Morphology Of Nanorods Research Articles

Z-scheme S-modified Zn0.2Cd0.8S/α-Fe2O3 heterostructure for enhanced photoelectrochemical water oxidation

A Z-type heterojunction system is proven to be an efficient strategy to promote the separation of photo-generated carriers and maintain strong redox capacity for an enhanced photoanode. Herein, we synthesized a S-modified Fe2O3/Zn0.2Cd0.8S (Fe/ZCS) photoanode by one-pot hydrothermal treatment of FeOOH/Zn0.2Cd0.8S precursor film, followed by vapor deposition treatment. The as-synthesized S-modified Fe/ZCS displayed enhanced PEC water oxidation performance with a photocurrent density (2.76 mA cm−2) of about 2.63 times that of a pure phase Fe2O3 and 2.05 times that of Fe/ZCS at 1.23 VRHE. After 8 h of continuous operation, the photocurrent density retention rate was still 96.4 % demonstrating its satisfactory stability. Benefiting from the morphology of fine nanorods, the fabricated Z-scheme heterostructure exhibited strong oxidation–reduction ability and the well-distributed Fe(III)-SO42- bonds played key roles as the electron capture centers. The fabricated Z-scheme photoanode exhibited prospective applications in sustainable photoelectrochemical water oxidation.

Role of solvent on morphology and photoluminescence property of ZnO nano rods synthesized by hydrothermal method

Zinc oxide nano rods are synthesized by hydrothermal method. X ray diffraction studies confirm that the synthesized ZnO exhibited hexagonal wurtzite structure. The crystallite size is found to be 35 nm and 29 nm for the sample prepared from water-ethanol solvent mixture and water respectively. Transmission electron microscopic (TEM) images confirms that ZnO samples prepared from water solvent are nano rods, whereas samples prepared from ethanol-water mixture are agglomerated. Photoluminescence (PL) emission of the ZnO nano particles prepared from water solvent with peaks at 414 nm, 442 nm and broad emission at 555 nm. The sample prepared from ethanol-water mixture solvent exhibit broad emission at 500 nm.

Synthesis and Electrochemical Properties of One‐Dimensional γ‐MnOOH Nanorods

AbstractMnOOH has received much attention from researchers as a supercapacitor electrode material. In this article, one‐dimensional γ‐MnOOH nanorods were prepared by the hydrothermal method using the redox reaction between MnO4− and Mn2+, and the effects of temperatures on the crystalline phases and electrochemical properties of the samples were investigated. The materials were characterized using XRD, FT‐IR, SEM, TEM, Raman and XPS; electrochemical properties were tested using CV, GCD and EIS. The results show that the reaction temperature plays an important role in the generation of γ‐MnOOH. The samples were pure phases of γ‐MnOOH (M‐140) at the reaction temperature of 140 °C, showing interlaced nanorod morphology, and when the reaction temperature was increased to 180 °C, a mixed phase of MnOOH and Mn3O4 appeared. In contrast, the electrochemical performance of γ‐MnOOH nanorods (M‐140) was superior to the other samples, reaching a specific capacitance of 221 F/g at a current density of 0.2 A/g. The capacitance retention was 93.8 % after charging and discharging the M‐140 2000 times at a current density of 6 A/g. Supercapacitors assembled with γ‐MnOOHand activated carbon (AC) have excellent energy storage performance, and a high energy density of 40.6 Wh/kg is obtained at a power density of 196.7 W/kg.

Nano-ZnO prepared by using chaya and mango leaves extract for photocatalyst of methylene blue

This research aimed to synthesize nano-ZnO from chaya (Cnidoscolus aconitifolius) and mango leaves extract (Mangifera indica) as environmentally friendly photocatalysts. Nano-ZnO was synthesized using green synthesis, with leaves extracts as reducing agents and nanoparticle size stabilizers. The samples were prepared using two methods, namely nano-ZnO-1 and nano-ZnO-2. The results of Fourier transform infrared spectroscopy (FTIR) analysis showed the contribution of metabolite compounds in nano-ZnO synthesis. X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed the crystal size in nano range, with spherical nanorod morphology observed. Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) determined the band gap energy of 2.97 eV and 3.17 eV. Furthermore, photocatalytic activity test showed that photocatalyst performance after 90 min was 68.86% (nano-ZnO-1) and 96.46% (nano-ZnO-2).

Interaction Studies of PVP and CTAB Capped CuO Nanorods with Aldicarb and Chlorpyrifos

Copper oxide uncapped nanorods (UC-CuO), capped with cetyltrimethylammonium bromide (CTAB-CuO), and polyvinyl pyrrolidine (PVP-CuO) were utilized for interaction study of Aldicarb (A.D.) and Chlorpyrifos (C.P.) pesticides. Electron microscopy (FE-SEM & TEM) studies confirmed the nanocrystalline structure and nanorod morphology of UC-CuO, CTAB-CuO, and PVP-CuO. The contact angle study showed the hydrophilic nature of the UC-CuO and PVP-CuO with contact angle of 51° and 57°, respectively. While CTAB-CuO exhibited hydrophobic nature with a contact angle of more than 90°. Interaction study of UC-CuO, CTAB-CuO, and PVP-CuO with A.D. and C.P was conducted using UV–vis absorption study (in the 250–400 nm region). UC-CuO showed the specific detection with A.D., while CTAB-CuO have shown with C.P. without using any bio-recognition elements. PVP-CuO did not show systematic change with both pesticides confirming the capping agent-dependent specific interaction of the pesticides.

Surface immobilization mechanisms of cobalt ions on hydroxyapatite catalyst supports

Cobalt deposition in an excess of solution was used to design Co-modified hydroxyapatite materials with various Co loadings and controlled dispersion. It is rationalized how the properties of hydroxyapatite supports (more or less stoichiometric compositions, nanorod or platelet morphologies and crystalline (100) zig-zag termination or non-apatitic hydrated external layer), influence the immobilization processes of Co by operating either with slightly acidic (natural) or basic pH of the suspension media. Four cobalt immobilization mechanisms impacting the final dispersion of Co on hydroxyapatites were identified by combining structural (XRD, 1H and 31P solid-state NMR, UV-Vis, Raman and X-ray fluorescence spectroscopies), surface (XPS) characterizations of Co-modified hydroxyapatites after drying and thermal treatment at 500 °C, and monitoring of the pH and the composition of the supernatant solutions during the Co deposition step. On dried Co-modified crystalline stoichiometric hydroxyapatite nanorods, cobalt is highly dispersed through cationic exchange or strong electrostatic adsorption (SEA) at slightly acidic or basic pH, respectively. After thermal treatment at 500 °C, only cation exchange preserved atomic dispersion of Co(II) ions since Co3O4 nanoparticles were observed on samples for which Co deposition occurred via SEA. On defective hydroxyapatite platelets, cobalt deposited at acidic natural pH could diffuse in an external non-apatitic layer, whereas under basic pH media, this surface layer was hydrolysed, resulting in the formation of a cobalt-substituted hydroxyapatite layer in which only a limited fraction of the surface cobalt species could be probed by XPS.

Investigational Study of Risk-Free Metal Oxide-Based Nanostructures for Identifying Urea in Dairy Products

Zinc oxide-based urea sensor was constructed over fluorine-doped tin oxide substrate using facile hydrothermal approach. X-ray diffraction and field emission scanning electron microscope were used to investigate the structural and morphological properties of the synthesized zinc oxide nanostructures, demonstrating the production of ZnO hexagonal Wurtzite structure (002 peak plane) and nanorod morphology, respectively. Cyclic voltammetry was performed on the constructed urea sensor at three different concentrations (0.1, 0.2, and 0.3 mmol). The experiment yielded an average sensitivity of 0.1053 AmM−1cm−2.

Preparation and investigation of Montmorillonite-K10 Polyaniline nanocomposites for optoelectronic applications

One-dimensional polyaniline (PANI) nanostructures were synthesized in situ in the presence of two-dimensional (2D) Montmorillonite (MMT) clay nanosheets. Strong interactions between the polymer and MMT platelets in the nanocomposites were confirmed through spectroscopic studies. X-ray diffraction and scanning electron microscopic studies revealed the clay's profound effect on the polymer's crystallinity and morphology. The clay nanosheets induced higher crystallinity and well-defined nanorod morphology in the polymer structure. Consequently, the nanocomposite showed an electrical conductivity of 8.72 S/cm, closer to that of the pristine polymer (8.97 S/cm), despite the presence of highly insulting clay material. Surprisingly, a notable decrease in the optical bandgap of the polymer from 3.73 to 2.88 eV of the nanocomposite was also observed. This novel integration of a narrow band gap and high conductivity in PANI/MMT nanocomposites can expand their utility for visible light interactions in areas encompassing photocatalysis, photovoltaics, electro/photochromism, and related technologies.

Visible-light‑sensitive AgCu nanocomposites for sustainable inactivation of virus

The coronavirus disease 2019 (COVID-19) caused a large number of deaths and serious economic losses. Safety precautions and effective measures are urgently demanded to control the virus spread in public places. Owing to the longevity of the viruses in the aerosols and surfaces, sustained nanomaterials with efficient antiviral abilities during both daytime and night appear to be a promising way to control virus spread. Here, AgCu nanocomposites, which are outstanding antibacterial and antiviral elements, including Ag2Cu2O3 and AgCuO2, have been successfully prepared via a simple co-precipitation method for inactivation of model Qbeta (Qβ) bacteriophage. Notably, Ag2Cu2O3 has uniform nanorods morphology with a width of 50–100 nm and a length of 200–500 nm, regular elemental states of Cu2+ and Ag+, and good visible light response. Instead, AgCuO2 has more complex elemental states of Cu2+, Ag+, and Ag3+, including morphology with large particles of 500–1000 nm surrounded by small nanorods and nanoplates. Density functional theory (DFT) calculations showed that Ag2Cu2O3 has a lower work function than AgCuO2, indicating the charges can be better released from the surface. The accumulated surface charge can bind to the virus to inactivate it. As a result, Ag2Cu2O3 shows outstanding antiviral properties with a 6-log reduction (99.9999 %) of Qβ phage after 45 min contact under dark condition, and the activity can be further promoted to 7.5-log inactivation of Qβ phage after the same time contact under visible light irradiation, revealing its potential to sustainably prevent viruses spread in indoor environments.

High pressure induced formation of carbon nanorods from tetracosane

Morphology control of carbon structures is essential for improving their performance in many applications. Direct pyrolysis of organic precursors, however, usually yields bulk amorphous carbon. Therefore, traditional methods for controlling the morphology of carbon structures involve multistep processes and complex precursor molecules. While various methods have been developed under ambient pressure, the impact of pressure on the morphology of the resulting carbon structures remains unexplored. Herein, we present the synthesis of carbon nanorods by direct pyrolysis of the low-cost aliphatic hydrocarbon tetracosane under high pressure conditions. The diameters of the carbon nanorods are adjusted by simply varying the synthetic pressures. High pressure allows controlling both the nanorod morphology as well as the degree of order, and local conductivity of the thus prepared nanorods has been confirmed by conductive atomic force microscopy measurements. Our method promises a convenient strategy to synthesize carbon structures with controlled morphology and high ordered chemical structure, which opens opportunities for potential electronic and electrochemical applications.

Novel copper vanadium oxide/g-C3N4 nano-composites for optoelectronic and biosensing properties

This study investigates into the synthesis, characterization, and multifaceted analysis of a composite material comprised of copper vanadium oxide (CVO) and graphitic Carbon Nitride g-C3N4 (GCN). The fabrication of the composite was achieved through wet-chemical method followed by annealing at 600 °C for 3 h, ensuring controlled composition and structure. The characterization process encompassed X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–visible spectroscopy, unveiling the composite's crystalline structure, novel nano-rod morphology with decorated flakes, and UV–visible light activation capability. The obtained band gap of approximately 2.7 eV signified the composite's optical properties. Electrochemical analysis, including cyclic voltammetry (CV), highlighted the composite's robust biosensing attributes, particularly in response to ascorbic acid. The conducting and metallic characteristics of the composite enhanced its reactivity, promising applications in biosensors and energy storage devices. This comprehensive investigation elucidates the multifaceted potential of the CVO/GCN nano-composite across diverse optoelectronic realms.

Fabrication of MoO3/rGO/Au composite for increased photocatalytic degradation of methylene blue

Water line purification and wastewater treatment have become challenging in the fast-growing industry, infrastructure, textile, manufacturing world, etc. with this challenge, photocatalysis has gained substantial attention as an environmentally friendly process on which researchers are working aggressively and, in this progress, two-dimensional (2D) are in focus because of their good photocatalytic ability. Therefore, in this study, we present the synthesis of one such ternary composite material comprising molybdenum trioxide nanorods (MoO3NR), reduced graphene oxide (rGO) and gold nanoparticles (AuNR), with a specific focus on its enhanced photocatalytic performance. The ternary composite is prepared via a combination of in situ hydrothermal and laser ablation methods allowing for precise control over the growth and integration of the constituent materials. The structural and morphological properties of the MoO3 nanorods, rGO and Au ternary material were systematically characterized using various techniques, including UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The obtained results suggest the successful formation of a composite, revealing the presence of uniformly dispersed MoO3 nanorods on the rGO sheets and evenly distributed Au nanoparticles throughout the structure. Photocatalysis evaluations conducted to assess the material performance under visible light irradiation exhibited significantly enhanced methylene blue degradation efficiency of 85.91% in 90[Formula: see text]min in comparison with individual MoO3 nanorods and rGO counterparts. The improved efficiency can be attributed to the combined effects arising from the integration of MoO3 nanorods, rGO and Au nanoparticles, which facilitate efficient light absorption, charge separation and catalytic reactions, which in turn reduces electron–hole recombination and improve photocatalytic performance. Also, the tunable morphology and collective effects of MoO3 nanorods, rGO and Au offer new avenues for designing highly efficient and stable photocatalytic materials.

Stacked Covalent Organic Ribbons Perpendicular to Graphene Oxide Sheets; a 1D-p-2D Design for Photocatalytic Tandem Reactions.

Development of one dimensional covalent organic frameworks (1D-COFs) with potential in light absorption and catalysis is still challenging, due to their rapid interpenetration to form 2D and 3D porous structures. Here we report a successful synthesis of imine-linked 1D covalent organic ribbons (COR), using two simple linear building blocks 1,4-Benzenediamine (Bda) and [2,2'-Bipyridine]-5,5'-dicarbaldehyde (Bpy). The obtained 1D structure with nanorod morphology could keep its physicochemical characteristic properties when it is perpendicular to the surface of graphene oxide (GO) sheets (1D-p-2D structure). Due to an AB π- π stacking and efficient charge transfer between perpendicular 1D COR and GO sheets, the obtained nanocomposite showed strong visible light absorbance (400-700 nm) with coefficient of 4.400 M-1 cm-1 and decreased recombination rate of photogenerated reactive species by 92 %. The strategy of 1D-p-2D light driven system greatly enhanced the photocatalytic activity in practical applications such as both oxidation and hydrogenation tandem reactions to a rate constant of higher than 0.02 min-1 . This study presents the first case of 1D covalent organic polymers grown perpendicularly on a carbon-based layer for boosting electron mobility through the junction between the two components.

Sn doping role in structural modifications and electrochemical performance of Co(OH)2 nanorods for supercapacitors applications

Herein, pristine and Sn–Co(OH)2 nanorods are prepared via hydrothermal method and pseudocapacitive properties are evaluated. The synthesized nanostructures are characterized by various sophisticated techniques including x-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET) analysis, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The SEM analysis discloses the structural modification of Co(OH)2 from nanoparticles to nanorods. Additionally, the presence of Sn in Co(OH)2 significantly influence the electrochemical active surface area which enhances the electrochemical properties as measured through cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS). The SnCo-4 sample indicates high surface area (93.1 m2/g), superior performance with specific capacitance of 1441.8 F/g at 1 A/g and remarkable stability of 84.3 % retention after 5000 GCD cycles. The pseudocapacitive nature (b = 0.799) is observed to increases with scan rate (i.e. 59.1 % at 75 mV/s). This higher performance is mainly due to greater charge transportation and conductivity associated with nanorod morphology and Sn ion. These parameters disclosed that the prepared samples have great potential to be used against energy crisis.

Why Ceria Nanoparticles Obtained from Ce-MOFs Exhibit Higher Catalytic Efficient in Soot Combustion? Understanding the Role of Intrinsic Properties of a Cerium-Organic Framework to Produce CeO2

Metal-organic framework (MOF) derivatives, such as porous metal oxides with controlled morphology have received great attention for applications in various fields. In this paper, the experimental results show that porous CeO2 with high specific surface area (90.5 m2 g-1) and nanorod morphology can be obtained by calcining a Ce-MOF template at optimized temperature (300-500 °C). The formation mechanism of this porous structure as well as the influence of the calcination temperature are well explained by taking into account thermal behavior and intrinsic structural features of the Ce-MOF precursor. We employed the oxides formed as heterogeneous catalysts to reduce the soot originating from the incomplete combustion of diesel or diesel/biodiesel blends. The CeO2 materials exhibit outstanding catalytic activity, lowering the temperature of soot combustion from 610 to 370 °C. Compared with similar work, our catalyst exhibits enhanced soot oxidation activity, making it highly promising for diesel particulate filter applications. Such outstanding catalytic performance of the porous CeO2 nanorods benefits from their large specific surface area, and morphological and structural characteristics.

Cobalt-Free Oxide Cathode Material with Phase Composition Control to High Electrochemical Performance in Li-Ion Batteries

Cobalt-free layered oxide cathode material (LiMn0.5Ni0.5O2) was obtained via a two-step synthesis method. Firstly, hydrothermal synthesis of MnOOH with nanorod morphology was achieved and then a co-precipitation process to obtain the LiMn0.5Ni0.5O2 active layered material was performed. Structural and morphological characterization revealed a promising disordered layered structure obtained at 800 °C with improved electrochemical performance. The thermal treatment performed on the active materials resulted in a controlled balance between the monoclinic and rhombohedral phase leading to good phases formation ratio in a cobalt-free layer cathode. It was found that the controlled mixing of structural phases plays an important role in improving the electrochemical performance of the active cathodic layer material, resulting in an adequate balance between high discharge capacity and electrochemical stability during the charge/discharge cycling. The morphological analysis showed two kinds of particles that played a crucial role in the structural stability and electrochemical performance. The active material thermally treated at 800 °C displayed outstanding discharge capacity of 235.05 mAh g−1 at 20 mA g−1 in CCCV (Current Constant-Constant Voltage) mode. While, in CC (Current Constant) mode showed the highest discharge capacity, of 178.95 mAh g−1 at 20 mA g−1 and good capacity retention (87.2% after 100 cycles).

2D organic nanosheets of self-assembled guanidinium derivative for efficient single sodium-ion conduction: rationalizing morphology editing and ion conduction.

The resurgence of interest in sodium-ion batteries (SIBs) is largely driven by their natural abundance and favourable cost, apart from their comparable electrochemical performance when compared with lithium-ion batteries (LIBs). The uneven geographic distribution of the raw materials required for LIBs has also contributed to this. The solid-state electrolyte (SSE) is typically one of the vital components for energy storage in SIBs and for achieving high electrochemical performances. SSEs are preferred over liquid electrolytes primarily due to their enhanced safety and stability, apart from the option of achieving higher energy density. A single sodium-ion selective conductor minimises dendrite formation and cell polarisation, among many other benefits over binary ionic conductors in battery operation. Here, we demonstrate the first example of a sulfonated supramolecular organic two-dimensional (2D) nanosheet as a novel class of single sodium-ion conductors prepared from the self-assembly of a functionalised guanidinium ion (AD-1). Solvent-assisted exfoliation of the bulk powder in water yielded nanosheet morphology, whereas nanotube morphology was achieved in isopropanol (IPA). In contrast, self-assembly with systematic water/IPA solvent ratio variations produced marigold, sunflower, and nanorod morphologies. Thermodynamic parameters, crystallinity, elemental composition, and varying natures of hydrogen bonding in five distinct morphologies were determined using microscopic and spectroscopic studies. The single Na+ conducting properties of each morphology are correlated in terms of morphology, crystallinity, and the solvent used to achieve that specific morphology. Importantly, with high crystallinity and directional ion channels, 2D nanosheet morphology exhibits the highest single Na+-ion conductivity of 3.72 × 10-4 S cm-1 with an activation energy of 0.28 eV, showing a moderately high Na+-ion transference number of 0.83 at room temperature without incorporating any additional sodium salts and organic solvents. This report is believed to be the first to show the significance of nanostructure morphologies in achieving high single-Na+-ion transport.

Potentiality of zinc phosphate@hydroxyapatite/β-cyclodextrin composites for carrying cisplatin: loading, release and cytotoxicity

A zinc phosphate/hydroxyapatite composite (ZP/HAP) with a core–shell nano-rod morphology and its functionalized derivative with β-cyclodextrin (β-CD) were evaluated as potential carriers of the cisplatin drug (CPN).

Efficient glycolysis of used PET bottles into a high-quality valuable monomer using a shape-engineered MnOx nanocatalyst

The nanorod morphology of the MnOx material with the application of optimal calcination temperature exhibited good catalytic efficiency in the chemical recycling of PET bottles into a valuable monomer.

Halloysite nanotubes decorated with Co(OH)F nanorods as a novel binary composite for the enhanced electrocatalytic water oxidation

Oxygen evolution reaction is central to several emerging electrochemical energy conversion and storage technologies. This study reports the synthesis, characterization, and OER electrocatalytic performance of binary nanocomposites composed of halloysite nanotubes (HNTs) and Co(OH)F. Five Co(OH)F/HNT with different compositions were fabricated by a facile hydrothermal synthesis. The crystalline phase and microstructure of the as-prepared materials were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The synthesized Co(OH)F (pristine or mixed with HNTs in the nanocomposites) revealed an orthorhombic crystal system with a nanorod morphology. The nanocomposite with ∼19 wt% of Co (designated as Co(OH)F/HNT_3) was found to possess an appreciably improved activity in OER compared to the pristine HNTs, Co(OH)F, and other Co(OH)F/HNT nanocomposites. Co(OH)F/HNT_3 displayed an overpotential of 252 mV (at the current density of 10 mA cm−2), a Tafel slope of 51.1 mV dec−1, and a robust operational performance under harsh alkaline conditions. Furthermore, nitrogen adsorption–desorption isotherms indicated a much higher specific surface area for this nanocomposite than its components. Overall, the versatile synthesis and outstanding catalytic performance of Co(OH)F/HNT_3 make it an auspicious earth-abundant transition metal-based electrocatalyst for OER in an alkaline medium.