Fabrication of a novel electrochemical sensor based on MnFe_(2)O_(4)/graphene modified glassy carbon electrode for the sensitive detection of bisphenol A

Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal symmetry.Herein,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposites modified glassy carbon electrode(GCE),which is very efficient and sensitive to detect bisphenol A(BPA).MnFe_(2)O_(4)/graphene(GR)was synthesized by immobilizing the MnFe_(2)O_(4) microspheres on the graphene nanosheets via a simple one-pot solvothermal method.The morphology and structure of the MnFe_(2)O_(4)/GR nanocomposite have been characterized through scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).In addition,electrochemical properties of the modified materials are comparably explored by means of cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).Under the optimal conditions,the proposed electrochemical sensor for the detection of BPA has a linear range of 0.8-400μmol/L and a detection limit of 0.0235μmol/L(S/N=3)with high sensitivity,good selectivity and high stability.In addition,the proposed sensor was used to measure the content of BPA in real water samples with a recovery rate of 97.94%-104.56%.At present,the synthesis of MnFe_(2)O_(4)/GR provides more opportunities for the electrochemical detection of BPA in practical applications.

Characterization of carbon fibers recovered through mechanochemical-enhanced recycling of waste carbon fiber reinforced plastics

In this study,we present the characterization of the carbon fibers recovered from the mechanochemical-enhanced recycling of carbon fiber reinforced fibers.The objectives of the study were to investigate the effect of our modified recycling method on the interfacial properties of recovered fibers.The reinforced plastics were recycled;the recycling efficiency was determined and the recovered fibers were sized using 1 wt%and 3 wt%concentration of(3-aminopropyl)triethoxysilane.We characterized the morphologies utilizing the electron spectroscopy for chemical analysis(ESCA),atomic force microscopy(AFM),FTIR-attenuated total reflection(ATR)spectroscopy and scanning electron microscopy(SEM).Although the surface of the fibers had no cracks,there was evidence of contaminations which affected the interfacial properties and the quality of the fibers.Results showed that the trends in the recovered and virgin fibers were similar with an increase in sizing concentration.The results highlighted the perspectives of increasing the quality of recovered fibers after the recycling process.

Adsorption Characteristics of 2,4-Dichlorophenoxybutric Acid Using Bamboo Activated Carbon in a Fixed Bed

Adsorption and desorption characteristics of 2,4-dichlorophenoxybutyric acid (2,4-DB) from aqueous solution on bamboo activated carbon (BAC) were studied in a fixed bed adsorber. The adsorption equilibrium capacity of 2,4-DB on BAC increased with decreasing initial pH of the solution and with a maximum adsorption capacity of 1.61 mol/kg. The adsorption rate of 2,4-DB on BAC could be best fitted by the pseudo first-order model. The adsorption model based on the linear driving force approximation (LDFA) was used for simulating the adsorption behavior of the 2,4-DB in a fixed bed. More than 95% desorption of 2,4-DB was obtained using distilled water.

Chrysoeriol ameliorates hyperglycemia by regulating the carbohydrate metabolic enzymes in streptozotocin-induced diabetic rats

The present study aimed to evaluate the effects of chrysoeriol from Cardiospermum halicacabum in streptozotocin induced Wistar rats.Thirty rats were categorized as control,diabetic control supplemented with 0,20 mg/kg chrysoeriol and 600μg/kg BW of glibenclamide for 45-day trial period.Our results indicated that the inclusion of chrysoeriol(20 mg/kg)showed a significant reduction in plasma glucose,hemoglobin and glycosylated hemoglobin level with a rising of plasma insulin sensitivity.Further,downregulated enzymes including glucose 6-phosphatase,fructose 1,6-bisphosphatase,and glycogen phosphorylase as well upregulated enzymes such as hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,and hepatic glycogen content.There was a diminish action found in liver glycogen synthase of tested rat with a rise in gamma-glutamyl transpeptidase,towards normal levels upon treatment with chrysoeriol.The histopathological study confirmed that renewal of the beta cells of pancreatic of chrysoeriol and glibenclamide treated rats.In addition,the molecular docking of chrysoeriol against glycolytic enzymes including hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,using Argus software shows chrysoeriol had greatest ligand binding energy as equivalent to glibenclamide,as a standard drug.Thus,chrysoeriol found to be non-toxic with potential regulation on glycemic control and upregulation of the carbohydrate metabolic enzymes.

Machine learning for CO_(2) capture and conversion:A review

Coupled electrochemical systems for the direct capture and conversion of CO have garnered significant attention owing to their potential to enhance energy-and cost-efficiency by circumventing the amine regeneration step.However,optimizing the coupled system is more challenging than handling separated systems because of its complexity,caused by the incorporation of solvent and heterogeneous catalysts.Nevertheless,the deployment of machine learning can be immensely beneficial,reducing both time and cost owing to its ability to simulate and describe complex systems with numerous parameters involved.In this review,we summarized the machine learning techniques employed in the development of CO_(2)capture solvents such as amine and ionic liquids,as well as electrochemical CO_(2)conversion catalysts.To optimize a coupled electrochemical system,these two separately developed systems will need to be combined via machine learning techniques in the future.

Silica-quaternary ammonium “Fixed-Quat” nanofilm coated fiberglass mesh for water disinfection and harmful algal blooms control

Intensification of pollution loading worldwide has promoted an escalation of different types of disease-causing microorganisms, such as harmful algal blooms(HABs), instigating detrimental impacts on the quality of receiving surface waters. Formation of unwanted disinfection by-products(DBPs) resulting from conventional disinfection technologies reveals the need for the development of new sustainable alternatives. Quaternary Ammonium Compounds(QACs) are cationic surfactants widely known for their effective biocidal properties at the ppm level. In this study, a novel silica-based antimicrobial nanofilm was developed using a composite of silica-modified QAC(Fixed-Quat) and applied to a fiberglass mesh as an active surface via sol–gel technique. The synthesized Fixed-Quat nanocoating was found to be effective against E. coli with an inactivation rate of 1.3 × 10^(-3) log reduction/cm min. The Fixed-Quat coated fiberglass mesh also demonstrated successful control of Microcystis aeruginosa with more than 99% inactivation after 10 hr of exposure.The developed antimicrobial mesh was also evaluated with wild-type microalgal species collected in a water body experiencing HABs, obtaining a 97% removal efficiency. Overall,the silica-functionalized Fixed-Quat nanocoating showed promising antimicrobial properties for water disinfection and HABs control, while decreasing concerns related to DBPs formation and the possible release of toxic nanomaterials into the environment.

Bio-assembled MgO-coated tea waste biochar efficiently decontaminates phosphate from water and kitchen waste fermentation liquid

Crystal morphology of metal oxides in engineered metal-biochar composites governs the removal of phosphorus(P)from aqueous solutions.Up to our best knowledge,preparation of bio-assembled MgO-coated biochar and its application for the removal of P from solutions and kitchen waste fermentation liquids have not yet been studied.Therefore,in this study,a needle-like MgO particle coated tea waste biochar composite(MTC)was prepared through a novel biological assembly and template elimination process.The produced MTC was used as an adsorbent for removing P from a synthetic solution and real kitchen waste fermentation liquid.The maximum P sorption capacities of the MTC,deduced from the Langmuir model,were 58.80 mg g^(−1) from the solution at pH 7 and 192.8 mg g^(−1) from the fermentation liquid at pH 9.The increase of ionic strength(0-0.1 mol L^(−1) NaNO_(3))reduced P removal efficiency from 98.53%to 93.01%in the synthetic solution but had no significant impact on P removal from the fermentation liquid.Precipitation of MgHPO4 and Mg(H_(2)PO_(4))_(2)(76.5%),ligand exchange(18.0%),and electrostatic attraction(5.5%)were the potential mechanisms for P sorption from the synthetic solution,while struvite formation(57.6%)and ligand exchange(42.2%)governed the sorption of P from the kitchen waste fermentation liquid.Compared to previously reported MgO-biochar composites,MTC had a lower P sorption capacity in phosphate solution but a higher P sorption capacity in fermentation liquid.Therefore,the studied MTC could be used as an effective candidate for the removal of P from aqueous environments,and especially from the fermentation liquids.In the future,it will be necessary to systematically compare the performance of metal-biochar composites with different metal oxide crystal morphology for P removal from different types of wastewater.