Template-free sonochemical synthesis of flower-like ZnO nanostructures

Flower-like ZnO nanostructures have been successfully synthesized via a facile and template-free sonochemical method, using zinc acetate and potassium hydroxide as reactants only. The as-synthesized flower-like ZnO nanostructures were composed of nanorods with the width of ∼300–400 nm$\sim 300\text{–}400\text{nm}$ and the length of ∼2–3 μm$\sim 2\text{–}3\text{μm}$. The structures, morphologies and optical properties of the as-prepared products were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, UV-Vis spectrophotometry and Raman-scattering spectroscopy. A plausible formation mechanism of flower-like ZnO nanostructures was studied by SEM which monitors an intermediate morphology transformation of the product at the different ultrasonic time (t=80,90,95,105, and 120 min$t=80,90,95,105\text{, and}120\text{min}$).     

多孔玻璃微珠的研制

本文作者把研制的Ｎａ２Ｏ－Ｂ２Ｏ３－Ａｌ２Ｏ３－ＳｉＯ２系统玻璃放在自己设计的设备中制成了１～２ｍｍ粒径的玻璃珠，经分相处理、酸溶、水洗，得到了气孔率为２４％左右的多孔玻璃微珠。     

Facile sonochemical synthesis of nanosized InP and GaP

A novel sonochemical method for the preparation of MP (M = Ga, In) nanocrystalline materials has been developed. The procedure consists of the in situ synthesis of sodium phosphide and its subsequent reaction with the appropriate metal chloride using ultrasound. The products were characterized by X-ray powder diffraction, electron microscopy, and energy dispersive X-ray microanalysis (EDX). The choice of solvent and the use of high-power ultrasound are both important in the formation of the products.     

Template-free synthesis of hierarchical NiO microtubes as high performance anode materials for Li-ion batteries

Hierarchical nanostructured NiO (h-NiO) microtubes were prepared by a simple wet-chemical synthesis without the use of template or surfactant, followed by the calcination of α-Ni(OH)₂ precursor. The structural characterization of the h-NiO microtubes were performed by scanning microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD), the results of which indicated that the obtained h-NiO microtubes are covered by the nanosheet grown perpendicularly on the tube surface. The unique hierarchical nanostructure of h-NiO microtubes with high surface area and many voids facilitates the electrochemical reaction as well as the short ion and electron transport pathway. Therefore, as anode electrode of Li-ion batteries, the h-NiO microtubes deliver largely enhanced cycle capacity of 770 mAh·g⁻¹ at a current density of 0.5 C after 200 cycles with high columbic efficiency, compared to the NiO rods. These results suggest that the h-NiO microtubes can be a promising anode material for Li-ion batteries.     

A novel method for the preparation of III-V semiconductors: sonochemical synthesis of InP nanocrystals

A novel method for the preparation of III–V semiconductor has been provided in this paper. At room temperature, InP nanocrystals with diameter of ≈9 nm were successfully obtained under high-intensity ultrasonic irradiation for 4 h from the reaction of InCl₃·4H₂O, yellow phosphorus and KBH₄ in the mixed solvents of ethanol and benzene. Changing some parameters can effectively control the size of the products and possible explanations were offered. The products were characterized by X-ray powder diffraction, transmission electron microscope and electron diffraction pattern. The ultrasonic irradiation and the solvents are both important in the formation of the product.     

Selective hydrogenation by polymer-encapsulated platinum nanoparticles prepared by an easy single-step sonochemical synthesis

Polypyrrole-encapsulated platinum nanoparticles (PPy/Pt-NPs) prepared by an easy single-step sonochemical synthesis were used as catalysts for the liquid phase hydrogenation of substituted alkenes in methanol or methanol/water mixtures. Polypyrrole (PPy) coatings on the nanoparticles were able to act as nanoscopic filters for substrates molecules, and consequently substrate selectivity could be controlled in the catalytic processes.     

Room temperature synthesis of needle-shaped ZnO nanorods via sonochemical method

Single crystalline needle-shaped zinc oxide nanorods were synthesized via sonochemical methods using zinc acetate dihydrate and sodium hydroxide at room temperature. Morphological investigation revealed that the nanoneedles are of hexagonal surfaces along the length. The typical diameter and length vary from 120 to 160 nm and 3 to 5 μm, respectively. Sonication time appears to be a critical parameter for the shape determination. Detailed structural characterization confirmed that the nanorods are single crystalline with wurtzite hexagonal phase. A standard peak of zinc oxide was observed at 520 cm⁻¹ from the Fourier transform infrared spectroscopy. The ultra-violet visible and room temperature photoluminescence (PL) spectroscopic results demonstrate that the synthesized material has good optical properties.     

One-pot sonochemical synthesis of CuS nanoplates decorated partially reduced graphene oxide for biosensing of dopamine neurotransmitter

The sonochemical methods have been used as a straight forward method for the synthesis of various composite materials, including the transition metal dichalcogenide composites. In the present work, we report a simple sonochemical synthesis of CuS nanoplates decorated partially reduced graphene oxide (PrGO) nanocomposite for the first time. The PrGO-CuS nanocomposite was synthesized using bath-sonication (frequency: 37 kHz; power: 150 W) of graphene oxide (GO), and CuS precursors at 80 °C for 60 min. The physicochemical characterization (FESEM, XRD, FTIR, and Raman spectroscopy) results confirmed the successful formation of CuS nanoplates on PrGO nanosheets. The as-synthesized PrGO-CuS nanocomposite was further utilized for electroanalysis of dopamine neurotransmitter. The obtained electroanalytical results revealed that PrGO-CuS nanocomposite has superior electrochemical activity towards dopamine than those obtained for GO, CuS, and GO-CuS composite. The fabricated biosensor shows a lower limit of detection (0.022 µM) with a more comprehensive linear response range (0.1–155.1 µM) for the detection of dopamine. Moreover, the PrGO-CuS nanocomposite electrode was successfully used for the detection of dopamine in bovine serum albumin.     

Impact of sonochemical synthesis condition on the structural and physical properties of MnFe2O4 spinel ferrite nanoparticles

Herein, we report sonochemical synthesis of MnFe₂O₄ spinel ferrite nanoparticles using UZ SONOPULS HD 2070 Ultrasonic homogenizer (frequency: 20 kHz and power: 70 W). The sonication time and percentage amplitude of ultrasonic power input cause appreciable changes in the structural, cation distribution and physical properties of MnFe₂O₄ nanoparticles. The average crystallite size of synthesized MnFe₂O₄ nanoparticles was increased with increase of sonication time and percentage amplitude of ultrasonic power input. The occupational formula by X-ray photoelectron spectroscopy for prepared spinel ferrite nanoparticles was (Mn_0.29Fe_0.42)[Mn_0.71Fe_1.58]O₄ and (Mn_0.28Fe_0.54) [Mn_0.72Fe_1.46]O₄ at sonication time 20 min and 80 min, respectively. The value of the saturation magnetization was increased from 1.9 emu/g to 52.5 emu/g with increase of sonication time 20 min to 80 min at constant 50% amplitude of ultrasonic power input, whereas, it was increased from 30.2 emu/g to 59.4 emu/g with increase of the percentage amplitude of ultrasonic power input at constant sonication time 60 min. The highest value of dielectric constant (ε′) was 499 at 1 kHz for nanoparticles at sonication time 20 min, whereas, ac conductivity was 368 × 10⁻⁹ S/cm at 1 kHz for spinel ferrite nanoparticles at sonication time 20 min. The demonstrated controllable physical characteristics over sonication time and percentage amplitude of ultrasonic power input are a key step to design spinel ferrite material of desired properties for specific application. The investigation of microwave operating frequency suggest that these prepared spinel ferrite nanoparticles are potential candidate for fabrication of devices at high frequency applications.     

Photocatalytic properties of TiO2 and TiO2/Pt: A sol-precipitation,sonochemical and hydrothermal approach

In this work we prepared TiO₂ nano-powders and TiO₂/Pt nano-composites via three synthesis methods (sol-precipitation, sonochemical method, hydrothermal method) starting with the same precursors and media. To evaluate and compare the physical properties of the prepared materials, X-ray diffraction analysis, BET measurements, FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS) and electron microscopy (TEM, HRTEM, SAED) were applied. The results showed changes to the TiO₂ phase composition and crystallinity, the specific surface area as well as the platinum’s particle shape and size, depending on the method of synthesis. To determine the photocatalytic efficiency of the prepared materials, the photocatalytic discoloration of the methylene blue solution was evaluated using UV–Vis spectroscopy. The important properties required for a high photocatalytic activity, related to the surface characteristics and the phase composition, were determined in terms of the synthesis method. It was concluded that the optimum characteristics were obtained when using the hydrothermal approach, where the TiO₂ had two phases, i.e., – anatase and rutile, a Pt-phase in the form of nanoparticles and adsorbed Pt-molecular species, as well as the presence of available free surface hydroxyl groups. Such characteristics had a critical influence on the photocatalytic activity of the final material.     

Single-step sonochemical synthesis of Cu2O-CeO2 nanocomposites with enhanced photocatalytic oxidative desulfurization

In this paper, for the first time, composite nanostructures of Cu₂O-CeO₂ were prepared by a facile and single-step sonochemical method for thiophene photocatalytic oxidative desulfurization. Sonication was performed utilizing a high-intensity ultrasonic probe with a maximum output power of 80 Wcm⁻³ and operating frequency at 20 kHz. The direct effect of ultrasonic waves on the composition and morphology of the obtained products was also evaluated and it was found that under ultrasonic irradiation, Cu₂O-CeO₂ can be produced while the main product in the absence of ultrasonic waves is CuO-CeO₂. Cu₂O-CeO₂ exhibits much higher photocatalytic efficiency (84%) than CuO-CeO₂ (39%) due to its higher light absorption and electron synergistic effect. The effect of Ce:Cu on photocatalytic efficiency was examined by considering the ratios of 1:0.25, 1:1, 0.5:1, and 0.25:1 and yields of 64, 81, 84, and 76% were obtained, respectively. This indicates that there is an optimal value for the Ce:Cu ratio in the Cu₂O-CeO₂ nanocomposite.     

A simple sonochemical approach for synthesis and characterization of Zn2SiO4 nanostructures

Zn₂SiO₄ nanoparticles have been successfully prepared via a simple sonochemical method, for the first time. The effect of various parameters including ultrasonic power, ultrasonic irradiation time and different surfactants were investigated to reach optimum condition. The as-prepared nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmittance electron microscopy (TEM), Fourier transform infrared (FT-IR) spectra and energy dispersive X-ray microanalysis (EDX). The photocatalytic activity of Zn₂SiO₄ nano and bulk structures were compared by degradation of anionic dye methyl orange in aqueous solution under UV-light irradiation. Moreover, the cyclic voltammetry analysis of Zn₂SiO₄ nano and bulk structures were investigated.     

A sonochemical assisted synthesis of hollow sphere structured tin (IV) oxide on graphene oxide sheets for the low-level detection of environmental pollutant mercury in biological samples and foodstuffs

In modern approaches for nanomaterials synthesis, ultrasonication plays an important role in providing the larger surface area and smaller crystalline size properties that are favorable to electrochemical techniques. Herein, we report the tin (IV) oxide on graphene oxide nanoparticles were synthesized (SnO₂@GO NPs) by ultrasonic methodology (UZ SONOPULS HD 3400 Ultrasonic homogenizer) with the total power of 400 W and the (frequency of 20 kHz; 140 W/dm³). The formation of as-prepared SnO₂@GO NPs and its surface morphology were scrutinized over XRD, XPS, TEM, and FESEM. Besides, the sonochemically prepared SnO₂@GO NPs were employed for the determination of environmental hazardous mercury (Hg). As a result, the modified electrode acquired a very low-level detection limit of 1.2 nM with a wider range of 0.01–10.41-µM and 14.52–225.4-µM for the detection of Hg. Finally, the practical applicability of SnO₂@GO NPs in spiked human blood serum and tuna fish samples shows appreciable found and recovery values..     

Green sonochemical synthesis and fabrication of cubic MnFe2O4 electrocatalyst decorated carbon nitride nanohybrid for neurotransmitter detection in serum samples

The binary nanomaterials and graphitic carbon based hybrid has been developed as an important porous nanomaterial for fabricating electrode with applications in non-enzymatic (bio) sensors. We report a fast synthesis of bimetal oxide particles of nano-sized manganese ferrite (MnFe₂O₄) decorated on graphitic carbon nitride (GCN) via a high-intensity ultrasonic irradiation method for C (30 kHz and 70 W/cm²). The nanocomposites were analyzed by powder X-ray diffraction, XPS, EDS, TEM to ascertain the effects of synthesis parameters on structure, and morphology. The MnFe₂O₄/GCN modified electrode demonstrated superior electrocatalytic activity toward the neurotransmitter (5-hydroxytryptamine) detection with a high peak intensity at +0.21 V. The appealing application of the MnFe₂O₄/GCN/GCE as neurotransmitter sensors is presented and a possible sensing mechanism is analyzed. The constructed electrochemical sensor for the detection of 5-hydroxytryptamine (STN) showed a wide working range (0.1–522.6 μM), high sensitivity (19.377 μA μM⁻¹ cm⁻²), and nano-molar detection limit (3.1 nM). Moreover, it is worth noting that the MnFe₂O₄/GCN not only enhanced activity and also promoted the electron transfer rate towards STN detection. The proposed sensor was analyzed for its real-time applications to the detection of STN in rat brain serum, and human blood serum in good satisfactory results was obtained. The results showed promising reproducibility, repeatability, and high stability for neurotransmitter detection in biological samples.     

Synthesis of TiO2/WO3 nanoparticles via sonochemical approach for the photocatalytic degradation of methylene blue under visible light illumination

Through an ultrasound assisted method, TiO₂/WO₃ nanoparticles were synthesized at room temperature. The XRD pattern of as-prepared TiO₂/WO₃ nanoparticles matches well with that of pure monoclinic WO₃ and rutile TiO₂ nanoparticles. TEM images show that the prepared TiO₂/WO₃ nanoparticles consist of mixed square and hexagonal shape particles about 8–12 nm in diameter. The photocatalytic activity of TiO₂/WO₃ nanoparticles was tested for the degradation of a wastewater containing methylene blue (MB) under visible light illumination. The TiO₂/WO₃ nanoparticles exhibits a higher degradation rate constant (6.72 × 10⁻⁴ s⁻¹) than bare TiO₂ nanoparticles (1.72 × 10⁻⁴ s⁻¹) under similar experimental conditions.     

Facile sonochemical synthesis of rutile-type titanium dioxide microspheres decorated graphene oxide composite for efficient electrochemical sensor

In this reports the facile and green synthesis of rutile-type titanium dioxide nanoparticles decorated graphene oxide nanocomposite via the ultrasonication process (frequency: 50 kHz, Power: 100 W/cm² and Ultrasonic type: Ti-horn). Because, the sonochemical synthesis method is simple, non-explosive and harmless method than other conventional technique. Furthermore, the synthesized material was characterized by various analytical techniques including FESEM, EDX, XRD, EIS and electrochemical methods. Then, the synthesized TiO₂ MPs@GOS composite was applied for the electrocatalytic detection of theophylline (TPL) using CV and amperometric (current-time) techniques. Captivatingly, the modified sensor has excellent electrocatalytic performance with the wider linear range from 0.02 to 209.6 µM towards the determination of theophylline and the LOD and sensitivity of the modified sensor was calculated as 13.26 nM and 1.183 μA·µM⁻¹·cm⁻², respectively. In addition, a selectivity, reproducibility and stability of the TiO₂ MPs@GOS modified GCE were analyzed towards the determination of theophylline molecule. Finally, the real time application of TiO₂ MPs@GOS modified theophylline sensor was established in serum and drug samples.     

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 (0.02–892 µM) and low Limit of detection (LOD: 1.16 µM). 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.     

Superiority of sonochemical processing method for the synthesis of barium titanate nanocrystals in contrast to the mechanochemical approach

The results indicated that the ultrasonic sonochemistry which brings into play the acoustic cavitation phenomenon is more powerful and feasible in synthesizing the mixed oxides in contrast to the conventional solid-state approaches. The obtained results demonstrated that the sonochemical approach is able to obtain highly pure powder product at a much lower processing temperature of about 323 K (50 °C) in contrast to 1173 K (900 °C) which is essential for the synthesis by the mechanochemical approach. Sonochemical synthesis benefits from homogenous ordering the reactant ions (which have been dissolved in the solution mixture) into perovskite structure using ultrasonication. This indicates that the acoustic cavitation phenomenon is much more powerful and cost-effective than high energy ball milling in synthesizing nanopowders of the mixed oxide materials. Moreover, the sonochemical processing method is able to prepare the final powder products in a much shorter time by a one-step synthesis approach without the need for the successive calcination in contrast to the solid-state approach.     

Growth mechanism and optical property of ZnO nanoparticles synthesized by sonochemical method

ZnO nanoparticles have been synthesized by ultrasonic irradiation of an aqueous-alcoholic/aqueous-alcoholic-ethylenediamine (EDA) solutions of zinc nitrate and sodium hydroxide. ZnO nanoparticles possess hexagonal wurtzite structures and they exhibit special photoluminescence properties with a red-shift of 22 nm in UV emission band. It is found that the ultrasonic irradiation time and the solvents both influence the growth mechanism and optical properties of ZnO nanoparticles. The possible growth mechanism of ZnO nanoparticles formation by sonochemical method has been tried to discuss.     

Fabrication and characterization of silver/titanium dioxide composite nanoparticles in ethylene glycol with alkaline solution through sonochemical process

This paper aims to study fabrication and characterization of silver/titanium oxide composite nanoparticle through sonochemical process in the presence of ethylene glycol with alkaline solution. By using ultrasonic irradiation of a mixture of silver nitrate, the dispersed TiO₂ nanoparticle in ethylene glycol associated with aqueous solution of sodium oxide yields Ag/TiO₂ composite nanoparticle with shell/core-type geometry. The powder X-ray diffraction (XRD) of the Ag/TiO₂ composites showed additional diffraction peaks corresponding to the face-centered cubic (fcc) structure of silver crystallization phase, apart from the signals from the cores of TiO₂. Transmission electron microscopy (TEM) images of Ag/TiO₂ composites, which average particle size is roughly 80 nm, reveal that the titanium oxide coated by Ag nanoparticle with a grain size of about 2–5 nm. Additionally, the formation of silver nanoparticles on TiO₂ was monitored by ultraviolet visible light spectrophotometer (UV–Vis). As measured the optical absorption spectra of as-synthesized Ag nanoparticle varying with time, the mechanism of surface formatting silver shell on the cores of TiO₂ could be explored by autocatalytic reaction; the conversion of Ag particle from silver ion is 98% for the reaction time of 1000 s; and the activity energy of synthesizing Ag nanoparticles on TiO₂ is 40 kJ/mol at temperature ranging from 5 to 25 °C. Hopefully, this preliminary investigation could be used for mass production of composite nanoparticles assisted by ultrasonic chemistry in the future.