Sonochemical Method Research Articles

THE SONOCHEMICAL SYNTHESIS OF PVA/Mg-Al-OH LAYERED DOUBLE HYDROXIDE NANOCOMPOSITE FILM

In this study, we report the synthesis of PVA/Mg-Al-OH layered double hydroxide composite film by a sonochemical method under different reaction proceedings. The prepared nanocomposites were characterized by X-ray powder diffraction analysis (XRD), Ultraviolet-visible (UV-Vis) spectroscope, Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscope (EDS), and Fourier transform infrared (FTIR) spectroscopes to study structural, optical, and morphological properties. The basal spacing of PVA/Mg-Al-OH composite increased from 7.694Å to 8.424 Å and the basal spacing of layered double hydroxide enlarged after PVA attached to the surface effects. The average size of particles was determined 23.4 and 4.48 nm. The decrease of particle size explained by the influence of organic groups on the stability of the structure. The optical band gap of PVA/Mg-Al-OH layered double hydroxide was estimated to be 0.64 eV and 0.9 eV, respectively

Single-crystalline MoO3/functionalized multiwalled carbon nanotube nanocomposites for sensing phenothiazine in biological samples

The increasing use of pharmaceutical medications has significantly negative repercussions on the environment and human health. Here, a hydrothermal technique was employed to generate a single-crystalline molybdenum trioxide (MoO3)/functionalized multi-walled carbon nanotubes (MoO3/f-MWCNTs) nanocomposite that was then used as a novel electrode material for the electrochemical detection of phenothiazine (PTZ). The encapsulation of hydrothermal synthesized MoO3 nanorods on f-MWCNTs was achieved by the sonochemical method. Extensive characterization of the MoO3/f-MWCNTs nanocomposite is reported by means of spectroscopic and microscopic techniques. The electrode modified with the MoO3/f-MWCNTs nanocomposite displays superior electrocatalytic activity and lower oxidation overpotential (0.492 V vs.Ag/AgCl) to PTZ compared to benchmarking electrodes modified with MoO3 and f-MWCNTs, respectively. Electrodes performance is evaluated by means of differential pulse voltammetry that reveals a low detection limit (7 nM), more comprehensive linear response range (up to 226 µM), and superior sensitivity (2.04 µA µM−1 cm−2). The MoO3/f-MWCNTs nanocomposite electrode can also detect PTZ in the presence of several biological compounds and metal ions in various aqueous environments demonstrating the sensing practicality.

Synthesis and Characterization of ZnFe<sub>2</sub>O<sub>4</sub>- PEG/RGO Nanocomposites as Lead Heavy Metal Adsorbents

Lead waste that pollutes the environment can cause a variety of serious diseases. Various efforts have been made to remove lead waste from the environment, one of which is through the development of magnetic nanoparticles-based adsorbents. In this work, the synthesis of ZnFe2O4-PEG/RGO nanocomposites was carried out through co-precipitation and sonochemical methods. The structure, morphology, function groups, and adsorption performance of the ZnFe2O4-PEG/RGO nanocomposites were characterized using XRD, SEM, FTIR, and AAS. X-ray diffraction pattern showed the formation of a single phase ZnFe2O4 with a cubic spinel structure. The RGO peak was not detected because the RGO mass was much smaller inside the ZnFe2O4-PEG/RGO nanocomposites. Furthermore, refinement analysis through Rietica software obtained crystallite size of ZnFe2O4-PEG/RGO were 9.6 nm. The SEM result showed that the morphology of ZnFe2O4-PEG tends to be spherically distributed on RGO. Based on FTIR results, the functional groups of ZnFe2O4-PEG/RGO nanocomposites showed the presence of Zn-O and Fe-O bonds at 529 cm-1 and 428 cm-1. Meanwhile, C-O bonds at wavenumbers 1222 cm-1 showed typical absorption of RGO. Despite Fe-O and C-O bonds, the presence of C-O-C bonds at wavenumbers of 1031 cm-1 indicates the characteristics of PEG that successfully coats ZnFe2O4 nanoparticles. Interestingly, the AAS results showed that ZnFe2O4-PEG/RGO nanocomposites had an excellent performance as lead adsorbents, evidenced by the percentage of adsorption up to 97,7%.

Size-Controlled Low-Melting-Point-Alloy Particle-Incorporated Transient Liquid-Phase Epoxy Composite Conductive Adhesive with High Performances

With fast developments in the environmental-friendly industry, electrically conductive adhesive (ECA) composites with high electrical conductivity, mechanical strength, and electrochemical migration resistance as well as low cost are highly desirable for emerging power electronics applications. In this study, a category of ECAs, namely, size-controllable sonochemical low-melting-point-alloy (LMPA) particle-incorporated transient liquid-phase ECAs (TLP-ECAs), with excellent electrical conductivity, considerable mechanical strength, and high electrochemical migration resistance has been successfully demonstrated. Experimental results showed that the bulk resistivity of TLP-ECA decreased to a minimum value of 2.37 × 10–4 Ω-cm with the remaining filler content at a low level (the total content of metallic fillers, i.e., 70 wt % in TLP-ECAs), while the mechanical shear strength increased considerably (by 55.4%) compared with pure silver ECA with the same filler content, demonstrating that addition of sonochemical LMPA particles into ECA can simultaneously and considerably improve the electrical and mechanical properties. Moreover, the diffusional reaction mechanism of sonochemical LMPA particle-filled TLP-ECA was systematically investigated via differential scanning calorimetry (DSC), X-ray diffraction (XRD), and high-resolution scanning transmission electron microscopy in high-resolution high-angle annular dark-field mode (STEM-HAADF). The mechanism of the diffusion reaction of TLP-ECA with LMPA particles was rationalized, where Ag9In4 (γ phase, cP52, and P43m) and Ag3Sn (ε phase, oP8, and Pmmm) intermetallic compounds (IMC) and their corresponding nanostructures were responsible for the substantial enhancement in mechanical strength and the antielectrochemical migration property. The sonochemical method is the key to synthesize LMPA particles of desirable compositions and controllable size, thereby enhancing the overall performance of Ag-based TLP-ECAs. Accordingly, the sonochemical LMPA particle-incorporated-TLP-ECAs are the promising interconnection material candidates for power electronics packaging.

Wang-OSO3H catalyzed one-pot sonochemical synthesis of 1,2,4-benzothiadiazine-1,1-dioxide derivatives: Their in silico / in vitro assessments against MtbCM

The sonochemical synthesis, in silico assessment and in vitro MtbCM inhibitory activities of a series of 1,2,4-benzothiadiazine-1,1-dioxide derivatives are described. These compounds were synthesized via a one-pot two-step sonochemical method involving the Wang-OSO3H catalyzed reaction of 2-aminobenzenesulfonamide with aldehydes followed by treatment with NaHSO3 in the same pot. The reaction proceeded at room temp in pure water affording the desired products in good yields. The use of heterogeneous catalyst, common oxidant, water as a solvent and ultrasound as the source of green energy in addition to the mild conditions, shorter reaction time and simple operational procedure are the key features of this methodology. In silico studies suggested that most of the synthesized compounds interacted with the external surface pockets of the MtbCM (PDB: 2FP2) active site cavity. Indeed, a curved loop site was noted where these compounds were binding and aligned. Three compounds e.g. 3c, 3d and 3e interacted well with MtbCM via the -NHSO2- moiety of their 2H-benzo[e][1,2,4]thiadiazine-1,1-dioxide ring showing a common H-bond with SER70. They also showed good (55–63%) inhibition of MtbCM in vitro when tested at 10 µM. According to the SAR study a 4-substututed phenyl ring was preferred over a 3- or 2-substutited phenyl moiety at the C-2 position and the 4-MeOC6H4 substituent at this position was most effective in terms of activity. On the other hand, mediocre to low activity was observed when a heteroaryl ring or the bulky 2-naphthyl moiety was present at the C-2 position. Based on in silico and in vitro studies along with the ADME predictions the 1,2,4-benzothiadiazine-1,1-dioxide derivatives 3c, 3d and 3e emerged as pre-hits for further pharmacological evaluations.

Electrochemical sensor for determination of butylated hydroxyanisole in real samples using glassy carbon electrode modified by [Co(HL)2Cl2] nano-complex.

A new mononuclear Co(II) complex with the formula [Co(HL)2Cl2] (1) (HL= N-(2-hydroxy-1-naphthylidene)-2-methyl aniline) has been synthesized and characterized by Fourier transform infrared spectroscopy, UV-Vis, elemental analysis and single crystal X-ray structure analysis. Single crystals of the complex [Co(HL)2Cl2] (1) were obtained through slow evaporation of an acetonitrile solution at room temperature. The crystal structure analysis revealed that the two Schiff base ligands create a tetrahedral geometry via oxygen atoms and two chloride atoms. The nano-size of [Co(HL)2Cl2] (2) have been synthesized by the sonochemical process. Characterization of nanoparticles (2) was carried out via X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis, and FT-IR spectroscopy. The average sample size synthesized via the sonochemical method was approximately 56 nm. In this work, a simple sensor based on a glassy carbon electrode modified with [Co(HL)2Cl2] nano-complex was developed ([Co(HL)2Cl2] nano-complex/GCE) for convenient and fast electrochemical detection of butylated hydroxyanisole (BHA). The modified electrode offers considerably improved voltammetric sensitivity toward BHA compared to the bare electrode. Applying linear differential pulse voltammetry, a good linear relationship of the oxidation peak current with respect to concentrations of BHA across the range of 0.5-150 μM and a detection limit of 0.12 μM was achieved. The [Co(HL)2Cl2] nano-complex/GCE sensor was applied to the determination of BHA in real samples successfully.

Metal-Organic Framework-Based Materials for Wastewater Treatment: Superior Adsorbent Materials for the Removal of Hazardous Pollutants.

In previous years, different pollutants, for example, organic dyes, antibiotics, heavy metals, pharmaceuticals, and agricultural pollutants, have been of note to the water enterprise due to their insufficient reduction during standard water and wastewater processing methods. MOFs have been found to have potential toward wastewater management. This Review focused on the synthesis process (such as traditional, electrochemical, microwave, sonochemical, mechanochemical, and continuous-flow spray-drying method) of MOF materials. Moreover, the properties of the MOF materials have been discussed in detail. Further, MOF materials' applications for wastewater treatment (such as the removal of antibiotics, organic dyes, heavy metal ions, and agricultural waste) have been discussed. Additionally, we have compared the performances of some typical MOFs-based materials with those of other commonly used materials. Finally, the study's current challenges, future prospects, and outlook have been highlighted.

Rapid Probing of Self-Cleaning Activity on Polyester Coated by Titania-Natural Silica Nanocomposite Using Digital Image-Based Colorimetry.

Titania-silica nanocomposites (TiO2-SiO2) show outstanding performance and is very well applied in photocatalysis. In this research, SiO2 extracted from Bengkulu beach sand will be used as a supporting material of the TiO2 photocatalyst for application to polyester fabrics. TiO2-SiO2 nanocomposite photocatalysts were synthesized using the sonochemical method. The coating of the TiO2-SiO2 material on polyester was carried out using the sol-gel-assisted sonochemistry method. The method of determining self-cleaning activity uses a digital image-based colorimetric (DIC) method, which is much simpler than using an analytical instrument. The scanning electron microscopy-energy dispersive X-ray spectroscopy results showed that the sample particles adhered to the fabric surface and the best particle distribution was shown in pure SiO2 and 1:0.5 TiO2-SiO2 nanocomposites. Analysis of Fourier-transform infrared (FTIR) spectroscopy proved the presence of Ti-O and Si-O bonds as well as the typical spectrum of polyester, which indicated that the fabric had been successfully coated with nanocomposite particles. The analysis of the contact angle of the liquid on the polyester surface showed a significant change in the properties of the TiO2 and SiO2 pure coated fabrics, but changes occur only slightly in the other samples. Self-cleaning activity against the degradation of methylene blue dye has been successfully carried out using DIC measurement. The test results showed that the best self-cleaning activity was shown by TiO2-SiO2 nanocomposite with a ratio of 1:0.5 with the degradation ratio reaching 96.8%. Furthermore, the self-cleaning property remains after the washing process, which shows excellent washing resistance.

Fabrication of untreated and silane-treated carboxylated cellulose nanocrystals and their reinforcement in natural rubber biocomposites

In this study, cellulose nanocrystal (CNC) was extracted from Napier grass stems and subsequently functionalized to carboxylated cellulose nanocrystal (XCNC) by using an environmentally friendly method, namely, the KMnO4/oxalic acid redox reaction. The XCNC was subsequently modified with triethoxyvinylsilane (TEVS), called VCNC, by using ultrasound irradiation. The characterization of the prepared XCNC and VCNC was performed. The needle-like shape of XCNC was observed with an average diameter and length of 11.5 and 156 nm, respectively. XCNC had a carboxyl content of about 1.21 mmol g−1. The silane treatment showed no significant effects on the diameter and length of XCNC. When incorporated into natural rubber (NR), both XCNC and VCNC showed very high reinforcement, as evidenced by the substantial increases in modulus and hardness of the biocomposites, even at very low filler loadings. However, due to the high polarity of XCNC, tensile strength was not significantly improved with increasing XCNC loading up to 2 phr, above which it decreased rapidly due to the filler agglomeration. For VCNC, the silane treatment reduced hydrophilicity and improved compatibility with NR. The highly reactive vinyl group on the VCNC’s surface also takes part in sulfur vulcanization, leading to the strong covalent linkages between rubber and VCNC. Consequently, VCNC showed better reinforcement than XCNC, as evidenced by the markedly higher tensile strength and modulus, when compared at an equal filler loading. This study demonstrates the achievement in the preparation of a highly reinforcing bio-filler (VCNC) for NR from Napier grass using an environmentally friendly method and followed by a quick and simple sonochemical method.

Synthesis and Biological Activity Study of Co and Cr Complexes with α-(2-Salsayl)-<i>N</i>-phenyl Nitrone and Oxide Nanoparticles

This paper describes the synthesis of two complexes from the ligand α-(2-Salsayl)-N-phenyl nitrone with CoCl2 and CrCl2. The ligand was characterized by several spectroscopic techniques (ultraviolet/visible (UV/Vis), nuclear magnetic resonance (1H-NMR and 13C-NMR), Fourier-transform infrared spectroscopy (FTIR), and mass spectrometry (MS). While infrared, ultraviolet-visible (UV-Vis), thermal analysis, and job method studies were used to reveal the structure of the complexes. The synthesized complexes were then synthesized by the sonochemical method, and the copper and chromium oxide nanoparticles were produced using the thermal decomposition method. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) characterization confirmed the formation of Co3O4 and Cr2O3 nanoparticles. Antimicrobial studies of the complexes against some microorganisms, such as Staphylococcus epidermis and Escherichia coli, utilizing the disk diffusion method, revealed the antibacterial activity of the complexes.

Study of the bactericidal properties of ZnO/Ag0 nanoparticles in the treatment of raw sewage effluents

AbstractIn this work, the antimicrobial treatment of raw sewage effluents (RSE) of residences was studied. For this, the RSE was collected from a treatment plant and the antimicrobial activity was evaluated using Ag0 decorated ZnO nanoparticles. ZnO/Ag0 nanoparticles were synthesized by a microwave‐assisted hydrothermal method and sonochemical method. The effect of ZnO/Ag0 nanoparticles was evaluated by varying the concentration of the catalyst to the RSE, varying the amount of silver, and varying the contact time of the catalyst with the RSE, to optimize the process. The ZnO/Ag0 nanoparticles were characterized by X‐ray diffraction, surface area using the Brunauer‐Emmett‐Teller methodology, and field emission scanning electron microscopy. The results indicate that the particles synthesized by the association of sonochemical and hydrothermal methods provide a better antimicrobial result against all tested bacteria. The results obtained in this manuscript indicate an alternative methodology in the removal of 99% of the bacteria from tailings from a real sewer, showing its applicability in the treatment for later consumption.

A green functionalized method of Cu-BTC on poly(vinyl alcohol)/chitosan composite mat and its antibacterial potential

Recent outbreaks of infectious diseases have stimulated considerable interest with reports that millions of people are at risk of disease in different forms worldwide. Therefore, Cu-based framework functionalized nanofibers, were developed as modern antibacterial hybrid materials to produce outstanding synergistic properties derived from each composition. Cu-BTC, a well-known Cu-based framework, is proposed to provide antibacterial properties with lower cytotoxicity and prolonged durability. Chitosan/polyvinyl alcohol nanofibers were electrospun with increased diameter size by boosting chitosan concentrations within a range from 80 to 570 nanometers (nm). Cu-BTC nanopowders were synthesized by a simple sonochemical method and FTIR results indicated formation of frameworks from the Cu-O coordinated bond. Cu-BTC was functionalized onto chitosan/polyvinyl alcohol nanofibers by direct and self-assembly approaches. Results of SEM and EDX were that the direct method exhibited better Cu-BTC functionalization on fiber surface and provided good dispersion and uniform coverage of Cu-BTC particles with high Cu concentration content of 1.20% wt. Antibacterial test was quantified using the clear zone of inhibition (AATCC-147). The values exhibited the no bacterial growth against Staphylococcus aureus and Escherichia coli at 2.01±0.02 and 1.99±0.05 mm, respectively. Cu-BTC functionalized chitosan/poly vinyl alcohol hybrid nanofibers could improve antibacterial properties compared to neat composite mats, but limitation of their features might be inadequate for encouraging water uptake hydrated from body cells, resulting in lower than estimated performance.

A sonochemical synthesis of SrTiO3 supported N-doped graphene oxide as a highly efficient electrocatalyst for electrochemical reduction of a chemotherapeutic drug.

A sonochemical based green synthesis method playa powerful role in nanomaterials and composite development. In this work, we developed a perovskite type of strontium titanate via sonochemical process. SrTiO3 particles were incorporated with nitrogen doped graphene oxide through simple ultrasonic irradiation method. The SrTiO3/NGO was characterized by various analytical methods. The nanocomposite of SrTiO3/NGO was modified with laser-induced graphene electrode (LIGE). The SrTiO3/NGO/LIGE was applied for electrochemical sensor towards chemotherapeutic drug detection (nilutamide). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques have been used to examine the electrochemical performance of nilutamide (anti-cancer drug). DPV was found to be more sensitive and found to exhibit a sensitivity 8.627 µA µM-1 cm-2 for SrTiO3/NGO/LIGE with a wide linear range (0.02-892µM) and low Limit of detection (LOD: 1.16µM). SrTiO3/NGO/LIGE has been examined for the detection of nilutamide in blood serum and urine samples and obtained a good recovery in the range of 97.2-99.72%. The enhanced stability and selectivity and practical application results indicates the suitability of SrTiO3/NGO/LIGE towards the detection of nilutamide drug in pharmaceutical industries.

Formulation of dual functional gCN/TeO2-ZnO nanocomposites as a controlled release nanofertilizer and antibacterial agent

A simple cost-effective sono-chemical method was used for the synthesis of gCN/TeO2-ZnO ternary (2%, 5%, and 10%) nanocomposites, having crystallite size of 12 nm. FE-SEM and transmission electron microscopy images revealed the formation of core–shell type nanocomposites with an average size of 50 nm. Further, E. coli MTCC 443 strain is used as a model organism to study the antibacterial activity of the prepared nanocomposites, using disc diffusion method. Among all the concentrations, 2% gCN/TeO2-ZnO showed maximum zone of inhibition of 23 ± 0.10 mm and its antibacterial activity is like third-generation antibiotic cefotaxime. In addition, the prepared nanocomposites were used as nanofertilizer for the growth of gram seeds Chickpea (Cicer arietinum). The effect of nanocomposite concentration and its sterilising properties are studied on the rate of germination of Chickpea using both in vitro and in vivo studies (pot study). The root length of the gCN/TeO2-ZnO treated plants showed increase in seed germination (3.30 cm) compared to untreated plants (3.22 cm). In addition, enhancement in the shoot length about 28% is noticed in pot studies, compared to control batch samples. The accumulation of nanomaterial in plant roots was confirmed using SEM-EDX and ICP-MS. Finally, a 14-day experiment was conducted to ascertain the role of gCN/TeO2-ZnO in the controlled release of nutrients from the synthesised nanofertilizer. Owing to its excellent water holding capacity, sterilizing properties, and low toxicity this material can be used as a growth promoter in plants.

Fast and efficient green synthesis of CaWO4 NPs using eggshells as a biogenic calcium source: Structure, optical property, and morphology

In summary, we report a fast, easy, and low-cost green synthesis approach to obtain calcium tungstate nanoparticles (CaWO4NPs_GS) using eggshells as a source of calcium by the sonochemistry method at room temperature. These nanomaterials were structurally characterized by X-ray diffraction (XRD) and Rietveld refinement analysis, where a pure phase with very close structural parameters with calcium tungstate nanoparticles was synthesized at the conventional route (CaWO4NPs_CS). All vibrational Raman active modes characteristic of symmetry point C4h6 were confirmed. An optical band gap value (Egap = 3.92(2) eV) for CaWO4NPs_GS lower than for CaWO4NPs_CS (Egap = 3.92(2) eV) was archived, and that is associated with the intermediate electronic levels due to the oxygen vacancy and micro-strain effect. Field Emission Scanning Electron Microscopy (FE-SEM) images show several nanoparticles with a particle size of 62.7 ± 1.3 nm for CaWO4NPs_CS and 48.7 ± 1.2 nm for CaWO4NPs_GS, where all elements characteristic of calcium tungstate (Ca, W, and O) were appointed by Energy Dispersive X-ray (EDX) analysis. While the photocatalytic performance of CaWO4NPs_GS was 2.5 times faster than CaWO4NPs_CS in the photodegradation of Rhodamine B (RhB) dye in an aqueous solution under UV light in 120 min. Therefore, confirming that chicken eggshell is a promissory raw material as a biogenic source of calcium ions for synthesizing calcium tungstate with promissory photocatalytic properties.

Studies in synthesis of nano-zinc oxide mixed PVC matrix membrane and its application for ibuprofen drug removal

The present study performed pharmaceutical drug such Ibuprofen (IBP) separation by novel nano-Zinc oxide (ZnO) mixed PVC matrix membrane. The study represents an attempt to the synergistic effect of zinc oxide nanoparticle due to its catalytic nature and versatile PVC as polymeric membrane material to fabricate desired membrane for improving IBP removal considering hazardous environmental impacts of ibuprofen on aquatic as well as human life. The ZnO nanoparticles produced by novel sono-chemical precipitation method were confirmed by HRTEM analysis. The nano-ZnO mixed PVC membrane was prepared by phase inversion method using water as the non-solvent, N-Methyl-2-pyrrolidone (NMP) as the solvent and polyethylene glycol (PEG) 6 kDa as the pore forming agent. Membrane properties such as water uptake and contact angle, resistance estimation was also measured. The characterization Techniques such as FTIR, FESEM, FESEM-EDX were used to characterize zinc oxide and blended membranes to examine structural and functional groups. The effects of pH and transmembrane pressure and IBP concentration on IBP removal were taken into account to optimize membrane performance.1% nano-Zinc oxide mixed PVC membrane showed better flux recovery ratio 89%, IBP removal of about 67% among other modified membrane.

The Effect of Different Synthesis with Chemical and Biological Methods on Properties of Silver Oxide Nanoparticles

Silver oxide (Ag2O) nanoparticles have been successfully synthesized through several methods, namely sol-gel, sonochemical, and biological methods. X-ray diffraction studies revealed that the sonochemical method produces silver oxide with high phase purity, then the sol-gel method produces another phase, namely silver crystals, while the biological method produces Ag3PO4 phase from the precursor media. The research showed that the sol-gel method had the smallest crystallite and particle sizes of 9.5 and 232.7 nm, respectively, compared to sonochemical and biological methods. It is known that the specific surface area of the sol-gel method has the largest value, namely 60.09 m2/g, compared to the sonochemical and biosynthetic methods, which are 51.78 and 24.77 m2/g, respectively. Scanning electron microscopy study showed homogeneous spherical nanoparticles of silver oxide in the sol-gel and sonochemical methods, however, the biological method resulted in the formation of non-spherical silver oxide nanoparticles in the form like flakes. HIGHLIGHTS Synthesis of silver oxide by chemical method produces pure silver oxide crystals, smaller crystallite size, larger specific area, and more homogeneous particle size than biological methods The sol-gel method for the synthesis of silver oxide produces the smallest particle size than the sonochemical and biological methods The sonochemical method produces the highest crystallinity and size homogeneity compared to the sol-gel and biological methods GRAPHICAL ABSTRACT

Biopolymer templated strategized greener protocols for fabrication of ZnO nanostructures and their application in photocatalytic technology for phasing out priority pollutants.

Zinc oxide (ZnO) nanostructures have been successfully synthesized via template-assisted and template-free route using three different synthetic methods, i.e., sonochemical, mechanochemical, and hydrothermal. Biopolymer xanthan gum (XG) served as sacrificial template for ZnO synthesis as provided the surface for the growth of nanostructures in a controlled manner. The employment of multifarious synthetic techniques resulted in fabrication of ZnO nanoparticles with diverse morphologies such as needle shaped, hexagonal, and spherical particles. Further, the template-assisted protocols generated thermally stable highly crystalline nanostructures along with high surface area, larger pore size, and low band gap energies in contrast to template-free protocol. The structural and other physicochemical studies were manifested by XRD, N2 adsorption desorption, FESEM, TGA, and UV-Vis spectral analysis. The template-assisted ZnO nanostructures were explored as a potential photocatalyst for the catalytic degradation of emerging pollutants, i.e., triclosan (TCS) and imidacloprid (IMD) under the exposure of UV light. The products formed during the photocatalytic reaction were monitored by UV-Vis spectroscopy and HPLC. The results obtained revealed the high catalytic efficiency of ZnO synthesized via template-assisted sonochemical method for TCS (99.60%) and IMD (96.09%) which is attributed to the high surface area and lower band gap energy of the catalyst. The high catalytic potential of the sonochemically synthesized ZnO also substantiated from the kinetic data as high-rate constant was obtained. Thus, the template-assisted protocols developed led to preparation of nanostructures having tailored properties for efficient photocatalysis and can rapidly degrade selected emerging contaminants such as personal care products and organophosphate pesticides. Hence, environment-friendly synthesized photocatalyst can be appropriately employed to wastewater treatment contaminated with emerging pollutants.

A Petal-like Structured NiCuOOH-NF Electrode by a Sonochemical Combined with the Electrochemical Method for Ammonia Oxidation Reaction

Direct electrochemical oxidation, as an economical and efficient method, has recently received increasing attention for ammonia-nitrogen wastewater treatment. Developing a low-cost, efficient catalytic electrode is the key to solve the problem of sluggish ammonia oxidation reaction (AOR) kinetics. In this study, a three-dimensional (3D) Ni foam electrode coated with NiCuOOH petal-like cluster structures was prepared using a simple sonochemical method combined with a surface electrochemical reconstruction strategy. This structure has a large surface area and abundant NiCuOOH active sites, giving a good premise for extraordinary electrocatalytic activity of AOR. The results show that the maximum current density for AOR reaches 97.8 mA cm−2 at 0.60 V vs. saturated calomel electrode (SCE). Additionally, 96.53% of NH4+-N removal efficiency and 63.12% of TN removal efficiency were acquired in the electrolysis system based on the NiCuOOH-NF electrode, as well as a good stability for at least 24 h. It is a promising flow-through anode for the clean treatment of ammonia-nitrogen wastewater.

Fabrication, structural, morphological, and optical features of Mn2O3 polyhedron nano-rods and Mn2O3/reduced graphene oxide hybrid nanocomposites

Mn2O3 and Mn2O3/reduced graphene oxide (rGO) composites were prepared by the hydrothermal and sonochemical method, respectively. The prepared samples were characterized via X-ray diffraction, Transmission electron microscope, Fourier transform infra-red, and Raman spectroscopy. Di-Manganese tri oxide morphology appeared new morphology as polyhedron prism nano-rods as to the best of our knowledge, no work has described before for Mn2O3 nanoparticles (NPs). The Raman vibrational band at 694 cm−1 is related to the Mn-O bond of trivalent manganese ions (Mn3+). XRD and TEM analysis confirmed the decrease of particle sizes with the insertion of rGO sheet to the matrix. The optical properties were measured by UV–visible spectrometer. The obtained data from the absorption spectra was used to investigate the optical parameters. The optical band gap was tuned to a lower value of about 1.57 eV and the refractive index increased from 4.031 for Mn2O3 to 4.429 for Mn2O3/rGO. The obtained results revealed that the optical and morphological structure of Mn2O3 were enhanced via the addition of rGO sheets to the matrix which make it useful in optoelectronic applications.