CTAB-assisted Synthesis Research Articles

The formation mechanism of MnZn ferrite by the CTAB-assisted synthesis

The formation mechanism of MnZn ferrite by the CTAB-assisted synthesis

Interfacial engineering in SnO2-embedded graphene anode materials for high performance lithium-ion batteries

Tin dioxide is regarded as an alternative anode material rather than graphite due to its high theoretical specific capacity. Modification with carbon is a typical strategy to mitigate the volume expansion effect of SnO2 during the charge process. Strengthening the interface bonding is crucial for improving the electrochemical performance of SnO2/C composites. Here, SnO2-embedded reduced graphene oxide (rGO) composite with a low graphene content of approximately 5 wt.% was in situ synthesized via a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. The structural integrity of the SnO2/rGO composite is significantly improved by optimizing the Sn–O–C electronic structure with CTAB, resulting a reversible capacity of 598 mAh g−1 after 200 cycles at a current density of 1 A g−1. CTAB-assisted synthesis enhances the rate performance and cyclic stability of tin dioxide/graphene composites, and boosts their application as the anode materials for the next-generation lithium-ion batteries.

CTAB-assisted synthesis of reduced graphene oxide supported Pd nanoparticles (Pd@rGO) as a sustainable heterogeneous catalyst for C-2 arylation of indoles with arylboronic acids

A series of Pd nanoparticles (NPs) incorporated in reduced graphene oxide (rGO), viz. Pd@rGO0.16, Pd@rGO0.32, Pd@rGO0.48, and Pd@rGO1 were synthesized employing water as a solvent. The subscript values correspond to the millimoles of cetyltrimethylammonium bromide (CTAB) utilized in the synthesis process. The quantity of CTAB was varied to finely tune both the morphology and size of the resulting nanoclusters. Transmission Electron Microscopy (TEM) analysis indicated that the average particle sizes of Pd@rGO0.16 and Pd@rGO0.32 fall in the range of 4.5–5.0 nm and 20–25 nm, respectively. On the other hand, particles were found to be agglomerated in Pd@rGO0.48 and Pd@rGO1. The Pd@rGO0.16 composite was exhaustively characterized by TEM, Scanning Electron Microcopy-Energy Dispersive X-ray analysis (SEM-EDX), powder X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements. ICP-AES analysis of Pd@rGO0.16 indicated that 0.01 g of Pd@rGO0.16 contains 0.09 mol% Pd. The catalytic potentiality of these NPs was investigated for direct C(sp[1])-H bond activation of various indoles with aryl boronic acids. Among the four composites, Pd@rGO0.16 exhibited the best activity for the abovementioned organic transformation. Different indoles with diverse electronic groups underwent coupling with aryl boronic acids giving up to 86 % product yield. It was retrievable for up to five consecutive catalytic cycles without compromising its catalytic activity.

CTAB-Assisted Synthesis of FeNi Alloy Nanoparticles: Effective and Stable Electrocatalysts for Urea Oxidation Reactions.

Development of highly efficient electrocatalysts for treating urea-rich wastewater is an important problem in environmental management and energy production. In this work, an iron-nickel alloy (Fe-Ni alloy) was synthesized via soft-template cetyltrimethylammonium bromide (CTAB)-assisted precipitation using low-temperature calcination. The as-synthesized nanoalloy was characterized by X-ray diffraction (XRD), which revealed the formation of a face-centered cubic (FCC) structure of the Fe-Ni alloy; field emission-scanning electron microscopic (FE-SEM) analysis revealed the spherical shape of the Fe-Ni alloy; high-resolution transmission electron microscopy (HR-TEM) revealed the average size to be ∼33.09 nm; and X-ray photoelectron spectroscopy (XPS) showed the presence of Fe, Ni, C, and O components and their chemical composition and valence states in the Fe-Ni alloy. The electrochemical urea oxidation reaction (UOR) was investigated by conducting linear sweep voltammetry (LSV) tests on the synthesized electrocatalysts with different Ni/Fe ratios in alkaline electrolytes with urea. The potential required to reach a current density of 10 mA cm-2 is 1.27 V vs RHE, which demonstrates the higher electrochemical activity of the Fe-Ni alloy compared to other individual compounds. This could be due to CTAB which improved the structural stability and synergetic and electronic effects in the nanoscale. This study will further contribute to renewable energy generation technology with long-term energy sustainability and also opens up great potential for reducing water pollution.

Surfactant-Assisted synthesis of α-and β-Ag2WO4 modified with Sulphur, Phosphorous, and boron and their applications in wastewater elimination

The surfactant cetyltrimethylammonium bromide (CTAB) was utilized to synthesize a combination of α and β-Ag2WO4 phases, which were accordingly doped with 20 % nonmetallic moieties including phosphorous (p), boron (B), and sulphur (S) via a mild precipitation route. Through characterization tools, information was obtained on surface and elemental concentration distribution, vibration, optical, morphological, and electronic properties. These materials were used as nanoadsorbents and photocatalysts. The S doped Ag2WO4 adsorbent (SAgW) has the best removal results (98.7 %) and it follows the Freundlich model of adsorption isotherm. The kinetics of dye adsorption follow the pseudo-second-order kinetic model. It was shown to achieve removal percentages of 98.6 % for indigo carmine dye (IC) and 98.8 % for methyl red dye (MR), demonstrating that the presence of other dyes has no effect on the removal percentage. AgW (CTAB-assisted synthesis) demonstrated high photocatalytic oxidation of IC at 20 mg/L in only 40 min with first-order kinetics of 0.12 min−1, exceeding that of PAgW by 6 times.

CTAB-assisted synthesis of porous cuboid NiCo2O4 powders for high-performance supercapacitor

NiCo2O4 powders with columnar-, rod-, porous cuboid-, and octahedral-like morphologies were prepared by hydrothermally treatment of oxalate precipitates in the presence of various amounts of cetyltrimethylammonium bromide (CTAB) surfactant. The structural, microstructural, and electrochemical properties of NiCo2O4 powders were characterized by X-ray diffractometry, scanning electron microscopy, cyclic voltammetry, and galvanostatic charge/discharge techniques. Because of agglomeration of NiCo2O4 nanoparticles, the specific surface areas decreased from 36.3 to 14 m2 g−1 with CTAB content. The porous cuboid-like NiCo2O4 powders showed the highest specific capacitance of 1353 F g−1 at 1 A g−1, decreasing to 1021 F g−1 at 10 A g−1. The analyzed contribution of various storage mechanisms showed that a mixture of capacitive and diffusion-controlled processes was necessary for obtaining the highest specific capacitance. The porous cuboid-like NiCo2O4 powders//activated carbon hybrid capacitor showed the comparable performance of electrochemical energy storage, including energy density of 23.3 Wh kg−1 at power density of 1398 W kg−1.

Ppb-Level 2-Butanone Gas Sensor Based on CTAB-Assisted Synthesis of Small-Size ZnSnO Nano Cube

The cubic Zn2SnO4 with different sizes is synthesized by adjusting the concentration of surfactant cetyltrimethyl ammonium bromide (CTAB) in the hydrothermal process. The structure, morphology, and specific surface area of Zn2SnO4 nanoparticles are characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and so on. By adding surfactant in the synthesis process, the Zn2SnO4 material is changed into a regular cubic structure from an irregular shape. When the concentration of surfactant is further adjusted, the size of the cubic structure first decreased and then increased. The test results show that the response of the Zn2SnO4 sensor prepared with 0.5-mmol CTAB to 100-ppm 2-butanone reaches 80 at the optimal working temperature of 300 °C. Under the same test conditions, its response is 2.34, 2.58, and 4.79 times that of ZTO-0, ZTO-0.1, and ZTO-1, respectively. Compared with the ZTO-0 sensor, the response time is scaled back from 33 to 6 s, and the detection limit is cut down to 100 ppb. The exceedingly superior gas sensitivity is caused by the regular morphology and small size effect of the powder materials.

CTAB-assisted synthesis of Bi2MoO6 hierarchical microsphere and its application as a novel efficient and recyclable adsorbent in removing organic pollutants

Herein we have synthesized Bi2MoO6 (BMO) hierarchical microspheres via a solvothermal method using hexadecyl trimethyl ammonium bromide (CTAB) as surfactant, and demonstrated that the synthesized BMO can be used as an efficient and recyclable adsorbent for removing organic pollutants. By using methylene blue (MB) as the target pollutant, the adsorption kinetics, adsorption isotherms and adsorption thermodynamics of MB onto the BMO adsorbent were systematically investigated. The effects of pH, temperature and adsorbent dosage on the MB adsorption by BMO were predicted by response surface methodology (RSM) with Box-Behnken design (BBD). It is interestingly demonstrated that the BMO adsorbent can be easily regenerated via a simple calcination process in air and exhibits excellent reusability. To promote the practical application of the BMO adsorbent in water purification, we have further compared its adsorption capability in removing 18 kinds of organic pollutants (including various organic dyes, antibiotics and other serious organic pollutants) at different acidic-alkaline environments. In the normal and alkaline (pH 12) environments, the highest adsorption is observed for Congo red (CR) with qe = 216.331 and 232.723 mg g−1, respectively; whereas in the acidic environment (pH 2), the highest adsorption is observed for eriochrome black T (EBT) with qe = 64.362 mg g−1. Based on the experimental results, the involved adsorption mechanism was analyzed.

Corrigendum: CTAB-Assisted Synthesis of C@Na3V2(PO4)2F3 With Optimized Morphology for Application as Cathode Material for Na-Ion Batteries

C@Na3V2(PO4)2F3 samples were obtained by using Cetyl Trimethyl Ammonium Bromide (CTAB) as a surfactant. The optimization of the added amount allowed controlling the eventual nanometric morphology of the particles. The morphological and structural properties of these samples were discussed in the light of solid-state techniques as X-ray diffraction, Raman and XPS spectroscopies, and electron microscopy. Galvanostatic test in sodium half-cells revealed that the nanometric spherical and porous particles provided by the addition of intermediate amounts of CTAB showed excellent cycling stability and superior high rate capability reflected in the minimization of the cell polarization and the determination of a high apparent diffusion coefficient.

CTAB-Assisted Synthesis of C@Na3V2(PO4)2F3 With Optimized Morphology for Application as Cathode Material for Na-Ion Batteries

C@Na3V2(PO4)2F3 samples were obtained by using Cetyl Trimethyl Ammonium Bromide (CTAB) as a surfactant. The optimization of the added amount allowed controlling the eventual nanometric morphology of the particles. The morphological and structural properties of these samples were discussed in the light of solid-state techniques as X-ray diffraction, Raman and XPS spectroscopies, and electron microscopy. Galvanostatic test in sodium half-cells revealed that the nanometric spherical and porous particles provided by the addition of intermediate amounts of CTAB showed excellent cycling stability and superior high rate capability reflected in the minimization of the cell polarization and the determination of a high apparent diffusion coefficient.

Solid-state CTAB-assisted synthesis of mesoporous Fe3O4 and Au@Fe3O4 by mechanochemistry

Mesoporous iron oxides have shown excellent performance in many research areas such as catalysts, biosensors, enzyme immobilization, heavy metal adsorption, and drug delivery. The state-of-the-art synthesis methods are mostly wet chemistry processes. This paper reports a solvent-free approach for the rapid synthesis of mesoporous Fe3O4 (specific surface area up to 170 m2/g) and Au@Fe3O4 (highly dispersed Au nanoparticles, average particle size: ∼4 nm). With different amounts of added template agent, cetyltrimethylammonium bromide (CTAB), the pore structure could easily be adjusted. More importantly, the mesoporous Fe3O4 exhibited good catalytic activity in carbon monoxide (CO) oxidation, outperforming commercially purchased Fe3O4 with 100% CO conversion at around 274 °C vs. 490 °C for the commercial product.

CTAB-Assisted Synthesis of N-Doped Fe3C Nanowires and Their Magnetic Properties

N-doped iron carbide (N-doped Fe3C) nanomaterials have a wide range of applications. In this study, a hexadecyltrimethylammonium bromide (CTAB)-assisted two-step process was used to prepare N-doped Fe3C nanomaterials. The effect of CTAB addition on the phase, structure, and morphologies of the products has been investigated in detail based on the characterization results of X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectra (Raman), N2 adsorption–desorption, and elemental analysis. By tuning the amount of CTAB, N-doped Fe3C nanowires were prepared. The magnetic hysteresis loops at room temperature of the N-doped Fe3C nanomaterials show ferromagnetic characteristics.

CTAB-assisted synthesis of ZnCo2O4 nanoparticles embedded in N-doped carbon as superior anode materials for lithium-ion battery

One of the most effective methods to reduce the volume expansion of metal oxides is by designing nanosized metal oxides and forming composites with carbon materials. In this work, we report a simple method for constructing quasi-spherical ZnCo2O4 nanoparticles using a cetyltrimethylammonium bromide (CTAB) assisted sol-gel autocombustion method, followed by coating with an N-doped carbon layer to form a core-shell structure. When evaluated as anode material for Lithium ion battery, the novel core-shell structure electrode delivers a high capacity of 1146.6 mAh g−1 at a current density of 500 mA g−1 after 100 cycles. The electrode also demonstrates a high cycle stability with a good capacity of 811.3 mAh g−1 for 200 cycles at a current density of 2 A g−1. This performance is due to the carbon coating layer, which improves the electrical conductivity, relieves the volume expansion and mitigates the agglomeration of the ZnCo2O4 nanoparticles. Furthermore, the coating also ensures that a stable SEI layer forms at the outer surface of the robust carbon.

Facile room temperature CTAB-assisted synthesis of mesoporous nano-cobalt ferrites for enhanced magnetic behaviour

We report a facile, room temperature synthesis of nanostructured mesoporous cobalt ferrites using the cationic surfactant, cetyltrimethylammonium bromide (CTAB). The synthesis was carried out at various concentrations of CTAB ranging from its pre- to post-micellar concentrations. The pristine and calcined samples exhibit pure cobalt ferrite phase which are confirmed by XRD studies. The morphology of all uncalcined samples was quasi-spherical as shown by TEM images. Nitrogen adsorption – desorption study on pristine samples indicates the presence of mesopores in them. The magnetic properties of the uncalcined and calcined samples were studied by vibrating sample magnetometry. Coercivity and saturation magnetization were found to vary with the concentration of the CTAB employed. Also, the pristine samples were soft magnets, whereas the calcined samples tended towards exhibiting hard magnetism. We have proposed a mechanism to explain the mesoporosity of nanostructured ferrite based the role of CTAB in the present synthetic method.

CTAB-assisted synthesis of eight-horn-shaped Cu2O crystals via a simple solution approach

A novel type of eight-horn-shaped Cu2O microstructures with a high degree of symmetry in structure was prepared via a simple solution route. The copper(II) chloride dehydrate was reduced by glucose as an environmental friendly reductant in the presence of cetyltrimethylammonium bromide (CTAB) surfactant. The size of these Cu2O crystals is about 4 µm, and the total 24 edges of eight horns are truncated. The obtained Cu2O was characterized by XRD, SEM, and HRTEM techniques, and the results showed that the formation of such eight-horn-shaped Cu2O microstructures was strongly depended on the addition of CTAB. This work might provide a low-cost and naturally abundant microstructured material for use in electronic devices and catalysis.

CTAB-assisted synthesis of 3D Sn doped ZnO nanostructures with enhanced acetone sensing performance

The flowerlike Sn doped ZnO nanostructures were synthesized by a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal process at low temperature (150°C). The morphology and structure of sample were characterized by XRD, EDS, XPS, SEM and TEM analysis. The results indicate that the sample is well crystallized wurtzite hexagonal phase of ZnO, and preferentially grows up along [0001] direction. The possible formation mechanism of flowerlike ZnO nanostructures is proposed. Moreover, the sensor based on flowerlike ZnO nanostructures exhibits enhanced sensing performances to acetone at 300°C. The response is up to 600 when the sensor is exposed to 100ppm acetone. The response and recovery times are about 24 and 8s, respectively. These results demonstrate that the Sn doped ZnO nanoflowers can be used as the sensing materials for fabricating high performance acetone sensor.

CTAB-assisted synthesis of unique 3D ZnO and the acetone sensing performances

Flower-like ZnO nanostructure composed of orderly nanoplates was synthesized by a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. The unique ZnO nanostructure was characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy analysis. The possible formation mechanism of flower-like ZnO nanostructure is proposed. The positively charged CTA+ surfactant can act as an ionic carrier, as well as an agglomeration inhibitor in the orientation growth of ZnO nanoplates. Moreover, the gas sensing properties for acetone were also investigated. The sensor shows high response and good selectivity to acetone gas at the optimum operating temperature of 300°C. The excellent gas sensing performances of the flower-like ZnO indicate that ZnO sensor synthesized by the CTAB-assisted hydrothermal method can be used as a promising sensing material for fabricating acetone sensors.

CTAB-assisted synthesis of S@rGO composite with enhanced photocatalytic activity and photostability

S@rGO(reduced graphene oxide) composites were synthesized by a facile electrostatic attraction in the presence of cetyltriethylammnonium bromide (CTAB). Scanning electron microscopy images show that sulfur particles were wrapped by a thin layer of rGO. The rGO nanocoating enhanced the absorption of visible light, facilitated the separation of photogenerated charges, promoted the adsorption of dye moleculars, and provided the perfect chemical protection to inner sulfur particles. As a result, the rGO nanocoating improved the photocatalytic activity and photostability of the sulfur photocatalyst for the degradation of methylene blue under simulated solar light irradiation. Our results might open up a promising way to develop stable and highly efficient sulfur-based photocatalyst.

Improved low temperature NH3-SCR performance of FeMnTiO(x) mixed oxide with CTAB-assisted synthesis.

FeMnTiOx mixed oxide is prepared by the CTAB-assisted co-precipitation method, and the transformation of anatase into rutile is inhibited by CTAB to some extent. The catalyst obtained in the present work shows nearly 100% NO conversion at 100-350 °C, more than 80% N2 selectivity at 75-200 °C, and excellent H2O durability for the selective catalytic reduction of NO by NH3 with a space velocity of 30,000 mL g(-1) h(-1).

CTAB-assisted synthesis of mesoporous CoFe2O4 with high carbon monoxide oxidation activity

Mesoporous CoFe2O4 nanomaterials were successfully synthesized via the cetyltrimethylammonium bromide (CTAB)-assisted method at normal pressure. The structure and morphology of the as-prepared CoFe2O4 samples were characterized by XRD, TG-DTA, FT-IR, TEM and N2-sorption analysis. XRD studies indicated that the as-prepared product was well-crystallized spinel cobalt ferrite. The TEM image showed that the obtained CoFe2O4 sample consisted of nanoparticles with the size about 15nm. N2-sorption analysis indicated that the mesoporous CoFe2O4 possesses a wormhole-like mesoporous structure with a narrow pore size distribution and high surface area (94.3m2/g). The catalytic property of the as-prepared CoFe2O4 for low-temperature CO oxidation was evaluated by using a microreactor-GC system, and the result shows that it is very active for CO total oxidation at 140°C.