Chemical Oxidative Method Research Articles

Fabrication of a Janus Copper Mesh by SiO2 Spraying for Unidirectional Water Transportation and Oil/Water Separation.

Massive discharge of oily wastewater and frequent occurrence of offshore oil spills have posed an enormous threat to the socioeconomic and ecological environments. Janus membranes with asymmetric wettability properties have great potential for oil/water separation applications and have attracted widespread attention. However, existing Janus membranes still suffer from complex and costly manufacturing processes, low permeability, and poor recyclability. Herein, a novel and facile strategy was proposed to fabricate a Janus copper mesh with opposite wettability for unidirectional water transport and efficient oil/water separation. The hydrophilic side of the Janus copper mesh was prepared by coating it with Cu(OH)2 nanoneedles via a chemical oxidation method. The hydrophobic side was fabricated by coating it with hydrophobic SiO2 nanoparticles via a facile spraying method. The as-prepared Janus copper mesh showed asymmetric surface wettability, which can achieve unidirectional water transport and efficient oil/water separation with excellent recyclability, exhibiting great application potential for droplet manipulation and wastewater purification.

Sources and Treatment Methods of Excessive Manganese Ion in Groundwater in A Certain Area

Trace element manganese is an essential element for human body, but the high concentration of manganese will adversely affect human health and all aspects of daily production and life. Elevated levels of manganese directly affect the color of the water, making it more prone to discoloration when used to wash clothes or dishes. Prolonged exposure to this water may cause organ damage. The groundwater in the study area is sampled and tested, and the test data is analyzed. The main results are as follows: the groundwater manganese ions in the study area exceed the standard, and the concentration of manganese ions in the southwest mountainous area is higher than that in other areas. In southwest China, due to the planting of a large number of tea trees, the main source of manganese in groundwater is manganese-containing fertilizer, and sewage recovery and treatment should be considered in combination with slope rainwater recovery equipment. In other fields, the manganese in groundwater is mainly from domestic sewage. The combined treatment of manganese ions in groundwater by chemical method and contact oxidation method is considered.

An improved method for isotopic and quantitative analysis of dissolved organic carbon in natural water samples.

A wet chemical oxidation (WCO) method has been widely used to obtain the dissolved organic carbon (DOC) content and carbon isotope (δ13CDOC) ratios. However, it is sometimes difficult to get high precision results because not enough CO2 was oxidized from the natural water samples with low DOC concentrations. This improvement primarily aims to increase the water sample volume, improve the removal rate of dissolved inorganic carbon (DIC), and minimize the blank DOC from the standard solution. Following the improved procedure, the δ13C ratios of standardized DOC solutions were consistent with their actual values, and their differences were less than 0.2‰. The improved method demonstrated good accuracy and stability when applied to natural water samples with DOC concentrations ≥0.5 mg L-1, with the precisions of DOC concentrations and δ13C ratios were better than 0.07 mg L-1 and 0.1‰, respectively. More importantly, this method saved much pre-treatment time and realized batch processing of water samples to obtain their DOC contents and isotope ratios.

Synthesis and electrical properties of Reused-Graphite/Polyaniline composites

Polyaniline graphite composites have been synthesized using chemical oxidative polymerization method. The graphite powder has been reused which is obtained by used batteries. XRD patterns of graphite show (002) peak and no impurity peaks. Different wt. % (5, 10, 15, 20) of graphite is used for synthesis of composites and studied their electrical conductivity. XRD patterns of composites show increasing intensity with an increasing graphite content. SEM images show plate-like morphology of graphite whereas granular-morphology for PANI. Composite samples show both plate-like morphology and granular morphology indicating that graphite is embedded in the polymer matrix. Electrical characteristics of composite samples have shown a systematic increase in conductivity with an increase in the graphite concentration. Conductive fillers within the polymer matrix can increase the overall conductivity. Higher filler content provides more conductive pathways for electrons, resulting in enhanced conductivity. The detailed studies of these results are discussed and presented in this paper.

Wetability and dielectric property of DL-PLA/CLOISITE 20A/PANI nanocomposite

DL-PLA/CLOISITE 20A nanocomposite is fabricated by solution casting method. , DL-PLA/CLOISITE 20A/PANI Nanocomposite is also synthesized by chemical-oxidation method. Characterization of that nanocomposite is made using XRD, FTIR, UV Visible. TGA studies a wettability studies and dielectric analysis of prepared materials. Results reveal enhancement of thermal stability and crystallinity of the nanocomposite. Further, nanocomposite shows that it is hydrophilic in nature. Frequency dependent ac-conductivity and dielectric loss are estimated for the nanocomposite. Dielectric loss is observed to possess low value (0.2). Fabricated DL-PLA/Cloisite 20A may serve as insulating layers to suppress dielectric loss effectively.

Current Advances in the Enzyme Engineering of O2‐Dependent Enzymes – Boosting the Versatility and Applicability of Oxygenases and Oxidases

AbstractOxidation reactions catalysed by O2‐dependent enzymes are gaining increasing interest in the chemical industry due to their potential to provide a more selective and sustainable alternative to conventional chemical oxidation methods. O2‐dependent enzymes, like oxidases and oxygenases, catalyse a versatile range of oxidative reactions using only molecular oxygen as an oxidant. However, their practical application on a larger scale has been limited up to this point, primarily due to factors like their low catalytic rates combined with a narrow substrate spectrum and low stability. Nonetheless, enzyme engineering studies have significantly addressed these challenges in recent years and moved O2‐dependent enzymes closer towards industrial utilisation. This review aims to concisely overview the most recent engineering approaches to O2‐dependent enzymes. We will highlight recent studies that have targeted various aspects of O2‐dependent enzymes, including activity, selectivity, stability, and substrate spectrum, focusing on engineering studies where the engineered enzymes catalysed synthetically valuable reactions.

Optimised and percolated nanocomposite of polyaniline/tungstic anhydride modified electrode implemented in Vanadium redox flow battery

In order to make vanadium redox flow batteries (VRFB) economically viable on a large scale, it is crucial to create graphite-based electrode nanomaterials with an excellent performance. In this research work, we synthesized the various percentage nanocomposites of polyaniline (PANI)/nano-tungsten oxide (NTO) by in situ chemical oxidative polymerization method. The impact of crystal phases, elements present in nanocomposites, thermal stability, surface analysis, and morphological factors were studied. We investigated electrochemical behavior such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel studies for PANI and NTO and prepared nanocomposites (NPATO) with different proportions sprayed over graphite felt (GF). Characterization analysis was used to examine the impact of various NTO loading concentrations on the PANI, and an ideal best percolated sample NPATO20/GF (3 mg cm−2) was inserted as a positive electrode in the cell stack to examine the charge–discharge cycles. At 60 mA cm−2 current density, their coulombic (η C), voltaic (η V), and energy (η E) efficiencies are outstanding. The concentration of 3 mg cm−2 nanoparticles on GF provided sufficient availability of active sites for electrochemical reactions, resulting in an increased electrochemical reaction. It has been proven that this work creates an affordable and efficient method for the forthcoming VRFBs.

Adsorptive capacity of PANI/Bi2O3 composite through isotherm and kinetics studies on alizarin red

Adsorption offers numerous advantages for eliminating organic pollutants such as dyes, making it a valuable method for water treatment. Polyaniline/Bi2O3 (PANI/Bi2O3) nanocomposite is synthesized from aniline by the chemical oxidative polymerization method. The sample shows a high positive surface charge density as seen from zeta potential analysis. X-ray Diffraction analysis, FTIR analysis, UV–vis spectroscopy technique, thermogravimetric analysis, BET N2 Adsorption-desorption analysis, DLS, and zeta potential analysis are the tools employed to characterize the PANI/Bi2O3 nanocomposite. The impact of PANI/Bi2O3 on the outcome of adsorption is confirmed by comparing the composite with pristine Bi2O3 and PANI. The effect of various factors like time, temperature, initial dye concentration, and varying pH on the adsorption efficiency is studied. A maximum adsorption efficiency of 95 % is observed when 100 mg of PANI/Bi2O3 nanocomposite is utilized for a duration of 100 min. The adsorption efficiency increases at higher temperatures, and a maximum adsorption efficiency is observed at a pH of 11.4. The adsorption isotherms proposed by Freundlich and Langmuir are examined to confirm the adsorption mechanism, which entails the creation of a single layer of dye molecules on the adsorbent's surface. Analysis of kinetic parameters indicates that the reaction follows pseudo-second-order adsorption kinetics. The composite produced demonstrates effectiveness as an adsorbent for removing harmful organic pollutants from water sources.

Sulfate-functionalized ternary metal oxide/Polypyrrole nanocomposites: Synergistic enhancement in Photocatalytic, Corrosion inhibition, Magnetic, and Electrical properties

The effect of functionalization of conducting polymer/metal nanocomposites with sulfate functional groups on their physical, chemical, mechanical, optical, and electrical properties was investigated. Vanadium, Manganese, and Zinc oxide nanoparticles were prepared by the modified Sol-gel method. Conducting polymer, Polypyrrole was synthesized by the chemical oxidation method. Polypyrrole + ternary metal oxide nanocomposites were synthesized by in situ technique. The characterization of functionalized nanocomposites was carried by Raman spectroscopy, FTIR, UV–visible, magnetic, SEM, and XRD techniques. The photocatalytic, anticorrosive, magnetic, optical, and electrical properties of functionalized nanocomposites were investigated. The functionalized nanocomposites show 85 % corrosion inhibition efficiency. The functionalized nanocomposites degrade 87 % of the methyl blue dye in 120 min under UV light. The magnetic study shows the paramagnetic character of functionalized nanocomposites. The optical band gap of functionalized nanocomposites decreases to 0.5 eV, showing a high order of conductivity. The sulfate-functionalized ternary metal oxide/polypyrrole nanocomposites show synergistic enhancement in their photocatalytic, electrical, magnetic, and anticorrosive properties.

Investigation of polypyrrole/TiO2 and poypyrrole/WO3 nanocomposites as anode modifier in salt bridge microbial fuel cell using municipal wastewater

Developing nanocomposite materials based on conducting polymers (CPs) and metal-oxide nanoparticles, which combine redox electrochemistry of CPs with intrinsic properties of nano-scale semiconducting materials, may offer improved microbial fuel cells (MFCs) performances. Polypyrrole (PPY) based nanocomposites were synthesized by chemical oxidative polymerization method and were further used as an anode modifier in salt bridge MFCs. The PPY-based nanocomposites were characterized by X-ray diffraction, Fourier-Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM). The maximum power density of 16.7 mW/m2, 20.1 mW/m2, and 22.5 mW/m2 were obtained for MFC2-PPY, MFC3-PPY/TiO2 and MFC4-PPY/WO3 respectively, suggesting that modification of the anode with PPY- based nanocomposites is beneficial in the electricity generation of the MFC, and have superior performance as compared to the controller MFC1-CC (11.6 mW/m2).

Tailoring polypyrrole film characteristics with multi-step oxygen plasma treatment for high-performance strain sensors: Impact on bonding, microstructure, and electrical responsivity

We investigate the impact of oxygen plasma treatment (O2 PT) on the performance of polypyrrole (PPy)/polydimethylsiloxane strain sensors. Utilizing a three-step chemical oxidative polymerization method for PPy growth, we explore various durations of O2 PT (0, 30, 60, and 90 s) during intermediate growth stages. Through analyses using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, we elucidate the relationship between O2 PT, structural changes, and strain sensor performance. Sensor devices plasma-treated for 30 s exhibit exceptional characteristics: a gauge factor of 432 at 50% strain and a response time of 50 ms under quasi-step function strain variation from 0% to 1% in 40 ms. These results underscore the pivotal role of O2 PT in enhancing the performance of PPy-based strain sensors, providing insights for advanced sensor design and fabrication techniques.

Copolymerization of pyrrole and carbazole onto polyester textile.

The purpose of this study was the polymerization of carbazole (Cz), pyrrole (Py) and copolymerization of them onto polyester (PES) textile with chemical oxidative method by using FeCl3. First, in order to determine the optimum conditions, the effect of polymerization steps, the immersion order of the PES to the oxidant and monomer solutions, time, monomer, oxidant, and surfactant concentrations and types on the conductivities of PES/PCz composite were investigated and at this conditions, conductive composite, PES/P[Py-co-Cz] was obtained. The highest conductivities were obtained as 12.4 mS/cm and 9.0 mS/cm for PES/PCz and PES/P[Py-co-Cz], respectively. Further characterization of PES/P[Py-co-Cz] was performed by conductivity, FTIR, scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA) measurements, and results were compared with PES/PCz and also PES/PPy. The presence of Py and Cz in the same polymer chain created synergy and improved the conductivity and mechanical properties of the composite.

Tailoring a Multifunctional PEDOT/Co3O4‐CeO2 Composite for Sustainable Energy Applications

AbstractEnergy sources play a crucial role in the development of the society. The gargantuan depletion of fossil fuels creates new glitches in the routine activities of human beings. Electrocatalysts can efficiently produce and store energy and, therefore, have the potential to alleviate this situation. A multifunctional electrocatalyst, Poly (3,4‐ethylenedioxythiophene)/cobalt oxide‐cerium oxide(PEDOT/Co3O4‐CeO2), is synthesized by incorporating mixed metal oxide to 3,4‐ethylenedioxythiophene (EDOT) using the in situ chemical oxidative polymerization method and is employed for both energy production and storage applications. The successful synthesis of the catalyst is confirmed through various characterization techniques. The composite shows a specific capacity of 617.8 C g−1 and a specific capacitance value of 1298.1 F g−1. The hydrogen evolution reaction (HER) analysis shows that the composite requires a low overpotential of 163.1 mV at a current density of 10 mA cm−2. Synthesized electrocatalysts can effectively handle the energy related issues prevailing in the society.

Co-doped polyaniline composites for biological application: Morphological, functional, optical and antibacterial activities

In the present work, we have successfully synthesized co-doped polyaniline (PANI) composites with various organic acids DBSA, phthalic acid, oxalic acid and Calotropis proceralatex using a simple chemical oxidative polymerization method. The structural, optical, surface morphology and antibacterial analyses were carried out for the synthesized PANI (DBSA-Phthalic acid), PANI (DBSA-Oxalic acid) and PANI (DBSA-C.Procera latex) composites. The structural characterization using XRD and FT-IR measurements confirmed the formation of emeraldine salt form of PANI from the observed characteristic peaks of PANI in all the composites. The observed UV–visible absorption and PL emission peaks also assured the synthesis of PANI in emeraldine form. SEM micrographs of PANI (DBSA-phthalic acid) composites exhibited continuous rock-like agglomerated structure. The antibacterial activity tested against medically important bacteria Bacillus subtilisrevealed a maximum inhibition zone for the DBSA-phthalic acid doped PANI composites when compared with other composites. The average value of zone of inhibition for the PANI composites is found to be 21–24 nm. The minimum inhibitory concentration (MIC) is found to be 1 mg/L for all the PANI composites whereas the minimum bactericidal concentration (MBC) is found to be 60 mg/L for PANI (DBSA-Phthalic acid) and 80 mg/L for PANI (DBSA-Oxalic acid), PANI (DBSA-C.Procera latex) composites. A larger and clear zone of inhibition exhibited by the synthesized co-doped PANI composites confirms their potential as an effective antibacterial agent.

Acetone gas sensing behavior of polypyrrole/ZnO nanocomposites synthesized via chemical oxidation method

Acetone gas sensing behavior of polypyrrole/ZnO nanocomposites synthesized via chemical oxidation method

High-performance supercapacitor based on NiCo2S4/g-C3N4/polyaniline deposited on carbon cloth for structural stability

Although the synthesis of NiCo2S4(NCS)/g-C3N4(GCN)/PANI as an electroactive material has been extensively documented, assembling a Nickel cobalt sulfide (NCS) electrode with outstanding electrochemical efficiency at high current density is still difficult. In this work, the fabrication of a supercapacitor (Sc) electrode of petal-like NiCo2S4/g-C3N4/PANI using a hydrothermal, thermal condensation, and chemical oxidative polymerization method was done. In this nanocomposite, g-C3N4 stabilized the metal atoms and PANI integration considerably improves ion mobility, leading to rapid charge transmission. Due to improvement in electron mobility, the eventual NiCo2S4/g-C3N4(0.40wt%) /PANI(A-3) electrode had shown a specific capacitance (Cs) of 3.4 F/cm2 (1799.07 F/g) with 90% retention and 2700 cycles at the current density of 2 mA/cm2. A good rate capacity of 87.36% at 5 mA/cm2, 82.92% at 10 mA/cm2, and a 50.35% decline of its original capacitance at a high charge/discharge current density of 20 mA/cm2. This work demonstrates that the produced NiCo2S4/g-C3N4/PANI electrode has a high potential for use in energy storage gadget technologies.

Remediation of arsenic-contaminated soil using nanoscale schwertmannite synthesized by persulfate oxidation with carboxymethyl cellulose stabilization

Schwertmannite (SCH) is a promising material for adsorbing inorganic arsenic (As). We synthesized SCH nanoparticles (nano-SCH) via a modified chemical oxidation method and investigated the application of nano-SCH for the remediation of As-contaminated soils. The production of nano-SCH was successfully prepared using the persulfate oxidation method with carboxymethyl cellulose stabilization. The spherical structure of the nano-SCH particles had an average hydrodynamic diameter of 296 nm with high specific surface areas (108.9 m2/g). Compared with SCH synthesized via the H2O2 oxidation method, the percentage of Fe3+ precipitation in nano-SCH synthesis increased from 63.2% to 84.1%. The inorganic As adsorption capacity of nano-SCH improved by 2.27 times at solution pH = 6. After remediation of heavily As-contaminated soils by using 5% nano-SCH, the leachability of inorganic As rapidly decreased to 0.01% in 30 d. Correspondingly, the immobilization efficiencies of inorganic As in soil reached >99.9%. The inorganic As fractions in treated soil shifted from specifically and nonspecifically bound forms to amorphous and crystalline hydrous oxide-bound fractions. After treatment with 5% nano-SCH for 60 d, soil pH slightly decreased from 5.47 to 4.94; by contrast, soil organic matter content increased by 20.9%. Simultaneously, dehydrogenase concentration in soil decreased by 22.4%–34.7% during the remediation process. These changes in soil properties and As immobilization jointly decreased microbial activity and initiated the re-establishment of bacterial communities in the soil. In summary, this study presents a novel and high-productivity technology for nano-SCH synthesis and confirms the high As immobilization effectiveness of nano-SCH in the remediation of As-contaminated soils.

A novel coalescing material for high efficiency oil-water separation

Among numerous oil-water separation materials, coalescence materials have received widespread attention. In this work, we prepared a lotus leaf-shaped Janus coalescing material by physically mixing polyethylene (PE) and polypropylene (PP) first, pressing it into sheets, then single-face hydrophilic modifying by chemical oxidation method, followed by pressing into a lotus leaf shape. Finally, holes were physically punched at the upper and lower sides of the coalescing material to let the oil drops pass through freely, greatly reducing the time for oil droplets to float. The shape of lotus leaves could provide more opportunities for oil droplets to collide and coalesce. The coalescing materials had asymmetric wettability, with specific surfaces that were oleophilic on the one hand and hydrophilic on the other. The oil droplets adhered to the oleophilic side of the coalescing material, coalesced and grew, then floated up and passed through the coalescing sheet layer by layer until they reached the oil collecting port to realize oil-water separation. The structural parameters of the coalescing material were progressively optimized. The obtained coalescing material exhibited a high oil-water separation efficiency of 99.40 ± 0.5% with good stability during a 48 h continuous oil-water separation, which provided a reference for the development of efficient coalescing materials.

Effect of zinc oxide incorporation of poly (aniline)-titanium dioxide ternary nanocrystalline photo-anode for dye-sensitized solar cell applications

In this work, we have developed optically transparent zinc oxide nanoparticles doped with highly efficient of poly (aniline)-titanium dioxide (PANI/TiO2/ZnO) ternary composites were prepared by simple chemical oxidative polymerization method and its used as photo-anode for dye-sensitized solar cell (DSSC) applications. The as prepared PANI/TiO2/ZnO characterized by the various techniques such as FT-IR, XRD, HR-TEM, SAED, FE-SEM, AFM, and UV–Visible analysis. Morphological analysis was observed in the surface morphology of ZnO doped PANI/TiO2 in crystalline nature. The topographical AFM images were also observed in crystalline nature. Tauc plot analysis were examined the optical band-gap energy (2.95 eV) of PANI/TiO2/ZnO. The DSSCs assembled and as prepared PANI/TiO2, PANI/ZnO, TiO2/ZnO, PANI/TiO2/ZnO were used as photo-anode, 1-hexyl-3-methylimidazolium iodide containing the iodide/triiodide redox mediator used as the electrolyte, platinum paste used as a counter electrode. Among the devices, PANI/TiO2/ZnO photo-anode gives 8.31% efficiency.

Synthesis of pyrene and pyrrole-appended fluorescent turn-off sensor toward Cr(VI) detection: Chemical oxidative and electrochemical polymerization of carboxamide

A carboxylic amide compound containing pyrrole and pyrene groups, referred to as PP, was synthesized and characterized for its structural, optical, and electrochemical properties. Upon excitation with 320 nm light, PP displayed blue emission at 387 nm, which was found to be quenched due to chelate formation in the presence of Cr(VI). Conducted competition experiments involving chloride salts of Ag+, Al3+, Cd2+, Co2+, Cr3+, Fe3+, Hg2+, K+, Mn2+, Ni2+, Pb2+, Sn2+, and Zn2+ demonstrated the notable selectivity of compoundPP towards Cr(VI)ions. This selectivity was evidenced by a pronounced turn-off fluorescent effect, attributed to a chelation-enhanced quenching (CHEQ) mechanism by the formation of 1:2 chelation between Cr(VI) and the ligand PP. Moreover, addition of EDTA toPP– Cr(VI)chelation recovered the fluorescence offering receptorPPas a reversible sensor. The PP probe demonstrated remarkable selectivity in detection Cr(VI)ions among various metallic ions, displaying a limit of detection (LOD) value of 0.106 µM. Chemical oxidative and electropolymerization methods were employed to synthesize two distinct polymers, namely Poly(PP)-O and Poly(PP)-E, respectively. The electropolymerization of PP was carried out in 0.1 M TBAF6P serving as a supporting electrolyte solution, while oxidative polymerization was conducted in the presence of FeCl3. Mass average molecular weight of the oxidative polymerization product was 5200 Da, as determined by GPC analysis. Thermal characterization was performed via TG-DTA-DTG curves. The electropolymerization product of PP coated on the ITO surface was further characterized by SEM.