Templating Agent Research Articles

An experimental investigation on the influence of pore foaming agent particle size on cell morphology, hydrophobicity, and acoustic performance of open cell poly (vinylidene fluoride) polymeric foams

Abstract Globally, the development of porous structured materials has been receiving incredible responses for various high-performance engineering applications. Piezoelectric cellular foams have recently attracted the attention of researchers to emerging applications of acoustic sensors, low-frequency hydrophones, and energy-harvesting devices. As pore morphology is closely related to the shape and the size of the pore-foaming agent, it is necessary to address the influence of particle size of the foaming agent on cell morphology to expand their application area. Hence, this research article establishes the impact of particle size of pore foaming agents on pore morphology, hydrophobicity, and acoustic characteristics of open-cell polyvinylidene fluoride (PVDF) based piezoelectric cellular composites. Open-cell PVDF cellular composites have been fabricated using the template removal method with sodium chloride (NaCl) as a sacrificial templating agent in three different particle sizes: larger, medium, and finer. Based on the experimental results, it can be stated that the particle size of the templating agents dramatically influences the pore morphology, hydrophobicity, and acoustics performance of the PVDF foam samples. The PVDF foams possessing medium pore size have exhibited a maximum sound absorption coefficient of 0.89 at a frequency range of 1,000–1,500 Hz, indicating that PVDF foams have great potential for noise-controlling applications.

Synergetic Combination of Carbon Xerogels, Graphene Oxide and nano‐ZnO for Aqueous and Organic Supercapacitors

Three‐dimensional carbon xerogels were synthesised via a facile approach that included the use of ZnO nanostructures both as a templating agent and as a catalyst for resorcinol–formaldehyde resin polymerisation simultaneously. Graphene oxide (GO) served as a stabilising agent during the drying and pyrolysis processes, avoiding the collapse of structure and improving the area surface. The method enabled the asobtained materials to possess optimised 3D porous structures for energy‐storage devices, such as wires or spaghetti‐like structures. Also, a high BET surface area was obtained (1661 m2•g−1) without using an additional activating agent. This great surface area improved the specific capacitance compared to materials without GO (358.1 F•g−1 vs 170.4 F•g−1). The carbon‐containing devices derived from resorcinolformaldehyde resin, GO, and Zn oxide showed better performance than the devices without GO. In particular, the sample that contained 2.5% of GO in the synthesis showed a specific capacitance of 166.6 F•g−1 at 0.5 A•g−1 and remained at ∼120 F•g−1 at 5 A•g−1. Also, it showed interesting energy density values at 0.5 A•g−1 (14.8 Wh•kg−1) and a power density of 200.7 W•kg−1. This reveals that the synthesis process made it possible to obtain composite materials with large surface areas without using a supercritical drying process.

Study on the catalytic performance of Fe in-situ modified small crystallite Silicalite-1 zeolite in Chichibabin condensation reaction

Pyridine and its derivatives, collectively referred to as pyridine bases, are widely used in industries such as pesticides and pharmaceuticals, serving as crucial intermediates in the chemical industry. In recent years, with the development of the pesticide and pharmaceutical industries, the demand for pyridine bases has rapidly increased. The Chichibabin condensation reaction is the most commonly route for industrial production of pyridine bases. Currently, the most used ZSM-5 zeolite catalyst is limited by the instability of its silicon-aluminum framework structure, resulting in a short active reaction cycle (5 h). To address this limitation, this study selected the thermally stable and hydrothermally stable Silicalite-1 zeolite. Polyvinylpyrrolidone (PVP) was employed as a colloidal dispersant and Fe was introduced into the MFI framework through in-situ modification during the hydrothermal synthesis of zeolite. The influence of PVP dosage, template agent dosage, and other crystallization conditions on the crystallinity, pore structure, and acidity of Silicalite-1 zeolite products was investigated using XRD, SEM, TG, and N2 adsorption-desorption measurement. The acidity of Fe-modified Silicalite-1 zeolites was characterized using NH3-TPD, Py-FTIR, FT-IR, and XPS. These results indicated that the introduction of seed crystals effectively reduced the particle size of the zeolite to about 200 nm. Fe-modified Silicalite-1 displayed a disk-like morphology with excellent crystal dispersion. The highest relative crystallinity of the zeolite reached 103% with 15% seed crystal input and 3.75% PVP addition. The Fe-modified Silicalite-1 possessed a significantly enhanced abundance of both Lewis (L) and Brønsted (B) acid sites, resulting in an increase in the initial activity from 66% to 85% for the pyridine bases synthesis through the Chichibabin condensation. Compared to ZSM-5, Fe-modified Silicalite-1 exhibited superior catalytic stability, maintaining the total carbon conversion and pyridine bases yield above 66% and 40%, respectively, over a 15 h reaction period. Furthermore, the strategy proposed in this study, employing polyvinylpyrrolidone as a colloidal stabilizer to modify Silicalite-1 zeolite, could significantly broadened the application prospects of weakly acidic pure silica zeolites in the field of acid catalysis. This approach has demonstrated significant scientific value and industrial potential.

Study on porous carbon materials derived from Chitosan

Abstract The materials with high specific surface area, uniform pore size distribution, and high nitrogen content were prepared by using chitosan as raw material and a low co-soluble mixture (lithium nitrate, potassium nitrate, and potassium sulfate) as a pore-forming agent and salt template agent. The CO2 adsorption capacity of the material was tested at 25°C (2.15 mmol/g) and 0°C (2.88 mmol/g). It was found that more pores and higher nitrogen content were conducive to the adsorption of CO2 by the material.

Synthesis and evaluation of a novel ternary quaternary ammonium salts-fluorescent template copolymer: Integrating flocculation, sterilization, and monitoring functions

Developing flocculants with sterilization and monitoring functions is of practical significance for optimizing water treatment agents. In this research, a fluorescent monomer, EtFl, with double bonds was synthesized and copolymerized with acrylamide (AM) and 3-(methacryloyloxy)propyltrimethylammonium chloride (MAPTAC) using a linear anionic template agent. This synthesis successfully produced a multifunctional template copolymer, TP(AM-MAP-EtFl), with flocculation, sterilization and monitoring capabilities. The fluorescence intensity of TP(AM-MAP-EtFl) was measured using a fluorescence spectrophotometer, demonstrating strong performance even with an EtFl monomer mass fraction as low as 0.5 wt‰, resulting in a fluorescence intensity value of 1000 a.u., suitable for analytical detection. In flocculation experiments with simulated wastewater containing E. coli, the introduction of the fluorescent monomer did not affect E. coli flocculation. When flocculation conditions are optimized, the OD600 readings of the clear liquid remaining after treating with TP(AM-MAP-EtFl#0.5) and TP(AM-MAP-EtFl#5) are 0.0297 and 0.0457, respectively, illustrating superior sterilization effects. Interestingly, SEM and 3D-EEM results confirmed TP(AM-MAP-EtFl)’s bactericidal effect on E. coli, with the introduction of the fluorescent monomer not affecting the sterilization capability of quaternary ammonium. This work integrates flocculation, sterilization and fluorescence properties to provide sterilization-type flocculants with monitoring capabilities, enabling accurate calculation of polymer concentration by detecting solution fluorescence intensity, thereby offering potential for online detection and automatic control of water treatment systems, demonstrating good applicability.

Hydrolysis of carbonyl sulfide using non-ionic surfactant-modified mesoporous γ-Al2O3 catalysts with high efficiency

Carbonyl sulfur (COS) was difficult to be removed by conventional desulfurization technologies because of its stable chemical properties. Mesoporous γ-Al2O3 (MA) showed excellent potential for hydrolysis of COS, but the catalyst life was greatly shortened with the progress of the reaction. Therefore, improving the catalyst life is the key to MA which can apply to hydrolysis of COS. In this study, P123 modified mesoporous γ-Al2O3 (P-MA) catalyst was prepared by sol–gel method, and it was regulated by template agent and acidity regulator. These preparation conditions of P-MA were optimized to improve the hydrolysis efficiency of COS. The effects of temperature, space velocity, relative humidity and oxygen concentration for the hydrolysis efficiency of COS were studied. The results show that the optimized P-MA catalyst is suitable for COS low-temperature hydrolysis reaction, and it can maintain 99 % for 10 h under the tough reaction conditions. The only crystal of P-MA was γ-Al2O3 with large specific surface area and uniform distribution pore, which are beneficial to the COS hydrolysis. In addition, the hydrolysis efficiency of COS can also remain 97 % for 10 h in the O2 and CO2 atmosphere, indicating that the P-MA catalyst has a specific anti-poisoning ability. The kinetics and reaction mechanism of COS catalytic hydrolysis were studied, which showed that the adsorption of H2S was the key to hindering the continuous reaction. The P-MA can effectively inhibit the adsorption of H2S, which greatly improved COS hydrolysis life of P-MA. This study provided a theoretical basis for the application of Al2O3 catalyst in the COS hydrolysis.

Preparation of highly hydrophilic cesium ion sieve and its performance in adsorbing Cs+

The unique properties of cesium compounds have garnered increasing attention, among which Cs2Ti6O13 shows great potential for applications. This paper synthesized Cs2Ti6O13(CTO-3) using a template-assisted solvothermal method with cesium carbonate as the cesium source and tetrabutyl titanate as the titanium source. Among them, F127 and hexadecylamine are used as template agents to modulate the surface morphology and hydrophilicity of the precursor. The cesium ion sieve H2Ti6O13 (HTO-3) synthesized after hydrochloric acid pickling has a large specific surface area and good hydrophilicity. This structure is conducive to the ion exchange between Cs+ and H+, resulting in a fast adsorption rate. It is completed within 2 h, and the adsorption capacity reaches 360 mg/g, which is significantly greater than that of the traditional high-temperature solid-phase method. The adsorption process of Cs+ on HTO-3 is more consistent with the pseudo-second-order kinetic equation model, and the adsorption process is chemical adsorption. HTO-3 exhibited good selectivity and cycle stability. At the fifth time of the adsorption-resolution cycle, the adsorption capacity was 87.1 % of the first time.

Fluorine and sulfur atoms induced N-doped 3D porous carbon catalyzing oxygen reduction in the zinc-air battery

Introducing other heteroatom is considered to be a highly effective approach to improve the limited catalytic activity from single nitrogen element doping in nitrogen-doped porous carbon materials. In this work, F and S-modified nitrogen-doped porous carbon (F-S-N-C) is prepared by annealing the assembly material of poly3-fluoro aniline, hydroxyethyl sulfonic acid and g-C3N4, in which the g-C3N4 is employed as template agent and pore-forming agent. A series of characterization techniques indicate that simultaneous doping of F and the S atoms enhance the electron transfer and construct more defects for N-doped 3D porous carbon, resulting in improved electrocatalytic performance. The prepared F and S-cooperated nitrogen-doped porous carbon (F-S-N-C) exhibits significantly improved oxygen reduction reaction electrocatalytic activity in alkaline media with a half-wave potential of 0.808 V. The zinc-air battery (ZAB) with F-S-N-C as the air cathode catalyst demonstrates a peak power density of 167 mW cm−2, which is higher than that of commercial Pt/C (158 mW cm−2). Moreover, the specific capacity of the F-S-N-C-based ZAB reaches to 817 mAh·g−1.

Macroporous Structures of Nb-SnO2 Particles as a Catalyst Support Induce High Porosity and Performance in Polymer Electrolyte Fuel Cell Catalyst Layers.

Macroporous niobium-doped tin oxide (NTO) is introduced as a robust alternative to conventional carbon-based catalyst supports to improve the durability and performance of polymer electrolyte fuel cells (PEFCs). Metal oxides like NTO are more stable than carbon under PEFC operational conditions, but they can compromise gas diffusion and water management because of their denser structures. To address this tradeoff, we synthesized macroporous NTO particles using a flame-assisted spray-drying technique employing poly(methyl methacrylate) as a templating agent. X-ray diffraction analysis and scanning electron microscopy confirmed the preservation of crystallinity and revealed a macroporous morphology with larger pore volumes and diameters than those in flame-made NTO nanoparticles, as revealed by mercury porosimetry. The macroporous NTO particles exhibited enhanced maximum current density and reduced gas diffusion resistance relative to commercial carbon supports. Our findings establish a foundation for integrating macroporous NTO structures into PEFCs to optimize durability and performance.

Programmable Assembly of Semiconductor Mesostructures Via Inorganic Phototropism

Plants exhibit a phototropic response and direct the addition of new biomass to optimize collection of solar insolation. Analogous inorganic phototropism growth enables the programmable assembly of complex 3D nanoarchitectures with instruction by an incoherent, unstructured, mW cm-2 intensity light beam. Inorganic phototropism has been demonstrated via the light-mediated electrochemical assembly of semiconductor deposits from solution-phase precursor ions. No structured light field (no photomask), no lithographic processes and no templating agents (ligands, surfactants, etc.) are utilized. Nevertheless, ordered nanoscale features are conformally assembled over full macroscale (cm2) areas with feature heights on the order of several um with growth times < 5 min. In-plane anisotropy is a function of the input polarization. Isotropic morphologies consisting of ordered arrays of nanoscale holes were generated using unpolarized illumination whereas linearly polarized light resulted in anisotropic lamellar structures with in-plane orientations set by the polarization direction. The structure pitch was dependent on the spectral distribution of the input light with shorter wavelengths effecting higher feature densities. The out-of-plane growth direction is related to the propagation direction of the input light. Time-varying optical inputs enable programming of 3D intricacy by evolving the in-plane structure along the out-of-plane dimension, e.g. an abrupt reduction in the input wavelength results in a concomitant increase in the interfacial density resulting in tuning fork structures. Additional morphological control has also been effected by using multiple simultaneous illumination inputs. Modeling of the growth using a combination of full-wave electromagnetic simulations of light absorption and scattering coupled with Monte Carlo simulations of mass addition successfully reproduced the experimentally observed morphologies and indicated that assembly was directed by evolution of the growth front to maximize anisotropic light collection. The assembly was observed to be a highly emergent phenomenon involving optical communication between neighboring features including cooperative scattering and synergistic absorption.

Molybdenum oxide catalyzed low temperature preparation of mullite whisker from silica-alumina gel slag

Catalyzed by MoO3, mullite whiskers were synthesized through a molten salt method. This study comprehensively explored the impact of reaction temperature, MoO3 mass fraction, and calcination temperature on the morphology of mullite whiskers. Employing analytical techniques such as XRD and SEM, the phase composition and morphology of the samples were meticulously scrutinized. The results unveiled that at a MoO3 mass fraction of 7–8% (molar fraction) and a calcination temperature of 800 °C, mullite whiskers demonstrated a heightened level of purity. Building on these observations, the study delved into the mechanistic underpinnings of MoO3 as a catalyst in mullite whisker synthesis. It is proved that the metal oxides contained in the silica-alumina glue slag can also form a local liquid phase at low temperatures, reducing the viscosity of the reaction system and liquefaction temperature. The addition of molybdenum oxide makes the reaction process of mullite whisker growth shorter. At the same time, the addition of molybdenum oxide can effectively reduce the viscosity of the reaction system, thus lowering the reaction temperature and increasing the reaction efficiency. In addition molybdenum oxide can be used as a templating agent to induce the growth of mullite whiskers along specific crystal planes. Compared with aluminum fluoride catalysis, molybdenum oxide does not produce the hazardous gas HF, the sublimated molybdenum oxide gas can be recycled, and the molybdenum oxide attached to the whiskers can also be dissolved in water. These theories provide experience in the large-scale preparation of mullite whiskers.

Temperature-Sensitive Template for Preparation of ZnO/CeO2 Composite Photocatalytic Materials and Its Catalytic Performance.

In this work, a series of thermosensitive ionic liquid functionalized polymers, PNx(IL)y, with controllable morphology and particle size were prepared by free radical polymerization. Then, using the polymer PN64(IL)8 with uniform morphology as a templating agent, the ZnO composite photocatalytic materials doped with rare earth metal Ce were prepared in combination with a microwave-assisted and templated hydrothermal reaction method. Series different Ce-doping amount photocatalytic materials ZnO-Ce-x‱ were characterized by XRD, SEM, TEM, XPS, and other methods. The results demonstrated that the templated materials PN64(IL)8 can prepare ZnO-Ce-2‱ with uniform petaloid ambulacra shape, good distribution of elements, and excellent photocatalytic performance. Photocatalytic degradation experiments of methyl orange (MO) showed that when the Ce-doping amount is only 2‱, the degradation rate of organic dyes can reach 96.5% by reacting the photocatalytic materials in water for 1 h. In addition, this kind of photocatalyst can be used for the degradation of high-concentration MO, as well as being easily recovered and effectively reused by simple filtration. Therefore, the structure of this kind of photocatalyst is controllable in the preparation process with an extremely low Ce-doping amount compared with current reports, and it has a good application prospect in the field of wastewater treatment technology.

Development of a Molecularly Imprinted Polymer for Determination of Atenolol Based on Selective Solid Phase Extraction and Application in Pharmaceutical Samples

This paper demonstrates the synthesis and storage of molecular-imprinted polymers (MIP) at room temperature using bulk polymerization of atenolol (Ate), which is characterized by high sensitivity, low costs, and high stability. The research used 0.99:6:20 mmol ratios of template, monomer, and cross-linking agents for the polymerization in order to ensure an appropriate adsorption capacity. By making MIP for atenolol as Ate-MIP, which could be looked at with a UV-VIS spectrophotometer at 276 nm, Fourier- transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM), a functional monomer of allyl chloride with cross-linking ethylene glycol dimethyl acrylate was made. Mass spectrometric (MS) detection may use allyl chloride to determine atenolol levels in pharmaceutical preparations. The GC/MS methods developed in this study are accurate, sensitive, and precise and can be easily applied to (NOVATEN/India and ATENOIOI/U.K.) tablets in pharmaceutical preparation. The elution process was applied to the template (Ate) from the Ate-MIP, which developed cavities, caused by using porogenic solutions of methanol, chloroform, and acetic acid (70:20:10, respectively). The maximum adsorption capacity of Ate-MIP was 2.9957 µmol/g, and the ratio of template to monomer was 1:1 in adherence to the Langmuir isotherm model. A solid-phase extraction (SPE) syringe packed with molecular imprinted polymers (MIPs) was used to selectively separate and pre-concentrate Ate from aqueous solutions and estimations of atenolol.

Catalytic cracking of oleic acid to generate aviation kerosene using platinum–modified ZSM–5 nanosheets

AbstractBACKGROUNDA series of Pt@NZSM–5 and Pt/NZSM–5 nanosheets having different Si/Al ratios were prepared via an in situ synthesis and impregnation method, respectively, using C22H45–N+(CH3)2–C6H12–N+(CH3)2–C6H13 (C22–6–6) as the template agent. The oleic acid decarboxylation reaction was carried out using these materials under CO2 atmosphere and the oleic acid cracking mechanism was inferred from the product distribution of the C8‐C17 alkanes.RESULTSThe Pt@NZSM–5 and Pt/NZSM–5 was found to comprise thinner nanosheets and exhibited strong metal–substrate interactions. Pt@NZSM–5 nanosheets with a Si/Al molar ratio of 100 had thicknesses of only 8–9 nm along with a mesopore/micropore capacity ratio of 2.7, an acid content of 11 cm3/g STP and a high Pt0/PtOx ratio.CONCLUSIONThe Pt@NZSM‐5 and Pt/NZSM‐5 nanosheets had an interconnected hierarchical system and a large number of metal active sites that facilitated the decarboxylation of oleic acid. The Pt@NZSM–5 nanosheets demonstrated excellent catalytic activity during the cracking of oleic acid under a CO2 atmosphere, giving a yield of C8–C17 alkanes as high as 83.8% after 5 h at 320 °C. These Pt@NZSM–5 nanosheets also showed greater stability than the Pt/NZSM–5 specimens. © 2024 Society of Chemical Industry (SCI).

Enhancing Stability of SAPO-37 Molecular Sieve through Aluminum Phosphate Utilization: Synthesis, Stability Mechanism, and Catalytic Performance.

SAPO-37 molecular sieve, characterized by its three-dimensional 12-membered-ring FAU structure, has drawn wide attention due to its unique properties and catalytic potential. However, its susceptibility to framework collapse under low-temperature and humid conditions hinders practical applications, affecting both the reaction performance and sample storage. To tackle this, we utilized aluminum phosphate as a precursor for synthesizing SAPO-37, aiming to modify Si incorporation mechanisms and improve P and Al environments. Solid NMR spectroscopy combined with other techniques proves that the resulting SAPO-37-AP has enriched silicon islands, leading to reduced water adsorption, more reversible structural change, and significantly enhanced stability after low-temperature vapor treatment compared to conventional SAPO-37. Remarkably, SAPO-37-AP, after water vapor treatment, still exhibits superior performance in the liquid-phase Beckmann rearrangement reaction. This approach enhances stability, reduces templating agent amounts, and improves the solid product yield, offering promising practical applications.

Two-Step Hydrothermal Synthesis of Submicrometric and Hierarchical Hollow SAPO-34 with Superior Catalytic Performance in Methanol to Olefin (MTO) Reaction.

A submicrometric and hierarchical hollow SAPO-34 molecular sieve was synthesized by an easy and low-cost two-step hydrothermal method. First, the crystallized mixture was obtained by direct drying after a first-step hydrothermal reaction. Then, the SAPO-34 product was obtained by adding the crystallized mixture to silicon-free gel and using cheap and common template agents. Compared to conventional SAPO-34, the submicrometric and hierarchical hollow SAPO-34 exhibits superior catalytic activity in the MTO reaction.

الاستخلاص الانتقائي للكليميبيرايد في المستحضرات الصيدلانية وفي مصل الانسان عن طريق تقنية MIP-SPE المركبة

This paper demonstrates that the synthesizing and storage of molecular-imprinted polymers (MIP) at room temperature using bulk polymerisation of Glimepiride (Glim.) is characterized by high sensitivity, reduced costs, increased stability, and extended life. The research used 1:15:20 mmol ratios of template, monomer and cross-linking agents for the polymerisation in order to ensure an appropriate adsorption capacity. Benzoyl peroxide BPO was employed as the initiator for the functional monomer Allyl chloride C3H5Cl , cross-linked with Ethylene glycol dimethacrylate EGDMA C10H14O4, thereby creating MIP for Glimepiride (Glim-MIP) that could be characterised with UV-Visible Spectrophotometry at 274.5nm, for pharmaceutical drugs. Fourier-transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) was used for the human serum. The elution process that was applied to the template (Glim.) from the Glim-MIP created cavities that were caused by the porogenic mixture solvents that were created from (acetic acid, methanol) 1:9 respectively, successfully removed by repeated washing for 20 hours, the polymer was dried at room temperature. The maximum adsorption capacity was 11.7797 µmol/g using (0.1) g weight of Glim-MIP. which adhered to the Langmuir isotherm model. A solid-phase extraction (SPE) syringe packed with molecular imprinted polymers (MIPs) was employed to selectively separate and pre-concentrate the Glimepiride in multiple pharmaceutical drugs from several sources. The human serum was based on the use of deionized water to dilute the serum, followed by heating of the serum with methanol. Subsequently, few drops of 1N hydrochloric acid were applied to detect Glimepiride at UV region 274.5 nm by applying the standard addition method.

تخليق وتحديد الطور الصلب البوليمري المطبوع بايون الكالسيوم في السيرم وتطبيقها في عينات سيرم

This study was aimed to synthesis new molecular imprinted polymers from different monomers which useful for determination of calcium ion in different serum samples. Calcium ion play an important role in blood clotting and bone mineralization. In plasma, 40 percent of circulating calcium is bound to proteins, 10 percent is in the form of inorganic complexes, and 50 percent is present as free (ionized) calcium. In this study, Blood samples were taken from patients with type 2 diabetes from Kadhimiya Hospital in order to determine the concentration of calcium ions in the blood, enter it into the column, and then calculate the final concentration in order to know the amount of dose taken by the patient. To acquire the highest adsorption capacity, molar ratios of the template, monomer, and cross-linking agent, as well as solvents and multiple monomers were investigated. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyze the calcium ion polymer. The elution of calcium has a small effect on the surfaces of the three-dimensional network structure. Calcium (II) ions were successfully eluted using a mixture of methanol and acetic acid. The calcium absorption capacities were7.989 µmol/g and 8.250 µmol/g (Qmax), respectively. Solid-phase extraction (SPE) syringes packed with ionic imprinted polymers (IIPs) were used to selectively separate and preconcentration the calcium (II) ion from serum to determine the calcium ion by flame atomic absorption spectroscopy (FAAS). Through the results obtained and compared to the atomic absorption device, which is considered the most accurate and sensitive device for the elements, there is no difference in the results, and because the atomic absorption device test is expensive and needs electricity all the time, we can use the molecular printing technique to separate, assign, and concentrate the elements.

Environmental analysis of nitrobenzene using newly synthesized anisotropic gold nanostructures: Reaction kinetics and electrocatalytic activity

In this article, we established to produce anisotropic, colloidally stable gold nanostructures (AuNS) by rapidly mixing aqueous solutions of gold(III) chloride trihydrate (HAuCl4) and citric acid (CA) as dual reducing and capping agents at room temperature without the aid of a templating agent. Furthermore, the impact of various anions and shape-directing agents on the morphology and reaction kinetics of citric acid-capped gold nanostructures (CA-AuNS) was investigated. Additionally, the electrocatalytic activity of AuNS towards nitrobenzene (NB) was examined using a CA-AuNS modified glassy carbon (GC) electrode. The rate of reaction for the formation of CA-AuNS increased rapidly with higher concentrations of CA, indicating a strong dependence on the reductant’s concentration. This process followed first-order kinetics, suggesting that the reaction rate is directly proportional to the citric acid concentration. Consequently, optimizing CA levels can effectively control the synthesis rate and yield of CA-AuNS. The presence of nitrite ions led to rapid aggregation of gold nanostructures (AuNS) and a quick reaction time. Chloride ions increased the size of the AuNS. As bromide ion concentration increased, the reaction time slowed significantly, resulting in spherical gold nanoparticles. Both acetate ions and polyvinylpyrrolidone (PVP) inhibited the growth of AuNS. High-resolution transmission electron microscopy (HR-TEM) images showed the formation of various shapes, including spherical, hexagonal, pentagonal, and boat-like structures. In the presence of cetyltrimethylammonium bromide (CTAB), both complex formation between CTAB and HAuCl4 and the formation of spherical gold nanoparticles occurred. Upon addition of silver nitrate (AgNO3) to the colloidal solution, the color shifted to pale violet, and the morphology transitioned from anisotropic to irregular. However, when ascorbic acid (AA) was utilized, it proved ideal for maintaining the morphology of gold nanostructures (AuNS). The analysis of X-ray diffraction spectroscopy (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Fourier transform infrared spectroscopy (FT-IR) further confirmed the synthesized CA-AuNS. The FT-IR spectra of CA before and after the formation of AuNS indicated the participation of carboxylic acid (–COOH) and hydroxyl (–OH) groups in the reduction process of Au3+ metal ions. The GC/CA-AuNS electrode exhibits a larger electroactive surface area due to the coating of AuNS onto the electrode surface, enhancing the electrode’s electrical conductivity by providing additional active sites for electron transfer. In addition, the electrocatalytic activity of NB was investigated in this study. The GC/CA-AuNS electrode had better electrocatalytic activity than the unmodified GC electrode. As a result, with a LOD of 28.2 nM (S/N = 3), this electrode was chosen for sensitive NB determination.

Enhanced visible light photocatalytic activity of SDBS/C/Nd/TiO2 synthesized by using anionic surfactant SDBS as template agent

&lt;p&gt;The catalyst SDBS/C/Nd/TiO2 was synthesized by sol-gel method using TiO2 co-doped with C and Nd and anionic surfactant SDBS as template agent. The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron (SEM), X-ray photoelectron spectrometer (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and so on. Experimental results show that the crystal structure of the catalytic material is anatase type. Since doped elements change the energy band structure and electronic structure of TiO2, photogenerated electrons and holes can transition through the intermediate energy level, resulting in a decrease in the required excitation energy, thereby increasing the distance of its absorption edge moving toward the long wave direction, and meanwhile improving the utilization rate of visible light. The bandgap energy of the catalyst SDBS/C/Nd/TiO2 was 2.78 eV. Compared to pure TiO2 (3.1 eV), the band gap is reduced by 0.32eV. The photocatalytic experiments show that the degradation rate of the catalyst SDBS/C/Nd/TiO2 for methyl orange solution can reach 67%, and the catalytic performance is much improved than that of pure TiO2.&lt;/p&gt;