Synthesis,characterization and in-vitro bioactivity evaluation of mesoporous Ca10-xFex(PO4)6(OH)2 nanorods-like particles

Multifunctional nanomaterials with superior super-paramagnetic and bioactivity properties with regulated particle morphology can be advantageous for several therapeutic applications. In this investigation, nanorods-like mesoporous particles of Ca_10-xFe_x(PO₄)₆(OH)₂ with varying concentrations of Fe ions were hydrothermally synthesized. In addition to the evaluation of structural and physicochemical properties, magnetic and in-vitro bioactivity attributes were further investigated. Results suggested that with increasing concentration of Fe ions; lattice parameters, crystal size and crystallinity decreased, whereas, surface area, porosity and magnetization of nanorods-like mesoporous particles increased. Nanocomposites exhibited superior super-paramagnetic property. Particles were bioactive and non-resorbable in simulated conditions. Thus, the amalgamation of super-paramagnetism with superior textural and bioactive properties of nanoparticles suggested their high potential for multifunctional applications, including anti-cancer hyperthermia treatment, drug delivery and tissue regeneration.     

Solution combustion synthesis of new metal borophosphates (Fe1-xCrx)2B(PO4)3: Structural,thermal, surface,and magnetic properties

The new borophosphates were successfully synthesized by solution combustion synthesis assisted with glycine. The obtained materials were systematically characterized by Fourier-transform infrared spectroscopy, X-ray powder diffraction, UV–visible spectroscopy, thermogravimetric analysis, scanning electron microscopy, Brauner-Emmett-Teller surface area, and magnetometry. The Rietveld refinements indicated that Fe₂B(PO₄)₃ is a hexagonal, space group P63/m with a = b = 8.029 and c = 7.408. As Cr substitutes the Fe atoms, there is a significant decrease in the lattice parameters. When all Fe atoms are replaced by Cr, Cr₂B(PO₄)₃ is formed and the structure turns out to be a trigonal, space group P3 with a = b = 7.950 and c = 7.360. The materials are thermally stable and demonstrate paramagnetic behavior at room temperature. The magnetization increases as the iron content increases because of the high magnetic moment of the iron ion. Temperature-dependent magnetic measurements reveal that Fe₂B(PO₄)₃ has a Néel transition at 30 K and the Néel temperature decreases with Cr substitution.     

Microwave assisted hydrothermal synthesis of (Fe,Co)3O4 nanoparticles in the presence of surfactants and effects of Co/Fe ratio on microstructure and magnetism

Microstructure and magnetic properties of nanoparticles can be tailored by optimising the synthesis procedure and changing chemical composition. In this study, a two-step procedure, i.e., coprecipitation in the presence of PEG 300 followed by microwave assisted (MW) hydrothermal synthesis, was introduced to obtain Co_xFe_3-xO₄ (x?=?0, 0.1 and 0.2) nanoparticles. It was found that with the increase of Co content, particle/crystallite size increased, with significant change of coercivity (H_c). The mixed samples of Co_xFe_3-xO₄ (x?=?0.1 and 0.2) were magnetically harder in comparison with Fe₃O₄. Тhe H_c of Fe₃O₄ was 91?Oe, while for Co_0.10Fe_2.90O₄ and Co_0.20Fe_2.80O₄, H_c was 256?Oe and 1070?Oe, respectively. Saturation magnetisation (M_s) of mixed samples also increased up to 6% compared to Fe₃O₄. A special effort was devoted to study the effects of introducing different surfactants (PEG 300, PEG 4000 or SDS) during the synthesis procedure in order to improve morphological and microstructural properties of CoFe₂O₄ nanoparticles. The influence of surfactants on physical/chemical properties of nanoparticles is discussed.     

Synthesis and magneto-electrical properties of MFe2O4 (Co,Zn) nanoparticles by oleylamine route

In this study, nearly monodisperse cobalt ferrite (CoFe₂O₄) and zinc ferrite (ZnFe₂O₄) nanoparticles (NPs) without any size-selection process have been fabricated through an alluring method in an oleylamine (OAM)/benzyl ether system. Samples were synthesized by thermal decomposition of metal acetylacetonates in a high-boiling solvent and in the presence of oleylamine as surfactant and reducing agent. XRD analysis confirmed the purity and nanosized of both products and TEM analysis showed the monodispersion of them also. The oleylamine coated nanoparticles exhibited semiconducting nature at lower frequencies i.e. conductivity enhances with temperature. The dc conductivity curves of ZnFe₂O₄@OAm and CoFe₂O₄@OAm NPs indicate significant temperature-dependent behavior. The temperature and frequency-dependent variations of dielectric loss (ε″) of MFe₂O₄@OAm NPs display an almost sharp exponential decrease with frequency which becomes more considerable at higher temperatures and at low at low frequency regime. From ⁵⁷Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values have been determined. Although the Mössbauer spectra for the ZnFe₂O₄@OAm consists only one paramagnetic central doublet and CoFe₂O₄@OAm NPs have also one paramagnetic doublet and three magnetic Zeeman sextet.     

Magnetite/poly(D,L-lactide-co-glycolide) and hydroxyapatite/poly(D,L-lactide-co-glycolide) prepared by W/O/W emulsion technique for drug carrier: Evaluation of in vitro release of dexamethasone from composite nanoparticles

Biocompatible polymeric carriers containing inorganic materials for delivering therapeutic agents to a targeted site are promising candidate for drug delivery. Two nanocomposite nanoparticles, magnetite/poly(D,L-lactide-co-glycolide) and hydroxyapatite/poly(D,L-lactide-co-glycolide) (Fe₃O₄/PLGA and HAp/PLGA, respectively), with different weight ratios of inorganics to polymer and different polymer molecular weights were prepared by water-in-oil-in-water (W/O/W) emulsion technique to determine incorporation and in vitro release profile of the small molecule drugs water-insoluble dexamethasone acetate (DEX-Ac) and water-soluble dexamethasone phosphate (DEX-P). The in vitro release for DEX-Ac nanoparticles showed an initial burst release followed by a continuous slower release, whereas DEX-P nanoparticles showed only rapid initial release behavior.     

Effect of nanosize CaSO4 and Ca3(PO4)2 particles on the rheological behavior of polypropylene and its simulation with a mathematical model

Nanosize CaSO₄ and Ca₃(PO₄)₂ fillers were synthesized with an in situ deposition technique, and their sizes were confirmed by X‐ray diffraction. CaSO₄ was prepared in 12‐ and 22‐nm sizes, and Ca₃(PO₄)₂ was prepared in 13‐ and 24‐nm sizes. Experimental variables, such as torque, shear viscosity, shear stress, and shear rate, of the nanofilled polypropylene (PP) composites were measured with torque rheometry and melt flow index (MFI) measurements. Torque versus time, shear viscosity versus weight percentage, and MFI versus weight percentage were plotted to investigate the rheological behavior of the nanofilled composites. The Cross–Williamson (CW) model was simulated with the MATLAB simulation package to study the thinning behavior of the PP composites. The experimental results show a decrease in the shear viscosity with increasing weight percentage of filler. Shear thinning in the molten PP composites was comparatively greater with decreasing nanosize of CaSO₄ and Ca₃(PO₄)₂. This kind of behavior was confirmed by the N parameter as determined from the CW model. The simulation of experimental data also showed similar trends as the theoretical data. At a certain stage, a violation of theoretical data was observed. This was because of practical limitations of the equation, as the equation does not include consideration of the physical situation of chain entanglements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4190–4196, 2006     

Rapid microwave-assisted synthesis and magnetic properties of high-entropy spinel (Cr0.2Mn0.2Fe0.2Co0.2-xNi0.2Znx)3O4 nanoparticles

High-entropy oxide (HEO) has recently become popular because of its unique multifunctional performance. In this study, we developed a novel microwave-assisted method for the production of HEO nanoparticles with the composition (Cr_0.2Fe_0.2Mn_0.2Co_0.2-xNi_0.2Zn_x)₃O₄ (x = 0, 0.05, 0.1, and 0.2). The results revealed that all metallic elements were uniformly distributed throughout the single-phase cubic spinel structure of the HEO nanoparticles. The particle size distributions of four fabricated samples ranged from 10 to 50 nm. Because of its numerous advantages such as the ultrafast and low-temperature fabrication of nanoscale and high-purity products at a relatively low cost, the suggested methodology is an excellent synthesis method. The original HEO spinel (x = 0) achieved saturated magnetization (M_s) and coercivity (H_c) values of 24.3 emu/g and 160 Oe, respectively, at room temperature. Zinc substitution in the HEO composition indicated that M_s and H_c decreased with increasing zinc concentration owing to its non-magnetic nature.     

Magnetic doping effects on the superconductivity of Y1-xMxBa2Cu3O7-δ (M = Fe,Co, Ni)

The discovery of superconductivity in copper oxide compounds has attracted considerable attention over the past three decades. The high transition temperature (T_c) in these compounds, exhibiting proximity to an antiferromagnetic order in their phase diagrams, remains one of the main areas of research. It is believed that magnetic fluctuations provide substance for the exotic superconductivity observed in these compounds. The present study attempts to introduce Fe, Co and Ni magnetic impurities into the superconducting cuprate YBa₂Cu₃O_7-δ with the aim of exploring the T_c behavior. The solid-state synthesis method is exploited to prepare fully oxygenated Y_1-xM_xBa₂Cu₃O_7-δ (Y_1-xM_x-123) (M = Co, Fe, Ni) samples with low levels of doping (0.00000 ≤ x ≤ 0.03000). Systematic measurements are then employed to assess the synthesized samples using AC magnetic susceptibility, electrical resistivity and X-ray diffraction (XRD). The measurements revealed an increase in T_c as a result of magnetic substitution for Y. However, the study of non-magnetic dopings on the fully oxygenated Y_1-xM'_xBa₂Cu₃O_7-δ (Y_1-xM'_x-123) (M' = Ca, Sr) samples showed a decrease in T_c. Quantitative XRD analysis further suggested that the internal pressure could have minor effects on the increase in T_c. The normal state resistivity vs temperature showed a linear profile, confirming that the samples are at an optimal doping of the carrier concentration.     

Structural,magnetic and cryogenic magneto-caloric properties in RE2FeCrO6 (RE = Er and Tm) compounds

In this work, polycrystalline Er₂FeCrO₆ (EFCO) and Tm₂FeCrO₆ (TFCO) oxides were fabricated via conventional sol-gel method, and studied with respect of crystal structure together with cryogenic magnetic and magneto-caloric properties. Both oxides are confirmed to exhibit B-site disordered hexagonal perovskite-type crystal structure. Two magnetic transitions around 11.7 and 5.7 K for EFCO, whereas only one transition around 10.5 K for TFCO, have been observed. Both oxides exhibit considerable cryogenic reversible magneto-caloric effects. The values of magnetic entropy change peak and relative cooling power (refrigerant capacity) with 0–5 T magnetic field change reach 11.95 J/kg-K and 215.8 (169.8) J/kg for EFCO, and 4.78 J/kg-K and 123.6 (97.8) J/kg for TFCO, respectively, indicating the present Er₂FeCrO₆ oxide is also considerable for cryogenic magnetic cooling application.     

Band gap modulation and improved magnetism of double perovskite Sr2KMoO6 (K = Fe,Co, Ni,Mn) doped BaTiO3 ceramics

BaTiO₃ ceramics doped with double perovskite Sr₂KMoO₆ (BT-SKM) are fabricated via solid-state reaction technology. The effects of SKM dopants on the structure, band gap and electrical/magnetic properties of BT are systematically studied. XRD and Raman spectra analysis show polycrystalline perovskite structure of the samples, which confirms the structural changes. With the addition of SKM dopants, the grain size of the samples decreases significantly. The band gaps of doped BT samples reduce, and the minimum band gap of BT-SCM is 1.77 eV, which is apparently reduced compared with the band gap of pure BT of 3.22 eV. However, the ferroelectric properties are weakened in samples doped with SKM. This ascribes to the introduction of more oxygen vacancies by dopants, which impedes the switching of domains, resulting in deterioration of ferroelectric properties. Furthermore, ferromagnetism of BT-SNM is observed, which may be attributed to the long-range exchange interaction between Ni²⁺ ions and oxygen vacancies. These results reveal the potential applications of these perovskite oxides in photovoltaic and memory devices.     

Influence of rare-earth La3+ ion doping on microstructural,magnetic and dielectric properties of Mg0.5Ni0.5Fe2-xLaxO4 (0 ≤ x ≤ 0.1) ferrite nanoparticles

A series of La³⁺ ion doped magnesium nickel ferrites, Mg_0.5Ni_0.5Fe_2-xLa_xO₄ (0 ≤ x ≤ 0.1) having a cubic spinel structure were prepared by the co-precipitation method. Various characterization techniques, including X-ray diffractometer (XRD), high resolution transmission electron microscopy (HR-TEM), electron spin resonance (ESR) and vibrating sample magnetometer (VSM) were used to investigate structural and magnetic properties. The average crystallite size decreases and lattice parameter increases with La³⁺ ion doping and lie in the range of 12–7 nm and 8.347–8.361 Å respectively. Analysis of ESR spectra reveals that, g-value with La³⁺ ion addition decreases from 2.57 to 2.12. The saturation magnetization and the coercivity decrease with increasing rare-earth content. Magnetic-hysteresis (M − H) loop shifts from a ferromagnetic to a superparamagnetic nature with La³⁺ ion addition. The dielectric study was carried out in the frequency range of 1 KHz to 4000 KHz and temperature ranging 30 °C–350 °C using the impedance analyzer. The dielectric constant decreases with increasing frequency and the La³⁺ ion concentration. The dielectric loss of the sample increases with increasing temperature. The magnetic properties of the synthesized nanoparticles make them a potential material for stable ferrofluid application and the low tangent loss value makes these material a potential candidate for frequency-based applications.     

Photoluminescence and energy transfer of efficient and thermally stable white-emitting Ca9La(PO4)7:Ce3+, Tb3+, Mn2+ phosphors

The development of novel single-component white-emitting phosphors with high thermal stability is essential for improving the illumination quality of white light-emitting diodes. In this work, we synthesized a series of Ce³⁺, Tb³⁺, Mn²⁺ single- and multiple-doped Ca₉La(PO₄)₇ (CLPO) phosphors with β-Ca₃(PO₄)₂-type structure by the simple high-temperature solid-state reaction. The crystallization behavior, crystal structure, surface morphology, photoluminescence performance, decay lifetime and thermal stability were systematically investigated. The PL spectra and decay curves have evidenced the efficient energy transfer from Ce³⁺ to Tb³⁺ and from Ce³⁺ to Mn²⁺ in the CLPO host, and corresponding energy transfer efficiency reaches 41.8% and 54.1%, respectively. The energy transfer process of Ce³⁺→Tb³⁺ and Ce³⁺→Mn²⁺ can be deduced to the resonant type via dipole-dipole and dipole-quadrupole interaction mechanism, and corresponding critical distance were determined to be 12.23 and 14.4 Å, respectively. Based on the efficient energy transfer, the white light emission can be successfully achieved in the single-component CLPO:0.15Ce³⁺, 0.10Tb³⁺, 0.04Mn²⁺ phosphor, which owns CIE chromaticity coordinates of (0.3245, 0.3347), CCT of 5878 K, internal and external quantum efficiency of 84.51% and 69.32%. Especially, compared with the emission intensity at 25 °C, it still remains 98.5% at 150 °C and 92.0% at 300 °C. Based on these results, the single-component white light emission phosphor CLPO:0.15Ce³⁺, 0.10Tb³⁺, 0.04Mn²⁺ is a potential candidate for UV-converted white LEDs.     

Magnetic properties and microwave absorption of Ni0.7Zn0.3A0.05Fe1.95O4 (A = La,Ce, and Nd) powders within the range of 2–18 GHz

Ni_0.7Zn_0.3A_0.05Fe_1.95O₄ (A = La, Ce, and Nd) powders were obtained by the sol-gel combustion technique. The phase composition, microstructure, and electromagnetic properties of La³⁺, Ce³⁺, and Nd³⁺ substituted Ni_0.7Zn_0.3Fe₂O₄ were investigated. Compared with the Ni_0.7Zn_0.3Fe₂O₄ ferrite, the saturation magnetization of substituted Ni_0.7Zn_0.3Fe₂O₄ powders decreases due to the reduction of the super-exchange interaction by the substitution of La³⁺, Ce³⁺, and Nd³⁺at the Fe site. Furthermore, the enhanced dielectric constant of the substituted Ni_0.7Zn_0.3Fe₂O₄ ferrites prompts to the formation of good impedance matching and thereby improving the microwave absorption performance. The best reflection loss of Ni_0.7Zn_0.3Ce_0.05Fe_1.95O₄ ferrite is −17.5 dB at 13.8 GHz, and the corresponding absorption bandwidth (RL ≤ 5 dB) can be achieved 10.9 GHz. These results suggested that the Ni_0.7Zn_0.3Ce_0.05Fe_1.95O₄ ferrite is a potential composite for electromagnetic applications, particularly for broadband microwave absorption.     

Structure,magnetic properties and cryogenic magneto-caloric effect (MCE) in RE2FeAlO6 (RE = Gd,Dy, Ho) oxides

In this study, we present the crystal structure, magnetic properties, and cryogenic magneto-caloric effect (MCE) of RE₂FeAlO₆ (RE = Gd, Dy, Ho) oxides. The XRD refinement analysis suggests that all the RE₂FeAlO₆ oxides are crystallized in B-site disordered orthorhombic structure. The RE₂FeAlO₆ oxides exhibit large MCEs around T_C. The peak magnetic entropy change (-ΔS_M) and refrigeration capacity (RC) are 25.9 J/(kgK) and 240.1 J/kg for Gd₂FeAlO₆, 10.7 J/(kgK) and 274.9 J/kg for Dy₂FeAlO₆, 9.6 J/(kgK) and 249.6 J/kg for Ho₂FeAlO₆ under ΔH of 0–70 kOe, respectively. Notably, Gd₂FeAlO₆ exhibits promising magneto-caloric performance and therefore is a favorable candidate for cryogenic magnetic refrigeration.     

Incorporation of ZnO–ZrO2 nanoparticles into TiO2 coatings obtained by PEO on Ti–6Al–4V substrate and evaluation of its corrosion behavior,microstructural and antibacterial effects exposed to SBF solution

In this research, Plasma Electrolytic Oxidation technique was used to incorporate ZnO–ZrO₂ nanoparticles into TiO₂ ceramic coating on Ti6–Al–4V using sodium phosphate as an electrolyte. The effect of adding these nanoparticles on corrosion, morphology, wettability and antibacterial properties in the simulated body fluid (SBF) solution was investigated. The results indicated nanoparticles modified the microstructure of coating, which increased corrosion resistance 12 times higher than that of substrate. Besides, ZrO₂ nanoparticles had the most significant effect on increasing the contact angle. In addition, due to the compatibility of zirconium and zinc oxides with human body environment, the antibacterial properties of coatings were significantly improved.     

Magnetic phase transition and magneto-dielectric analysis of spinel chromites: MCr2O4 (M = Fe,Co and Ni)

In this work, we present magnetic phase transition temperatures and magneto-dielectric coupling in MCr₂O₄ (M = Fe, Co and Ni) ceramics, synthesized using sol–gel auto-combustion route. In order to develop their respective crystalline textures, all these chromites were calcined at 650?°C for 2?h. X-ray diffraction patterns confirmed that FeCr₂O₄ had a rhombohedral structure while NiCr₂O₄ and CoCr₂O₄ exhibited a spinel-type cubic structure. The presence of relevant elements in the specific stoichiometric ratios was confirmed using energy dispersive X-ray spectroscopy. The shapes and sizes of the grains for all the samples were determined using the images obtained from a field emission scanning electron microscope. Temperature dependent magnetic analysis have shown that FeCr₂O₄, CoCr₂O₄ and NiCr₂O₄ are ferromagnetic at 5?K and their magnetic phase transition temperatures were measured as 80, 83 and 90?K, respectively. Spin-orbit interference was also studied through magneto-dielectric coupling for these chromites using a modified impedance analyzer set-up.     

钕(Ⅲ)-氨基酸-邻菲啰啉三元配合物的合成及其抑菌活性

60℃下,在体积比为1∶1的乙醇水溶液中,采用常规溶液法合成了钕(Nd)-氨基酸-邻菲啰啉三元配合物。利用配合滴定、摩尔电导、红外光谱(IR)、热重-差热分析(TG-DTG)、紫外光谱(UV)和荧光光谱(FS)等分析手段对配合物的组成和光学等性质进行了分析与表征,推测系列配合物的化学组成为:[Nd(Amino)3Phen]Cl3.3H2O。通过抑菌实验对配合物的生物活性进行了研究。结果表明,组氨酸的羧基氧原子和邻菲啰啉的氮原子均与Nd3+配位,且配合物对大肠杆菌、枯草芽孢杆菌以及金黄色葡萄球菌有较好的抑菌效果。     

Local structure and superconductivity in (Bi1.6Pb0.4Sr2Ca2Cu3O10+δ)1-x(Fe3O4)x compounds

In this work, a close correlation between variations of critical temperature (T_c) and the hole concentration of (Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_10+δ)_1-x(Fe₃O₄)_x systems was studied. The (Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_10+δ)_1-x(Fe₃O₄)_x samples were fabricated using the solid-state reaction method, where x ranged from 0 to 0.2. The T_c values of the samples deduced from magnetization versus temperature measurement gradually decreased with increasing the Fe₃O₄ content (x). To investigate a possible reason for the observed decrease in the values of T_c in the samples, the valence state of copper (V) and the hole concentration (p) in all samples were examined by analyzing the Cu K-edge and Cu L_2,3-edge X-ray absorption near edge structure (XANES) spectra. The values of V and p monotonously decreased with the increase in Fe₃O₄ doping content (x) and agreed with the behavior of T_c. The existence of Fe³⁺ was confirmed by analyzing Fe L_2,3-edge XANES. Hence, Fe³⁺ ions possibly entered the lattice structure of the samples and filled the holes in CuO₂ planes. The degradation of superconductivity in Fe₃O₄ doped samples was then explained.     

Ibuprofen grafted on poly(2-hydroxyethylmethacrylate): Synthesis,mass transfer,and in vitro drug release investigations

Poly(2-hydroxyethylmethacrylate-graft-ibuprofen) (IpGH) of different ibuprofen (Ibu) contents was prepared by grafting of Ibu groups on poly(2-hydroxyethyl methacrylate) (PHEMA) in an esterification reaction route. The resulted copolymers were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, differential scanning calorimetry, thermal gravimetric analysis, X-ray diffraction, and scanning electron microscope analysis. The cytotoxicity test and the free radical scavenging ability of this material were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium (MTT) and 1,1-diphenyl-2-picryl-hydrazyl assay methods, respectively. The in vitro release study of Ibu through a retro-esterification reaction of IpHG material during 3 days reveals that the release dynamic depends on the initial Ibu grafted, pH media, and the swelling degree of PHEMA. It was also revealed that the water solubility of Ibu easily reached a maximum of 0.216?mg?mL^?1. The diffusion of Ibu through the polymer matrix obeys the Fickian model. The estimated distribution of the cumulative drug released in different simulated digestive organs reveals that the IpHG7 containing 6.69?mol% of Ibu content showed the best performance.     

Preparation and Characterization of Titanium Dioxide (TiO2) from Sludge produced by TiCl4 Flocculation with FeCl3, Al2(SO4)3 and Ca(OH)2 Coagulant Aids in Wastewater

Abstract

In this study, TiCl₄ coagulant together with coagulant aids such as FeCl₃, Al₂(SO₄)₃, and Ca(OH)₂ were investigated to improve the photoactivity of titanium dioxide (TiO₂) produced from sludge and to increase the resulting low pH value. After TiCl₄ flocculation with three coagulant aids, the settled floc (sludge) was incinerated at 600°C to produce TiO₂ doped with Fe, Al, and Ca elements. Fe-, Al-, and Ca-doped TiO₂ was characterized in terms of structural, chemical, and photo-electronic properties. All the coagulant aids used together with Ti-salt flocculation effectively increased the pH values. The surface area of TiO₂-WO (without any coagulant aids), Fe/TiO₂, Al/TiO₂, and Ca/TiO₂ was 122 m²/g, 77 m²/g, 136 m²/g and 116 m²/g, respectively. The TiO₂-WO, Fe/TiO₂, Al/TiO₂, and Ca/TiO₂ was found to be of anatase phase. The XRD pattern on the Fe/TiO₂ included an additional peak of hematite (α-Fe₂O₃). The majority of gaseous acetaldehyde with TiO₂-WO and Ca/TiO₂ for photocatalytic activity was completely removed within 40 minutes under UV irradiation.