Thermogravimetry And Differential Scanning Calorimetry Research Articles

Irinotecan-loaded magnetite-silica core-shell systems for colorectal cancer treatment

Colorectal cancer represents a worldwide spread type of cancer and it is regarded as one of the leading death causes, along with lung, breast, and prostate cancers. Since conventional surgical resection and chemotherapy proved limited efficiency, the use of alternative drug delivery systems that ensure the controlled release of cytostatic agents possess immense potential for treatment. In this regard, the present study aimed to develop and evaluate the efficiency of a series of irinotecan-loaded magnetite-silica core–shell systems. The magnetite particles were obtained through a solvothermal treatment, while the silica shell was obtained through the Stöber method directly onto the surface of magnetite particles. Subsequently, the core–shell systems were physico-chemically and morpho-structurally evaluated trough X-ray diffraction (XRD) and (high-resolution) transmission electron microscopy ((HR-)TEM) equipped with a High Annular Angular Dark Field Detector (HAADF) for elemental mapping. After the irinotecan loading, the drug delivery systems were evaluated through Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry and differential scanning calorimetry (TG-DSC), and UV–Vis spectrophotometry. Additionally, the Brunauer–Emmett-Teller (BET) method was employed for determining the surface area and pore volume of the systems. The biological functionality of the core-shells was investigated through the MTT assay performed on both normal and cancer cells. The results of the study confirmed the formation of highly crystalline magnetite particles comprising the core and mesoporous silica layers of sizes varying between 2 and 7 nm as the shell. Additionally, the drug loading and release was dependent on the type of the silica synthesis procedure, since the lack of hexadecyltrimethylammonium bromide (CTAB) resulted in higher drug loading but lower cumulative release. Moreover, the nanostructured systems demonstrated a targeted efficiency towards HT-29 colorectal adenocarcinoma cells, as in the case of normal L929 fibroblast cells, the cell viability was higher than for the pristine drug. In this manner, this study provides the means and procedures for developing drug delivery systems with applicability in the treatment of cancer.

Drying shrinkage mitigation of alkali-activated blast furnace slag-copper slag by polyether-based shrinkage reducing admixture and MgO-based expansion agent

Volume stability is a critical challenge for the practical applications of alkali-activated materials. To mitigate the drying shrinkage of alkali-activated blast furnace slag-copper slag (AAS-CS), different contents of polyether-based shrinkage reducing admixture (PSRA) and MgO-based expansion agent (MEA) are used in this study. The effects of PSRA and MEA on the hydration process, mechanical property and drying shrinkage are investigated. Meanwhile, the mechanisms for drying shrinkage compensation of PSRA and MEA are deeply analyzed by nuclear magnetic resonance (NMR), Fourier transform infrared spectrum (FTIR), thermogravimetry and differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). Results show that the drying shrinkage rate and the compressive strength of AAS-CS gradually decrease with the PSRA content increases from 0 to 2.0 wt%. This is mainly attributed to the coarser pore size and the lower surface tension caused by PSRA. When the content of MEA is 4.0 wt%, AAS-CS exhibits the lower drying shrinkage rate and the higher compressive strength in comparison with the reference sample. The addition of MEA promotes the formation of hydrotalcite (Ht). As an expansive product, an appropriate amount of Ht can exert the filling effect and the shrinkage compensating effect.

Characterization of enalapril maleate: An approach using thermoanalytical, thermokinetic and spectroscopic techniques

Enalapril maleate is a widely used drug for the treatment of cardiovascular diseases. Its mechanism of action is to inhibit the angiotensin-converting enzyme selectively. Therefore, it is metabolized to enalaprilat by liver cells. The thermal behavior of enalapril maleate was investigated by simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), and evolved gas analysis by simultaneous thermogravimetry and differential scanning calorimetry coupled infrared spectroscopy (TG-DSC-FTIR). The results provided information on thermal stability, purity, thermal decomposition steps, and the main products formed in the heating. The enalapril maleate was found to be stable up to 148 ?C. Above this temperature causes thermal degradation of the substance, which occurs in two stages in an inert atmosphere (N2) and three stages in an oxidizing atmosphere (air). Through the TG-DSC-FTIR the released gases were identified as maleic anhydride as a thermal decomposition intermediate. DSC analysis showed that the material obtained 99.5% purity, which indicates high purity. Employing both the Kissinger and Friedman equations, alongside Model Fitting methods, the study reveals key insights. The Kissinger method unveils an apparent activation energy of 47.07?15.45 kJ mol?? for the complete thermal breakdown, a finding corroborated by the Friedman method. Model Fitting methods, the article applies them, yielding an apparent activation energy of 55.70?3.4 kJ mol?? with a three-dimensional diffusion thermal degradation model.

Green Synthesis, Characterization and Thermal Investigation of Ni(II) and Cu(II) Complexes Constructed by Pyridine-2,6-Dicarboxylic Acid

Two complexes [Ni(pda)(H2pda)]·3H2O (1) and [Cu(pda)(H2pda)] (2) containing pyridine-2,6-dicarboxylic acid (H2pda) were synthesized by room-temperature solid state reaction and characterized by elemental analyses, powder X-ray diffraction (PXRD), single crystal X-ray diffraction and infrared spectroscopy. The powder complexes were confirmed as single phase with their PXRD. The thermal property was studied using simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC) techniques. The complexes were decomposed in several stages and the final products of their thermal decomposition were NiO and CuO, respectively. In order to explore application of the complexes, the nano-NiO and nano-CuO particles were produced by using the powder complexes as precursors at different temperatures. The particles were characterized and observed by PXRD and scanning electron microscope (SEM), and their average diameters of the pyrolysis products at 500 and#176;C were about 12 and 30 nm, respectively.

Microwave-Assisted Silanization of Magnetite Nanoparticles Pre-Synthesized by a 3D Microfluidic Platform.

Magnetite nanoparticles (Fe3O4 NPs) are among the most investigated nanomaterials, being recognized for their biocompatibility, versatility, and strong magnetic properties. Given that their applicability depends on their dimensions, crystal morphology, and surface chemistry, Fe3O4 NPs must be synthesized in a controlled, simple, and reproducible manner. Since conventional methods often lack tight control over reaction parameters and produce materials with unreliable characteristics, increased scientific interest has been directed to microfluidic techniques. In this context, the present paper describes the development of an innovative 3D microfluidic platform suitable for synthesizing uniform Fe3O4 NPs with fine-tuned properties. On-chip co-precipitation was performed, followed by microwave-assisted silanization. The obtained nanoparticles were characterized from the compositional and microstructural perspectives by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Moreover, supplementary physicochemical investigations, such as Fourier Transform Infrared Spectroscopy (FT-IR), Kaiser Test, Ultraviolet-Visible (UV-Vis) Spectrophotometry, Dynamic Light Scattering (DLS), and Thermogravimetry and Differential Scanning Calorimetry (TG-DSC) analyses, demonstrated the successful surface modification. Considering the positive results, the presented synthesis and functionalization method represents a fast, reliable, and effective alternative for producing tailored magnetic nanoparticles.

Occurrence and transformation behaviour of silicon-bearing minerals during high silicon coal combustion from Yunnan Province, China

To understand the mineralogical characteristics and transformation behaviours of silicon-bearing minerals during coal combustion, seven typical high silicon (high-Si) coals and two high-Si fly ashes generated from high-Si coal-fired power plants were chosen. The coals were first treated by a method of low temperature ashing and the float-sink test for heavy minerals separation. Subsequently, low temperature ashes (LTA), light mineral fractions (LM), heavy mineral fractions (HM), and fly ashes from coal-fired power plants were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) combined with energy spectrum analysis (EDX), X-ray fluorescence spectrometry (XRF), and simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC).The results show that The mineral compositions in the LTA and LM are almost the same and majorly composed of quartz, kaolinite, calcite, dolomite, daphnite, chlorite-serpentine, pyrite, and anatase. The mineral compositions identified in the HM are clearly different from those in the LTA and LM. Pyrite, fluorapatite, anatase, siderite, dolomite and a plenty of silicate minerals including quartz, clinochlore, daphnite, chlorite, and chamosite are found in the HM. Chlorite is a quite common mineral in the HM with different shapes, including schistose, long tetragonal prism, cylindrical, block-shaped, and near-spherical, can be identified. The minerals identified in the fly ashes from the high-Si coal-fired power plants include quartz, mullite, and hematite. The mullite in the fly ashes is derived from the transformations of quartz, kaolinite, and chlorite in the coals. The quartz in the fly ash is mainly derived from the unchanged quartz in coal and a secondary origin from the SiO2-Al2O3 phase transformation. The high-Si fly ash with the size fraction of 38.5–74 μm contains the highest SiO2 content.

Sol-Gel Synthesis of Nanosized Powders and Obtaining Ceramic Composites Based on Zircon and Zirconium Oxide

Nanosized precursor powders of (1 – x)ZrSiO4‒xZrO(OH)2 are synthesized by the sol-gel method with the separate precipitation of components to obtain (1 – x)ZrSiO4‒xZrO2 ceramic composites. The thermal behavior of precursor powders is studied by differential scanning calorimetry and thermogravimetry (DSC/TG). Ceramic composites with a high level of microhardness are obtained by sintering powders, preliminarily calcined at 850°C, in air in the temperature range 1000‒1300°C. In the future, such ceramic composites can be used as matrices for solidification and isolating high-level waste (HLW).

Microfluidic Synthesis of Magnetite Nanoparticles for the Controlled Release of Antibiotics.

Magnetite nanoparticles (MNPs) have been intensively studied for biomedical applications, especially as drug delivery systems for the treatment of infections. Additionally, they are characterized by intrinsic antimicrobial properties owing to their capacity to disrupt or penetrate the microbial cell wall and induce cell death. However, the current focus has shifted towards increasing the control of the synthesis reaction to ensure more uniform nanoparticle sizes and shapes. In this context, microfluidics has emerged as a potential candidate method for the controlled synthesis of nanoparticles. Thus, the aim of the present study was to obtain a series of antibiotic-loaded MNPs through a microfluidic device. The structural properties of the nanoparticles were investigated through X-ray diffraction (XRD) and, selected area electron diffraction (SAED), the morphology was evaluated through transmission electron microscopy (TEM) and high-resolution TEM (HR-TEM), the antibiotic loading was assessed through Fourier-transform infrared spectroscopy (FT-IR) and, and thermogravimetry and differential scanning calorimetry (TG-DSC) analyses, and. the release profiles of both antibiotics was determined through UV-Vis spectroscopy. The biocompatibility of the nanoparticles was assessed through the MTT assay on a BJ cell line, while the antimicrobial properties were investigated against the S. aureus, P. aeruginosa, and C. albicans strains. Results proved considerable uniformity of the antibiotic-containing nanoparticles, good biocompatibility, and promising antimicrobial activity. Therefore, this study represents a step forward towards the microfluidic development of highly effective nanostructured systems for antimicrobial therapies.

Production of green autoclaved bricks from waste quarry sludge: Mechanical and microstructural aspects

Quarry sludge (QS) is a common by-product of quarry mining and the subsequent aggregate washing process, but its utilization in construction materials was limited by fine particle size and high crystallization. This paper assesses the feasibility of reusing QS as siliceous materials to prepare a novel eco-friendly brick via press moulding and autoclave treatment. Three types of calcium sources including CaO, Ca(OH)2, and CaCO3 were employed to evaluate the binding efficiency with QS by using X-ray diffraction (XRD), thermogravimetry and differential scanning calorimetry (TG-DSC) and scanning electron microscopy (SEM). The effect of curing temperature, Ca/Si ratio and exposing time on the reaction activity of QS were estimated, and their roles on the microstructure and compressive strength of QS-based bricks were evaluated. Results demonstrate that the activity of QS can be effectively activated by Ca(OH)2. The morphology of the curing phases is determined by the dosage of QS. Moderating curing temperature (160 °C to 200 °C) and exposing time (≤15 h) contribute to higher reaction activity of QS and favor the generation of plate-like tobermorite and C-S-H, which induced a denser structure of QS-based autoclaved bricks and further promoted the strength development. In addition, 24 h of exposing time induced the transformation from tobermorite to xonotlite, prejudicing the strength of QS-based autoclaved bricks. Considering the performance and energy consumption, the optimum manufacturing parameters of QS-based autoclaved bricks are curing at 200 °C for 15 h, with a Ca/Si ratio of 0.83. Under this treatment, the compressive strength of QS-based autoclaved brick is as high as 49.9 MPa with a QS dosage of 63.5%. In addition, an assessment of the mobility of heavy metals associated with QS-prepared bricks reveals that autoclaved treatment can solidify heavy metals and QS-based autoclaved bricks can be regarded as an environmentally friendly building product. This research provides a foundational framework for the efficient utilization of QS through hydrothermal activation.

Fabrication of mixed-mode amphoteric β-cyclodextrin polymer for the simultaneous extraction of acidic and alkaline drugs

A multifunctional mixed-mode β-CD polymer adsorbent PNVCD-SIM containing amphoteric ions and multiple functional groups was prepared. Its physicochemical properties were characterized by scanning electron microscope (SEM), 1H nuclear magnetic resonance (1H NMR), 13C NMR, Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption–desorption test, elemental analysis (EA), and thermogravimetry and differential scanning calorimetry (TGA-DSC). The acidic indomethacin and alkaline promethazine were selected to evaluate the adsorption properties of PNVCD-SIM at different pH. Under optimal neutral pH conditions, the adsorption performance of PNVCD-SIM on acidic NSAIDs, alkaline phenothiazine, and neutral steroid hormone drugs was investigated. The results showed that PNVCD-SIM exhibited excellent diversified adsorption properties for acidic, alkaline, and neutral mixed drug components through the synergistic effects of β-CD inclusion, electrostatic interaction, hydrogen bond, π-π conjugation, and π-cation effect. The adsorption mechanism was consistent with the pseudo-second-order kinetic model and Langmuir isotherm model. Under the optimized conditions, a dispersive solid phase extraction method combined with high-performance liquid chromatography (dSPE-HPLC) using PNVCD-SIM as the adsorbent was established. The simultaneous extraction and detection of acidic-alkaline multi-component drugs in actual urine and lake water samples were successfully realized. This study provides new insight into the design and preparation of mixed-mode adsorption materials suitable for the rapid analysis and detection of multiple analytes.

Infrared radiation properties of La3Ni2O7 and performance of the La3Ni2O7-based coating considering the effect of thermal reactivity

Materials with excellent infrared radiation properties are important for preparing infrared radiation coatings that are applied in industrial furnaces, to improve the efficiency of heating equipment. To find a new material with better infrared radiation performance, La3Ni2O7, a layered perovskite structural material, was prepared by the sintering method, and its infrared radiation performance was studied in detail. It was found that La3Ni2O7 has excellent infrared radiation properties, and the measured emissivity values at the 3–5 μm waveband were above 0.970, which was determined by its narrower forbidden bandwidth. Furthermore, La3Ni2O7-based coatings on clay brick substrates were prepared. The thermal behavior of the coatings, from room temperature to 1400 °C, was studied using thermogravimetry and differential scanning calorimetry (TG-DSC). The results indicated that a series of reactions occurred for the coatings at temperatures higher than 1000 °C. Furthermore, the coatings were heated in a muffle furnace at 1000 °C, 1100 °C, and 1200 °C, for 60 min to study the effect of thermal reactivity on the infrared radiation performance of the coatings. The results showed that at high temperatures, although the thermal reactivity led to a phase change for the coatings, the change had little effect on the emissivity. Above 1100 °C, La3Ni2O7 starts to decompose into La2NiO4 and NiO, and above 1200 °C, the La2NiO4 content is above 50%, implying that the decomposition product La2NiO4 plays a key role in maintaining the high emissivity of the coatings. The emissivity of La2NiO4 specifically fabricated was tested and it was found that its emissivity was above 0.970. Furthermore, thermal shock resistance tests of the coatings were conducted. The results showed that the transition layer was formed by the chemical reactions between La3Ni2O7 and the oxides in the substrate, which plays a positive role in prolonging the service life of the coating.

Preparation of PrCoO3 by sol-gel method and its photocatalytic properties under ultraviolet light irradiation

Using praseodymium nitrate, cobalt acetate and citric acid as main raw materials, the PrCoO3 photocatalyst was prepared by sol-gel method. The PrCoO3 samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR). The photocatalytic activity of PrCoO3 was tested by simulating polluted water with 10 mg/L methyl orange solution under ultraviolet light irradiation. The results show that pure PrCoO3 can be prepared by calcination in the range of 600 to 900 °C. The average particle size of PrCoO3 is about 30 μm. The photocatalytic performance of PrCoO3 is the best under the conditions of 700 °C calcination and ultraviolet light irradiation for 120 min, and the degradation rate of methyl orange (10 mg/L) can reach 98%. The PrCoO3 samples are consistent with first-order kinetics for the degradation of methyl orange. And the apparent rate constants is k = 0.0346 min−1. PrCoO3 sample shows good ultraviolet light photocatalytic activity and has a broad application prospect in the field of photocatalysis.

Characterization of a Novel Artemisinin Algicidal Particle and Its Inhibitory Effect on Microcystis aeruginosa

A new artemisinin sustained-release particle (ASP) was developed that significantly inhibits Microcystis aeruginosa (M. aeruginosa) growth. The physical and chemical properties of ASPs were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetry (DSC-TG). The results demonstrated that ASPs are thermally stable and have sustained-release properties. On the sixth day, the ASPs (0.2g L-1) inhibited M. aeruginosa with an inhibition rate (IR) greater than 70%. Additionally, ASPs inhibited M. aeruginosa without increasing microcystin-LR release (MC-LR). This research offers a novel approach to the management of cyanobacterial blooms.

The interaction of triglycidyl phosphate with europium nitrate and properties of obtained metal-containing polymer

The interaction of phosphorus-containing epoxy trifunctional monomer – triglycidyl phosphate (TGPhT), with europium (III) nitrate hexahydrate is studied. A dissolution of europium salt added into TGPhT is occurred due to the interaction of the cation with phosphoryl groups and oxygen atoms of the epoxy ring, that is accompanied by the opening reaction and led to the formation of a polymer. The interaction of triepoxide with salt is investigated by FTIR-spectroscopy and differential scanning calorimetry (DSC). The thermal stability of the samples is determined by combined method of thermogravimetry and differential scanning calorimetry (TG/DSC), coupled with a quadrupole mass spectrometry to identify the gaseous products evolved during the thermal analysis of the samples. The kinetic parameters of the curing reaction are computed by using Thermokinetics software. The interaction of TGPhT with europium nitrate is suggested to occur through opening of epoxy rings in the presence of europium ions via the mechanism of cationic polymerization. The cured epoxy polymer exhibits luminescent properties.

Enhancing the thermal stability of alkali-activated Fe-rich fayalite slag-based mortars by incorporating ladle and blast furnace slags: Physical, mechanical and structural changes

A proper and detailed understanding of the thermal stability of Fe-rich fayalite slag-based alkali-activated materials (AAMs) is important due to their potential use in refractory and fire-resistant applications. Here, fayalite slag (FS) was used as the main precursor for AAMs. The effects of incorporating ladle slag (LS) or blast furnace slag (BFS) and different temperature exposures up to 1000 °C were investigated through visual observation, compressive strength, ultrasonic pulse velocity (UPV), thermal conductivity, x-ray diffraction (XRD), thermogravimetry and differential scanning calorimetry (TG/DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope coupled with electron probe microanalyzer (SEM-EPMA). The experimental results indicated that the incorporation of LS or BFS as additional calcium and aluminum sources positively affected the high-temperature behavior of blended mortars, which exhibited a reduction in voids, cracks, and thermal shrinkage while having higher residual strength and thermal stability than solely FS-based AAMs. This was mainly due to the differences in mineralogical transformation and the phases formed. Interestingly, the joint effect of elevated temperature exposure and the addition of LS or BFS enhanced the formation of more stable crystalline phases and densified the structure of blended mortars at 1000 °C.

SYNTHESIS AND PHOTOLUMINESCENCE PROPERTIES OF ELLIPSOIDAL La2O2SO4:Eu3+ PHOSPHORS

This research was focused on the homogeneous precipitation synthesis of a series of Eu3+ ion-activated ellipsoidal La2O2SO4 phosphors based on the La2(SO4)3-CO(NH2)2 reaction system. The structural identification, thermal analysis, morphology and luminescence properties of the as-prepared products were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry and differential scanning calorimetry (TG/DSC), field emission scanning electron microscopy (FESEM) and photoluminescence (PL) spectra. Pure La2O2SO4 ellipsoidal particles with a long radius of about 2 µm and a short radius of about 1 µm were successfully prepared by calcining a rhombus-like precursor at 800 °C for 2 h in air. The formation mechanism of the precursor and its corresponding calcination product were also proposed. Photoluminescence results revealed that the strongest red emission peak was centered at 619 nm upon 249-nm ultraviolet (UV) light excitation in La2O2SO4:x%Eu3+ (x = 3, 6, 9, 12 and 15) phosphors. The exchange interaction was responsible for the concentration quenching mechanism of the 5D0→7F2 transition of Eu3+ ions in the La2O2SO4 host lattice. The optimal x value was 15 and the corresponding decay process showed a single exponential decay behavior whose lifetime t and color correlation temperature (CCT) were calculated to be 2.112 ms and 2752 K, respectively.

The Synthesis and Characterisation of the High-Hardness Magnetic Material Mn2N0.86.

High-quality P6322 Mn2N0.86 samples were synthesised using a high-pressure metathesis reaction, and the properties of the material were investigated. The measurements revealed that the Vickers hardness was 7.47 GPa, which is less than that predicted by commonly used theoretical models. At low air pressure, Mn2N0.86 and MnO coexist at 500 to 600 °C, and by excluding air, we succeeded in producing Mn4N by heating Mn2N0.86 in nitrogen atmosphere; we carefully studied this process with thermogravimetry and differential scanning calorimetry (TG-DSC). This gives a hint that to control temperature, air pressure and gas concentration might be an effective way to prepare fine Mn-N-O catalysis. Magnetic measurements indicated that ferromagnetism and antiferromagnetism coexist within Mn2N0.86 at room temperature and that these magnetic properties are induced by nitrogen vacancies. Ab intio simulation was used to probe the nature of the magnetism in greater detail. The research contributes to the available data and the understanding of Mn2N0.86 and suggests ways to control the formation of materials based on Mn2N0.86.

Microfluidic Synthesis of -NH2- and -COOH-Functionalized Magnetite Nanoparticles.

Microfluidics has emerged as a promising alternative for the synthesis of nanoparticles, which ensures precise control over the synthesis parameters, high uniformity, reproducibility, and ease of integration. Therefore, the present study investigated a one-step synthesis and functionalization of magnetite nanoparticles (MNPs) using sulfanilic acid (SA) and 4-sulfobenzoic acid (SBA). The flows of both the precursor and precipitating/functionalization solutions were varied in order to ensure the optimal parameters. The obtained nanoparticles were characterized through dynamic light scattering (DLS) and zeta potential, X-ray diffraction (XRD), selected area electron diffraction (SAED), transmission electron microscopy (TEM) and high-resolution TEM (HR-TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry and differential scanning calorimetry (TG-DSC), and vibrating sample magnetometry (VSM). The results demonstrated the successful synthesis of magnetite as the unique mineralogical phase, as well as the functionalization of the nanoparticles. Furthermore, the possibility to control the crystallinity, size, shape, and functionalization degree by varying the synthesis parameters was further confirmed. In this manner, this study validated the potential of the microfluidic platform to develop functionalized MNPs, which are suitable for biomedical and pharmaceutical applications.

Preparation of SmCoO3 by Sol-Gel Method and Its Photocatalytic Activity

Using citric acid (C6H8O7·H2O), samarium nitrate (Sm(NO3)3·6H2O) and cobalt nitrate (Co(NO3)3·6H2O) as main raw materials, the SmCoO3 samples were successfully prepared by sol-gel method. The prepared samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), X-ray diffractometer (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). Using azo dye methyl orange solution as the simulated sewage, the photocatalytic activity of SmCoO3 samples was explored at different synthesis temperatures and illumination times. The experimental results show that pure SmCoO3 samples can be prepared at a calcination temperature of 600 °C to 1000 °C. Under ultraviolet light conditions, the sample of SmCoO3 calcined at 800 °C has the best photocatalytic activity. When illumination times is 120 min, the degradation rate of methyl orange of 10 mg/L can reach more than 97%, and SmCoO3 shows good photocatalytic performance.

Preparation of EuVO4 by Hydrothermal Method and Its Photocatalytic Activity

Using europium trioxide(Eu2O3), ammonium metavanadate(NH4VO3), nitric acid, ammonium hydroxide and citric acid hexahydrate, the EuVO4 was prepared by hydrothermal method. The structure and morphology of samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and UV-visible diffuse reflectance spectroscopy (DRS). Using methyl orange as simulated sewage, the visible-light photocatalytic activities of EuVO4 were investigated on synthesis temperatures and illumination time. The results showed that the purely rare earth perovskite structure EuVO4 was prepared in the range of hydrothermal temperature of 120 ∼ 180 °C. The EuVO4 particles are uniform size prepared in 140 °C, which have a particle size of 2 ∼ 4 μm and an optical band gap of 2.07 eV. The photocatalytic experiment demonstrates that hydrothermal synthesis at 140 °C is the best. Under visible-light irradiation, the degradation rate methyl orange of 10 mg/L can reach 93% for 60 min. The EuVO4 shows excellent photocatalytic activities.