Anatase TiO2 Research Articles

Harnessing C@Zn@TiO2 nanocomposites for cadmium adsorption in aquatic media

ABSTRACT In this work, the elimination of Cd+2 ions in aqueous solution using carbon/Zn/TiO2 nanoparticles, synthesised by sol – gel based Pechini method at intermediate temperature, was studied. The synthesised C@Zn@TiO2 was characterised by SEM, TEM, EDX, XRD, BET, and XPS techniques to verify the formation of semi-spherical nanoparticles with dominant anatase TiO2 phase and elemental composition of the expected elements. Concurrently, the impact of the solution pH, pHpzc, contact time, adsorbent dose, and initial ions concentration were discussed. The findings revealed that at pH 7.0, a maximum of 174 mg. g−1 of Cd+2 ions were adsorbed at 120 minutes of equilibrium time. The Langmuir and pseudo-second-order models appropriately fitted the isotherm and kinetics data. The intraparticle model analysis indicated that film diffusion controls the adsorption of metal ions adsorption at the initial stage and, the intraparticle diffusion at the second stage. The FTIR and XPS analysis further proved Cd+2 ions being adsorbed onto the surface via an electrostatic mechanism. The fabricated nanostructure could be recycled and reused four times with a high competence above 71.5%. The facile synthesis, low cost, harmlessness, and remarkable removal efficiency make the C@Zn@TiO2 a promising material for treating heavy metal-contaminated water.

Anisotropic Valence Band Structure of Anatase TiO2(101) Studied by Polarization-Dependent Angle-Resolved Photoelectron Spectroscopy

Anisotropic Valence Band Structure of Anatase TiO₂(101) Studied by Polarization-Dependent Angle-Resolved Photoelectron Spectroscopy

Retraction notice to "TiO2 nanoparticles derived from egg shell waste: Eco synthesis, characterization, biological and photocatalytic applications" [Environ. Res. 214-P1 (2022) 113829

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor. Concerns with this article were reported on PubPeer at https://pubpeer.com/publications/DEE93691BDEADCEC931BA7CE58F685 regarding figure 4 and it is impossible for the Ti peaks to appear outside their supposed locations. The response from the authors did not satisfactorily address this point. Further serious concerns were subsequently identified. Firstly, related to figure 2, comparison of the XRD pattern with published results shows that the one presented in this article is inconsistent with TiO2 anatase (JCPDS card no: 89-4921). Secondly, following minor editing of the labels, two of the images that form part of figure 5 have previously been published as part of figure 5 of an earlier article (Journal of Plant Growth Regulation, 41 (2022) 3387-3394, https://doi.org/10.1007/s00344-021-10520-1) which deals with different materials and different microbes. For all of the above reasons, the editor has lost confidence in the reliability of the findings presented in this article as a whole and is therefore retracting it.

Multifunctional properties of cotton fabric tailored via green synthesis of TiO<sub>2</sub>/curcumin composite

In this study, a novel green process was developed to produce a multifunctional cotton (CO) fabric incorporating TiO2/curcumin composites that simultaneously provides UV protection and photocatalytic performance. For this purpose, TiO2 was synthesised using the sol–gel process; loaded with the natural colourant curcumin as a visible light absorber at two temperatures, i.e., 70 and 350 °C; and applied to the CO fabric via the pad–dry–cure process. For comparison, TiO2 was synthesised without curcumin under the same conditions. The synthesis conditions at 70 °C ensured the formation of predominantly amorphous TiO2, while curcumin promoted TiO2 crystallisation despite the low synthesis temperature. A 350 °C synthesis temperature was high enough to form the polymorphic TiO2 anatase phase. Although the increase in synthesis temperature and the presence of curcumin in the composites caused a bathochromic shift in light absorption, the photocatalytic activity of all samples was mainly driven by UV light. Chemically modifying the CO fabric significantly reduced the light transmittance of the samples, with the highest absorption of UV light obtained for the sample containing the TiO2/curcumin composite synthesised at 70 °C. This sample provided excellent UV protection with a UPF value of 51.6. All chemically modified CO samples showed photocatalytic activity, degrading coffee stains and decolourising methylene blue and Rhodamine B dye solutions. The highest photocatalytic efficiency and recyclability were obtained again for the CO sample with the TiO2/curcumin composite synthesised at 70 °C, demonstrating the synergistic effect between TiO2 and curcumin in the composite prepared under these synthesis conditions.

Developing a multi-scale model for the simulation of adsorption phenomena based on MD and CA: a Li-ion battery case study

Abstract Adsorption, an essential surface phenomenon, is involved in many industries, from water purification to energy storage and carbon capture, aiming at negative emission technologies. The need to synthesize new materials for these applications necessitates the development of new, flexible modeling tools to simulate complex conditions. This work introduces a multi-scale model to simulate various adsorption scenarios. It involves simulating the details of interatomic interactions in molecular dynamics simulations and scaling up to a laboratory scale through cellular automaton modeling. To showcase its capabilities, we utilized the simplest form of the model to simulate Li-ion adsorption on the surface of an anatase TiO2 sheet. The probability of adsorption and desorption for a Li-ion is quantitatively determined through molecular dynamics simulations and subsequently incorporated into the cellular automaton model. This secondary model simulates the kinetic process of adsorption and quantifies the equilibrium degree of surface coverage across varying concentrations, facilitating comparison with the Langmuir isotherm. An inverse relationship between surface coverage and temperature is consistent with theoretical predictions. Given the model’s computational efficiency, which complements molecular dynamics simulations, it offers extensive potential for extension across a broad spectrum of applications where adsorption, intercalation, diffusion, and other critical surface phenomena are fundamental.

In situ formed Se-TiO2 as a highly reusable photocatalyst for selenium reduction and removal from industrial wastewater.

Selenium (Se) release from anthropogenic activities such as mining, power generation, and agriculture poses considerable environmental and ecological risks. Increasing prevalence and awareness of Se-related issues have driven the development of many innovative Se treatment technologies. Photocatalysis has shown promise towards Se removal from industrial wastewaters with minimal residuals, and is generally considered a low-cost, robust, non-toxic, and potentially solar-powered method. Despite this, its real-world application towards environmental remediation remains extremely limited. This is because research into practical considerations, such as photocatalyst stability and reusability, is often overlooked or understudied in favor of developing academically interesting but impractical materials. In this work, commercial anatase TiO2 is stress tested through fifteen cycles of reuse towards the photocatalytic reduction and removal of selenate in synthetic mining-influenced brine (SMIB) without washing or regeneration. Remarkably, selenate removal exceeds 99.3% throughout all cycles. In situ Se-TiO2 heterojunction formation, and changes to its properties including Se loading, particle size, and crystal phase, are characterized through X-ray absorption spectroscopy, scanning transmission electron microscopy, and diffuse reflectance UV/vis, while their effects on catalyst performance are elucidated. This work underscores the importance of catalyst recyclability for practical photocatalytic environmental remediation and discusses the effects of extensive use on photocatalyst performance.

Titanium dioxide nanoparticles on flexural strength of conventional and injection moulded denture base materials

The effect of anatase TiO₂ nanoparticles on the flexural strength of PMMA resins, comparing conventional and injection molding techniques is of interest. A total of 120 acrylic specimens were prepared and divided into control, 0.5% TiO₂, and 1% TiO₂ groups. Flexural strength was measured using a three-point bend test and analyzed with ANOVA. The injection molded group showed superior flexural strength compared to the compression molded group, with control specimens exhibiting the highest values. Increasing TiO₂ concentration led to a significant reduction in flexural strength, indicating a negative correlation between nanoparticle content and mechanical performance

Material Characterization and Technological Properties of Biocompatible Ti-12Al-42Nb Spherical Powder Alloy for Additive Manufacturing of Personal Medical Implants

The paper focuses on material characterization and technology properties of a new Ti-12Al-42Nb spherical powder alloy for additive manufacturing of personal medical implants. The electrode induction melting inert gas atomization (EIGA) method was used to produce the powder alloy. The powder sphericity coefficient (PSC) was 1.02. Image J software was used to calculate the spherical degree by processing images sets from scanning electron microscopy (SEM) and optical microscopy (OM). SEM of particles cross-sections indicated internal thermal-induced porosity (TIP) with a 2.3 μm pore diameter. Particle size distribution was in the range from 15.72 μm (d10) to 64.48 μm (d100) as measured by laser particle analyzer. It was indicated that flowability and powder bulk density were 196 sec and 2.79 g/cm3, respectively. XRD analysis confirmed the beta phase of the powder alloy with no additional phases. X-ray fluorescence spectrometry confirmed the alloyed composition. Reducing and oxidative melting methods of analysis showed a slight amount of impurities: oxygen (0.0087 wt.%), nitrogen (0.03 wt.%), hydrogen (0.0012 wt.%), sulfur (0.0016 wt.%), and carbon (0.022 wt.%). Simultaneous thermal analysis (STA) was performed to indicate weight growth and losses and thermal effects in argon, nitrogen, and air as well as the oxidation of Al2O3, TiO2, and Nb2O5 on the surface layer of Ti-12Al-42Nb powder alloy particles. Different phase transformations of γAl2O3 → θAl2O3 → αAl2O3 and TiO2 rutile → TiO2 anatase phase transformation were detected by STA in the oxidative layer.

Optimization of Anatase TiO2 Photocatalyst for Diclofenac Degradation by Using Response Surface Methodology

Titanium oxide semiconductors are considered effective photocatalysts for the degradation of organic pollutants. The photocatalytic activity of titanium dioxide is influenced by several factors, one of which is its phase composition, with anatase being considered the phase with the highest photocatalytic activity. In this work, a simple acid-assisted sol–gel process was used to synthesize a pure anatase phase by varying the synthesis and calcination temperature. The synthesized materials were characterized using various techniques and tested under simulated sunlight irradiation for the photocatalytic degradation of the drug diclofenac sodium (DCF), for which the pseudo-first-order apparent degradation rate constant and mineralization efficiency were determined. A pure anatase phase with high photocatalytic activity (up to 97% TOC removal) was obtained when TiO2 was synthesized at between 70 °C and 100 °C and calcined at between 400 °C and 500 °C. Furthermore, the obtained data were used to predict the optimal anatase synthesis and calcination temperatures for DCF removal using a response surface methodology (RSM) method. The model predicted a synthesis temperature of 71 °C and a calcination temperature of 440 °C, which should result in a pseudo-first-order DCF decay rate constant of 0.055 min−1 and a TOC removal rate of 100%. The experimentally determined values for the degradation rate (0.063 min−1) and TOC removal (97%) were in good agreement with the model’s predicted values.

Glycerol Adsorption on TiO2 Surfaces: A Systematic Periodic DFT Study.

Conversion of glycerol to added-value products is desirable due to its surplus during biodiesel synthesis. TiO2 has been the most explored catalyst. We performed a systematic study of glycerol adsorption on anatase (101), anatase (001), and rutile (110) TiO2 at the Density Functional Theory level. We found several adsorption modes on these surfaces, with anatase (101) being the less reactive one, leading to adsorption energies between -0.8 and -0.4 eV, with all adsorptions molecular in nature. On the contrary, anatase (001) is the most reactive surface, leading to both molecular and dissociative adsorption modes, with energies ranging from -4 to -1 eV and undergoing severe surface reconstructions in some cases. Rutile (110) also shows both molecular and dissociative adsorptions, but it is less reactive than anatase (001). Surfaces with oxygen vacancies affects the adsorbed states and energies. The electronic structure analysis reveals that glycerol adsorption mainly affects the band gap of the material and not the individual contributions to the valence and conduction band. Bader charge analysis shows that strong adsorption modes on anatase (001) and rutile (110) are associated with large charge transfer from glycerol to the surface, while weak and molecular adsorption modes involve low charge transfer.

Melamine-Induced Carbon-Doped Anatase TiO2 for Enhanced Visible-Light-Driven Photocatalytic Degradation: Synthesization, Performance, and Mechanism

Melamine-Induced Carbon-Doped Anatase TiO₂ for Enhanced Visible-Light-Driven Photocatalytic Degradation: Synthesization, Performance, and Mechanism

From Anatase TiO2 Nano-Cuboids to Nano-Bipyramids: Influence of Particle Shape on the TiO2 Photocatalytic Degradation of Emerging Contaminants in Contrasted Water Matrices.

Water pollution, resulting from industrial effluents, agricultural runoff, and pharmaceutical residues, poses serious threats to ecosystems and human health, highlighting the need for innovative approaches to effective remediation, particularly for non-biodegradable emerging pollutants. This research work explores the influence of shape-controlled nanocrystalline titanium dioxide (TiO2 NC), synthesized by a simple hydrothermal method, on the photodegradation efficiency of three different classes of emerging environmental pollutants: phenol, pesticides (methomyl), and drugs (sodium diclofenac). Experiments were conducted to assess the influence of the water matrix on treatment efficiency by using ultrapure water and stormwater (basic) collected from an urban drainage system as matrices. The size and shape of the nano-cuboids were accurately controlled during synthesis to assess their impact on photoactivity and selectivity. Regarding total organic carbon removal using TiO2 nano-cuboids in basic environments, the results were particularly remarkable. TiO2 nano-cuboids and truncated bipyramids synthesized in the 200-250 °C temperature range showed an enhanced photocatalytic efficiency when compared to alternative formulations. Diclofenac, methomyl, and phenol were fully mineralized from ultrapure water and basic stormwater. The TiO2 nano-cuboids/nano-bipyramids demonstrated better selectivity and photoactivity in comparison to irregular TiO2 nanoparticles. The differences in photoactivity and selectivity are explained in terms of charge carrier separation and trapping on the different crystal facets. Their performance demonstrates their potential as sustainable materials for the photodegradation of emerging pollutants in various water matrices.

Characterization of anatase TiO2 nanoparticle: Comparative synthesis via microwave combustion and sol-gel techniques

Using polyacrylic acid (PAA) as the template polymer and titanium tri-chloride as the titanium source, two distinct methods were employed in this study to prepare TiO2 nanoparticles: a sol-gel method and a microwave combustion method. The methods described above were used to determine the ideal polymer ratio to create three distinct molar proportions of TiCl3 and PAA (1:1, 1:2, and 1:3) at 300 °C. After calcination at various temperatures (400, 450, 500, and 550 °C), the TiO2 nanoparticles prepared by the two different methods were characterized by XRD. Infrared (FTIR) spectroscopy was used to determine the chemical structures of the TiO2 and polymer. The morphology and particle size of TiO2 at the ideal temperature were evaluated by transmission electron microscopy (TEM). UV-VIS spectroscopy was used to characterize the optical properties of the TiO2 samples. X-ray diffraction (XRD) analysis determined that a 1:2 ratio of TiCl3 to PAA (MW2 and SG2) is optimal for producing well-crystallized TiO2 in the anatase form through a microwave-based method. Calcination at 550 °C further enhanced the crystallization of anatase nanoparticles, mainly when the microwave method was applied. In contrast, the sol-gel method indicated that the powder remained amorphous at 300 °C, with higher calcination temperatures leading to the formation of both anatase and rutile phases. The size of the TiO2 nanoparticles created by the microwave approach was determined to be 3–9 nm, whereas that of the TiO2 particles prepared by the sol-gel method was 8–20 nm. MW2 and SG2 had band gaps of 3.17 eV and 3.15 eV. In this study, we successfully synthesized nano-anatase TiO2 using an efficient and time-saving approach (microwave combustion method) in conjunction with heat treatment. The resulting material has potential applications in various fields, including energy storage, supercapacitor electrodes, photoelectric conversion, optical coatings, beam splitters, and anti-reflection coatings.

Microstructure, wear, and corrosion properties of PEEK-based composite coating incorporating titania- and copper-doped mesoporous bioactive glass nanoparticles.

Poor wear- and corrosion-resistance of 316L SS implants are critical problems in orthopedic implants. This study aims to improve the wear- and corrosion-resistance of 316L SS through surface coating. In this study, a bilayer composite coating consisting of polyether ether ketone (PEEK) as the first layer, and titania (TiO2)- and Cu-doped mesoporous bioactive glass nanoparticles (Cu-MBGNs) were deposited as the second layer on a 316L SS via electrophoretic deposition (EPD). Scanning electron microscopy (SEM) images of the bilayer composite coating showed the distribution of TiO2 and Cu-MBGNs within the PEEK matrix. Energy dispersive spectroscopy (EDS) analysis confirmed the presence of TiO2 and Cu-MBGNs in the bilayer composite coating. Fourier transform infrared spectroscopy (FTIR) identified the functional groups attributed to the PEEK, TiO2 and Cu-MBGNs. X-ray diffraction (XRD) analysis confirmed the presence of TiO2 (anatase) and Cu-MBGNs in the bilayer composite coating. The coating exhibited a strong antibacterial effect against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Incorporating TiO2/Cu-MBGNs into the bilayer composite coating significantly modified the surface of 316L SS by improving the wear- and corrosion-resistance. Pin on disc test revealed that the specific wear rate of ∼(0.4570 ± 0.009) × 10-6 mm3 Nm-1 of the PEEK coating decreased to (0.0482 ± 0.007) × 10-6 mm3 Nm-1 on incorporating TiO2/Cu-MBGNs in PEEK coating under a normal load of 10 N in Dulbecco's Modified Eagle Medium (DMEM). Furthermore, electrochemical impedance spectroscopy (EIS) results revealed that the impedance value of the bilayer composite coating remained ∼4.56 × 105 Ω cm2 compared to 8.81 × 103 Ω cm2 of 316L SS after 24 h immersion in phosphate-buffered saline (PBS). Thus, this study demonstrated that the wear- and corrosion-resistance of 316L SS can be improved by incorporating TiO2/Cu-MBGNs in PEEK-based composite coatings for orthopedic applications.

IrOx Supported on Submicron-Sized Anatase TiO2 as a Catalyst for the Oxygen Evolution Reaction

IrOx Supported on Submicron-Sized Anatase TiO2 as a Catalyst for the Oxygen Evolution Reaction

Facile Sol-Gel Synthesis of C, N Codoped-TiO2 for Efficient Degradation of Palm Oil Mill Effluent.

Wastewater treatment has been regarded as an effective solution in lowering the potential environmental hazards caused by palm oil mill effluent (POME). To ensure the efficient remediation of POME, the implementation of a promising strategy is necessary to overcome the limitations of conventional water treatment methods for the treatment of this pollutant. In this study, the synthesis of carbon, nitrogen codoped titanium dioxide nanoparticles (C, N-TiO2 NPs) was successfully performed by a sol-gel approach for the treatment of POME as a model pollutant under solar light irradiation. The synthesized C, N-TiO2 NPs displayed unique characteristics including an anatase phase with an average crystallite size of 11.35 nm and irregular spherical structures. Additionally, C, N-TiO2 possessed a lower band gap energy of 2.95 eV than 3.2 V of bulk anatase TiO2 and slower electron-hole (e--h+) pair recombination rate as evidenced by photoluminescence (PL) studies. The adsorption isotherm study of POME was most compatible with the Langmuir isotherm model, and the POME degradation kinetics proceeded according to first-order kinetics. Accordingly, the photocatalytic degradation of POME displayed a maximum degradation efficiency of 100% under the optimum condition of pH 7 in the presence of 0.12 g of the C, N-TiO2 photocatalyst within 150 min. The scavenging study showed that the superoxide radical (•O2 -) was the primary active species in the POME photodegradation. Finally, the reusability analysis confirmed that the C, N-TiO2 NPs could be reused for a maximum of five cycles, making them promising photocatalysts for wastewater treatment.

Defect-Mediated Crystallization of the Particulate TiO2 Photocatalyst Grown by Atomic Layer Deposition.

Nanopowders or films of pure and mixed oxides in nanoparticulate form have gained specific interest due to their applicability in functionalizing high-surface-area substrates. Among various other applications, our presented work primarily focuses on the behavior of TiO2 as a photocatalyst deposited by atomic layer deposition (ALD) on a quartz particle. The photocatalytic activity of TiO2 on quartz particles grown by ALD was studied in terms of ALD growth temperature and post-treatment heating rate. Amorphous TiO2 thin films (30 nm) were grown from tetrakis(dimethylamido)titanium (TDMAT) at 100 and 200 °C on quartz particles (0.35-3.5 μm) and crystallized using oxidative heat treatment at 500 °C with variable heating rates. The growth temperature was found to affect the TiO2 defect structure: TiO2 grown at 200 °C is black due to Ti3+ defects, whereas the film grown at 100 °C is white but contains some traces of the TDMAT ALD precursor. During the oxidative heat treatment, precursor traces desorbed and Ti3+ defects were oxidized. ALD TiO2 grown at 100 °C crystallized as anatase, whereas the rutile-to-anatase ratio of 200 °C grown TiO2 increased with the heating rate. The hydrogen production rate of mixed-phase TiO2 was found to outperform that of anatase TiO2.

Experimental and Computational Synthesis of TiO2 Sol-Gel Coatings.

During the experimental formation of sol-gel coatings, the colloid dispersions go through a drying process, and the structure of the coatings is formed as a result of complex chemical, colloidal, and capillary interactions. While computer simulations provide guidelines to tune and even design the nanomaterials synthesis, simulations of coating structure formation are hitherto unknown in the literature. Based on real experiments, we establish here a ReaxFF reactive force field-based molecular dynamics simulation protocol in order to investigate and determine the role of the experimental conditions on the pore structure formation in the coatings. Anatase TiO2 sol-gel coatings with a thickness of 50 nm, 7% open porosity, and a 2.4 nm pore radius were prepared on solid substrates using the dip-coating method. In the computational synthesis of porous TiO2 layers, the attractive capillary forces present during the drying step were accounted for by applying an external pressure, and their effect on the coatings' pore structure was investigated. It was found that the TiO2 layer structure corresponding to an external pressure of 10,000 atm in the simulations exhibited a porosity comparable to that determined by experimental methods. This demonstrates the impact of immersion capillary forces on sol-gel layer formation. The created computer model accurately describes the layer structure using real parameters, making it suitable for designing the coating structure through computer simulation.

High-Entropy Metal Interstitials Activate TiO2 for Robust Catalytic Oxidation.

Substitution metal doping strategies are crucial for developing catalysts capable of activating O2, but the leaching of metal dopants has greatly hindered their potential for extensive oxidation reactions under mild conditions. Here, the study develops an entropy-increase strategy to synthesize high-entropy metal (Mg, Ca, Mn, Fe, and Co) interstitial functionalized anatase TiO2 (HE-TiO2) nanosheets, demonstrating remarkable degradation efficiency across a wide pH range and exceptional stability in a flow-by electro-catalytic reactor. Relative to that of pristine TiO2, the intense lattice distortion on the (001) plane, an average lattice expansion of 2% on the (100) plane, and decrease of second shell peak of X-ray absorption spectra serve as compelling evidence for the formation of metal interstitials in HE-TiO2. Theoretical analysis and in situ synchrotron radiation Fourier transform infrared studies reveal that the electron of metal interstitials can populate the subgap states within the host TiO2, enabling a moderate adsorption band for robust and efficient O2 activation. This study introduces a universal strategy for synthesizing a novel class of high-entropy materials with integrated metal interstitials in metal oxides, promising to enhance the stability and efficiency of O2 activation catalysts and broaden their potential applications.

Fe-TiO2 WITH LOW QUANTITY OF IRON EXTRACTED FROM (ILMENITE) MINING WASTE TO THE PHOTOCATALYTIC DEGRADATION OF CYANIDE IN WATER

Nanoparticles of TiO2 doped with low amount of Fe were synthesized from natural ilmenite obtained from alluvial gold mine wastes. The obtained TiO2 were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance, thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), N2 adsorption-desorption isotherms, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results confirm the formation of mesoporous TiO2 nanoparticles in anatase phase with 0.05 wt.% of iron possibly replacing some titanium places. All the characterizations were performed to the synthesized solid and the reference materials (TiO2 anatase and Degussa P25). The photocatalytic activity of both the synthesized solid and references were evaluated in the photo-oxidation of cyanide in aqueous medium under UV illumination. An experimental design type Box-Behnken was performed choosing three different parameters: the initial concentration of cyanide (50, 150 and 250 ppm) the catalyst load (0.1, 0.5 and 1.0 g L-1) and the oxygen source. The percentage of cyanide conversion was chosen as response in the design obtaining as optimal conditions [CN-]0 = 50 ppm, catalyst load = 0.6 g L-1 and air bubbling. Under these conditions it was reached 32, 32 and 89% of cyanide conversion for Fe-TiO2 synthesized, TiO2 anatase and Degussa P25, respectively.