No abstract

No abstract

No abstract

No abstract

Ternary nanocomposites (NCs) containing copper oxide (CuO)/poly(methyl methacrylate)/various carbon‐based nanofillers have been successfully prepared as thin films by an ex situ method as a selective Hg+2 sensor. The structural, morphological, and electrochemical properties of the NCs were identified by all common characterization tools. The FT‐IR curves of these NCs proved the efficiency of CuO mixed with single‐walled CNTs (CuO/SWCNTs), multi‐walled CNTs (CuO/MWCNTs), or graphene (CuO/G) nanoparticles in the PMMA polymer matrix. The mixed nanofillers significantly improved the properties of the PMMA film. The thermal characteristics of the pure PMMA polymer matrix were highly developed by adding nanofillers in the form of NCs. The maximum composite degradation temperature (CDTmax) values were comparable for all the NCs and were in the range of 345 to 406°C. For fabrication, the CuO‐PMMA‐SWCNT, CuO‐PMMA‐MWCNT, and CuO‐PMMA‐GNCs were coated onto a glassy carbon electrode (GCE) to form a tiny layer with orderly thickness using a conductive 5% Nafion chemical binder. During the electrochemical investigation, it was found that CuO‐PMMA‐SWCNT had the maximum response toward Hg2+ ions compared to the other nanofillers in a buffer medium (phosphate type). To calibrate the Hg2+ ionic sensor, the data were plotted against Hg2+ ion concentration and the proposed sensor showed linearity over a wide range of concentrations (0.1‐0.01 mM), which is called the linear dynamic range (LDR). The analytical parameters, such as sensitivity (1.70 × 102 μAμM‐1 cm−2), detection limit (55.76 ± 2.79 pM), and limit of quantification (185.87 pM) were calculated from the calibration curve. Moreover, it showed good reproducibility, fast response time, good linearity, large LDR, and good stability. The CuO‐PMMA‐SWCNT NC‐modified GCE offers a new route to fabricate novel heavy metal ionic sensors, which might be used in green environment and health development applications.

The nanocomposites (NCs) of cross-linked polyaniline (CPA) with a variety of carbon nanomaterials (CNMs) (CPA/CNMs NCs) was prepared by the chemical oxidative copolymerization of PANI and p-phenylenediamine (PPDA) with triphenylamine (TPA) in the presence of CNMs. The results of XRD, FTIR and Raman indicated that the CPA/CNMs NCs were effectively synthesized with strong interactions among the constituents. The morphology study demonstrated that CNMs were well coated by CPA and produce a well-aligned nanorod core-shell structure with the large surface area which may be more beneficial to electrical conductivity when used as electrode materials. Differential thermal analysis techniques (TGA-DTG) were used to characterize the thermal stability of NCs. The heat of formation of CPA monomer from TPA, PPDA and aniline (ANI) were computed using Density Functional Theory (DFT) calculations. The NCs of G-MWCNTs demonstrate higher affinity to oxidation of Chlorophenols (CPHs) than glassy carbon electrode (GCE), CPA/GCE and the other NCs. Differential pulse voltammetry (DPV) was used for the trace determination of 2,4-dichlorophenol (2,4-DCP). Under the optimum conditions, the peak current of 2,4-DCP was proportional to its concentration in the range of 0.05-0.6 μmol/L. The detection limit was 7.6 nmol/L. The method was successfully applied for the determination of 2,4-DCP in fish farm water with satisfactory recoveries. The suggested method has an advantage to be used for water samples due to its short analytical time, rapid response, high sensitivity, and excellent selectivity with good reproducibility. K E Y W O R D S 2,4-dichlorophenol sensor, crosslinked polyaniline/G-MWCNTS nanocomposite, density functional theory, electrochemical properties, thermal properties 1 | INTRODUCTION Conducting polymer (CPs) based sensors have the advantages of the processability of environmental, simplicity, high electrical conductivity, mechanical flexibility as well as low cost 1-2 P.ANI in many applications has appeared as one of the most promising CPs materials. 3-6 PANI composites have been used in the fabrication of diverse devices, such as thermoelectric and energy storage devices, biofuel cells and batteries. 7-16 However, the electrochemical applications are the most promising application of these composites. Particularly, in many electroanalytical studies, the fabrication of PANI and PANI composite electrochemical sensors has become a common way and offers high selectivity as well as sensitivity to detect target molecules. 17-19 Crosslinking may be a candidate to enhance the PANI electrical and

Nanocomposites (NCs) of crosslinked polyaniline (CPA)-coated oxidized carbon nanomaterials (OXCNMs) were fabricated as a very sensitive and simple electrochemical sensor to be utilized in 2,4-dichlorophenol (2,4-DCPH) detection. CPA/OXCNMs NCs were prepared by chemical copolymerization of polyaniline with triphenylamine and p-phenylenediamine in the presence of OXCNMs. The CPA/GO-OXSWCNTNCs exhibited a higher affinity for the oxidation of chlorophenols compared to the glassy carbon electrode (GCE), CPA/GCE, and other NCs. Cyclic voltammetry was performed to investigate and assess the electrocatalytic oxidation of 2,4-DCPH on the modified GCE. The compound yielded a well-defined voltammetric response in a Britton-Robinson buffer (pH 5) at 0.54 V (vs. silver chloride electrode). Quantitative determination of 2,4-DCPH was performed by differential pulse voltammetry under optimal conditions in the concentration range of 0.05 to 1.2 nmol L-1 , and a linear calibration graph was obtained. The detection limit (S/N = 3) was found to be 4.2 nmol L-1. In addition, the results demonstrated that the CPA/GO-OXSWCNTs/GCE sensor exhibited a strong anti-interference ability, reproducibility, and stability. The prepared CPA/GO-OXSWCNTs/GCE sensor was used to rapidly detect 2,4-DCPH with a high degree of sensitivity in fish farm water with proven levels of satisfactory recoveries.

No abstract