Structure Of BaTiO3 Research Articles

Light reflectance and photoelectron yield spectroscopy enable acceptor level measurement in p-type Ba1−xTiO3 semiconductor

We report the band structure of Ba-deficient BaTiO3 as a p-type semiconductor, studied by a combination of light reflectance and photoelectron yield spectroscopy. Two acceptor levels were observed at the tail of a valence band. As the quantity of Ba vacancies increased, the density of state of the two acceptor levels also increased. The levels of the conduction band minimum and the valence band maximum shifted far away from the vacuum level, but the bandgap seems to be independent of Ba deficient concentration. For classical semiconductors such as Si and GaAs, the observation of impurity levels is restricted to low temperatures (∼20 K) owing to their narrow bandgaps. Oxide semiconductors have now been demonstrated with wide bandgaps and acceptor levels, at normal operating temperatures, which could lead to new device designs in the future.

Optical, Structural, and Dielectric Properties of Composites Based on Thermoplastic Polymers of the Polyolefin and Polyurethane Type and BaTiO3 Nanoparticles.

In this work, new films containing composite materials based on blends of thermoplastic polymers of the polyurethane (TPU) and polyolefin (TPO) type, in the absence and presence of BaTiO3 nanoparticles (NPs) with the size smaller 100 nm, were prepared. The vibrational properties of the free films depending on the weight ratio of the two thermoplastic polymers were studied. Our results demonstrate that these films are optically active, with strong, broad, and adjustable photoluminescence by varying the amount of TPU. The crystalline structure of BaTiO3 and the influence of thermoplastic polymers on the crystallization process of these inorganic NPs were determined by X-ray diffraction (XRD) studies. The vibrational changes induced in the thermoplastic polymer’s matrix of the BaTiO3 NPs were showcased by Raman scattering and FTIR spectroscopy. The incorporation of BaTiO3 NPs in the matrix of thermoplastic elastomers revealed the shift dependence of the photoluminescence (PL) band depending on the BaTiO3 NP concentration, which was capable of covering a wide visible spectral range. The dependencies of the dielectric relaxation phenomena with the weight of BaTiO3 NPs in thermoplastic polymers blends were also demonstrated.

Study of changes in the crystal structure of BaTiO<sub>3</sub> under the effect of X-ray radiation

X-ray diffractometers are widely used in studying the atomic structure of mono- and polycrystalline substances. The radiation source of conventional laboratory diffractometers is a soldered x-ray tube with the maximum power consumption 1 – 3 kW. The radiation spectrum of the tube is determined by the anode material (usually, these are spectrally pure metals Cr, Ni, Fe, Cu, Mo, Ag). The wavelengths of the characteristic radiation range within 0.56 – 2.29 Е . We present the results of studying the effect of X-ray radiation power on the structure of barium titanate. Comparison of the diffraction spectra of BaTiO 3 (laminar polydomain ferroelectric single crystal and nanopowder samples) showed that the spectrum structure changes significantly with an increase in the power of X-ray beam (Cu K α radiation) from 100 (5 mA, 20 kV) to 800 W (20 mA, 40 kV). For example, a rearrangement of the domain structure and, hence, a change in the dielectric characteristics of the material were observed for BaTiO 3 single crystal. The rearrangement was accompanied by the formation of continuous transition zones (between domains) containing a cubic phase. As for the BaTiO 3 nanopowder, a change in the structure was observed in the direction of the axis of spontaneous polarization c and an invariance of the structure in the plane a – c . The results obtained can be used to control the physical properties of ferroelectric and ferroelastic materials, in particular, the memristor characteristics of epitaxial films based on YBa 2 Cu 3 O 7– δ due to changes in their twin structure under X-ray irradiation.

Enhanced Dielectric properties of Bismuth Doped Barium Titanate Ceramics with their Structural and Compositional Studies

Several strategies have been employed to tune the functional properties of environmentally friendly Barium titanate (BaTiO3). In this work, bismuth (Bi) doped BaTiO3 with a general formula Ba1-xBi2x/3TiO3 (where x = 0.00, 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06) were prepared by the conventional solid-state reaction method. The effect of Bi on the structure of BaTiO3; and their morphological and compositional studies were carried out by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX) respectively. Furthermore, the effect of Bi on the transport properties of BaTiO3 was investigated. Our studies revealed that for x = 0.01, Bi doping gives rise to the highest tetragonality of the crystal with more homogeneous grains and pores distribution among all the doping concentration. Furthermore, the dielectric constant for x = 0.01 samples has been observed to be the highest, which is consistent with the structural and morphological studies. Also, the tetragonal to cubic phase transition temperature (Curie temperature) of the sample is found to increase with increasing Bi doping concentration. Our studies suggest that the higher value of the dielectric constant with higher Curie temperature can be obtained by a small amount of Bi doping (x = 0.01), which has potential applications in various electronic and energy storage devices.

A new strategy to realize phase structure and morphology of BaTiO3 nanowires controlled in ZnO-B2O3-SiO2 glass

A novel strategy was designed to realise the control of the phase structure and morphology of BaTiO3 nanowires in ZnO-B2O3-SiO2 glass. BaTiO3 nanowire-(ZnO-B2O3-SiO2) glass-ceramics were fabricated and controlled by the sol-gel method and two-step sintering process. The influence of the amount of BaTiO3 nanowires on the glass-ceramics phase composition, morphology, and dielectric and energy storage properties was investigated. X-ray diffraction results show that all samples have a perovskite structure of BaTiO3 and a large amount of amorphous glass phases, which is the background, primarily distributed at 10-40°. With an increase in the amount of BaTiO3 nanowires in glass-ceramics, linear grains appear in the sample first, after which they transfer into rod grains as the linear grains are exhausted. The glass-ceramics dielectric constant and energy storage density first increase and then decrease with increasing amount of BaTiO3. For the sample of BaTiO3 nanowire-(ZnO-B2O3-SiO2) glass-ceramics with 30 wt% BaTiO3 nanowires, the linear grains, and the phase structure of BaTiO3 nanowires can be controlled by sintering the sample at 1200 °C for 30 min and then holding at 900 °C for 2 h. Most importantly, this work realised the control of the phase structure and morphology in glass-ceramics, which provides a significant baseline for exploring high-energy storage materials with optimal composition and structure.

Electric-field-induced structural changes for cubic system of lead-free and lead-based perovskite-type oxides

Changes in crystal structures of lead-free BaTiO3 (BT) and lead-based 0.70Pb(Mg1/3Nb2/3)–0.30PbTiO3 (PMN–PT) single crystals with a perovskite-type structure have been investigated under applied electric field by analyzing the high-energy synchrotron radiation X-ray diffraction data. The experiment is performed within the cubic phase in the phase diagram with the range of temperatures and electric fields where no electric field-induced phase transition is caused. The crystal structure analysis demonstrates that the crystal system is change to a tetragonal system by electrostriction when the electric field is applied along the crystal axis. The atomic arrangement in BT corresponds to the displacement pattern attributed to the Slater mode where Ti and O ions are mutually shifted in the opposite directions along the electric field, while that in PMN–PT is of the Last mode where Pb ions and (Mg, Nb)O6 oxygen octahedra are mutually shifted. The electron charge density study demonstrates that the Ba–O bonding in BT is ionic, whereas the Pb–O bonding in PMN–PT is highly covalent in the cubic structure. PMN–PT is revealed to have a characteristic Pb–O covalent bond which induces the atomic displacement attributed to the Last mode under applied electric field within the cubic phase despite no phase transition.

Insights into the Impact of Yttrium Doping at the Ba and Ti Sites of BaTiO3 on the Electronic Structures and Optical Properties: A First-Principles Study.

We reported a systematic study of the effects of Y doping BaTiO3 at Ba and Ti sites. We assessed the structural, electronic, and optical properties by employing first-principles calculations within the Tran–Blaha-modified Becke–Johnson (TB–mBJ) potential and generalized gradient approximation + U approaches. We calculated the lattice constants and bond lengths for pure and Y-doped BaTiO3. We explored the consequences of electronic structure and optical property modification because of Y doping in BaTiO3. Indeed, Y doping has led to various modifications in the electronic structures of BaTiO3 by inducing a shift of the conduction band through lower energies for the Ba site and higher energies for the Ti site. It was found that Y doping, either at Ba or at Ti sites, strongly enhanced the BaTiO3 dielectric constant properties. The transformation in bonding was explored via the charge density contours and Born effective charges. We used the state of art of polarization theory based on finite difference and Berry-phase approaches to investigate piezoelectricity. Y doping has increased the dielectric constants but canceled the piezoelectricity as they changed to metallic nature. We could look into the future for potential doping, preserving the semiconductor nature of BaTiO3 and increasing the permittivity with large dielectric loss.

Dielectric properties and discharge energy density of epoxy composites with 3D BaTiO3 network structure

A three-dimensional network structure of BaTiO3 (3D-BTO) ceramic was constructed using cellulose sponge as a template at 1200 °C. The 3D-BTO/epoxy composites were prepared at various BTO contents of 5, 7, and 10 vol%. The dielectric constant and tanδ of the composites increased as the BTO content increased. With a BTO content of 10 vol%, the dielectric constant and discharged energy density were 42.0 at 1 MHz and 1.57 mJ/cm3 at 25 kV/cm, respectively. However, tanδ and energy loss density were larger. The enhancement of dielectric constant and discharge energy density at low BTO content (10 vol%) was attributable to a continuous 3D network structure of BTO phase in the composites.

Neutron Diffraction Study of Multiferroic 0.6NiFe2O4/0.4BaTiO3 Composite

Neutron diffraction study on the 0.6NiFe2O4/0.4BaTiO3 multiferroic composite has been carried out. The 0.6NiFe2O4/0.4BaTiO3 multiferroic composites have been synthesized by solid reaction method. In this study, 20 g of BaTiO3 (BTO) and 20 g of NiFe2O4 (NFO) compounds were prepared from the powder raw materials of BaO3 and TiO2 for BTO, and NiO and Fe2O3 for NFO. Furthermore, both BTO and NFO were each crushed for 5 hours using High Energy Milling (HEM). Then the BTO and NFO were calcined in the furnace at 950°C/5 hours and 900°C/5 hours, respectively. Both NFO and BTO precursors were manually mixed with a weight percent ratio of NFO:BTO was 100:0, 60:40, and 0:100, hereinafter referred to NFO, NFO/BTO, and BTO, respectively. Then the three samples were pressed into pellets. The pellets were then sintered at 1150 °C/5 hours with a heating rate of about 44.8°C/min. Once cooled to room temperature within the furnace it was obtained NFO, BTO, and NFO/BTO multiferroic composite. The magnetic properties of the material were observed with the aid of the Vibrating Sample Magnetometer (VSM) instrument. The nuclear structure of BTO, and the magnetic structure of NFO, and NFO/BTO multiferroic composite were determined by neutron diffraction technique using the high resolution powder neutron diffractometer. The cations arrangement of NFO was obtained by whole pattern fitting with the Rietveld method based on neutron diffraction data using FullProf software. The cations arrangement was obtained by refining the occupancy of individual cation at tetrahedral and octahedral sites. The results of the analysis show that both NFO and 0.6NFO/0.4BTO samples have a mixed spinel structure, it means that there are cations of Ni2+ and Fe3+ on A-site and B-site. In NFO sample, the cations distribution among the A-site and B-site of NiFe2O4 is [Ni0.002Fe0.852][Ni0.006Fe0.862]2O4. The cations distribution among the A-site and B-site of NiFe2O4 in 0.6NFO/0.4BTO samples is [Ni0.0250Fe0.8975] [Ni0.012Fe0.950]2O4. So, the effect of adding BTO as a composite is to increase Ni2+ occupancy by 12.5 times on A-site and 2 times on B-site. The magnetic moment of multiferroic 0.6NFO/0.4BTO composite is 2.4(5) µB same as one of NFO. The BTO content in the composite has caused tensile strains induced into the NFO lattice, and at the same time, tensile strains of NFO caused the compressive strain on the c lattice of BTO even though the unit cell volume of BTO is also increasing from 64.100(5) to 64.374(6) A3.

Multifunctional composite membrane based on BaTiO3@PU/PSA nanofibers for high-efficiency PM2.5 removal

In this study, a new barium titanate@polyurethane/polysulfonamide (BaTiO3@PU/PSA) composite nanofibrous membrane with comprehensive properties for high temperature filtration and robust PM2.5 removal was successfully fabricated through the blending spinning of PU and PSA and the introduction of BaTiO3. As a consequence, the BaTiO3@PU/PSA membrane achieved the high capture efficiency of 99.99 % for fine particulates, low pressure drop of 39.4 ± 0.2 Pa, good mechanical property (13.27 MPa), sufficient flexibility, high thermal stability (up to 300 °C), favorable flame-retardancy as well as superior chemical resistance against acid and alkali. Especially, to intuitively reveal the relationship between the fiber structure, high temperature environment, gas velocity and filtration performance of the composite membrane, the filtration processes were carefully investigated through the analog simulation. More importantly, the BaTiO3@PU/PSA membrane exhibited high-efficiency PM2.5 purification capacity, and the removal efficiency kept stable after high temperature, acid or alkali treatment, ascribing to the advantageous structure of PSA, PU and BaTiO3. Overall, the BaTiO3@PU/PSA nanofiber membranes with versatility are a promising high-efficiency candidate for dust removal, particularly in harsh conditions.

Recrystallization of fine-crystalline barium titanate in low-density water medium

Fine-crystalline barium titanate was synthesized from a mixture of barium hydroxide monohydrate and titanium dioxide in water vapor medium at 200 °C and 1.55 MPa and subsequently treated in subcritical vapor and supercritical water at 200−400 °C and 1.55-26.3 MPa. Recrystallization of synthesized powder led to an increase in average crystal size and to tetragonal distortion of BaTiO3 structure. Formation of highly tetragonal BaTiO3 was observed after the treatment in supercritical water at 400 °C, 26.3 MPa. Treatment of BaTiO3 crystals in water vapor and supercritical water made for elimination of structural defects and for changes in the morphology and dispersion composition of the powder. The results are of importance for effective production of barium titanate powder of different dispersion as raw material for ferroelectric ceramics.

Structure, ferroelectric and magnetic characteristics of SmFeO3 and BaTiO3 co-modified BiFeO3 ceramics

BiFeO3 is the most important single-phase room temperature multiferroic materials. In this work, the structure, ferroelectric and magnetic properties of ternary SmFeO3 and BaTiO3 co-substituted BiFeO3 ceramics prepared by standard solid-state reaction method were investigated. The phase composition and structural transformation were characterized by X-ray diffraction and Raman spectrum analysis. The substitution of BaTiO3 leads to the phase transformation from rhombohedral R3c to pseudocubic, and the pseudocubic phase is obtained at BF008-017 ceramic. Meanwhile, the orthorhombic Pbnm phase content gradually increases with the addition of SmFeO3. According to differential scanning calorimetry (DSC) analysis results, the magnetic transition temperature TN decreases linearly with increasing B-site substitution content. The P–E hysteresis loops measured with Positive-Up-Negative-Down (PUND) method showed the enhanced ferroelectricity at BF008-01, and the maximum piezoelectric coefficient d33 obtained was 17.3 pC/N. The magnetic properties were significantly enhanced, and the best magnetic properties were achieved at BF017-008 sample, where the maximum magnetization ~ Mmax = 0.99 emu/g and remnant magnetization ~ Mr = 0.44 emu/g. The origin of the enhanced magnetism of BiFeO3-based ceramics is complex, and the substitutions of A and B sites would affect magnetic properties.

Structure and properties of nanocrystalline tetragonal BaTiO3 prepared by combustion solid state synthesis

Barium titanate (BaTiO3) attracts high scientific and technological attention due to good dielectric and electromechanical properties. Although BaTiO3 is one of the most frequently investigated ferroelectric materials, the need for finding new and/or improved synthesis methods of this material still exists. In this paper, a novel, mild synthesis route for producing tetragonal BaTiO3 from barium nitrate and Ti-oxalate precursor is presented. Morphology of the prepared and subsequently sintered BaTiO3 was determined by SEM. Particle size distribution of the as prepared powder was monitored by the laser diffraction. The phase composition, structure and lattice dynamics were investigated by XRD and Raman spectroscopy. Finally, dielectric parameters were determined in the temperature range from 30 to 180?C, and within a variety of frequencies. Curie temperature was detected at 130?C.

Understanding the electronic properties of BaTiO3 and Er3+ doped BaTiO3 films through confocal scanning microscopy and XPS: the role of oxygen vacancies.

Photonic and electronic properties exist inherently in ferroelectric barium titanate (BaTiO3); severe luminescence quenching also exists due to the insufficient confinement of excitons. In this sense, high optical emission can only be achieved by its chemical and structural modification. Thin BaTiO3 and Er:BaTiO3 films were grown by the spin coating method on a glass substrate at room temperature. Self-trapping of excitons in the thin BaTiO3 film and its structural modification due to the doping with Er3+ ions (Er:BaTiO3) are verified using scanning confocal fluorescence microscopy (SCFM), where self-trapping excitons never occured in its pure state. By thermal treatment and doping (BaTiO3 and Er:BaTiO3) we obtained localization of the excitons, which would further induce lattice strain around the surface defects, to accommodate the self-trapped excitons. With such a self-trapped state, the structure of BaTiO3 generates broadband emission of several overlapping bands between 1.95 and 2.65 eV at room temperature, while the structure Er:BaTiO3 showed defined emission bands at 2.24 and 2.35 eV, with very weak contributions of the emission due to the self-trapping state. The influence of the variation of the excitation wavelength using 1PE and 2PE on the emission bands of BaTiO3 and Er:BaTiO3 is also investigated. The results of enhanced emission bands suggest a clear dependence of the emission intensity on the excitation energy, where a ∼3 fold enhancement in emission has been demonstrated under Er3+ (1.55 eV) excitation, which can be attributed to effective energy transfer between the Er3+ ions. As a result, it is concluded that the developed BaTiO3 and Er:BaTiO3 can pave the way for future photonic devices.

Suspended single-crystalline oxide structures on silicon through wet-etch techniques: Effects of oxygen vacancies and dislocations on etch rates

Wet-etch techniques to realize suspended microscale structures of single-crystalline SrTiO3 and BaTiO3 grown on Si are explored. The authors examine the effects of oxygen vacancies and dislocations on etch rates. Both oxygen vacancies and dislocations enhance etching, yielding rates that are sufficiently high to enable conventional photoresist to serve as a mask layer. Suspended bridge structures are realized by etching the underlying Si substrate using a potassium hydroxide solution. The ability to realize suspended microscale structures using wet-etch techniques that are compatible with standard semiconductor device processing opens a pathway to integrate multifunctional oxides in microelectromechanical systems.

Modification of photocatalytic property of BaTiO3 perovskite structure by Fe2O3 nanoparticles for CO2 reduction in gas phase.

In this work, perovskite structure of BaTiO3 was coupled with Fe2O3 in different molar ratios achieving the best photocatalytic performance of CO2 reduction in the presence of CH4 as reducing agent; both of them are main greenhouse gases. The photocatalysts were synthesized by facile hydrothermal method. The samples were characterized by XRD, FTIR, FESEM, EDX, UV-Vis DRS, and photoluminescence (PL) analyses. The BaTiO3 synthesized in this research showed a weak PL signal which is due to the intrinsic ferroelectric property as has been observed in previous reports. Compared to the pure BaTiO3 and Fe2O3, the heterojunctions exhibited enhanced photocatalytic activity. The maximum CO2 reduction under visible light irradiation was obtained to be 22% during 60min process time. The enhanced photocatalytic activity could be attributed to the increased optical absorption, the good separation, and immigration of photogenerated charge carriers that decreased the recombination rate of charge carriers in the n-n heterojunction.

Niobium doping effect on BaTiO3 structure and dielectric properties

The effect of Nb on the microstructure and dielectric properties of BaTiO3 ceramics was investigated. The Nb/Mn–BaTiO3 ceramics were prepared using a conventional solid-state method. The concentration of Nb varied from 0.1 to 5.0 at% but Mn was fixed at 0.05 at%.The SEM indicated that compositions of 0.1 and 0.5 at% Nb displayed a fairly uniform microstructure and homogeneous distribution of additives, with a grain size of less than 2 μm. In highly doped samples a wide range of microstructural features was observed, from homogeneous and completely fine-grained microstructure to the appearance of secondary abnormal grains with core-shell structure.The dielectric constant and the loss tangent of modified ceramics were measured as a function of temperature (20–180 °C) and frequency (100 Hz-1MHz) for different concentrations of additives. The obtained results have shown that the dielectric constant at, both, room temperature (εr) and Curie temperature (εrmax), decreased as the concentration of Nb5+ increased. Thus, the highest values for the dielectric constant at room temperature (εr = 6648) as well as at Curie temperature (εrmax = 7680) were measured for the 0.1Nb/Mn–BaTiO3 samples sintered at 1350 °C.The highly doped BaTiO3 ceramics were found to exhibit lower values of the dielectric constant and low dielectric losses at room temperature. In these samples, stable dielectric permittivity with a flat dielectric behavior over a wide temperature range is observed.The Curie constant for all series of samples decreases with an increase of dopant concentration and the highest values were measured from samples doped with 0.1 at% Nb. The effect of additives on the Curie constant change is more pronounced at higher sintering temperatures. The analysis of the critical nonlinearity exponent (γ = 1.07–1.27), for lower dopant concentrations, shows a sharp phase transformation. For samples with increased Nb content, the degree of nonlinearity γ is higher indicating a diffuse phase transformation.

Microstructure of BaCO3 and BaTiO3 coatings produced on titanium by plasma electrolytic oxidation

BaCO3 and BaTiO3 layers were coated on titanium by plasma electrolytic oxidation at 5 mA/cm2 in 0.5 M Ba(CH3COO)2 and 2 M NaOH electrolyte. Coatings were investigated by scanning electron microscopy, X-ray and electron diffraction, and high-resolution transmission electron microscopy (HRTEM). Processing for 1 h required low voltages producing a BaCO3 coating along with a thin TiO2 interlayer (~60 nm). The coating is composed of orthorhombic BaCO3 nanorods that were vertically oriented at the bottom layer close to Ti substrate and horizontally oriented in the top layer close to the surface. Processing for 4 h required higher voltages resulting in generation of microarc discharges and discharge channel formation. These conditions produced a tetragonal BaTiO3 coating along with a broader TiO2 interlayer at the Ti interface composed of rutile and brookite nanostructures. It is suggested that the discharge channels promote the oxidation of the substrate along with the migration of titanium ions to the coating facilitating the BaCO3 to BaTiO3 transformation. The HRTEM evidence suggests that the latter transformation occurs via an epitaxial relationship existing between the BaTiO3 and BaCO3 crystal structures. Based on the present evidence, a structural model is proposed to describe the BaTiO3 growth from the BaCO3 lattice.

Structure of amorphous BaTiO3 by molecular dynamics simulations using a shell model

We studied the structure of amorphous BaTiO3 by molecular dynamics (MD) simulations. The local bonding units (LBUs) were mainly TiO6 in agreement with an X-ray absorption fine-structure (XAFS) study. An LBU was linked to its neighboring ones with their apexes, edges, and/or faces shared. The first peak of the Ti–Ti radial distribution function (g(r)) was located at ~ 3 Å with a trimodal distribution that results from the three linkage types, supporting extended X-ray absorption fine structure (EXAFS) experiments. If the number of Ba atoms around a Ti atom was larger than the average, the number of non-bridging oxygen (NBO; [1]O) atoms was larger around that Ti atom. In the opposite case, the number of tricluster oxygen (TO; [3]O) atoms was increased around it, and the number of edge or face-sharing linkages with the neighboring Ti atoms was also increased.

Enhanced photocatalytic degradation of tetracycline using hydrothermally synthesized carbon fiber decorated BaTiO3

Barium titanate (BaTiO3) has been emerged as an efficient photocatalyst due to its optical and electromechanical properties. However, due to large band gap of BaTiO3, different materials are used to decrease band gap energy. In this study, carbon fiber (CF) was used to decrease band gap energy of BaTiO3 and the photocatalytic activity for the degradation of tetracycline was investigated under UV and visible light irradiation. BaTiO3/CF was synthesized by hydrothermal method for different CF ratios (5–15 wt %). BaTiO3/CF/5 catalyst showed the best degradation efficiency (96% under UV light) among the other samples. The photocatalysts were characterized by XRD, SEM-EDAX, FTIR analysis, etc. According to XRD analysis, high crystallinity was observed for both BaTiO3 and BaTiO3/CF. Besides, FTIR results also show the evidence of carbon fiber over the BaTiO3 structure. First-order reaction rate constant, kapp, was calculated using Langmuir-Hinshelwood equation. The kapp values were found as 1.63*10−2 min−1 under UV-A light and 1.46*10−2 min−1 visible light irradiation for BaTiO3/CF/5. According to stability tests, after the first cycle tetracycline degradation was found as 96%, while it was 77% after fifth cycle.