four reuse cycles, the degradation ratio remained at 66.2%. Three potential mechanisms were proposed for photocatalytic degradation. The water and alkali resistance of BFSF markedly increased after the TiO2 thin film was loaded. This study therefore provides strategies to improve the photocatalytic activity of TiO2 and expands the high-value-added application of BFSF.