Pechini Method Research Articles

Photodegradation of Carbol Fuchsin Dye Using an Fe2−xCuxZr2−xWxO7 Photocatalyst under Visible-Light Irradiation

Fe2−xCuxZr2−xWxO7 (x: 0, 0.05, 0.015) nanoparticles were synthesized following the Pechini method and characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS) measurements to be used as photocatalysts in colored water remediation. All of the prepared materials were crystallized in a cubic fluorite phase as the major phase. The band gap was reduced upon doping with W6+ and Cu2+ from 1.96 eV to 1.47 eV for Fe1.85Cu0.15Zr1.85W0.15O7. Carbol fuchsin (CF) dye was used to determine the photocatalytic degradation efficiency of the prepared catalysts. Degradation efficiency was directly proportional to the dopant’s concentration. Complete removal of 20 mg/L CF was achieved under optimal conditions (pH 9, and catalyst loading of 1.5 g/L) using Fe1.85Cu0.15Zr1.85W0.15O7. The degradation rate followed pseudo-first-order kinetics. The reusability for photocatalysts was tested five times, decreasing its efficiency by 4% after the fifth cycle, which indicates that the prepared Fe1.85Cu0.15Zr1.85W0.15O7 photocatalyst is a promising novel photocatalyst due to its superior efficiency in dye photodegradation.

Impact of the Synthesis Method on the Conventional and Persistent Luminescence in Gd3-xCexGa3Al2O12.

The series of Gd3–xCexGa3Al2O12 nanopowders doped with different concentrations of Ce3+ ions were prepared by Pechini (sol–gel) and combustion methods. The structure and morphology of the powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. It was found that the synthesis method has a great impact on the morphology and, consequently, spectroscopic properties of the powders. Optical properties of the powders were examined using excitation, emission, and luminescence kinetic measurements. For all powders, persistent luminescence and emission decay processes were studied. The most intense luminescence was observed for the powder with 0.5 mol % of Ce3+ synthesized using the combustion method and 1 mol % in the case of the sol–gel sample. The longest and brightest persistent luminescence was observed for the powders doped with 0.1 mol % (combustion) and 0.2 mol % of Ce3+ ions (sol–gel). The thermoluminescence measurements were done for the powders prepared using different methods to understand the impact of the synthesis conditions on the number and depths of the traps involved in persistent luminescence. On the basis of spectroscopic measurements, the mechanism of persistent luminescence was constructed and discussed.

Modified Pechini method by PVP addition for Nd:Gd2O3 nanophosphors fabrication

Gadolinium oxide nanopowders doped with neodymium were prepared via modified Pechini method based on double stabilization of nanoparticles. Polyvinylpyrrolidone was used as an additional stabilizer at low-temperature stage of synthesis. This polymer also acts as a fuel during thermal treatment of precursors. Photoluminescence and FTIR spectroscopy, DTA/TG, XRD and SEM analysis were used for the analysis of thermal evolution of initial materials, chemical intermediates and final products at different stages of thermal treatment. Photoluminescence characterization included measurements of excitation and emission spectra of synthesized powders at different stages of thermal treatment.

Structural and morphological characterization of Y1-xNdxAl3(BO3)4 micron-sized crystals powders obtained by the urea precipitation method and its random laser properties

The search for efficient photonic materials for laser action has grown since 1960, after the invention of the ruby laser. Among the elements that exhibit stimulated emission, Nd3+ has received great attention for use in conventional or random lasers. Several host matrices have been developed for lanthanides ions, and aluminum borates (as YAl3(BO3)4, YAB) have proven to be excellent laser hosts due to their physicochemical properties. YAB can be synthesized by various routes, including flux methods, the Pechini method, and the sol–gel methodology. We report a new synthesis route to prepare Y1-xNdxAl3(BO3)4 micron-sized crystals, x = 0.1, 0.2, 0.4, 0.6, or 0.8, on the basis of the urea precipitation method. Structural characterization confirmed that all the particulate samples have trigonal symmetry with hexagonal space group. Powder X-Ray Diffraction (PXRD), High-Resolution Transmission Electron Microscopy (HRTEM), and Selected Area Electron Diffraction (SAED) showed that the particles are well crystallized. Photoluminescence studies revealed that Nd3+ replaces Y3+ in the YAB host matrix. Stimulated emission leading to random lasing in the Nd3+:YAB powder is demonstrated, which also opens the possibilities of its use as efficient materials for superluminescent sources.

Pressure assisted sintering of Al2O3–Y2O3 glass microspheres: sintering conditions, grain size, and mechanical properties of sintered ceramics

Abstract Glass microspheres with yttria-alumina eutectic composition (76.8 mol% Al2O3 and 23.2 mol% Y2O3) were prepared by sol-gel Pechini method and flame synthesis with or without subsequent milling. Prepared amorphous powders were studied by X-ray powder diffraction (XRD), particle size analysis (PSA), scanning electron microscopy (SEM) and differential thermal analysis (DTA). Hot pressing (HP), rapid hot pressing (RHP) and spark plasma sintering (SPS) were used to sinter amorphous precursor powders at 1600 °C without holding time (0 min). The preparation process including milling step resulted in amorphous powders with narrower particle size distribution and smaller particle size. All applied pressure assisted sintering techniques resulted in dense bulk samples with fine grained microstructure consisting of irregular α-Al2O3 and Y3Al5O12 (YAG) grains. Milling was beneficial in terms of final microstructure refinement and mechanical properties of sintered materials. A material with the Vickers hardness of HV = (17.1 ± 0.3) GPa and indentation fracture resistance of (4.2 ± 0.2) MPa.m1/2 was prepared from the powder milled for 12 h.

Self-Assembly of Au-Fe3O4 Hybrid Nanoparticles Using a Sol-Gel Pechini Method.

The Pechini method has been used as a synthetic route for obtaining self-assembling magnetic and plasmonic nanoparticles in hybrid silica nanostructures. This manuscript evaluates the influence of shaking conditions, reaction time, and pH on the size and morphology of the nanostructures produced. The characterization of the nanomaterials was carried out by transmission electron microscopy (TEM) to evaluate the coating and size of the nanomaterials, Fourier-transform infrared spectroscopy (FT-IR) transmission spectra to evaluate the presence of the different coatings, and thermogravimetric analysis (TGA) curves to determine the amount of coating. The results obtained show that the best conditions to obtain core–satellite nanostructures with homogeneous silica shells and controlled sizes (<200 nm) include the use of slightly alkaline media, the ultrasound activation of silica condensation, and reaction times of around 2 h. These findings represent an important framework to establish a new general approach for the click chemistry assembling of inorganic nanostructures.

Green self-assembly of CuCe2(MoO4)4/montmorillonite-K10 nanocomposites; a promising solid-state hydrogen storage profile

Rapid scale-up of the technologies for clean energy production, conversion and storage have been adopted by many countries in order to reduce demand for fossil fuels. Primary renewable energy such as solar, wind, and hydro are developed for energy production particularly for electricity generation. However, there are still some deficiencies in direct use of primary renewable energy sources; therefore, secondary energy sources (or carriers) have been recently established as clean energy sources. Hydrogen is a type of secondary energy sources with almost low density and light weight; therefore, it must be stored in the form of liquid or gas. The storage of hydrogen in the form of liquid requires very low temperature. Solid-state hydrogen storage on the surfaces of solids or within solids is a promising solution to above shortcomings for high-density energy storage. Herein, multi-layers solid-state materials with ability of hydrogen adsorption are presented, for the first time, including “mixed metal oxide (MMO) nanostructures” and “silicate layers”. The MMO is CuCe2(MoO4)4 nanostructures which synthesized via Pechini method in front of various chelating agents such as trimesic acid, maleic acid, succinic acid, and malonic acid, while the silicate layer is nanoclay montmorillonite K10. In this study, the experimental observations reveal a pure formation of CuCe2(MoO4)4 nanostructures in malonic acid at 500 °C, with almost regular nanosized morphology of 20–25 nm. The selected sample is then used for nanocomposite formation by dispersing the CuCe2(MoO4)4 nanostructures into the montmorillonite K10 solution. The final nanocomposites exhibit a superior electrochemical hydrogen storage performance, in terms of “maximum discharge capacity of ∼ 3750 mAh/g)” and “efficiency of about 70%” in an alkaline medium. It must be mentioned that though the maximum discharge capacity of the CuCe2(MoO4)4 nanostructures is higher than nanocomposites (for example ∼ 6000 mAh/g), but the efficiency (discharge/charge) is lower (∼48%). It can be emphasized that this nanocomposite can be applied as promising host in an electrochemical hydrogen storage system, which can meet the U.S. Department of Energy (DOE) hydrogen storage targets.

(Invited) Facile Synthesis of Spherical and Highly Sinterable SDC Particles by Using Molten Salts

Sm-doped ceria (SDC) has been widely used as an electrolyte itself and active layer for high-temperature electrochemical devices such as SOFCs. Even though SDC shows an excellent oxide-ion conductivity at intermediate-temperature range, high temperature is required for sintering. To use SDC for additive manufacturing process, which is of great interest in this research field, the reduction of its sintering temperature is highly demanded. In this study, we propose a facile synthesis technique of spherical and highly sinterable SDC particles by using molten salts. Ce0.8Sm0.2O1.9 (SDC) powders were synthesized by the Pechini method by using Ce(NO3)3·6H2O, Sm(NO3)3·6H2O, and additional nitrates forming liquid phase at elevated temperature. Microstructure and compositional analyses were performed by TEM/STEM coupled with EDS and EELS.The sintering behavior of SDC at low temperature will be also discussed.

Rationally Engineering Interfaces at Cathodes and Anodes in Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have received increasing attention due to the high theoretical capacity and low cost of the naturally abundant sulfur cathode.However, its practical application suffers formidable challenges due to instable solid electrolyte interphases (SEIs) on Li metal anode, shuttle caused by the dissolution of intermediate polysulfides into the electrolyte and sluggish kinetics of the sulfur redox reaction, etc. In order to address the above issues, in our presentation, we will propose the novel approaches to rationally engineer the interfaces at both cathode and anode sides to improve Li-S performances. On the one hand, a modified Pechini method is developed to synthesize nanoporous carbon host decorated with Ni3S2@Ni particles. Such cathode delivers enhanced specific capacities with extended cycling life in lean electrolytes, due to the dual functions of Ni3S2 shell, which can both facilitate reaction kinetics and promote electrolyte wetting. On the other hand, we demonstrated a bi-layer structure, constructed of an interconnected, tortuous, porous LiF-rich layer in contact with lithium and a dense in-situ formed inorganic-rich layer on top of the porous structure, showing enhanced anode stability. The porous layer increases the number of Li/LiF interfaces, which reduces local volume fluctuations and improves Li+ diffusion along these interfaces. Additionally, the tortuous porous structure guides uniform Li+ flux distribution and mechanically suppresses dendrite propagation. The dense upper layer of the SEI accomplishes a closed-host design, preventing continuous consumption of active materials. The duality of a dense top layer with porous bottom layer led to extended cycle life and improved rate performance, evidenced with symmetric cell testing, as well as full cell testing paired with sulfur cathodes.

Investigation of reactive perovskite materials for solar fuel production via two-step redox cycles: Thermochemical activity, thermodynamic properties and reduction kinetics

The investigation and optimization of solar fuels production by H2O and CO2 splitting reactions using non-stoichiometric redox materials as oxygen carriers relies on materials-related studies. The thermochemical cycles performance strongly rely on the thermodynamics and kinetics of redox reactions, as well as the chemical composition and morphology of the reactive redox materials commonly based on ceria and perovskites. This study focusses on the evaluation and selection of suitable non-stoichiometric metal oxides for two-step thermochemical cycles with high fuel production yields, rapid reaction rates, and performance stability. The redox activities of different A- and B-site substituted perovskite materials (ABO3) were experimentally investigated (with A = La, Sr, Y, Ca, Ce, Pr, Sm and B = Mn, Co, Fe, Mg, Al, Ga, Cr). The reactive powders were synthesized via modified Pechini methods providing a porous microstructure especially suitable for thermochemical cycles, while their redox activity was evaluated by thermogravimetric analysis. This experimental screening highlighted the difficulty to combine high reduction extent (δ) achievable by the reactive material with complete re-oxidation extent and fast reaction rates. From the redox activity study of manganite perovskites, La0.5Sr0.5Mn0.9Mg0.1O3 (LSMMg) was pointed out as a good compromise between CO2 splitting activity and thermal stability, possibly competing with ceria as a promising material for two-step thermochemical cycles. Both thermodynamic and kinetic studies were also performed to provide a better understanding of the mechanisms involved in thermochemical cycles. Thermodynamic properties derived from experimental δ(T,pO2) diagrams were used to predict the upper bounds for both reduction extent and fuel production performance at equilibrium. Regarding kinetics, the activation energy during LSMMg reduction was shown to increase with the increase of the non-stoichiometry extent.

Influence of synthesis process on the structural and microstructural behavior of neodymium doped sodium and potassium niobate powders

In this paper are presented the synthesis of sodium-potassium niobate doped with neodymium. The powders were obtained carried out by means of three synthesis methods (mixture of oxides, hydrothermal and pechini methods). It was possible to observe in function of the synthesis method, particles cohered to form agglomerates and variation in shape, and size particles. Changes in calcination temperatures were found as a function of synthesis methods (using thermogravimetric analysis). Secondary phases were not observed in neodymium-doped sodium-potassium niobate powders obtained by mixture of oxides; however, secondary phases formation was observed in the powders obtained by hydrothermal and pechini method. Into solid-state physics, this study is important because can be used as a reference for establish the synthesis parameters of sodium potassium niobate powders with other rare earth elements. Besides, the results are the input to obtain secondary phases free ceramics and be able to study multifunctional properties as future work.

Enhanced performance of CH4 dry reforming over La0.9Sr0.1FeO3/YSZ under chemical looping conditions

Catalytic dry reforming of methane is an attractive route for CO2 valorization that yields syngas (CO + H2) for subsequent synthesis of chemical and fuels. Alternatively, chemical looping approaches based on discontinuous cyclic operation are lately gaining relevance because, among other advantages, these processes are less prone to deactivation, and they are amenable to be used for thermosolar fuel production. With this background, here we investigate the isothermal activity of CO2 and CH4 over La0.9Sr0.1FeO3 perovskite modified with yttria-stabilized zirconia (YSZ), comparing conventional catalytic activity, tested by continuous feeding an equimolar blend of these two gases, with the chemical looping process, where the inlet composition swings between CH4 and CO2 in 20 min intervals. Two preparation methods were used to obtain these composites: direct synthesis by Pechini method of the perovskite in the presence of YSZ support and mechanical mixing by ball-milling of the two pre-synthetized oxides. Catalytic activity feeding a CH4 and CO2 blend showed a moderate but rather stable activity (226 µmols.min−1.g−1 of H2 and 206 µmols.min−1.g−1 of CO) at 850 °C for 24 h, with little difference between catalysts. Chemical looping operation at the same temperature, resulted in enhanced production of syngas, with the sample with perovskite synthetized on the support showing significantly higher peak performance (476 µmols.min−1.g−1 of H2 and 432 µmols.min−1.g−1 of CO). The observed high H2/CO ratio in the methane stage (up to 6.5) indicates the relevant contribution of methane cracking. Characterization of the fresh materials confirmed the formation of the expected phases in both cases, while after CH4 treatment at high temperature the perovskite decomposed mainly into La2O3 and reduced Fe phases. In addition, carbon is also deposited, mainly as multiwall nanotubes. However, the initial perovskite composition is recovered after re-oxidation with CO2, allowing a stable operation of the La0.9Sr0.1FeO3/YSZ system for at least five cycles.

Response surface optimization and modeling of caffeine photocatalytic degradation using visible light responsive perovskite structured LaMnO3

Caffeine is a refractory pollutant of emerging concern that evades conventional waste-water treatment techniques. Here, we report the synthesis of visible light responsive perovskite structured LaMnO­3 photocatalyst using modified Pechini method and utilized it as an efficient photocatalyst for caffeine degradation. XRD, BET, UV-Vis, NH3-TPD, and SEM were used to characterize the photocatalyst. Response surface methodology using Central composite design was used to investigate the effect of three operational variables; catalyst dosage, initial caffeine concentration and pH on the caffeine photocatalytic degradation efficiency. The functional relationship between these operational variables and caffeine photocatalytic degradation efficiency was established be a second order polynomial model. The results of the response surface analysis indicate caffeine degradation efficiency is most significantly affected by catalyst dosage and pH. The optimal values of operational obtained by response surface optimization were found be 3.5 g/L for catalyst dosage, 7.9 and 44.6 mg/L for pH and initial caffeine concentration respectively given the caffeine degradation efficiency of 93.9%.

A high-performance ethanol gas sensor based on Ce-doped SnO2 nanomaterials prepared by the Pechini method

Ce doped SnO2 composite nanomaterials with different concentrations were prepared by a modified green Pechini method. The crystalline phases, elemental composition, and surface topography of the composite material were characterized by various characterization methods. The test results reveal that the sensor with appropriate Ce doping SnO2 has excellent gas sensing properties for ethanol. The device doped with 2% Ce showed a response as high as 69.4 in 50 ppm ethanol, which is 2.4 times that of the device based on Pure-SnO2. Moreover, the sensor has a lower optimum operating temperature, better ethanol selectivity, linearity, and stability. The enhancement factors of the sensing characteristics are further discussed. Ce-doped SnO2 nanomaterials prepared by the Pechini method have great application potential in gas sensors.

Microstructure, composition and magnetic properties of Nd-(Fe1-xCox)-B oxide magnetic particles synthesized by Pechini-type chemical method

This work deals with the investigation and optimization of the crystalline phases, magnetic properties, chemical composition and morphology of Nd-(Fe1-xCox)-B oxide magnetic particles (where x = 0, 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, and 0.5) synthesized by Pechini method that can be used as a precursor for the production of Nd2(Fe,Co)14B hard magnetic phase. The polymerization mechanism of Pechini process was investigated by Fourier transform infrared (FTIR) and Raman spectroscopy to confirm the formation of metal-CA complexes and successive esterification reactions between citric acid (CA) and ethylene glycol (EG). The chemical composition of the synthesized samples was studied via energy dispersive (EDS) and X-ray photoelectro (XPS) spectroscopy methods. The structure, morphology, and the crystalline phase of resulting Nd-(Fe1-xCox)-B oxide magnetic particles were characterized by Rietveld refinement of X-ray diffraction (XRD) patterns, scanning electron microscopy ( SEM), and high-resolution transmission electron microscopy (HR-TEM) and its selected area electron diffractograms (SAED). The results obtained from the Rietveld refinement of XRD patterns show that (Fe2O3/Fe3O4) phase ratio decreases with the amount of cobalt that can be attributed to the reduction of enthalpy . The SEM micrographs indicate that the oxide particles have an elongated structure with irregular shapes supported by TEM observations. The results of structural analysis by HR-TEM and SAED are consistent with the Rietveld results which confirms the presence of different oxide phases in Nd-(Fe1-xCox)-B oxide particles. The magnetic behaviorstudied by VSM was interpreted by the variances of the morphology, structure and chemical composition of Nd-(Fe1-xCox)-B oxide particles, all of which were influenced by the cobalt content. First‐Order Reversal Curve (FORC) diagrams show that the magnetic interaction between oxide particles decreases as the cobalt content increases.

Formation of Solid Solutions and Physicochemical Properties of the High-Entropy Ln1-xSrx(Co,Cr,Fe,Mn,Ni)O3-δ (Ln = La, Pr, Nd, Sm or Gd) Perovskites.

Phase composition, crystal structure, and selected physicochemical properties of the high entropy Ln(Co,Cr,Fe,Mn,Ni)O3−δ (Ln = La, Pr, Gd, Nd, Sm) perovskites, as well as the possibility of Sr doping in Ln1−xSrx(Co,Cr,Fe,Mn,Ni)O3−δ series, are reported is this work. With the use of the Pechini method, all undoped compositions are successfully synthesized. The samples exhibit distorted, orthorhombic or rhombohedral crystal structure, and a linear correlation is observed between the ionic radius of Ln and the value of the quasi-cubic perovskite lattice constant. The oxides show moderate thermal expansion, with a lack of visible contribution from the chemical expansion effect. Temperature-dependent values of the total electrical conductivity are reported, and the observed behavior appears distinctive from that of non-high entropy transition metal-based perovskites, beyond the expectations based on the rule-of-mixtures. In terms of formation of solid solutions in Sr-doped Ln1−xSrx(Co,Cr,Fe,Mn,Ni)O3−δ materials, the results indicate a strong influence of the Ln radius, and while for La-based series the Sr solubility limit is at the level of xmax = 0.3, for the smaller Pr it is equal to just 0.1. In the case of Nd-, Sm- and Gd-based materials, even for the xSr = 0.1, the formation of secondary phases is observed on the SEM + EDS images.

Electronic structure engineering of Gd2.97Tb0.03Ga5−xAlxO12 persistent luminescence phosphors

Gd2.97Tb0.03Ga5−xAlxO12 powders with different Ga:Al ratio were prepared using modified Pechini method. Changing Ga:Al ratio opens the way to modulate the energy gap, and so, to modify the spectroscopic properties of the phosphors. Al3+ ions stabilize the metastable Gd3Ga5O12 garnet structure widening the energy gap. With increasing Ga content in the garnet structure, the energy gap between an excited 5d level of Tb3+ ions and the conduction band (CB) decreases, which leads to an overlap of the conduction band with the 5d band suppressing the energy transfer between the 5d band and the 4f levels of Tb3+ ions. The band gap changes lead to the blue shift of charge transfer band due to an expansion of the unit cell and decreased interaction between oxygen ligands and luminescent ions. The collected spectroscopic data show significant effect of crystal field strength of the host matrix on both conventional and persistent luminescence. From the resultant data the influence of Ga:Al ratio on the luminescence properties and trapping/releasing of electrons is discussed. The mechanism of Tb3+ persistent luminescence in Gd2.97Tb0.03Ga5−xAlxO12 is proposed.

Synthesis and high thermal stability of Mn doped Y2/3Cu3Ti4O12 negative temperature coefficient ceramic

In this paper, high thermal stability of Mn doped Y2/3Cu3Ti4O12 negative temperature coefficient (NTC) ceramics have been successfully fabricated by the combination of Pechini powder synthesis and solid-state reaction sintering. The substitution of Mn for Ti plays a critical role in controlling the phase structure, microstructure, electrical properties, and stability. The structure of as-sintered ceramics is a single Y2/3Cu3Ti4O12 phase at x ​≤ ​0.5, while the CuO phase begins to appear at x ​≥ ​0.7. X-ray photoelectron spectroscopy further confirms the change of cation concentration, one of the critical factors for electrical conductivity in Y2/3Cu3Ti4-xMnxO12 ceramics. In the temperature of −50–250 ​°C, the resistivity all decreases with increasing temperature and Mn content, the aging coefficient of all samples is within 0.4%, and the minimum can reach 0.2%. We strongly propose that the Mn substitution and Pechini method are highly desirable for the fabrication of high stability NTC thermistors for medi-temperature region application.

Green photocatalytic remediation of Fenthion using composites with natural red clay and non-toxic metal oxides with visible light irradiation

ABSTRACT In the present work, composites with non-toxic metal oxides, such as TiO2 and ZnO, and a natural red clay (taua) reach in hematite were used in the photocatalytic degradation of Fenthion. The composite TiO2/Taua (0.5:1 wt. ratio) and pure TiO2 were prepared by sol-gel method while ZnO/Taua (0.5:1 wt. ratio) and pure ZnO were prepared by Pechini method. The materials were characterized by XRD, SEM, EDX, and DRS. The anatase phase was formed in both pure TiO2 and TiO2/Taua, while the hexagonal phase was formed in pure ZnO and ZnO/Taua. The bandgap energies for the two composites were narrowed compared to the respective pure oxides as consequence of the hematite (α-Fe2O3, E g = 2.1 eV) in the red clay, reaching 2.1 eV for TiO2/Taua and 2.0 eV for ZnO/Taua, while the bandgap energies for pure TiO2 and ZnO were 3.2 and 3.0 eV, respectively. Fenthion was not degraded in the dark, but the concentration droped 20% after 180 min under visible light irradiation without photocatalyst and 60% after 210 min in the presence of the pure red clay. Both TiO2/Taua and ZnO/Taua composites were also photocatalytic active to degrade Fenthion (λ > 420 nm), with degradation of 78% (in 180 min) and 85% (in 210 min) respectively. In the optimized conditions (pH 2, 100 mg L−1 of H2O2 and 30 mg L−1 of Fenthion), the ZnO/Taua composite was the most efficient, reaching 89% degradation in up to 30 min, with Fenthion sulfoxide as the degradation product.

Structure and Luminescence Properties of Gd2(WO4)3 and Gd2(WO4)3:Tm3+,Yb3+ Nanopowders Prepared by Solid-State Sintering and the Pechini Methods

Structure and Luminescence Properties of Gd2(WO4)3 and Gd2(WO4)3:Tm3+,Yb3+ Nanopowders Prepared by Solid-State Sintering and the Pechini Methods