Sonochemical synthesis, structural, magnetic and grain size dependent electrical properties of NdVO4 nanoparticles

The Use of Diatoms in the Synthesis of New 3D Micro-Nanostructured Composites (SiO2/CaCO3/Corg/NdVO4NPs and SiO2/CaO/Corg/NdVO4NPs) Exhibiting an Intense Anti-Stokes Photoluminescence

New 3D micro-nanostructured composite materials have been synthesised. These materials comprise SiO2/CaCO3/Corg/NdVO4NPs and SiO2/CaO/Corg/NdVO4NPs, exhibiting strong upconversion luminescence. The synthesis was accomplished by metabolically doping diatom cells with neodymium and vanadium. Subsequently, the biomass of these doped diatoms was subjected to pyrolysis at 800 °C. The morphology, structure, and physicochemical properties of the doped diatom biomass as well as dried (SiO2/CaCO3/Corg/NdVO4NPs) and pyrolysed (SiO2/CaO/Corg/NdVO4NPs) samples were characterised using scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), thermal analysis (TG), and fluorescence spectroscopy (FS). Studies have shown that the surface of diatom shells is covered with trigonal prismatic nanocrystallites (nanoparticles) of NdVO4 with dimensions of 30-40 nm, forming the crystallite clusters in the form of single-layer irregular flakes. The synthesised composites produced intense anti-Stokes fluorescent emission in the visible region under xenon lamp excitation in the near-infrared (λex = 800 nm) at room temperature in an ambient atmosphere. Such materials could be attractive for applications in solar spectrum conversion, optical sensing, biosensors, or photocatalysts.

Simple sonochemical synthesis, characterization of TmVO4 nanostructure in the presence of Schiff-base ligands and investigation of its potential in the removal of toxic dyes

Thulium vanadate (TmVO4) nanorods were successfully prepared by a simple sonochemical approach using Schiff-base ligands. Additionally, TmVO4 nanorods were employed as a photocatalyst. The most optimal crystal structure and morphology of TmVO4 have been determined and optimized by varying Schiff-base ligands, the molar ratio of H2Salen, the sonication time and power, and the calcination time. A Eriochrome Black T (EBT) analysis revealed that the specific surface area was 24.91 m2/g. A bandgap of 2.3 eV was determined by diffuse reflectance spectroscopy (DRS) spectroscopy, which makes this compound suitable for visible photocatalytic applications. In order to assess the photocatalytic performance under visible light, two anionic dyes (EBT) and cationic dyes (Methyl Violet (MV)) were used as models. A variety of factors have been studied in order to improve the efficiency of the photocatalytic reaction, including dye type, pH, dye concentration, and catalyst loading. Under visible light, the highest efficiency was achieved (97.7%) when 45 mg TmVO4 nanocatalysts were present in 10 ppm Eriochorome Black T at pH = 10.

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. .

Sonochemical synthesis, characterization and application of PrVO4 nanostructures as an effective photocatalyst for discoloration of organic dye contaminants in wastewater

In the current research, various conventional chemical preparation methods without ultrasound aid (precipitation, microwave, and hydrothermal) were compared with sonochemical procedure and were performed for providing of PrVO₄ nanostructures using Schiff-base ligands. The small size products with monodisperse particles (~39 nm) optimized by sonochemical fabrication method and using H₂ acacpn ligand via ultrasonic probe with power of 60 W and frequency of 18 KHz. The produced PrVO₄ nanostructures applied for degradation of diverse organic dyes through the photocatalytic process. Dye types, pH adjusting of dye, dosage of catalyst, synthesis method of nanoparticles and light source as impressive factors inquired for dye removal ability. The outcomes presented the removal efficiency of Eriochorom Black T in optimal conditions of pH = 11 and the catalysts amounts of PrVO₄ were adjusted to be 0.05 g. The PrVO₄ photocatalyst shows high removal efficiency (ca 86.92 and 89.61%) after 90 min of operation under UV light. The best-obtained framework confirmed the basic study to compare different method in order to acquire suitable catalyst materials. The simple, fast and economic strategy for synthesis PrVO₄ with high photodegradation efficiency is sonochemical method against other ways, and it could be extended to the most efficient catalyst materials for water treatment. Consequently, the PrVO₄ may suggestion a hopeful avenue for designing the novel generation, low-cost and outstanding potential photocatalyst materials for water treatment.

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.

Enhanced photoconversion performance of NdVO4/Au nanocrystals for photothermal/photoacoustic imaging guided and near infrared light-triggered anticancer phototherapy

Although neodymium vanadate (NdVO₄) has been investigated and applied in some fields owing to its intensive ultraviolet (UV) light absorption, weak absorption in visible (Vis) and near infrared (NIR) regions constrains its environmental remediation and biomedical applications. Herein, plasmonic precious metal Au as light trapping agent is deposited onto NdVO₄ to form metal/semiconductor hybrid nanostructure for improving the Vis/NIR light absorption. NdVO₄/Au heterojunction nanocrystals (NCs) were synthesized by NdVO₄ nanorods (NRs) and plasmonic Au nanoparticles (NPs), followed by introducing polyvinylpyrrolidone (PVP) to enhance stability and biocompatibility, which exhibit elevated photocatalytic performance for organic dye degradation, photothermal conversion effect as high as 32.15% and cytotoxic reactive oxygen species (ROS) production ability. NdVO₄/Au can be internalized efficiently via endocytosis and cause apparent phototoxicity on HeLa cells. In vivo experiments further show that NdVO₄/Au can act as a high-efficiency NIR light-triggered anticancer agent with excellent tumor inhibition effect. In addition, based on outstanding light-to-heat conversion performance and thermal expansion effect under NIR irradiation, NdVO₄/Au provides photothermal (PT) and photoacoustic (PA) dual-modal imaging platform for precise cancer diagnosis and treatment. STATEMENTS OF SIGNIFICANCE: It's the first report on integrating precious metal Au and rare earth orthovanadates semiconductor into NdVO₄/Au heterojunction NCs. The as-prepared NdVO₄/Au heterojunction NCs exhibits improved absorption in Vis/NIR region and increased generation efficiency of photo-induced electron/hole pairs due to the LSPR effect, which results in enhanced photothermal conversion efficiency and the production ability of cytotoxic O₂^- and OH in comparison with pristine NdVO₄. For further clinical application, NdVO₄/Au heterojunction NCs could be served as anticancer therapeutic agent for PA/PT dual-modal imaging guided and NIR-triggered photothermal/photodynamic synergistic anticancer treatment.

Utilizing of neodymium vanadate nanoparticles as an efficient catalyst to boost the photocatalytic water purification

Neodymium Vanadate (NdVO₄) nanostructures were successfully synthesized via a modified solid state method in the presence of ligand. These nanoparticles were further used as a photocatalyst. Primarily the best structural formations and smallest crystallite sizes of the systems were identified and optimized by changing the calcination time, calcination temperature and molar ratio of the ligand. The cationic (Methyl Violet (MV)), and anionic (Eosin Y (EY) and Eriochrome Black T (EBT)) dyes were used as a model to evaluate the photoactivity under UV-Vis irradiation. Several operational factors were examined to improve the photocatalytic efficiency include type of dye, type of light source, pH and dye concentration. As a result, the best efficiency in 5 ppm Eriochorome Black T at pH = 11 was achieved in the presence of 0.05 g NdVO₄ nanocatalysts.

Ultrasound-assisted synthesis of YbVO4 nanostructure and YbVO4/CuWO4 nanocomposites for enhanced photocatalytic degradation of organic dyes under visible light

YbVO₄ nanostructure and YbVO₄/CuWO₄ nanocomposites were successfully synthesized using sonochemical method, for the first time. In this disquisition, we tried to compare various parameters and reaction conditions on size, morphology, and uniformity of as-obtained samples. To reach optimum condition, some parameters including time, power, temperature, and solvent were investigated. The structural, morphological, optical, and magnetic properties of as-obtained products were characterized by some techniques such as FT-IR, XRD, EDS, SEM, TEM, UV-Vis, and VSM. Furthermore, due to occurrence of red shift in nonanocomposite, during the coupling of CuWO₄ into YbVO₄, photocatalytic and optical properties of final products were improved which lead to improve photo-destruction efficiency for methylene blue from 65% to 100%, during 120 min irradiation. The effect of the ultrasonic radiation on the photocatalytic behavior of YbVO₄/CuWO₄ shows that methylene blue pollutant destruction was about 100% with ultrasonic wave and 61% in the absence of ultrasonic radiation.

Application of ultrasound-aided method for the synthesis of NdVO4 nano-photocatalyst and investigation of eliminate dye in contaminant water

This paper presents a new approach to preparation of neodymium vanadate nanostructures via facile sonochemical route. Several parameters were compared to reach optimum size and uniformity of as-made samples. These factors include sonication time, sonication power, solvent and using ethylenediamine as alkaline and capping agent, for the first time. Neodymium vanadate nano-photocatalyst applied in decolouration of dye as organic contaminant. Effect of type of dye, type of irradiation source, pH and catalyst loading was described on improving efficiency of catalyst function. Numerous techniques were specified in order to determine purity, morphology and optical properties of products consist XRD, FT-IR, EDX, SEM, TEM and DRS.

Enhanced photodegradation of dye in waste water using iron vanadate nanocomposite; ultrasound-assisted preparation and characterization

The paper proposes a new approach to Schiff-base ligand assisted sonochemical synthesis of iron vanadate. In this disquisition, we tried to comparing various factors and reaction condition on morphology, size and uniformity of as-obtained samples. Some parameters including Schiff-base capping agent (Bis(acetylacetone) ethylenediamine=H₂acacen), electrolyte (NH₄F), solvent and reaction time were investigated to reach optimum condition. XRD, FT-IR, EDS, SEM and TEM were used in order to determine purity and structural morphology of as-synthesized products. Also, we explore the possibility of coupling vanadium pantaoxide into iron vanadate that improves optical properties and photocatalytic activity. With this in mind, FeVO₄/V₂O₅ nanocomposite was prepared via in-situ ultrasound-assisted procedure by using NH₄F in one step. Influence of different parameters such as type of dye (Rhodamine B=Rh B, Phenol red=Ph R and Methyl violet=MV) and light source (Ultraviolet and visible) on photocatalytic ability of samples were studied.

Photocatalytic Water Splitting for O₂ Production under Visible Light Irradiation Using NdVO₄-V₂O₅ Hybrid Powders

The study investigated photocatalytic water splitting for O₂ production under visible light irradiation using neodymium vanadium oxide (NdVO₄) and vanadium oxide (V₂O₅) hybrid powders. The results in a sacrificial agent of 0.01 M AgNO₃ solution were obtained, and the highest photocatalytic O₂ evolution was 2.63 μmol/h, when the hybrid powders were prepared by mixing Nd and V at a volume ratio of 1:3 at a calcination temperature of 350 °C for 1 h. The hybrid powders were synthesized by neodymium nitrate and ammonium metavanadate using the glycothermal method in ethylene glycol at 120 °C for 1 h. The hybrid powders consisted of two shapes, NdVO₄ nanoparticles and the cylindrical V₂O₅ particles, and they possessed the ability for photocatalytic oxygen (O₂) evolution during irradiation with visible light. The band gaps and structures of the hybrid powders were analyzed using UV-visible spectroscopy and transmission electron microscopy.

The role of oxygen adsorption and gas sensing mechanism for cerium vanadate (CeVO4) nanorods

Square-section CeVO₄ nanorods with highly active and exposed (010) facets have been shown to be highly promising as an acetone gas sensor.

A robust super-paramagnetic TiO2:Fe3O4:Ag nanocomposite with enhanced photo and bio activities on polyester fabric via one step sonosynthesis

High intensity ultrasound was used for the synthesis and simultaneous deposition of TiO2:Fe3O4:Ag nanocomposites on polyester surface providing a feasible route for imparting magnetic and enhanced antibacterial and self-cleaning activities with controllable hydrophilicity/hydrophobicity at low temperature. Synergistic impact of sonochemistry and physical effects of ultrasound originating from implosive collapse of bubbles were responsible for the formation and adsorption of nanomaterials on the fabric surface during ultrasound irradiation. The increase in photocatalytic activity of TiO2 was obtained attributing to the co-operation of iron oxide and silver nanoparticles nucleated on TiO2 surface boosting the electron-hole pair separation and prolonging their recombination rate. The process was further optimized in terms of reagents concentrations including Fe(2+)/TiO2 and Ag/TiO2 molar ratios using central composite design in order to achieve the best self-cleaning property of the treated fabric. The magnetic measurements indicated the super-paramagnetic behavior of the treated fabric with saturation magnetization of 4.5 (emu/g). Findings suggest the potential of the proposed facial method in producing an intelligent fabric with durable multi-functional activities that can be suitable for various applications including medical, military, bio-separation, bio-sensors, magneto graphic printing, magnetic screens and magnetic filters.

A review on textile sonoprocessing: a special focus on sonosynthesis of nanomaterials on textile substrates

The chemical and physical effects of ultrasound with a frequency above 16kHz, higher than the audible frequency of the human ear, have proven to be a useful tool for variety of systems ranging from the application of ultrasound in environmental remediation to the cooperation of ultrasound waves with chemical processing regarding as sonochemistry. Ultrasound opened up new advances in textile wet processing including desizing, scouring, bleaching, dyeing, printing and finishing and also nanoprocessing including nanopretreatment, nanodyeing, nanoprinting and nanofinishing. Use of ultrasound appears to be a promising alternative technique to reduce energy, chemicals and time involved in various operations. Over the past years there has been an enormous effort on using sonochemistry for the synthesis of nanomaterials on various textile materials. In situ sonosynthesis of nanoparticles and nanocomposites on different textiles is a pioneering approach driving future investigations. With such wide range of applications and vast ever increasing publications, the objective of this paper is presenting a comprehensive review on ultrasound application in textile from early time to now by the main emphasis on the sonosynthesis of nanomaterials outlining directions toward future research.

Effect of pH on the sonochemical synthesis of BiPO4 nanostructures and its electrochemical properties for pseudocapacitors

Using sonochemical method, BiPO4 nanocrystals were prepared at different pH conditions (pH-1, 3, 5, 7, 9 & 12) for the possible applications of pseudocapacitor electrodes. The prepared BiPO4 nanocrystals belong to monoclinic structure with P21 space group. The SEM image revealed that the particles changed from irregular coarse shape into rod like structure (pH-1 to 7) which finally collapsed into irregular aggregates (pH-9 to pH-12). The observed spot patterns from SAED inferred the polycrystalline nature of the material. The electrochemical performance of the synthesized BiPO4 in various ultrasound irradiation conditions such as irradiation time (30min, 1h, 2h and 3h) and ultrasonication power (40%, 50%, 60% and 70% of instrumental power) was studied. A maximum specific capacitance of 1052F/g (pH-7 at 2mV/s) was observed for the BiPO4 prepared in the ultrasonication reaction condition of 2h with 60% power. Also the obtained specific capacitance was high compared with the conventional precipitation method (623F/g at 2mV/s) that revealed the prominence of sonication method. Similarly, BiPO4 prepared at pH-7 delivered a maximum specific capacitance of 302F/g at 2mA/cm(2) calculated from galvanostatic charge-discharge (GCD) method than the other pH conditions. However, the cycling stability of BiPO4 (pH-7) was not appreciable even for 200 cycles. So, attempts were taken to enhance the cycling stability of the material by employing various carbon matrices such as acetylene black, activated carbon and MWCNT instead of carbon black during electrode preparation. BiPO4 material with activated carbon delivered good capacitance retention compared with other carbon matrices. This enhanced electrochemical performance of BiPO4 (pH-7) using activated carbon matrix inferred that it could be utilized as efficient negative electrode material for pseudocapacitors.