Iron-doped TiO2 Research Articles

Enhancing photocatalytic performance of iron-doped TiO2 nanoparticles: Effects of annealing temperature on anatase-rutile mixed phase structure

Enhancing photocatalytic performance of iron-doped TiO2 nanoparticles: Effects of annealing temperature on anatase-rutile mixed phase structure

Synthesis and Characterization of Iron-Doped TiO2 Nanotubes (Fe/TiNTs) with Photocatalytic Activity

One of the most significant global challenges for humans is environmental pollution. The technology to control this problem is the utilization of semiconductors as photocatalysts. In the current study, iron-doped titania nanotubes (Fe/TiNTs) with increased photocatalytic effect were synthesized via a modified hydrothermal method. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy (TEM), gas adsorption, electron spin resonance (ESR) and UV–Vis diffuse reflectance spectroscopy (DRS). TEM results indicated that Fe/TiNTs have a tubular and uniform structure with an average outer diameter of 23–48 nm and length of 10–15 µm. ESR and DRS revealed that Fe3+ ions were successfully introduced into the TiNT structure by replacing Ti4+ ions. An enhanced light absorption in the range of 400–600 nm additionally indicated successful doping. The band gap was narrowed as iron wt% was increased. The photocatalytic activity was evaluated by the degradation of methyl orange (MO) in the presence of Fe/TiNTs and TiTNs by monitoring the degradation of MO under UV light irradiation. An acceleration on the hydration of Portland cement was observed in the presence of 2.0 wt% Fe/TiNTs. Fe/TiNTs can be used as a nanomaterial in cement-based building materials to provide self-cleaning properties to the surface of concrete even in indoor environments.

A novel preparation of trace iron-doped 3D urchin-like TiO2 for efficient degradation and mineralization of trimethoprim under simulated sunlight

A novel preparation of trace iron-doped 3D urchin-like TiO2 for efficient degradation and mineralization of trimethoprim under simulated sunlight

The Use of Iron-Doped Anatase TiO2 Nanofibers for Enhanced Photocatalytic Fenton-like Reaction to Degrade Tylosin.

The removal of antibiotics from wastewater to prevent their environmental accumulation is significant for human health and ecosystems. Herein, iron (Fe)-atom-doped anatase TiO2 nanofibers (Fe-TNs) were manufactured for the photocatalytic Fenton-like decomposition of tylosin (TYL) under LED illumination. Compared with the pristine TiO2 nanofibers (TNs), the optimized Fe-TNs exhibited improved visible-light-driven photocatalytic Fenton-like activity with a TYL degradation efficiency of 98.5% within 4 h. The effective TYL degradation could be attributed to the expanded optical light absorption and accelerated separation and migration of photogenerated electrons and holes after the introduction of Fe. The photogenerated electrons were highly conducive to the generation of active SO4•- radicals as they facilitated Fe(III)/Fe(II) cycles, and to oxidizing TYL. Moreover, the holes could be involved in TYL degradation. Thus, a significant enhancement in TYL degradation could be achieved. This research verifies the use of iron-doped anatase nanofibers as an effective method to synthesize novel photocatalytic Fenton-like catalysts through surface engineering for wastewater remediation.

Physico-chemical characterization and photocatalytic activity assessment under UV-A and visible-light irradiation of iron-doped TiO2 nanoparticles

Physico-chemical characterization and photocatalytic activity assessment under UV-A and visible-light irradiation of iron-doped TiO2 nanoparticles

Iron-doped TiO2 nanorods coupled with naphthalenediimide (NDI) and 3,4-ethylenedioxythiophene (EDOT)-based donor-acceptor-donor type small organic molecule for visible-light water oxidation

Iron-doped TiO2 nanorods coupled with naphthalenediimide (NDI) and 3,4-ethylenedioxythiophene (EDOT)-based donor-acceptor-donor type small organic molecule for visible-light water oxidation

Effect of Iron-Doped TiO2 Nanotubes on the Hydration of Tricalcium Silicate

Environmental pollution is one of the most serious and global problems for humans. Photocatalysis is a promising technology to control environmental pollution via the utilization of semiconductor materials as a photocatalyst. In this study, iron-doped TiO2 nanotubes (Fe/TiNTs) with an increased photocatalytic effect at longer wavelengths compared to undoped TiNTs were used, and the effect on the early hydration and mechanical properties of the main clinker phase tricalcium silicate (C3S) was investigated for the first time. Prior to the incorporation of nanotubes into C3S, it was treated with a supersaturated Ca(OH)2 solution. The addition of 1 and 2 wt.% of Fe/TiNTs into the C3S system significantly accelerated the course of hydration. The degree of hydration for the hydration products after 8 h, 1 d and 7 d have improved. The enhancement of compressive strength after 7 d, 14 d and 28 d were observed compared to normal TiO2 nanotubes (TiNTs). Treating Fe/TiNTs with a supersaturated Ca(OH)2 solution revealed a stronger interaction between Ca2+-ions and nanotubes. Fe/TNTs were synthesized via a modified hydrothermal process. The study shows that Fe/TiNTs can be used as a nanomaterial in cement-based building materials due to their enhanced interaction with the system.

Microwave-Assisted Hydrothermal Synthesis of Fe-Doped TiO2 Photoanode for Photocatalytic Hydrogen Evolution

One-dimensional TiO2 nanostructures like nanotubes, nanowires, and nanorods have received huge attention due to their photocatalytic hydrogen-generating ability. However, its wide band gap and high charge carrier recombination rate hampered the efficiency with which it converts solar energy into hydrogen. To improve this application, metallic doping employing a quick and easy synthesis method should be proposed. In this study, we report on the microwave-assisted hydrothermal synthesis of iron-doped TiO2 nanowires on an FTO substrate. The formation of TiO2 nano-wires was validated by structural and morphological analysis carried out using XRD and SEM imaging respectively. EDX was employed to provide a breakdown of their chemical composition to verify the presence of dopants in the samples. The impact of Fe-doping on optical and photoelectrochemical properties was studied. Electrochemical impedance spectroscopy was used to determine the mechanisms behind charge accumulation and charge transfer properties. The Mott-Schottky plot was used to examine the donor density and the flat-band potential of the pristine and Fe-doped TiO2 samples.

Easy way to produce iron-doped titania nanoparticles via the solid-state method and investigation their photocatalytic activity

This study focuses on the synthesis of iron-doped TiO2 nanoparticles “via solid-state” method, as an alternative to the more common doping strategies, with different iron content (0.5, 1.0, 1.5, and 2.0 wt%) using commercial titania Degussa P25 and TiO2 synthesized (sTiO2) via microemulsion method. The samples were characterized by SEM, BET, UV–Vis-DRS, and XRD. The photocatalytic activity was evaluated in terms of methylene blue (MB) degradation in aqueous solution under visible radiation (LED lamp 13 W) and under different conditions (pH, catalyst dosage, pollutant initial concentration, irradiance). The tests showed a big difference between sTiO2 and Degussa 25. The sTiO2 with an iron load of 1.0 wt% (1% Fe–TiO2) has been proven to be the best photocatalyst. This behavior is attributed to the Fe3+ species in sTiO2 crystal lattice whose presence decreases the bandgap.Graphical abstract

Enhancement of water soluble PDI-NapSO3H on the photocatalytic performance of Fe-TiO2 under visible light

Enhancement of water soluble PDI-NapSO3H on the photocatalytic performance of Fe-TiO2 under visible light

Nanoparticle layer via UV-induced directional migration of iron-doped titania nanoparticles in polyvinyl butyral films and superior UV-stability

The migration of nanoparticles in polymer matrix is significant for the structure and performance of polymer nanocomposites after the initial formation. However, the understanding and controlling of migration of nanoparticles in polymer matrix remains a challenge. Herein, we report using ultraviolet (UV) light to perform the directional migration of inorganic nanoparticles in polymer film, generating an ultrathin (100–200 nm) nanoparticle layer on the light exposure surface of the film. The prepared iron-doped titania nanoparticles (Fe–TiO 2 ) are initially uniformly dispersed into polyvinyl butyral (PVB) film, and homogeneous distribution remains unchanged even after thermal treatment. However, the UV irradiation induces the directional migration of nanoparticles towards the illuminated surface. The mechanism indicates that the directional migration of nanoparticles is related with the increase of interfacial energy and conformational entropic effect between Fe–TiO 2 and PVB upon UV irradiation. The formed nanoparticle layer endowed the PVB/Fe–TiO 2 film with superior UV-stability. Our work extends the study of controlling migration of nanoparticles in polymer matrix by applying external stimuli, and provides a novel strategy for the functionalization of polymer nanocomposite materials. • Iron-doped TiO 2 nanoparticles with low photocatalytic activity is prepared. • UV-induced unidirectional migration of iron-doped TiO 2 nanoparticles in polyvinyl butyral is firstly reported. • The mechanism of UV-induced migration of nanoparticles is investigated in detail. • A nanoparticle layer formed on the exposed surface by UV-induced unidirectional migration of nanoparticles. • Nanoparticle layer imparted superior UV-stability to polymer nanocomposite film.

Synthesis and Characterization of Iron-Doped TiO2 Nanoparticles Using Ferrocene from Flame Spray Pyrolysis

Iron-doped titanium dioxide nanoparticles, with Fe/Ti atomic ratios from 0% to 10%, were synthesized by flame spray pyrolysis (FSP), employing a single-step method. Ferrocene, being nontoxic and readily soluble in liquid hydrocarbons, was used as the iron source, while titanium tetraisopropoxide (TTIP) was used as the precursor for TiO2. The general particle characterization and phase description were examined using ICP-OES, XRD, BET, and Raman spectroscopy, whereas the XPS technique was used to study the surface chemistry of the synthesized particles. For particle morphology, HRTEM with EELS and EDS analyses were used. Optical and magnetic properties were examined using UV–vis and SQUID, respectively. Iron doping to TiO2 nanoparticles promoted rutile phase formation, which was minor in the pure TiO2 particles. Iron-doped nanoparticles exhibited a uniform iron distribution within the particles. XPS and UV–vis results revealed that Fe2+ was dominant for lower iron content and Fe3+ was common for higher iron content and the iron-containing particles had a contracted band gap of ~1 eV lower than pure TiO2 particles with higher visible light absorption. SQUID results showed that doping TiO2 with Fe changed the material to be paramagnetic. The generated nanoparticles showed a catalytic effect for dye-degradation under visible light.

Anatase/brookite biphasic surface fluorinated Fe–TiO2 photocatalysts to enhance photocatalytic removal of VOCs under visible and UV light

Abstract Volatile organic compounds (VOCs) are categorized as a major group of indoor air pollutants with several adverse health effects on humans. Photocatalytic oxidation (PCO) is a promising in-situ air purification technology for removing indoor VOCs. However, the PCO application by using TiO2 photocatalyst is hindered at high humidity and under visible light irradiation. A facile hydrothermal treatment was used to fabricate biphasic anatase-brookite iron-doped TiO2 with different Fe contents (0.2–4 atomic%) to enhance photoactivity of TiO2 under visible and UV light irradiations. Surface fluorination was then applied to reduce the surface hydrophilicity of Fe–TiO2 photocatalyst with the optimum Fe content (FeTi-0.4%). Surface fluorination of FeTi-0.4% moderates the surface hydrophilicity to repel water molecules from adsorption. The performance of developed photocatalysts was studied toward degradation of gaseous methyl ethyl ketone (MEK) using ultraviolet (UV) and visible light irradiations. The results reveal that iron metal dopants and surface fluorination promoted the performance of synthesized photocatalysts. It was found that the best single-pass removal efficiency was obtained at RH = 20% on F–FeTi-0.4% with values of 54% using visible and 70% using UV illumination. To advance the degradation efficiency and lessen the by-product formation rate, three layers of F–FeTi-0.4% and FeTi-0.4% photocatalyst films were examined. The photocatalytic degradation efficiency for three layers of FeTi-0.4% and F–FeTi-0.4% photocatalyst films were respectively 72% and 80% under UV, and 50% and 60% under visible light illumination. This study provided an effective visible-driven photocatalyst for indoor air purification technology. The results revealed the high MEK removal efficiency under visible light as an environmentally sustainable source of energy, leading to lower indoor pollutions to protect human health.

Single-step synthesis of Fe-TiO2 nanotube arrays with improved light harvesting properties for application as photoactive electrodes

Research on TiO2 nanotubes gained prominence in the past years due to their photoelectrochemical behavior. Metallic ion doping via a simple and fast method of production can dictate a path in order to achieve and improve such application. This work reports an innovative single-step anodization synthesis of iron-doped TiO2 nanotubes. Titanium foils were anodized at three potentials (20, 40 and 60 V) for 1 h. The resulting arrays were characterized by scanning electron microscopy, X-ray diffraction, Raman, XPS and UV–Vis diffuse reflectance spectroscopy. SEM images showed that higher anodization potentials successfully produced Fe-TiO2 nanotubes without a passivating top-layer. XRD and Raman results indicate that Fe ions were introduced in the anatase framework. Fe-doping produced a shift in the UV–Vis absorption edge towards the visible region, which reflected onto the photoelectrochemical performance of the electrodes. The Fe-TiO2 sample anodized at 60 V developed a current density of 1.9 × 10−4 A·cm−2, i.e., 2.5 times greater than that of the undoped TiO2 sample. The results indicate that the obtained Fe-TiO2 nanotube arrays are promising materials for application as photoactive electrodes.

Synthesis, characterization of iron-doped TiO2(B) nanoribbons for the adsorption of As(III) from drinking water and evaluating the performance from the perspective of physical chemistry

In this study, iron-doped TiO 2 (B) nanoribbons (Fe-TiO 2 (B) NR) have been synthesized using the anatase TiO 2 as a precursor. The formation of TiO 2 (B) with the monoclinic crystal system was confirmed by HRTEM, SAED pattern, and XRD analyses. The ESR and XPS analyses further revealed the presence of Ti 3+ and oxygen vacancies in Fe-TiO 2 (B) NR. The Fe-TiO 2 (B) NR, as an adsorbent, exhibited a fantastic performance in adsorbing As(III) from potable water at near-neutral pH. More than 94% of removal efficacy was observed for all the studied As(III) concentrations (50, 100, 250, 500, 750, and 1000 ppb) at 1 g L −1 dose at 30, 40, and 50 °C temperatures in dark condition. Irradiation with visible light, however, diminished the removal efficacy to ~88%. The Sips, the Toth, and the D-A isotherm model-based approximate site energy distributions had taken the unimodal quasi-normal distribution pattern. Nevertheless, the density functional theory (DFT) calculations showed that the adsorption of H 3 AsO 3 is highly favourable on the (001) crystal plane of monoclinic TiO 2 (B). Moreover, the DFT calculations meticulously suggested the exothermic nature of the adsorption process and the chances of oxidation of H 3 AsO 3 on the (001) crystal plane of monoclinic TiO 2 (B), which was further vindicated by XPS analysis. • TiO 2 (B) nanoribbons synthesized by doping Fe in anatase TiO 2 nanoparticles • SAED pattern, XRD analyses confirm the transformation of anatase TiO 2 to TiO 2 (B). • XPS, X-band ESR analyses confirm the presence of Ti 3+ and O vacancy in Fe-doped TiO 2 (B). • Fe-doped TiO 2 (B) can adsorb As(III) from potable water efficiently. • Adsorption of As(III) on it is chemisorption and exothermic in nature.

Physicochemical and magnetic properties of pure and Fe doped TiO2 nanoparticles synthesized by sol-gel method

Pure and iron-doped TiO 2 nanoparticles (NPs) for different moles were synthesized by the sol–gel method. The synthesized products were characterized by sophisticated instrumental techniques such as powder X-ray diffraction (XRD), Scanning Electron Microscope (SEM), ultraviolet–visible spectroscopy (UV–Vis) and vibrational sample magnetometer (VSM). XRD pattern confirmed the Rutile structure of Pure TiO 2 and Fe doped TiO 2 NPs. The doping of Fe into TiO 2 proved a great decrease in the size of nanoparticles as compared to undoped TiO 2 . The various functional groups were identified using FTIR analysis. The surface morphology of pure and Fe doped TiO 2 nanoparticles were revealed by scanning electron microscopic analysis. The SEM micrographs revealed flakes like structure of pure and Fe doped TiO 2 NPs. UV–Vis Spectrometer showed a sharp absorption edge for pure TiO 2 in the ultraviolet region at a wavelength of about 375 nm and the absorption edge for Fe doped TiO 2 NPs at a wavelength of about 339 nm. Vibrating Sample Magnetometer (VSM) revealed the ferromagnetic property. The value of magnetic moment showed an increase due to the suitable moles of Fe in TiO 2 NPs.

Low-temperature catalytic aqueous phase oxidation of microcystin-LR with iron-doped TiO2 pillared clay catalysts

ABSTRACT TiO2-PILCs and iron-doped TiO2-PILCs were employed in order to destroy toxic microcystin-LR in the presence of H2O2 under the UV light. While less than 5% of the initial microcystin-LR and TOC disappeared in 240 min with the TiO2-PILCs, almost complete conversion of microcystin-LR could be achieved in 180 min on the 10 wt% iron-doped TiO2-PILC-A. On the exterior surface of the iron-doped TiO2-PILCs were mainly located iron particles which had nano-sized diameter and Fe2+/Fe3+ cations together. Through Fenton-type oxidation on iron particles with H2O2, the big microcystin-LR molecules were converted primarily into smaller intermediate organic molecules of hydrocarbons, carboxylic acids and organic amines. The smaller intermediate molecules were believed to be diffused into the pores of the iron-doped TiO2-PILCs and to be further mineralized into CO2 and H2O through the action of photocatalysis on the TiO2 pillars. However, complete conversion of TOC could not be obtained due to the iron particle deactivation. XPS, TPO and TEM studies showed the continuous accumulation of carbonaceous materials onto the surface of iron particles.

Degradation of Ethylene Glycol Through Photo-Fenton Heterogeneous System

This work describes the ethylene glycol degradation in a photo-Fenton heterogeneous system. Iron-doped TiO2 photocatalysts prepared by different methods (incipient wet impregnation and sol-gel method), as well as the corresponding un-doped material were examined in this process. Different values of initial pH and H2O2 concentration were tested during the experiments. A lower photoactivity was observed for the un-doped materials than for the Fe-doped materials. Optimum results of initial pH and H2O2 concentrations were found to be 3.0 and 1,000 mg/L, respectively. Furthermore, the highest degradation percentage of ethylene glycol (61 %) was achieved for the material synthetized by sol-gel method. Such catalytic performance is explained on the basis of structural/morphological and electronic characterization results, reached by XRD, UV-vis DRS and XPS techniques. To the best of our knowledge, this is the first report related with the ethylene glycol degradation using Iron-doped TiO2 in a photo-Fenton heterogeneous system.

A simple synthesis way to obtain iron-doped TiO2 nanoparticles as photocatalytic surfaces

Mesoporous TiO2 nanoparticles synthesized by the sol-gel method were impregnated with different iron contents (0.0125, 0.025, 0.1, 1.0 wt%). The samples were characterized by XRD, UV–Vis DR, N2 adsorption/desorption, SEM and TEM. Their photocatalytic activity was evaluated in terms of the degradation and mineralization of acid orange 7 (AO7) in aqueous solution under UV–Vis and visible radiation. An iron loading of 0.1 wt% allowed enhance the photocatalytic performance. This behavior is attributed to the Fe3+ ions finely dispersed on the titania surface, whose presence decrease the band gap and could stabilize the separation between the photogenerated electron-hole pairs.

Characterization of Photoactive Fe-TiO2 Lime Coatings for Building Protection: The Role of Iron Content.

Iron-doped TiO2 nanoparticles, ranging in Fe concentrations from 0.05 up to 1.00% w/w, were synthesized through a simple sol-gel method. Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Ultraviolet-Visible (UV-Vis) spectroscopy, nitrogen adsorption−desorption isotherms, X-ray photoelectron spectroscopy (XPS), and X-ray absorption near-edge structure spectroscopy (XANES) were used to characterize the synthesized nanoparticles. The characterization of the Fe-doped TiO2 nanoparticles revealed the predominant presence of anatase crystalline form, as well as the incorporation of the Fe3+ ions into the crystal lattice of TiO2. The photocatalytic assessment of the Fe-doped TiO2 nanoparticles indicated that the low iron doping titania (0.05 and 0.10% w/w) have a positive effect on the photocatalytic degradation of Methyl Orange under visible radiation. Moreover, FTIR monitoring of calcium hydroxide pastes enriched with low Fe-doped TiO2 revealed enhancement of carbonation at both early and later stages. Improved photocatalytic performance and increased lime carbonation, observed in lime coatings with low Fe-doped TiO2 admixtures, established them as invaluable contributors to the protection of the built environment.