La Doping Research Articles

Theoretical Study of Electric, Dielectric, and Optical Properties in Ion Doped Multiferroic SrFe12O19 Nanoparticles.

Electric, dielectric, and optical (band gap) properties of pure multiferroic as well as La- and Ni-doped SrFe12O19 (SFO) (at different sites) are investigated using a microscopic model and Green's function technique. The concentration dependence of the polarization P is considered for substitution of rare earths ions on the Sr sites. For a small La ion doping concentration, x = 0.1, La-doped SFO is ferroelectric, whereas for a larger doping concentration, for example x = 0.5, it is antiferroelectric. The real part of the dielectric constant ϵ increases with an increasing magnetic field h. ϵ decreases with an increasing frequency and La dopants. Therefore, La-doped SFO is suitable for microwave application with a low dielectric constant. The magnetic properties of pure SFO NPs are also studied. Ni doping at the Fe site of SFO leads to enhanced ferroelectric polarization and dielectric constant. The band gap decreases or increases by substitution of Ni or In ions on the Fe site, respectively. The results reveal that the tuned band gap of Ni-doped SFO makes it a crucial candidate for optoelectronic and solid oxide fuel cell applications.

La doping of CoFe Prussian blue analogs for improved catalytic activity toward norfloxacin degradation

Prussian blue analogs (PBAs) are promising catalysts in heterogeneous oxidation processes. The catalytic activity of PBAs relies on exposed crystal facets and accessible active sites on the PBA framework. Employing a heteroatom doping strategy using a rare earth element (La), we regulated the crystal structure and optimized the catalytic activity of CoFe PBA for peroxymonosulfate (PMS)-driven degradation of the antibiotic norfloxacin (NOR). The La atoms were mainly doped in the interstitial sites of the CoFe PBA cubic lattices, without affecting the electron distributions of Co and Fe metals or the face-centered cubic crystal phase of the coordination skeleton. La doping dominated the (111) and (100) as the main exposed facets of CoFeLa PBA, increasing the affinity of CoFeLa PBAs for PMS adsorption due to the higher surface energy of the two facets. Consequently, the activation energy considerably declined from 77.57 kJ/mol in CoFe PBA to 51.66 kJ/mol in CoFeLa PBA and the catalytic activity for PMS-driven NOR degradation was largely improved, which can reach 76.4 % removal of NOR within 15 min, with an increased initial rate constant k of 0.095 min−1. 1O2 was proven as the main reactive specie responsible for NOR degradation in the PMS/CoFeLa system, and O2·− and SO4·− were verified as the important intermediates to generate 1O2. Thus, La doping can effectively enhance the catalytic performance of PBA-based catalysts for organic pollutant removal.

Boosting the catalytic activity of high-order Ruddlesden–Popper perovskite SrEu2Fe2O7-δ air electrode by A-site La doping for CO2 electrolysis in solid oxide electrolysis cells

Ruddlesden–Popper (R-P) oxides (An+1BnO3n+1) are potential air electrodes for solid oxide electrolysis cells (SOECs) because of their good electrochemical performance. Among them, SrEu2Fe2O7-δ (SEF) with n = 2 has received extensive attention because of its special structure and promising ionic–electronic conductivity. However, the SEF material is prone to degradation at high temperatures (600 °C–800 °C), and its long-term stability is easily affected. In this study, R-P oxide Sr1-xLaxEu2Fe2O7-δ (SLEFx; x = 0, 0.05, 0.1) was successfully synthesized using the sol–gel method. XRD results showed that La-doped SEF displayed good chemical and thermal compatibility with the gadolinia-doped ceria electrolyte. The SLEF0.05 electrode exhibited a polarization resistance of 0.075 Ω cm2 at 800 °C, which was 88.2 % lower than that of SEF. The half-cell based on the SLEF0.05 air electrode exhibited improved performance under the long-term stability test at a current density of − 0.5 A cm−2 for over 110 h at 800 °C, indicating excellent stability. Moreover, an electrolysis current density as high as 0.712 A cm−2 at 1.5 V was obtained for the full cell with the SLEF0.05 air electrode, which was 45.8 % higher than the SEF electrode when the temperature and feed gas were 800 °C and 50 % CO2–50 % CO, respectively. The XPS and cell testing results confirmed that La with high valance and small radius promoted the formation of oxygen vacancies and effectively enhanced the electrochemical performance and structural stability of the SEF material. Therefore, the R-P oxide SLEF0.05 is a promising air electrode material for SOECs.

Photostriction effect and electric properties of La-doped PMN-PT transparent ferroelectric ceramics

ABSTRACT Ferroelectric ceramics display a remarkable photostriction effect, which could facilitate the prevention of electromagnetic interference and promote the integration and miniaturization of actuator systems, indicating potential applications in glimmer sensors. In this work, highly transparent La-doped 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 (0.9PMN–0.1PT) ceramics were synthesized using a solid-state reaction method in an oxygenated atmosphere. XRD and SEM were used to analyze the phase structure of the dense samples, which displayed a pure perovskite structure, with no trace of a pyrochlore phase. With La doping, the phase transition temperature shows a decreasing trend, and its dielectric constant could reach up to 20,000. The P-E loop of the samples was gradually refined into a straight line with an increase in the doping amount. After La doping, the transparency of the 0.9PMN–0.1PT ceramics was significantly enhanced and reached up to 61% at the near-infrared band. Finally, the photogenerated voltage and deformation of the La-doped 0.9PMN–0.1PT ceramics were investigated under ultraviolet light of various intensities. After 20 s of irradiation at an intensity of 800 mW/cm2, the maximum voltage and deformation, with values of 40 V and 250 nm, respectively, were both found in the 1%La-doped 0.9PMN–0.1PT ceramics.

Crystal structural, morphological and Raman spectroscopy characterizations of Ba0.97La0.02Ti1-xNb4x/5O3 (0.00 < x < 0.10) ceramics

In our present study, we have synthesized polycrystalline ceramics with the chemical composition Ba0.97La0.02Ti(1-x)Nb4x/5O3, denoted as BLTi1-xNb4x/5, where x takes on various values, including 0.00, 0.02, 0.05, 0.07, and 0.10. The materials were prepared through a molten salt method, followed by the formation of powders into pellets, and subsequent sintering at 800 °C for 24 h in the air. Through X-ray diffractometer (XRD), we confirmed that the synthesized ceramics exhibited a tetragonal perovskite structure, and they were found to be in a single phase. Surface characteristics were determined using Scanning Electron Microscopy (SEM). Raman spectroscopic investigations further verified the tetragonal perovskite structure of our materials. Additionally, this analysis revealed the successful incorporation of La3+ ions in place of Ba2+ ions within the A-site and Nb5+ ions substituting for Ti4+ ions within the B-site of the BT lattice. Notably, our study demonstrated the capability to adjust the Raman shifts of essential optical modes. While the majority of Raman shifts remained unchanged, La and Nb doping had a significant impact specifically on the A1[TO3] mode. This mode is associated with the deformation of the oxygen octahedron centered on the central Ti ion, indicating that the influence of these dopant ions primarily pertains to the B-site of the material.

Controllable spatial distribution of La dopants in perovskite NaTaO3 enhancing its photocatalytic performance of formaldehyde solution degradation and simultaneous hydrogen evolution

Photocatalytic degradation of aqueous organic pollutant while hydrogen evolution has become an attractive and potential approach to address environmental pollution and energy shortages. The design of highly efficient photocatalyst and the mechanism study are the keys for this issue. For this purpose, a series of rare earth La doped perovskite NaTaO3 were prepared by an easy solid-phase synthesis method. La doping changed the morphology, structure and physicochemical properties of NaTaO3 crystal. More importantly, it also found that controllable La dopants formed a concentration gradient between the surface and bulk of NaTaO3 crystal, which would cause a gradient of energy band structure. Noteworthy, 0.5La/NaTaO3 was identified as the intermediate state with the La doping from A sites to B sites and from bulk to surface in NaTaO3 crystal. It possessed a large La concentration gradient, leading to the better photoelectrochemical properties and photocatalytic performance than any other xLa/NaTaO3 catalyst. For the photocatalytic reaction over 0.5La/NaTaO3, HCHO was partially mineralized and gradually converted to HCOOH due to the large energy barriers of the intermediate reaction steps, while H2 was produced stably in the five recycle runs. The active species of •O2−, •OH and h+ were detected by the control experiments with trapping agents, and •O2− was confirmed to be the dominant one in the photocatalytic reaction. On this basis, the possible mechanism was proposed to understand the photocatalytic system in depth.

Discrete ZnO p-n homojunction piezoelectric arrays for self-powered human motion monitoring

Zinc oxide (ZnO), as a typical piezoelectric semiconductor, has gained significant attention in the field of wearable electromechanical coupling. However, the presence of an intrinsic screening effect becomes a bottleneck in developing high-performance ZnO-based piezoelectric devices. To address this limitation, we propose the formation of p-n homojunction by La doping in ZnO nanorods (NRs) as well as discrete structural design to improve their electrical output and flexibility. The enhanced performance and the mechanism behind it are explored and revealed in terms of morphology, structure, built-in electric field, depletion layer width, and junction capacitance, respectively. Benefitting from the excellent electromechanical coupling performance of the developed devices, different human motions can be recognized and classified with the aid of machine learning. These findings provide a new insight into the impact of doping on the output performance of piezoelectric semiconductor devices, thus facilitating advancements in piezoelectric device design and application exploration.

Improved relaxor ferroelectrics and energy storage performance of polycrystalline Ba0.95Sr0.05Ti2O5 ceramics modified with La dopants

Lead-free relaxor ferroelectrics are useful in energy storage applications. In particular, BaTi2O5-based dielectric materials may have great potential for such applications. In this study, polycrystalline Ba0.95Sr0.05Ti2O5-xLa (BST2-xLa) ceramics were synthesized using a standard solid-state reaction method with as-prepared nanoparticles prepared via a modified Pechini polymeric precursor method. The structural and electrical properties of the BST2-xLa ceramics were systematically investigated using a series of measurements. The phase analysis results confirm that La3+ is a donor dopant that replaced Ba2+ sites in the structure, which results in a decrease in oxygen vacancies to maintain charge neutrality. The intrinsic electronic conduction mechanism for electrical conductivity was evaluated from the fitted activation energy based on the Arrhenius equation. The relaxor ferroelectric behaviour and energy storage density and efficiency are improved by the addition of a small amount of lanthanum (<3.6 mol%) because of the charge and ionic radius mismatch in the structure. These results suggest that lanthanum can effectively optimise the relaxor ferroelectrics of BST2-xLa ceramics, which have promising potential as energy storage materials.

Economical sodium source prepared Na3SbS4 electrolyte with improved electrochemical performance by La doping

Solid electrolytes are expected to improve the next-generation rechargeable batteries in terms of safety and cost issues. In the present study, we designed a conventional sulfide sodium-ion conductor Na3+2xLaxSb1-xS4 synthesized from Na2S·9H2O as raw material. For optimized electrochemical behavior, the partial substitution of Sb with La in Na3SbS4 was modified by broadening Na+ ion channels and increasing interstitial Na+ ions in the network lattice. The structural characterization verified the increase in crystallinity after subsequent heating at 450 °C. The composition and structural design realized a high room temperature conductivity of 0.52 mS cm−1 and low activation energy of 0.069 eV for the Na3·1La0·05Sb0·95S4 sample. Moreover, this sulfide electrolyte was equipped with additional advantages, such as much lower electronic conductivity than Na3SbS4 and air stability against the humid atmosphere.

La3+ substitution-adjusted magnetic and optical properties with enhanced photocatalytic activity and stability of copper zinc nickel ferrites for wastewater treatment applications

Copper-zinc-nickel (Cu–Zn–Ni) ferrite nanoparticles are used for wastewater treatment technology. However, low degradation efficiency and stability are two main issues that make them unsuitable for actual production needs. In this paper, the citrate-nitrate auto-combustion method was applied for the formation of Cu0.5Zn0.25Ni0.25LaxFe2–xO4; (0≤x≤0.1; step 0.02) (CZNL) nanoferrites. Although the substitution process entails the replacement of a small ion with a larger one, the lattice constant and crystallite size does not exhibit a consistent incremental pattern. This behavior is justified and discussed. The size of all the CZNL ferrite nanoparticles is in the range of 8–12 nm, and the lattice constant is in the range of 8.6230 to 8.4865 nm. The morphological analysis conducted using field emission-scanning electron microscopy (FE-SEM) reveals that the CZNL exhibits agglomerated spherical morphology. The energy dispersive X-ray spectrameter (EDAX) analysis was employed to confirm the elemental composition of CZNL nanoferrites. Since the process entails the substitution of Fe3+ magnetic ions with non-magnetic ions La3+, the magnetic parameters of CZNL nanoferrites show a general decreasing trend as predicted. At 20 K, saturation magnetization Ms shows an overall drop in its values from 59.302 emu/g at x = 0.0–41.295 emu/g at x = 0.1, the smallest value of 37.87 emu/g is recorded at x = 0.06. the highest coercivity (Hc = 125.9 Oe) and remanence (Mr = 13.32 emu/g) are recorded for x = 0.08 and x = 0.04 nanoferrite, respectvely. The band gap of all the CZNL nanoferrites was determined using the Kubelka–Munk function and Tauc plot for direct permitted transitions. La doping modifies the band gap (within 1.86–1.75 eV), increases light absorption, induces efficient e/h separation and charge migration to Cu0.5Zn0.25Ni0.25LaxFe2–xO4 surfaces. The nanoferrite Cu0.5Zn0.25Ni0.25La0.06Fe1.94O4 achieves a degradation efficiency of 97.3% for methylene blue (MB) dye removal after just 60 min. After five recycling processes, the nanocatalyst Cu0.5Zn0.25Ni0.25La0.06Fe1.94O4 is degraded by 95.83%, resulting in a negligible 1.51% decrease in photocatalytic activity efficiency. The new Cu0.5Zn0.25Ni0.25La0.06Fe1.94O4 has exceptional photocatalytic activity and remarkable stability, making it a promising candidate for applications in wastewater treatment.

Optimized energy storage properties of Bi0.5Na0.5TiO3-based lead-free ceramics by composition regulation

To meet the demand for miniaturization and integration of electronic and electrical equipments, developing dielectric capacitors with excellent energy storage properties is of utmost importance. Bi0.5Na0.5TiO3-based ceramics have been investigated extensively for potential energy storage applications. However, its low breakdown strength Eb and high remnant polarization Pr limit the energy storage density and efficiency (η). Therefore, we explored a synergistic design strategy of domain control and grain size adjustment via La doping to successfully synthesize 0.8Bi0.5Na0.5TiO3-0.2NaNbO3-xLa2O3 (0.8BNT-0.2NN-xLa2O3) ceramics with superior energy storage properties to overcome above issues. It shows that the composition regulation by antiferroelectric NaNbO3 results in improved disrupted long rang order ferroelectric domain structure, effectively promoting the formation of polar nanoregions, subsequently weakening Pr and enhancing relaxation behavior. The introduction of antiferroelectric NaNbO3 effectively improves the η of the system. Moreover, the grain size is decreased and densification is enhanced after La tailoring, which is beneficial for the Eb and recyclable energy storage density (Wrec). Finally, a high Wrec of 4.40 ± 0.20 J/cm3 and η of 80.1 ± 2.1% at 450 kV/cm are obtained in 0.8BNT-0.2NN-0.07La2O3 ceramic. Besides, the sample demonstrates admirable temperature stability (25–175 °C) and frequency stability (10–100 Hz). Simultaneously, it displays stable discharge energy density, rapid discharge time of 0.36 μs, and good fatigue endurance (105 cycles). The results offer useful guidance for the design of novel ceramic capacitors with comprehensive energy storage performance.

Tunable anomalous Hall effect and Curie temperature in perpendicular magnetic anisotropic lanthanum doped NiCo2O4 film

Perpendicular magnetic anisotropic NiCo2O4 (NCO) films show volatile physical properties due to the complicated ion occupation/valence disproportion, making it feasible to be manipulated. In this work, the tunable anomalous Hall effect is observed in high-quality lanthanum (La) doped NCO films grown by the off-axis RF sputtering technique. It reveals that the longitudinal resistance (Rxx) significantly increases as the growth of La doping level, while the Curie temperature (TC) decreases with the rising of La doping level. A universal scaling law between the longitudinal conductance (σxx) and the anomalous Hall conductance (σxy), including the terms of dirty scaling mechanism, intrinsic contribution, and side jump, is proposed to explain the observed anomalous Hall effect. Additionally, an intrinsic linear relation between σxx and TC is revealed. The evolution of anomalous Hall resistance (RA), TC, and Rxx is closely related to the complex valence state/occupation of Ni ions induced by La doping. This work provides a strategy to manipulate the physical properties of NCO film, making it a potential material for spintronic applications.

Development of magnetic La doped Al2O3 core-shell nanoparticle loaded hydrogel for selective recovery of fluoride from aquatic medium

The selective removal of pollutants from water bodies is regarded as a conciliation between the rapid expansion of industrial activities and need of clean water for sustainability. Fluoride is one such geogenic pollutant, and various materials have already been reported. Developing an efficient field employable material is however a challenge. Herein, we report the synthesis and competencies of strategically designed magnetic La-doped Al2O3 core-shell nanoparticle loaded polymeric nanohybrid as a benchmark fluoride sorbent. A facile synthesis strategy involved fabrication of Fe3O4 magnetic core followed by growth of La doped Al2O3 shell using sol-gel method. Doping of La2O3 into Al2O3 structure was optimised (6%), resulting in Fe3O4-Al0.94 La0.06O1.5 core-shell particles which provided exceptional fluoride affinity. The obtained magnetic Fe3O4-Al0.94La0.06O1.5 core-shell nanoparticles were then loaded (22%) into alginate to form cross-linked hydrogel beads (Fe3O4-Al0.94 La0.06 O1.5-Ca-ALG). These prepared hydrogel beads were characterised and utilized for selective recovery of fluoride under different ambient conditions. Driving forces for enhanced fluoride uptake by La doped Al2O3 were investigated and explained with the help of both experimental observation and theoretical simulation. Density functional theory calculations indicated significant expansion in the cell volume of Al2O3 due to La doping which favoured the fluoride sorption. The calculated defect formation energy for the incorporation of F into Al2O3 was found to decrease in the presence of La. XPS analysis suggested direct interaction of fluoride with Al, forming Al-F bond and breaking Al-O bond. Different vital parameters for uptake were optimised. Also, kinetics, isotherm and diffusion models were evaluated. Developed hydrogel beads attained record sorption capacity of 132.3mgg-1 for fluoride. Overall, excellent stability, no leaching of constituents, effectiveness for selective fluoride recovery from groundwater, brand it a perfect epitome of sustainable water treatment application.

How La substitute doping affects the magnetic properties of the 2-14-1 magnets (Ce1-xLax)2Fe14B: Standard DFT and DFT + U studies

We investigated different amounts of La doping on the magnetic characterizations of the (Ce1-xLax)2Fe14B (x = 0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1) structures using standard density functional theory (DFT) and DFT plus U (DFT + U) methods. Substitutions of Ce atoms by La atoms increased the magnetic moment of Fe atoms. The absolute values of the magnetocrystalline anisotropy energy (MAE) calculated by standard DFT method gradually decreased with increasing amounts of La doping, while the MAE using DFT + U method exhibited non-monotonic dependence on La concentration. The optimal magnetic performance occurred within the range of x = 0.25 to 0.375. The DOS showed that the rare earth atomic magnetic moments were in the opposite direction to the magnetic moments of the Fe atoms, and the f-orbital electronic states of Ce atoms predicted by DFT + U method were generally larger than that predicted by standard DFT method.

Preparation of La-doped Ti/SnO2-Sb2O4 anode and its electrochemical oxidation performance of rhodamine B.

In this paper, La-doped Ti/SnO2-Sb2O4 electrode was prepared by electrodeposition and used for electrochemical degradation of rhodamine B. The optimum preparation conditions of the electrode were optimized as deposition time of 15min and calcination at 500 ℃ for 2h. The water treatment conditions were selected as initial pH 3.0, electrolyte Na2SO4 concentration 0.1M, current density 30mAcm-2, and initial rhodamine B concentration 20mg L-1; the color and TOC removal of RhB reached 99.78% and 82.41% within 30min. The FESEM, XRD, XPS, CV, LSV, and EIS characterization studies demonstrated that Ti/SnO2-Sb2O4-1%La electrode had a dense structure and the highest oxygen evolution potential (2.14V) and lowest charge transfer resistance (0.198 Ω cm-2), indicating that doped La has lower energy consumption. Moreover, La doping can expand the specific surface area, active site, performance of pollutant degradation, and service life of the electrode. Especially, the service life of Ti/SnO2-Sb2O4-1%La is increased by three times, and the maximum life span reaches 90min (1000mAcm-2, 1M H2SO4). Free radical quenching experiments show that ·OH plays a major role in the degradation of RhB. The Ti/SnO2-Sb2O4-1%La electrode prepared in this paper and its results will provide data support and reference for the design of efficient electrocatalytic electrode.

Ultrathin LayCoOx Nanosheets with High Porosity Featuring Boosted Catalytic Oxidation of Benzene: Mechanism Elucidation via an Experiment-Theory Combined Paradigm.

Designing transition-metal oxides for catalytically removing the highly toxic benzene holds significance in addressing indoor/outdoor environmental pollution issues. Herein, we successfully synthesized ultrathin LayCoOx nanosheets (thickness of ∼1.8 nm) with high porosity, using a straightforward coprecipitation method. Comprehensive characterization techniques were employed to analyze the synthesized LayCoOx catalysts, revealing their low crystallinity, high surface area, and abundant porosity. Catalytic benzene oxidation tests demonstrated that the La0.029CoOx-300 nanosheet exhibited the most optimal performance. This catalyst enabled complete benzene degradation at a relatively low temperature of 220 °C, even under a high space velocity (SV) of 20,000 h-1, and displayed remarkable durability throughout various catalytic assessments, including SV variations, exposure to water vapor, recycling, and long time-on-stream tests. Characterization analyses confirmed the enhanced interactions between Co and doped La, the presence of abundant adsorbed oxygen, and the extensive exposure of Co3+ species in La0.029CoOx-300 nanosheets. Theoretical calculations further revealed that La doping was beneficial for the formation of oxygen vacancies and the adsorption of more hydroxyl groups. These features strongly promoted the adsorption and activation of oxygen, thereby accelerating the benzene oxidation processes. This work underscores the advantages of doping rare-earth elements into transition-metal oxides as a cost-effective yet efficient strategy for purifying industrial exhausts.

Enhancing humidity sensitivity properties through RE (Er, La, and Sm) dopants in TiO2 nanofiber composites

Enhancing humidity sensitivity properties through RE (Er, La, and Sm) dopants in TiO2 nanofiber composites

High-performance ammonia gas sensor based on spray pyrolysis developed In2O3:La films

La doped indium oxide (In2O3:La) thin films were deposited on glass substrate by nebulizer spray pyrolysis by different La doping concentrations. The crystalline structure, morphology, optical and gas sensing properties of thin films were investigated. XRD diffractograms present cubic crystal structure of In2O3 films, with decreased crystallite size with the incorporation of La dopants. SEM analysis of thin film samples exhibits approximately cube-shaped morphology without any cracks of microstructures. The optical band gap magnitude shows shift in energy values in the range of 3.12–3.29 eV with increasing La concentrations. For all films, the photoluminescence spectra showed violet-blue emission peaks at around 420–480 nm. All of the developed films were tested for ammonia (NH3) gas detection at ambient temperature. In2O3:La 5% sensor had the highest gas response value of 1720%, a quicker response and recovery times of 48/12 s, respectively, suggesting the sample could be better suited for the application of NH3 gas sensor.

Preparation of direct Z-scheme heterojunction la-doped Bi2WO6/CdS with enhanced visible light absorption and its photocatalytic degradation of antibiotics

In this paper, a novel direct Z-scheme heterojunction La-Bi2WO6/CdS composed of 3-dimensional flower-like Bi2WO6 and hexagonally stacked succulent CdS was successfully designed and synthesized. The morphology, optical properties, element valence and crystal structure of the catalysts were systematically characterized. When the dosage of LBC-40 was 1.0 g/L, the degradation rate of oxytetracycline (OTC, 20 mg/L, pH = 6) was 85.28 %, under low visible light illumination (65 W energy saving lamp) for 120 min and the reaction kinetic constant (0.01336 min−1) was 2.50 and 1.56 times that of pure Bi2WO6 and La-Bi2WO6, respectively. Moreover, La-Bi2WO6/CdS showed good photocatalytic activity for other single antibiotics, mixed antibiotics and antibiotics from different water sources. The photocatalytic activity only decreased by 7.69 % after 3 cycles. Furthermore, the possible photocatalytic degradation pathway and photocatalytic mechanism of OTC were proposed. The excellent photocatalytic performance of La-Bi2WO6/CdS is for that the doping of La3+ and the construction of direct Z-scheme heterojunction enhances the visible light absorption capacity and separation efficiency of photogenerated electron-hole pairs. This paper reports a new method, which can provide a reference for the design and development of visible light responsive photocatalysts with excellent photocatalytic properties.

Tailoring the crystal distortion and dielectric properties of 0.7CaTiO3-0.3NdAlO3 microwave ceramics by La, Sm and Eu doping into A-site Nd

The TiO6 octahedra titling and rotation play an important role in affecting the microwave properties of 0.7CaTiO3-0.3NdAlO3 microwave ceramics by A-site La, Sm and Eu doping. The oxygen octahedra of Sm-doped 0.7CaTiO3-0.3NdAlO3 ceramics exhibit antiphase tilting, while both in-phase and antiphase tilting coexist in the 0.7CaTiO3-0.3EuAlO3 ceramics. There is an undeniable correlation between the crystal distortion and the tolerance factor t. As the tolerance factor t continues to increase, the crystal structure of A-site doped CTNA ceramics changes from both in-phase tilting and antiphase tilting to untilted structure and the TiO6 octahedra exhibits an inclination to tilt around c axis. The weakening bending vibration of the Ti–O(2)-Ti bond results in the increase of the polarization and the damping coefficient of lattice vibration. The dielectric constant (εr) rises to 48 from 43 and Q × f values decrease to 36,000 GHz from 44,800 GHz (measured at 6 GHz). These findings could be used to guide the tailoring of the crystal distortion and microwave dielectric properties of technologically important perovskite 0.7CaTiO3-0.3NdAlO3 based ceramics.