Ultrasonic-assisted Co-precipitation Method Research Articles

Multifunctional Characterization and Anticancer Properties of Magnetic Zinc Ferrite Nanoparticles by Modified Ultrasonic Assisted Co-precipitation Method

Zinc Ferrite (ZnFe2O4) nanoparticles were synthesized successfully via the modified ultrasonic-assisted co-precipitation method. Structural characterization, conducted through X-ray diffraction (XRD) analysis and Rietveld refinement, revealed a single cubic phase with a mixed spinel structure. Fourier transform infrared spectroscopy confirmed the presence of functional groups indicative of the spinel ferrite structure. Morphological analysis using field-emission scanning electron microscopy showcased the nanoparticles’ uniform morphology and size distribution. UV–vis spectra revealed the optical properties, while the Tauc Plot method determined the optical band gap. Electron paramagnetic resonance spectra confirm the symmetric resonance peak with 1254 Oe line width and the Lande g value 2.133. Magnetic hysteresis loops confirm the soft magnetic nature of the nanoparticles with magnetic saturation and coercivity of 39.2 emu gm−1 and 77.5 Oe. The anticancer properties against various cancer cell lines (HeLa, HepG-2 and MCF-7) revealed significant anticancer activity against HepG-2 and HeLa cells compared to MCF-7 cancer cells, and the results were compared with the standard drug cisplatin. A comparative analysis of results among cancer cell lines was conducted and discussed.

Auto-combustion synthesis and characterization of La2CrMnO6/g-C3N4 nanocomposites in the presence trimesic acid as organic fuel with enhanced photocatalytic activity towards removal of toxic contaminates

Constructing semiconductor materials based on layered graphitic carbon nitride (g-C3N4) and metal oxides can help in extending the lifetime of charge carriers and aid in resolving the low number of active sites on their surface for light-driven processes. Herein, we initially designed La2CrMnO6 nanostructures through trimesic acid-assisted auto-combustion route and subsequently, La2CrMnO6/g-C3N4 nanocomposites were prepared by ultrasonic-assisted co-precipitation method with improved UV-catalytic performance. The shape, size distribution and various properties of nano-sized products were measured via diverse description systems of microscopic and spectroscopic. The photocatalytic performances of the La2CrMnO6 nanoparticles and La2CrMnO6/g-C3N4 nanocomposites were compared by degradation of artificial dyes under the UV-light region. Besides, the impacts of dye type, diverse weight percentages of g-C3N4:La2CrMnO6 in composite, scavenger kind and dye solution concentration were studied on modifying ability of nano-catalyst utility. The outcomes manifested La2CrMnO6/g-C3N4 (80:20) nanocomposites have the greatest efficiency, where the highest MO decomposition of 80.98 % was achieved at 10 ppm within 90 min of irradiation. Moreover, the feasible mechanism of MO elimination by UV catalytic purpose was considered.

Design and fabrication of graphitic carbon nitride incorporated zinc silicate hybrid nanocomposite for effective degradation of eriochrome black T dye as water pollutant under sunlight irradiations

This paper presents an approach to prepare zinc silicate (Zn2SiO4) and its nanocomposites with graphitic carbon nitride (g-C3N4) for enhanced photocatalytic performance. Zn2SiO4 was synthesized using a simple and cost-effective sonochemical method, followed by the fabrication of Zn2SiO4/g-C3N4 through an ultrasonic-assisted co-precipitation method. The characterization of Zn2SiO4 and its nanocomposites was carried out using various techniques such as XRD, FTIR, EDS, SEM, TEM, BET, and DRS. The main focus of this study was to investigate the photocatalytic efficiency of g-C3N4, Zn2SiO4, and different Zn2SiO4 nanocomposites for the degradation of eriochrome black T (EBT) and erythrosine (ER). It is worth noting that this is the first time Zn2SiO4 has been combined with carbon nitride, which resulted in excellent photocatalytic performance. The experimental results revealed that several factors influenced the efficiency of the photocatalytic process, including the content of Zn2SiO4 in the nanocomposite, catalyst loading, and initial concentration of EBT. Among all the tested compositions, Zn2SiO4/g-C3N4 with 10 % Zn2SiO4 exhibited the best performance. Specifically, when 70 mg of 10 % Zn2SiO4/g-C3N4 was used as a catalyst, it achieved a remarkable degradation efficiency of 75.5 % for 10 ppm EBT. This finding highlights the potential application of Zn2SiO4/g-C3N4 nanocomposites as efficient photocatalysts for environmental remediation. The results of scavenger test indicated that superoxide radicals and positive holes played significant roles in driving the photodegradation reactions. Furthermore, a kinetics study was performed to determine the rate constant (k) associated with the photocatalytic process. It was observed that a higher rate constant (k = 0.011 min−1) corresponded to a higher efficiency of 75.5 %. This finding suggests that the Zn2SiO4/g-C3N4 nanocomposites possess excellent photocatalytic activity and can effectively degrade organic pollutants.

Enhanced Photocatalytic Activity of π-Conjugated Pyridine Rings-Modified C3N4/Bi@BiOCl Z-Scheme Heterogeneous Material.

The enhanced photocatalytic properties of Z-Scheme Bi@BiOCl/C3N4-DPY heterojunction materials were successfully prepared by the ultrasonic-assisted coprecipitation method. The Bi@BiOCl/C3N4-DPY heterojunction exhibited remarkable photocatalytic activity under visible light irradiation, and the degradation rate of methyl orange (MO) was about 90.6% in 180 min. This impressive efficiency is mainly due to the Z-Scheme charge transfer mechanism in Bi@BiOCl/C3N4-DPY, resulting in the efficient separation of charge carriers and an increase in the REDOX potential of photogenerated electrons and holes. C3N4 was modified with a π-deficient conjugated pyridine ring, which caused the light absorption redshift, promoted the formation of oxidizing •O2-, and improved the photocatalytic activity. At the same time, a well-aligned heterojunction is formed at the interface between C3N4-DPY and BiOCl, facilitating the seamless transfer of light-induced electrons from the LUMO of C3N4-DPY to the CB of BiOCl. In addition, the addition of Bi introduces a unique band gap reduction effect, resulting in a change in the density of the band states, which further promotes charge transfer and separation. It is worth noting that the introduction of metallic bismuth (Bi) brings about a unique band gap reduction effect, resulting in a change in the density of states within the band, which ultimately promotes charge transfer and separation. The Z-scheme charge migration inside Bi@BiOCl/C3N4-DPY further promotes the efficient separation of photogenerated electron-hole pairs, greatly improving the overall efficiency of the material. The Z-structured photocatalyst developed in this study has great application potential in various fields of photocatalysis.

Electrochemical, Photocatalytic and Photoluminescence properties of BaWO4 and rGO-BaWO4 nano-composites: A Comparative study

The rGO-BaWO4 (rGO-BWO) nanocomposites were synthesized by employing the ultrasonic-assisted co-precipitation method. Nanocomposites formed with BWO nanoparticles anchored to layers of reduced graphene oxide through in situ reduction and a homogeneous distribution of BWO nanoparticles were confirmed by SEM images. The rGO-BWO nanocomposite showed improved photocatalytic activity for the visible light degradation of Methylene Blue (MB) dye with a rate constant of 27 × 10−3 min−1 compared to pristine BWO. The band gaps for BWO nanoparticles estimated using UV–Vis DRS are of the order of 3.25 eV–4.25 eV, while they were 2.78 eV–3 eV for rGO−BWO nanocomposites. The delocalized surface charges induced by the interactions between the rGO and BWO nanoparticles in the composite material might be responsible for the observed reduction in the band gap. Photoluminescent investigations demonstrate that rGO-BWO nanocomposites have a lower peak intensity compared to pure BWO particles, indicating a reduced recombination rate and better photocatalytic activity. In particular, when used as supercapacitor electrodes, the produced nanocomposites outperform BWO. Because of its larger surface area, the rGO-BWO nanocomposites display two-fold higher outcomes including 586, 571, 406, 375 and 307 F/g compared to BWO 391, 352, 291, 214 and 174 F/g at each current density 1, 2, 3, 5 and 10 A/g and faster charge transfer owing to improved porosity in the surface of rGO-BWO.

Preparation, characterization and application of BaZr0.1Ce0.7Y0.2O3-δ for a high-performance and stable proton ceramic electrochemical cell

The high sintering temperature (＞1500 °C) of the electrolyte is the main challenge for the application of proton ceramic electrochemical cells (PCECs). In this work, we prepare BaZr0.1Ce0.7Y0.2O3-δ (BZCY) electrolyte materials by various synthetic routes, compare their physicochemical properties and optimize their applications in PCEC. The BZCYs powder prepared by the solid state reaction method shows a large grain size of 2–3 μm and is used in the support layer. The optimal proportion of the support is determined according to the thermal expansion characterization. The BZCYp powder from the ultrasonic-assisted co-precipitation method presents well dispersed particles of 30∼50 nm and is used as the electrolyte layer and in the fuel electrode layer. The electrolyte becomes very dense after co-sintering with the support at 1400 °C without any sintering aids, giving a low conducting activation energy of 0.26 eV. The single cell demonstrates excellent performance and good stability. Under steam electrolysis mode, the cell gives 840 and 260 mAcm−2 @1.3V at 600 °C and 500 °C. Under cell mode, the cell displays 0.46 and 0.21Wcm−2@0.7V at 600 °C and 500 °C, respectively.

Magnetically Recoverable CMC/Fe3O4 Nanocomposite for Efficient Removal of Hg(II) and Cd(II) ions from the Aqueous Solution

ABSTRACT Heavy metals such as Mercury and Cadmium are highly cytotoxic metals when released into the environment and pose serious hazards to the ecosystem. The current study introduces CMC/Fe3O4 nanocomposite as an effective, magnetically recyclable, low-cost, and environment-friendly biopolymer-based adsorbent for removing these harmful contaminants from waste water. This nanocomposite was synthesized by ultrasonic assisted coprecipitation method and characterized using X-ray diffractometer, scanning electron microscope, BET surface area, Fourier-transform infrared spectroscopy, etc. Series of batch experiments were carried out at room temperature to determine the adsorption capacity of CMC/Fe3O4, which is found to be 243.52 mg g−1 and 414.04 mg g−1 toward Hg(II) and Cd(II), respectively, at optimum conditions. Optimum parameters for Hg(II) were pH 7, initial concentration 200 mg L−1, and 0.02 g of adsorbent loading, while for Cd(II) experiments were conducted using pH 6, initial concentration 500 mg L−1, and 0.03 g of adsorbent. The adsorption was well described by the Langmuir isotherm model and Pseudo-second order kinetic model, and the thermodynamic study reveals spontaneous and endothermic nature of adsorption.

In-situ synthesis of Bi2WO6/AgBr/Ag4V2O7 with double Z-scheme heterojunction for oxytetracycline degradation and weakening toxicity

Herein, a novel Bi2WO6/AgBr/Ag4V2O7 double Z-scheme heterojunction photocatalytic material was synthesized by the ultrasonic-assisted coprecipitation method. When the content of AgBr in Bi2WO6/AgBr/Ag4V2O7 is 30 wt% and the content of Ag4V2O7 is 1 wt%, under the optimized reaction conditions, the degradation rate of Bi2WO6/AgBr/Ag4V2O7 to oxytetracycline (OTC) reached 88.13 % within 60 min, and the photocatalytic activity decreased only slightly after repeated use for three times, other than that, the toxicity of OTC to wheat decreased significantly after degradation. The morphology, composition, crystal structure and visible light absorption capacity of the samples are investigated by a series of characterization techniques. Furthermore, free radical capture experiment, electron paramagnetic resonance (EPR) experiment and liquid chromatography-mass spectrometry (LC-MS) were used to explore the possible photocatalytic mechanism and degradation path of OTC. The results show that the improvement of photocatalytic activity is attributed to the construction of a double Z-scheme heterojunction, which provides a more effective structural space for the separation of photogenerated e--h+ pairs. This study provides a new idea for the separation of photogenerated e--h+ pairs and broadens the response range of visible light, and proposes a new strategy for the environmental treatment of photocatalysts.

Photocatalytic decolorization of methyl orange dye using SnO2-TiO2 nanocomposite particles synthesised by Ultrasonic Assisted Co-Precipitation Method

The ultrasonic-aided co-precipitation method was used to create SnO2-TiO2 nanocomposite particles. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and UV-vis spectroscopy were used to characterize the nanocomposite particles. XRD patterns revealed the crystalline structure of particles and the average particle size determined by Debye Scherrer’s equation was found to be 11.355, 4.9577, and 4.333 nm for TiO2 nanoparticles, SnO2 nanoparticles, and SnO2-TiO2 nanocomposites, respectively. The Ti, Sn, and O species were confirmed to exist by energy-dispersive X-ray spectroscopy (EDS). The UV absorption peaks at 288, 305, and 350 nm were attributed to SnO2, TiO2-SnO2, and TiO2 respectively. The photocatalytic aspect was investigated in a model organic contaminant (methyl orange). Data obtained by the above-mentioned characterization methods confirmed the superior photocatalytic activity of SnO2-TiO2 nanostructure than SnO2 or TiO2 alone.

Textile wastewater depuration using a green cellulose based Fe3O4 bionanocomposite

Supported iron oxide nanoparticles (NPs) on natural fiber surfaces have enormous potential in wastewater depuration strategies. We describe here the fabrication and advanced oxidation capabilities of a bionanocomposite based on cellulosic fique fibers (FF) decorated with magnetite (Fe3O4) NPs. The composite material’s assembly was monitored using FESEM, XPS, ATR-IR, XRD, and TGA. Cellulose in FF undergoes an alkaline treatment, resulting in a heterogeneous and positively charged microstructure with channels and cavities acting as nanoreactors, facilitating size control, dispersion, and stabilization of the Fe3O4 NPs via an ultrasonic-assisted co-precipitation method. The bionanocomposite material (FF/Fe3O4) promotes color removal from indigo carmine (IC) solutions via heterogeneous Fenton-like reactions. UV–vis and MS data show the removal of up to 90% of the color in IC-spiked model aqueous samples through oxidation reactions within 5 min for up to 10 cycles. The bionanocomposite catalytic performance is significantly affected by pH and oxidant (H2O2) concentration. In addition, after treating a real effluent from a denim factory with the FF/Fe3O4 bionanocomposite for 120 min, we observed reductions of 24% in chemical oxygen demand (COD), 100% in surfactant content, 99% in true and apparent color, and 99% in turbidity.

Preparation of copper-based catalysts from electroplating sludge by ultrasound treatment and their antibiotic degradation performance

The recovery of heavy metals from electroplating sludge is important for alleviating heavy metal pollution and recycling metal resources. However, the selective recovery of metal resources is limited by the complexity of electroplating sludge. Herein, CuFe bimetallic Fenton-like catalysts were successfully prepared from electroplating sludge by a facile room-temperature ultrasonic-assisted co-precipitation method. The prepared CuFe–S mainly consisted of nanorods with diameters of 20–30 nm and lengths of 100–200 nm and a small number of irregular particles. Subsequently, we performed tetracycline (TC) degradation experiments, and the results showed that the product CuFe–S had very good performance over a wide pH range (2–11). At an initial pH = 2, CuFe–S could degrade 91.9% of 50 mg L−1 TC aqueous solution within 30 min, which is better than that of a single metal catalyst. Free radical scavenging experiments and electron paramagnetic resonance (EPR) tests revealed that ·OH was the main active species for the degradation of TC by CuFe–S. In conclusion, a CuFe bimetallic Fenton-like catalyst was developed for the catalytic degradation of antibiotics, which provides a novel technical route for the resource utilization of electroplating sludge and shows an important practical application prospect.

Ultrasonic-assisted preparation of interlaced layered hydrotalcite (U–Fe/Al-LDH) for high-efficiency removal of Cr(VI): Enhancing adsorption-coupled reduction capacity and stability

Cr(VI) contamination in aquatic systems has been a challenge for environmental science researchers. To environmental-friendly, stable, and efficiently remove Cr (VI), a novel layered double hydroxide was prepared through the ultrasonic-assisted co-precipitation method. The ultrasonic-assisted step prevented the Fe2+ oxidation, improved the morphology and performance, and finally, the adsorption-coupled reduction capacity and stability were enhanced. By adding U–Fe/Al-LDH (1.0 g/L) for Cr(VI) (100 mg/L), the removal rate reached 82.24%. The removal data were well fitted by the pseudo-second-order kinetic and Langmuir isotherm model. Using U–Fe/Al-LDH can be performed over a wide pH range (2–10), with a theoretical maximum removal capacity of 118.65 mg/g. The Cr(VI) with high toxicity was adsorbed and reduced to low-toxicity Cr(III). In the final phase, stable Cr(III) complex precipitates were generated. After 30 days, the dynamic leaching amounts of total Cr in used U–Fe/Al-LDH-2 were 0.1052 mg/L. Combined with the results of the influence experiment of coexisting anions and oxidants and the SO42− release experiment, the stability of the removal effect and the safety of U–Fe/Al-LDH were proved. In conclusion, U–Fe/Al-LDH-2 is a promising remediation agent and a feasible Cr(VI) removal method for the practical remediation.

A comparative study of ultrasonic-assisted methods to synthesise spinel (CoAl2O4) nanoparticles

In this study, a spinel form of cobalt aluminate (CoAl2O4) was successfully synthesized using different experimental procedures assisted by ultrasonics. The effects of ultrasonic treatment with co-precipitation and hydrothermal experimental methods were compared with traditional techniques. The results indicated that enhanced chromatic features resulted from the experimental procedures modified by ultrasonic treatment. In chromatic analyses, the lowest b* value of −47.19 was observed in the sample synthesized by the ultrasonic-assisted co-precipitation method. This synthesized phase was identified as “Spinel” with the chemical formula of CoAl2O4 according to Powder Diffraction File number (PDF no.) 01-0820-2251 from XRD analyses. The optimum samples were determined to be UC-8 and UH-9 for the modified methods. For these samples the particle sizes were measured between 62 and 83 nm, whereas crystallite sizes were estimated to be in the range from 33 to 43 nm. The thermal analyses results proved the stability of the sample structure up to 1000 °C.

Synthesis of ultrasonic assisted co-precipitated Ag/ZnO nanorods and their profound anti-liver cancer and antibacterial properties

The current cancer Survey reports liver cancer is the second leading cause of cancer related death worldwide. Active liver cancer research is underway as several new therapies are emerging to treat it, with more showing promise. Our present study aims at preparation of silver/zinc oxide nanocomposites for potential applications in antibacterial, anti-inflammatory, anti-cancerous, against human liver cancer cells (hepG2). Silver ions added Zinc oxide (Ag/ZnO) have been synthesized by ultrasonic assisted co-precipitation method. It is found that 3% of silver ions added ZnO were precipitated as nanoplates. And interestingly the observation shows when the concentration of the silver ions increased to 5%, it reduced as nanorods. X-Ray diffraction, SAED patterns and Fourier Transform Infrared Spectrum confirms that silver ions are well attached in ZnO lattice. Ag/ZnO possesses good absorption in the UV region. The reduction in average particle size due to the increase of silver ion concentration in ZnO lattice was confirmed by dynamic light scattering (DLS).SEM and TEM studies witnessed the micro structural transformation from nanoplates (3% Ag) to the rod-like structure on (5% Ag).Ag/ZnO displayed strong antibacterial activity against different pathogens. The obtained results are comparable with standard antibiotics against pathogenic bacteria. Anti-inflammatory study reveals that Ag/ZnO prevents inflammation. Dose dependent response of Ag/ZnO against human liver cancer cells (HepG2) indicates its greater efficacy in killing cancer cells. The selective silver ion concentration (5%) in ZnO have reduced its cross-sectional area with respect to volume. This property helps the silver ion/ZnO nanorods to penetrate efficiently into the affected cells and fight against bacteria, suppress cell inflammation, eradicate the growth of liver cancer cells; which shows feasibility of this composites in further research for therapeutic applications.

Improved performance of Mn3O4-based nanocomposites in photocatalytic removal of methylene blue

In the present work, the ultrasonic-assisted co-precipitation method was applied to synthesize pure Mn3O4, Samarium-doped Mn3O4, and Zirconium-doped Mn3O4. Furthermore, as an additional stage, the hydrothermal method was utilized to prepare zeolite 4 A exploiting a natural zeolite (clinoptilolite). Afterward, some of the prepared Mn3O4-based photocatalysts were immobilized using the synthesized zeolite 4 A as a proficient support, resulting in the synthesis of some novel Mn3O4-based nanocomposites (including Sm(0.02)-Mn3O4/Zeolite 4 A and Zr(0.02)-Mn3O4/Zeolite 4 A). X-ray diffraction (XRD), Diffuse Reflectance Spectroscopy analysis (DRS), Scanning Electron Microscopy (SEM) as well as Energy Dispersive X-Ray Spectroscopy (EDX) were the techniques utilized for the characterization of the prepared samples. The XRD patterns of the doped Mn3O4 samples validated the presence of Hausmannite structure, excluding any impurities. Eventually, to evaluate the photocatalytic performance of synthesized photocatalysts, methylene blue (MB) aqueous solution as an organic pollutant was chosen to study. According to the results, Sm(0.02)-Mn3O4/Zeolite 4 A nanocomposite and Zr(0.1)-Mn3O4 nanoparticles revealed an outstanding photocatalytic efficiency of 95. 5% and 98.4% in photocatalytic removal of MB in the 210 min, respectively.

Impact of gadolinium oxide with functionalized carbon nanosphere: A portable advanced electrocatalyst for pesticide detection in aqueous environmental samples

In this study, we developed a portable electrochemical sensor for realizing the pesticide residue in biological, environmental, and vegetable samples. A lower concentration of carbendazim pesticide (CBZ) was electrochemically exposed by newly developed gadolinium oxide/functionalized carbon nanosphere modified glassy carbon electrode (Gd2O3/f-CNS/GCE). The Gd2O3/f-CNS composite was prepared by two-pot ultrasonic-assisted co-precipitation method and characterized by various physicochemical analytical techniques. In addition, the electrocatalytic activity of the composite was investigated by cyclic voltammetry (CV) towards the detection of CBZ. Besides, the Gd2O3/f-CNS/GCE exhibited excellent electrocatalytic capability and sensitivity towards the oxidation of CBZ due to its high electrochemical active surface area, good conductivity, and fast electron transfer ability. A wide linear range of CBZ (0.5–552 μM) was attained with a low level of detection (LOD) of 0.009 μM L−1 and exceptional stability of 93.41%. The proposed sensor exemplifies practical feasibility in blood serum, water, and vegetable samples with an remarkable recovery range of 96.27–99.44% and primary current response of ∼91% after 15 days.

High performance MnO2–Al2O3 nanocomposite as white light photocatalyst and bactericidal agent: Insights on photoluminescence and intrinsic mechanism

Mn-based photocatalyst and antimicrobial agent was synthesized by ultrasonic-assisted co-precipitation method by keeping MnO2 as active compound and Al2O3 was adopted as catalyst support. XRD and HRTEM analysis verified the co-existence of MnO2 and Al2O3 and the crystalline nature of NCs. The XPS and EDAX revealed the chemical states of elements namely Mn2p, Al2p and O1s. The presence of Mn–O and Al–O–Al bonds were noted through FTIR. The photon absorption ability of NCs in visible region was favoured by the energy bandgap of 2.51 eV. Photoluminescence revealed that the charge carriers in NCs showed an improvement in life time. The NCs exhibited enhanced photocatalytic effect due to its synergetic effect and the photocatalytic performance can be ordered as MnO2/Al2O3 > MnO2 > Al2O3. The enhancement in photocatalysis rate in NCs was attributed by the formation of heterostructure and it prevent the recombination of charge carriers. The OH· radical was the dominant species in dye degradation. The NCs showed high photostability and recyclability, and almost same photocatalytic activity preserved even after sixth recycle. In addition to that, the antimicrobial activity of MnO2/Al2O3 was demonstrated to be efficient in their action against the strains of gram positive and gram negative bacteria than that of the individual MnO2 and Al2O3 NPs. Thus, this multifunctional MnO2/Al2O3 can be used as an efficient candidate for the photocatalytic degradation of toxic dyes and an antimicrobial agent.

Novel SnZr oxides nanomaterials synthesized by ultrasonic-assisted co-precipitation method: Application in biodiesel production and DFT study

Novel solids as Sn2O3-ZrSnO4 nanoparticles were prepared by ultrasonic- assisted co-precipitation method and were characterized by several techniques. The catalytic efficiency of the sonicated SnZr oxide catalysts was evaluated by biodiesel production through a stearic acid esterification reaction with methanol. Also, the optimization conditions and the kinetic study for the esterification reaction were practically implemented. The optimized catalyst (SnZr15m) gave stearic acid conversion of 88.5% at the optimum conditions with pseudo- first order kinetic reaction and the thermodynamic parameters of the esterification reaction were inspected theoretically and compared with the practical data. Furthermore, the recycling experimental results and the theoretically DFT data proved that the stability of the SnZr15m catalyst in the esterification process was reasonable and possess useful quality. The different phases for tin zirconium oxides have been studied using density functional theory (DFT) calculations at the DFT/B3LYP level of theory, using the GENECP basis set in the gas phase. DFT modeling indicated that the stability of the Sn2O3-ZrSnO4 (Sn3ZrO7) phase is higher than the other phases of SnZr oxide which catalyzed the esterification process. The electronic parameters; dipole moment of these compounds in the ground state theoretically were analyzed by computing HOMO and LUMO pictures. Using frontier molecular orbital (FMO) analysis, non-linear optical (NLO) properties and quantum chemical parameters were evaluated. The charge transfer of the electron density in the studied compounds was characterized by natural bond orbital analysis (NBO). For understanding of the reactivity points, the molecular electrostatic potential surfaces (MEPS) plots have been computed. Finally, Illustration for the proposed interaction between stearic acid, the catalyst (Sn3ZrO7), and methanol to produce the biodiesel was proposed.

Visible light induced photodegradation of chlorinated organic pollutants using highly efficient magnetic Fe3O4/TiO2 nanocomposite

Herein, iron oxide/titanium oxide nanocomposite (Fe3O4/TiO2) has been synthesized via an ultrasonic-assisted co-precipitation method. The synthesized nanocomposite has been characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), photoluminescence spectra, photocurrent response, and UV-Visible spectroscopy. The nanocomposite exhibited magnetic property with a saturation magnetization of 16.02 emu/g. The synergetic effect of magnetite and titanium oxide makes the nanocomposite highly efficient, stable and reusable for water remediation applications. The higher photocurrent response confirms more charge separation, which is responsible for the enhanced photocatalytic activity. Nanocomposite showed superior photocatalytic ability (~100%) than P-25 TiO2 (20% and 22%) to degrade the chlorinated organic pollutants like 2,4-dichlorophenol (2,4-DCP) and chlorobenzene (CB) respectively under visible irradiation within 50 min. The optimum performance has been achieved at pH 5 using 100 mg/L Fe3O4/TiO2 nanocomposite with 98% of reusability. The kinetics of photodegradation of 2,4-DCP and CB under visible irradiation of magnetic Fe3O4/TiO2 nanocomposite is well fitted with first-order reaction. A facile synthesis method, outstanding photocatalytic activity under visible as well as sunlight, synergistic effect between Fe3O4 and TiO2 and easy separation for reusability makes the nanocomposite a prospective material towards environmental remediation and solar energy harvesting.

Facial synthesis of V-containing CuMgAl-LDHs as a new catalyst for the phenol hydroxylation

• Vanadate-intercalated LDHs was prepared by ultrasonic-assisted co-precipitation method. • One step hydroxylation of phenol to catechol and hydroquinone was carried out using H 2 O 2 as oxidant and H 2 O as solvent. • Excellent conversion of 50.22% and a yield of 28.75% was obtained for vanadate-intercalated LDHs. One step liquid phase hydroxylation of phenol to catechol and hydroquinone over vanadate-intercalated Cu/Mg/Al-layered double hydroxides (LDHs) was carried out using hydrogen peroxide as an oxidant and water as a solvent. The catalyst was synthesized by ultrasonic-assisted co-precipitation and ion-exchanged method under N 2 atmosphere. Also, the catalyst was characterized by IR, XRD, TG-DTA, ICP, BET, FE-SEM, TEM, and elemental mapping analyses. The result indicated the LDHs lamellar structure and plate-like shape particles of the synthesis catalyst with good vanadate intercalation. The effect of several reaction parameters, such as the amount of catalyst, phenol: oxidant ratio, reaction temperature, and time, were studied. After modifying the reaction condition, the CuMgAl-(V) catalyst exhibited an excellent conversion of 50.22% and a yield of 28.75% with the best selectivity of 57.26% at 80 °C, 6 h, phenol: oxidant ratio = 1:1, and phenol/ catalyst molar ratio = 125.