Simple Wet Chemical Synthesis Research Articles

Investigation of dose sensitivity and dose enhancement effect in silver nanoparticle enriched dose gels

In this study, dose sensitivity enhancing effect of silver (Ag) nanoparticles on dosimetric gels has been investigated. Nanoparticles were added to nMAG and NIPAM dose gel formulations. Ag nanoparticles were obtained via a simple wet chemical synthesis method from AgNO3. Synthesized nanoparticles were characterized using dynamic light scattering (DLS) and scanning electron microscopy (SEM) techniques. Nanoparticle-enriched dose gels were irradiated with 120 keV photons and investigated using Ultraviolet–visible (UV–Vis) and Fourier transform infrared (FTIR) spectroscopy techniques. Addition of Ag nanoparticles allowed to achieve higher sensitivity for both NIPAM and nMAG dose gels. Dose enhancement factor of 1.43 was achieved for nMAG dose gel, and 2.4 for NIPAM dose gel. FTIR spectroscopy also showed signs of radiation-enhancing effect of Ag nanoparticles. Improved gel dosimeters could be used as a valuable tool for dose verification procedures. However, due to variation of dose enhancement effect in different gel dosimeters, application of nano particle enriched dose gels for simulation of dose enhancement effect in the human tissue is not straightforward.

3D Flower-like Tin Monosulfide/Carbon Nanocomposite Anodes for Sodium-Ion Batteries.

The nanostructured tin monosulfide/carbon composites were synthesized by a simple wet chemical synthesis approach. It was revealed that the 3D flower-like tin monosulfide nanoparticles are usable as an active anode material for sodium-ion batteries, exhibiting a specific capacity of 480.4 mAh/g. The 3D flower-like tin monosulfide nanoparticles were wrapped with reduced graphene oxide sheets by a solvothermal heterogeneous synthetic method. By incorporating the reduced graphene oxide sheets as a mechanically flexible and electrically conductive additive, a specific capacity of 633.2 mAh/g was obtained from tin monosulfide/carbon nanocomposite anodes, providing an excellent rate capability even at a high current density condition of 5000 mA/g.

Metallic Gold-Incorporated Ni(OH)2 for Enhanced Water Oxidation in an Alkaline Medium: A Simple Wet-Chemical Approach.

The development of a highly efficient electrocatalyst for the oxygen evolution reaction (OER) with a lower overpotential and high intrinsic activity is highly challenging owing to its sluggish kinetic behavior. As an alternative to the state-of-the-art OER catalyst, recently, transition-metal-based hydroxide materials have been shown to play important roles for the same. Owing to the high earth abundance of various Ni-based hydroxide and its derivatives, these are known to be highly studied materials for the OER. Herein, we report a simple wet-chemical synthesis of metallic gold-incorporated (by varying the concentration of Au3+ ions) Ni(OH)2 nanosheets as an active and stable electrocatalyst for the OER in 1 M KOH medium. The Au-Ni(OH)2 (2) catalyst demanded a low overpotential of 288 mV to attain a geometric current density of 10 mA/cm2 with a lower Tafel value of 55 mV/dec compared to bare Ni(OH)2 with a lower mass loading of only 0.1 mg/cm2. Tafel slope analysis reveals that the incorporation of metallic gold on the hydroxide surfaces could alter the mechanistic pathways of the overall OER reaction. It has been proposed that the incorporation of metallic gold over the Ni(OH)2 surfaces led to a change in the electronic structure of the electroactive nickel sites (Jahn-Teller distortion), which favors the OER by electronic aspects.

Growth Mechanisms of ZnO Micro-Nanomorphologies and Their Role in Enhancing Gas Sensing Properties.

Zinc oxide (ZnO) is one of the main functional materials used to realize chemiresistive gas sensors. In addition, ZnO can be grown through many different methods obtaining the widest family of unique morphologies. However, the relationship between the ZnO morphologies and their gas sensing properties needs more detailed investigations, also with the aim to improve the sensor performances. In this work, seven nanoforms (such as leaves, bisphenoids, flowers, needles, etc.) were prepared through simple wet chemical synthesis. Morphological and structural characterizations were performed to figure out their growth mechanisms. Then, the obtained powders were deposited through screen-printing technique to realize thick film gas sensors. The gas sensing behavior was tested toward some traditional target gases and some volatile organic compounds (acetone, acetaldehyde, etc.) and compared with ZnO morphologies. Results showed a direct correlation between the sensors responses and the powders features (morphology and size), which depend on the specific synthesis process. The sensors can be divided in two behavioral classes, following the two main morphology kinds: aggregates of nanocrystals (leaves and bisphenoids), exhibiting best performances versus all tested gases and monocrystal based (stars, needle, long needles, flowers, and prisms).

Surface modification of Ni-rich LiNi0.8Co0.1Mn0.1O2 with perovskite LaFeO3 for high voltage cathode materials.

Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) is regarded as a potential cathode material due to its higher capacity. However, the severe capacity fading which occurs above 4.2 V vs. Li/Li+ needs to be addressed to enhance the electrochemical performance. Herein, we report the surface modification of NCM811 cathodes with a perovskite material, i.e., lanthanum iron oxide (LaFeO3), which has drawn attention for various research areas due to its non-toxicity, electric conductivity, chemical stability, and low cost and systematically investigate the influence of the LaFeO3 coating on NCM811. The LaFeO3 coating layer significantly protects the cathode material from corrosion due to the HF formation and restrains the dissolution of other ions into liquid electrolyte during high voltage charge–discharge processes. Even after 80 cycles, 0.5 wt% LaFeO3-coated NCM811 cathode material shows about 13% higher cycling stability when compared to the bare NCM811 and other ratios of coated materials. Furthermore, the 0.5 wt% LaFeO3-coated NCM811 delivers excellent rate capability and demonstrates improved structural stability at 4.6 V vs. Li/Li+ under high voltage conditions with Ni-rich cathode active materials.

Facile growth of high transmittance ZnO micro-rod clusters on indium tin oxide by a wet-chemical synthesis method

A simple wet-chemical synthesis method was developed to fabricate Zinc oxide micro-rod clusters. The synthesis process involved the rapid dilution of a zinc-bearing alkaline solution at 150°C in a convection oven on indium tin oxide (ITO) substrates. The synthesis was carried out by immersing an unseeded ITO substrate in a mixture of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and hexamethylenetetramine ((CH2)6N4) aqueous solution. The obtained sample was annealed at 400°C for 2 h. The structural, morphological and optical properties of the synthesized ZnO microstructures were investigated by X-ray diffraction, scanning electron microscopy and ultraviolet-visible spectroscopy, respectively. The ZnO rod clusters are hexagonal phase of the wurtzite structure. The crystal grain sizes of the films were found to be 72.6, 84.3 and 66.3 nm for the (100), (002) and (101) crystal planes, respectively. The optical bandgap of the ZnO was determined to be 3.147 eV.

Enhanced solar-light-driven photocatalytic properties of novel Z-scheme binary BiPO4 nanorods anchored onto NiFe2O4 nanoplates: Efficient removal of toxic organic pollutants

Global environmental problems have been increasing with the growth of the world economy and have become a crucial issue. To replace fossil fuels, sustainable and eco-friendly catalysts are required for the removal of organic pollutants. In this study, nickel ferrite (NiFe2O4) was prepared using a simple wet-chemical synthesis, followed by calcination; bismuth phosphate (BiPO4) was also prepared using a hydrothermal method. Further, NiFe2O4/BiPO4 nanocomposites were prepared using a hydrothermal technique. Numerous characterization studies, such as structural, morphology, surface area, optical, photoluminescence, and photoelectrochemical investigations, were used to analyze NiFe2O4/BiPO4 nanocomposites. The morphology analysis indicated a successful decoration of BiPO4 nanorods on the surface of NiFe2O4 nanoplate. Further, the bandgap of the NiFe2O4/BiPO4 nanocomposites was modified owing to the formation of a heterostructure. The as-prepared NiFe2O4/BiPO4 nanocomposite exhibited promising properties to be used as a novel heterostructure for tetracycline (TC) and Rhodamine B (RhB) removal. The NiFe2O4/BiPO4 nanocomposite degrades TC (98%) and RhB (99%) pollutants upon solar-light irradiation within 100 and 60 min, respectively. Moreover, the trapping experiments confirmed the Z-scheme approach of the prepared nanocomposites. The efficient separation and transfer of photogenerated electron-hole pairs rendered by the heterostructure were confirmed by utilizing electrochemical impedance spectroscopy, photocurrent experiments, and photoluminescence. Mott–Schottky measurements were used determine the positions of the conduction and valence bands of the samples, and the detailed mechanism of photocatalytic degradation of toxic pollutants was projected and discussed.

Development of a Copper-Based Metal Organic Electrode for Nitrite Sensing.

Nitrite is naturally present in vegetables and added to processed meats to enhance their color and prolong their shelf life. It is of concern because it reacts to form nitrosamines, which have been linked to cancer. To develop a quick, reliable, and inexpensive method for quantifying nitrite in foods. A copper-based metal organic framework (Cu-MOF)/gold-platinum alloy nanoparticle(Au@Pt)-modified glassy carbon electrode (GCE) was developed via a simple wet chemical synthesis followed by electrochemical deposition of gold-platinum alloy nanoparticles onto the surface of a GCE. Morphological characterization and component analysis of the prepared nanomaterials were carried out by Fourier transform infrared spectroscopy and scanning electron microscopy. Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electrochemical behavior of the fabricated electrodes. The quantitative and specific detection of nitrite was obtained by the amperometric i-t method. At a pH of 7, temperature of 25°C, and ionic strength of 0.4 M, the electrode exhibited a linear range of 0.001-12.2 mM nitrite with a low detection limit of 72 nM (S/N = 3). The Cu-MOF/Au@Pt/GCE exhibited good repeatability, reproducibility, stability, and selectivity to provide a capable analysis method for food samples. A Cu-MOF with a large surface area and high porosity was developed to provide an electrode with many active sites. The Au@Pt alloy nanoparticle improved the electrocatalytic activity toward nitrite. The synergistic action between the Cu-MOF and Au@Pt alloy nanoparticle enhanced the electrochemical performance of the sensor.

Highly active novel CeTi2O6/g-C3N5 photocatalyst with extended spectral response towards removal of endocrine disruptor 2, 4-dichlorophenol in aqueous medium

Heterogeneous photocatalysis process is emerging technology for the removal of toxic pollutants, but the photocatalytic responses of the widely studied materials like TiO2 and ZnO are still not good enough under the visible light and NIR region. Herein, we have prepared a highly proficient novel visible light active heterojunction photocatalyst using low bandgap semiconductor carbon nitride (g-C3N5) and cerium titanate (CeTi2O6). The CeTi2O6/g-C3N5 heterojunction with hefty surface area and fabulous visible-light response was achieved by a simple wet chemical synthesis route. The structural and morphological features of the CeTi2O6/g-C3N5 heterojunctions were premeditated by the X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), elemental analysis (EDS), and X-ray photoelectron spectroscopy (XPS) studies respectively. The CeTi2O6/g-C3N5 heterojunction exhibited outstanding photocatalytic response under the visible light towards the degradation of endocrine rupture material 2,4-dichlorophenol (2,4-DCP) than its single components. Radicals trapping experiments confirmed that the superoxide radicals, as well as hydroxide radicals, played the most prominent role in the removal of 2, 4 DCP. This study will offer new insight into the development of novel low bandgap g-C3N5 based stable photocatalyst materials with tunable bandgap for the degradation of hazardous pollutants.

High mobility solution processed MoS2 thin film transistors

A simple wet-chemical synthesis of layered MoS2 thin films on sapphire is reported. The gap in understanding solution processed MoS2 deposition needs to be closed to exploit all its excellent properties for low-cost applications. In this work, as deposited Mo-precursor thin films were prepared based on the solubility and coating properties of Molybdenum(V) chloride in 1-Methoxy-2-propanol. Subsequent annealing of the deposited amorphous Mo-precursor films in the presence of sulfur resulted in the formation of highly crystalline layered MoS2 films on sapphire. Improved crystallinity of the deposited films was achieved by increasing the process temperature and performing the post-annealing treatment. Post-annealing at temperatures above 900 °C increased the uniformity of multilayer films, together with the increase of MoS2 grain size. For charge transport analysis, top-gate top-contact thin film transistors (TFTs) based on these solution processed MoS2 films were fabricated. Ionic liquid gating of the TFT devices exhibited n-type semiconducting behaviour with field-effect mobility as high as 12.07 cm2/Vs and Ion/off ratio ∼ 106. X-ray photoelectron spectroscopy measurements revealed that the films annealed between 900 °C and 980 °C had an average chemical composition of S/Mo ∼ 1.84. This facile liquid phase synthesis method with centimeter-scale uniformity and controllable film thickness up to 1.2 ± 0.65 nm is suitable for low-cost preparation of other transition metal dichalcogenides thin films in next-generation electronics.

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.

Electrodeposition of gold nanoparticles on Cu-based metal-organic framework for the electrochemical detection of nitrite

Herein, an electrochemical sensing platform based on Cu-based metal-organic framework (Cu-MOF) decorated with gold nanoparticles (AuNPs) is constructed for the sensitive detection of nitrite. Cu-MOF was synthesized by a simple wet chemical synthesis at room temperature. AuNPs were electrodeposited on Cu-MOF modified glass carbon electrode (Cu-MOF/GCE) using potentiostatic method. The AuNPs decorated Cu-MOF (Cu-MOF/Au) displays synergetic catalytic effect for the oxidation of nitrite due to the large surface area and porosity of Cu-MOF, which could prevent the aggregation of AuNPs and increase the adsorption of nitrite, combining with the high conductivity and excellent catalytic activity of AuNPs. A nitrite sensing platform was constructed based on Cu-MOF/Au/GCE, and amperometric technique was adopted for quantitative determination of nitrite. The prepared electrochemical sensing platform demonstrates high sensitivity, selectivity and good stability for the detection of nitrite. It shows two wide linear ranges of 0.1–4000 and 4000–10000 μM, and the low detection limit of 82 nM. Moreover, the sensing platform can also be used for the nitrite detection in real samples. This work would broaden the application of MOFs material in constructing more novel electrochemical sensing platforms.

A straightforward route to obtain organic/inorganic hybrid network from bio-waste: Electroless deposition of ZnO nanostructures on eggshell membranes

Bio-waste eggshell membranes (ESM) present a unique micro-architecture consisting in an interwoven fibrous network which can be functionalized with metal oxides resulting in hybrid materials. ESM were covered with ZnO nanostructures by electroless deposition using Au as catalyst. The structural, optical, morphological and wetting properties of the pristine ESM and ESM/ZnO were evaluated. The ESM fibers were uniformly coated by ZnO hexagonal prisms, the hybrid ESM/ZnO preserving the water absorption characteristic of the pristine ESM. Combining an abundant bio-waste with a simple wet chemical synthesis method, flexible organic/inorganic hybrid networks based on ZnO-functionalized ESM can be designed for various applications.

Study of Optical and Magnetic Properties of Graphene-Wrapped ZnO Nanoparticle Hybrids

In this work, we report a one-step method for the preparation of graphene-wrapped zinc oxide (ZnO) nanoparticle (NP) (ZnO@G) hybrids. These hybrids are characterized by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, optical absorption measurements, photoluminescence (PL) emission spectroscopy, and M-H hysteresis measurements. All results reveal that the ZnO NPs are entirely covered with graphene sheets. In the PL spectra, the quenching of the band gap emission and the enhanced green emission serve as evidence of the electron transfer from the ZnO NPs to the graphene layer. The increase of the room-temperature magnetization of the hybrid, compared to pure ZnO NPs, is due to the increasing defect concentration. We suggest a band diagram model that accounts for these observations. We present the simple wet-chemical synthesis procedure to open a new way for the synthesis of NP-graphene hybrid systems having magnetic properties giving the large manifold potential application.

Hierarchical Nickel nanowire synthesis using polysorbate 80 as capping agent

Nanomaterials find applications in multiple fields including food and beverages, waste water management, electrical and electronics due to their interesting properties. These properties can be fine-tuned using various synthesis techniques ranging from solid state route to different wet chemical techniques like precipitation, sol-gel, hydrothermal and solvothermal methods Here, we report a simple wet chemical synthesis of nickel nanoparticles using Tween 80 as the capping agent. Scanning electron microscopy (SEM) revealed a hierarchical nanowire- like morphology with thorn like sharp edges while the presence of nickel in the sample was confirmed by energy dispersive spectroscopy (EDS). X-ray diffraction studies ascertained the crystalline nature of nickel nanowires and also the purity of the as-synthesized nanowires. Transmission electron Microscopy (TEM) and Selected Area Electron Diffraction (SAED) analysis of the sample indicated the existence of a small quantity of nickel hydroxide. The magnetic property of the synthesized nickel samples studied using vibrating sample magnetometer (VSM) revealed a high saturation magnetization of ∼43 emug−1. Antibacterial activity studies confirmed that nickel nanowire exhibited an excellent bactericidal activity against both gram- positive and gram- negative bacteria which could be attributed to the morphology of the nickel nanowires.

Simple wet-chemical synthesis of superparamagnetic CTAB-modified magnetite nanoparticles using as adsorbents for anionic dye Congo red removal

Magnetite (Fe3O4) and Fe3O4 coated with cetyltrimethylammonium bromide (CTAB) were successfully synthesized by simple wet-chemical method. The results show that the products were Fe3O4 nanoparticles. The saturation magnetization and BET method reveal these nanoparticles exhibited superparamagnetic behavior with high surface area. So, it is a very potential application for using as adsorbents for anionic dye Congo red (CR) removal. Its adsorption capacity, calculated by Langmuir isotherm, is 93.46 mg/g. Furthermore, the pseudo-second order model and intra-particle diffusion model (IPD) were also investigated.

High performance hydroxyiron modified montmorillonite nanoclay adsorbent for arsenite removal

In the present study, hydroxyiron-modified montmorillonite (HyFe-MMT) nanoclay was prepared using a simple wet chemical synthesis method. Arsenite (As (III)) removal using raw montmorillonite and HyFe-MMT was compared and evaluated by adsorption experiments conducted under various conditions (adsorbent dosage, iron loading, contact time, pH, and initial As (III) concentration). The nanoclays were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectrometry (FTIR), BET surface area analysis, thermogravimetric analysis, scanning electron (SEM) microscopy, and transmission electron microscopy (TEM). Fast adsorption kinetics were observed in which more than 55% of As (III) was removed using HyFe-MMT within the first 30 s of the adsorption process. The kinetics were most accurately modeled using the pseudo-second-order equation (R2 = 1). Optimum As (III) adsorption was obtained between a pH of 6 to 7. The Freundlich model properly described the adsorption process (R2 > 0.99). It was determined that the adsorption capacity of raw MMT was increased to more than five times after iron modification. The HyFe-MMT adsorbent presented could be used for arsenic contaminated groundwater, drinking water, or wastewater.

Influence of temperature on morphological and optical properties of MoS2 layers as grown based on solution processed precursor

A novel liquid phase synthesis of MoS2 thin films has been achieved. Solubility of Molybdenum(V) chloride in appropriate solvent was optimized while having good coating properties essential for thin film formation. Chemical conversion of the deposited Mo-precursor films on silicon/silicon dioxide substrate to MoS2 were obtained by annealing in presence of sulfur. This novel method allows facile upscaling process to large substrates with uniform film thickness down to 4nm, which are of high interest for future low-cost fabrication of electronic devices. UV–Vis, Raman spectroscopy, and X-ray photoelectron spectroscopy measurements confirm the formation of MoS2 films with a stoichiometric chemical composition of Mo/S ~0.47. Furthermore, X-ray diffraction and Transmission electron microscopy measurements revealed formation of polycrystalline films with random grain orientation attributed to the amorphous SiO2 surface of the substrate. Improved crystallinity of deposited films was achieved by increasing the process temperature. Annealing at temperatures above 750°C increased the uniformity of multilayer films, together with the increase of MoS2 grain size to 100nm. This simple wet-chemical synthesis approach allows upscaling, controllable film thickness and is suitable for preparation of other transition metal dichalcogenides thin films for applications in the future electronics.

A simple wet-chemical synthesis, reaction mechanism, and charge storage application of cobalt oxide electrodes of different morphologies

In the present work, cobalt oxide (Co3O4) electrodes of different morphologies are synthesized onto a stainless-steel (SS) substrate by a simple and cost-effective wet chemical deposition method in presence of different cobalt precursors and then used for energy storage application. Chemical reactions, responsible for different morphologies, are proposed and structural elucidation and morphological evolution studies of Co3O4 electrodes are attempted. Nano-platelets, nano-needles, and nano-grass-type of surface morphologies, corroborated from the scanning electron microscopy and the transmission electron microscopy digital photoimages, for cobalt acetate, cobalt chloride, and cobalt nitrate precursors of Co3O4 electrodes are obtained, respectively. Electrochemical analysis revealed that nano-grass-type Co3O4 electrode exhibits higher specific capacity (SC) (66.40mAhg−1 at 1mAcm−2 current density), excellent cycle life (∼90% after 1000 cycle) and high rate capability (77%) than that of nano-platelets (23.22mAhg−1) and nano-needles (61.22mAhg−1)-type Co3O4 electrodes.

Terephthalic acid capped iron oxide nanoparticles for sensitive electrochemical detection of heavy metal ions in water

This work describes a simple wet chemical synthesis of iron oxide (Fe3O4) nanoparticles (NPs) capped with terephthalic acid (TA) and their application for the individual detection of Hg(II), Pb(II) and Cd(II) ions as well as simultaneous and selective detection of Hg(II), Pb(II) and Cd(II) ions by electrochemical approach. Terephthalic acid capped Fe3O4 NPs were first characterized by cyclic voltammetry (CV) using redox couples Fe(CN)63−/4−, thereafter square wave anodic stripping voltammetry (SWASV) was utilized for the detection of Hg(II), Pb(II) and Cd(II) ions. Optimization of experimental parameters such as deposition time, deposition potential and pH value of the electrolyte towards electrochemical detection of target heavy metal ions was also carried out in SWASV method. Under optimized experimental conditions limit of detection (LOD) values for individual analysis of Hg(II), Pb(II) and Cd(II) ions were found to be 0.1, 0.05μM and 0.01μM respectively, whereas the LOD values for the simultaneous analysis of Hg(II), Pb(II) and Cd(II) ions were found to be 0.3μM, 0.04μM and 0.2μM respectively.