查看更多>>摘要：? 2022 Elsevier B.V.This work demonstrates the facile preparation of one-dimensional nanostructures of poly(N-methyl pyrrole) (PNMPy) with the guidance of anionic organic dyes, methyl orange (MO) or Acid Blue 25 (AB). The addition of MO dye to polymerization mixture resulted in a nanotubular morphology of PNMPy, whereas nanofibers were obtained with AB dye. In order to examine the effects on yield and conductivity of the obtained polymers, various concentrations of dye ranging from 5 mM to 40 mM with fixed molar ratio of the N-methyl pyrrole to oxidant were used. Addition of both the dyes showed enhancement in the conductivity of PNMPy by one order of magnitude independent on the dye concentration. FTIR and Raman spectroscopies were used to investigate the molecular structure of PNMPy and the possible interaction with dyes. Additionally, the enhanced specific surface areas were attained for both PNMPy nanotubes and nanofibers. The presence of either dye, displayed a pronounced effect on electrochemical activity, as higher gravimetric capacitances were achieved by 1-D nanostructures.
查看更多>>摘要：? 2022 Elsevier B.V.Composite coatings based on nickel have recently become popular in the automotive and aerospace industries owing to their corrosion-resistant qualities. However, as many cases have shown, this coating is ineffective in chloride-containing environments. As remediation, a graphene oxide/conducting polymer (Polypyrrole) composite with nickel has been proposed as an effective corrosion protective layer for bare mild steel. Furthermore, electrodeposition is one of the popular methods for coating metals with anti-corrosion coatings. A simple, cost-effective, and environmentally friendly electrodeposition process has been employed for the deposition of graphene oxide/polypyrrole composite with nickel (Ni-GO-PPy) on mild steel. XRD, EDAX, FE-SEM, and FT-ATR were used to analyze this coating extensively. A coated mild steel sample was evaluated in a 3.5% NaCl solution utilizing the Potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss immersion test to determine the coatings' anti-corrosion characteristics. In all of the experiments, the Ni-GO-PPy coating outperformed bare nickel and Ni–GO coatings in terms of anti-corrosion capabilities. As a result of this research, a practical and scalable technique for using Ni-GO-PPy composite coating to protect mild steel surfaces against corrosion has been demonstrated.
查看更多>>摘要：? 2022 Elsevier B.V.With the view to the poor coexistence between promoting molecular planarity towards improving the intramolecular charge transfer (ICT) effect and preventing charge recombination for dyes in Dye-sensitized solar cells (DSSCs). A novel 2-phenothiazine-amine-based organic dye PTZ-10 is synthesized and applied in DSSCs. The extra benzene and ethynyl conjugated groups are inserted as the isolation groups between the 2-phenothiazine-amine donor and benzothiadiazole auxiliary acceptor to obtain PTZ-17 in order to probe the possibility of reaching the aim of suppressing the charge recombination and strengthening molecular planarity synchronously in a better degree. Our photophysical measurement, electrochemical test and theoretical calculation demonstrate that the introduction of ethynyl and benzene is beneficial to the improvement of ICT effect and the inhibition of charge recombination, which can also be confirmed by the photovoltaic property and EIS study. Therefore, higher short-circuit photocurrent density (Jsc) and the open-circuit voltage (Voc) are exhibited in devices based on PTZ-17, along with the higher photoelectric conversion efficiency (PCE) up to 4.24 % relative to that of 3.37 % in PTZ-10. We demonstrated that the incorporation of different sizes of conjugated groups is a promising candidate to fine-tune the structure-performance of dye molecules in the development of DSSCs’ materials.
查看更多>>摘要：? 2022The hybridization of conductive polymers (CPs) with other nanomaterials is one of the effective ways to improve their electrical, optical, mechanical, and biological properties. The review reports the types, synthesis methods, physical and chemical properties, potential applications, and the prospect of future polypyrrole (PPy) nanocomposites. PPy nanocomposites can be classified into four types according to their composition: PPy/carbon series nanocomposites, PPy/ inorganic nanocomposites,PPy/organic nanocomposites and PPy multicomponent nanocomposite. The main synthesis methods of PPy nanocomposites include in situ chemical/electrochemical oxidation, electrochemical deposition, template method, interfacial polymerization, electrospinning, freeze drying and so on. Based on its high electrical conductivity and chemical properties, the applications of PPy nanocomposites in the field of energy storage, biomedicine, adsorption and impurity removal, electrocatalysis, wave-absorbing materials, sensors and corrosion protection are presented, which focus on recent literature. Finally, the perspectives on the challenges and opportunities in this emerging area of research are presented.
查看更多>>摘要：? 2022 Elsevier B.V.Non-peripherally tetra-2,6-dimethoxyphenoxy substituted Co(II) 3, Fe(II) 4, Mn(III) 5, and Ni(II) 6 phthalocyanines were prepared by refluxing the n-pentanol solution of their metal-free analogue H2Pc 2, (obtained by using 3-(2,6-dimethoxyphenoxy)phthalonitrile), metal salts (Co(CH3COO)2.4 H2O, Fe(CH3COO)2, Mn(CH3COO)2.4 H2O or NiCl2) and 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) as the catalyst under N2 atmosphere for 2 h. The molecular structure of metallophthalocyanines 3–6 were explained by common methods which are elemental analysis, MALDI-TOF mass, FTIR, and UV-Vis spectroscopies. The complexes are well dissolved in various solvents (dichloromethane, tetrahydrofuran, dimethylsulfoxide, dimethylformamide, and toluene. Electrochemical redox, electrocatalytic oxygen reducing and electrocolorimetric properties of the phthalocyanine complexes were also measured by voltammetric and in situ UV-Vis spectroelectrochemical techniques. The phthalocyanine complexes displayed highly reversible sequential one-electron redox processes occurring at metal and/or phthalocyanine ring. The association of these processes with net colour changes pointed out their functionality as electrochromic material. Furthermore, the phthalocyanine complexes 3-5 and especially Fe(II)Pc 4, showed striking electrocatalytic oxygen reducing activity, owing to the metal centres with redox activity, increasing their interplay with the O2 molecule.
查看更多>>摘要：? 2022 Elsevier B.V.Nanostructured Zinc Oxide (ZnO) was deposited by the spray pyrolysis technique. The ZnO was further functionalized by reduced Graphene Oxide (rGO) using the doctor blade method. The X-ray Diffraction (XRD) studies of bare and rGO functionalized ZnO showed multiple peaks and polycrystalline in nature. The morphological studies confirmed rGO distribution over the ZnO surface. The ammonia sensing studies of the bare and functionalized ZnO were analyzed by varying the temperature from room temperature (RT) to 450 °C. The rGO/ZnO exhibited increased sensitivity towards ammonia at a lower temperature (300 °C) compared with bare ZnO. The range of detection was found to be 0.5 ppm to 100 ppm. The selectivity studies towards 20 ppm ammonia in a mixed gas environment were also investigated.
查看更多>>摘要：? 2022 Elsevier B.V.This research was conducted to develop a novel adsorbent based on hyperbranched polyester dendrimers for selective determination and separation of donepezil hydrochloride. In this paper, different generations of hyperbranched polyester dendrimers were grafted onto graphene oxide. New types of carboxyl-terminated hyperbranched polyesters with aromatic-aliphatic structure were synthesized using the direct esterification reaction between succinic acid and phloroglucinol in the presence of p-toluene sulfonic acid catalysts. The 5th generation of polyester dendrimers was modified by p-aminohippuric acid to enhance its adsorption capacity and improve dendrimer biocompatibility. The hyperbranched polyester dendrimers with magnetic nanoparticles were obtained through vacuum freeze-drying process and was used in a new method for the preparation of three-dimensional/ graphene oxide-grafted hyperbranched polyester dendrimers. The synthesized nanoparticles were investigated using Fourier-transform infrared spectrometry, X-ray diffraction, field-emission scanning electron microscopy equipped with energy-dispersive spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller, thermal gravimetric analysis and vibrating sample magnetometry. The effective experimental parameters were optimized. Adsorption of donepezil hydrochloride by nanoadsorbent can be best described by a Langmuir isotherm with a high correlation coefficient. The three-dimensional/ graphene oxide -grafted hyperbranched polyester dendrimers were applied for extraction of donepezil hydrochloride from biological and pharmaceutical samples through high-performance liquid chromatography-ultraviolet technique.
查看更多>>摘要：? 2022 Elsevier B.V.In this study, the halloysite nanotubes/polypyrrole/Fe3O4 (HPF) nanocomposites were synthesized, and their microwave absorption properties were investigated. Fe3O4 nanoparticles were synthesized by the hydrothermal method. By adding halloysite nanotubes (HNTs) to Fe3O4 nanoparticles and using the polypyrrole (PPy) as a conductive polymer, the in-situ polymerization process on the surface of HNTs and Fe3O4 nanoparticles was performed. The characteristic peaks of PPy and HNTs in Fourier transform infrared (FTIR) spectra confirmed the well-synthetized nanocomposites processes. Field emission scanning electron microscopy (FE-SEM) images illustrated the morphology and uniform structure of nanocomposites. The HPF1 (1 mL PPy) and the HPF2 ((2 mL PPy) nanocomposites exhibit a saturated magnetization of 26.22 emu/g and 13.94 emu/g, respectively. The microwave adsorbents were prepared by adding 20 wt% of synthesized nanocomposites to the resin. The complex permittivity and permeability parameters of adsorbents were investigated in the range of 8–12 GHz. The minimum reflection loss (RL) was ? 31.18 dB at 10.58 GHz for HPF1 nanocomposites corresponding for a thickness of 3 mm. The results indicate that the HNTs as an additive can improve the adsorption properties of PPy/Fe3O4 nanocomposites.
查看更多>>摘要：? 2022 Elsevier B.V.This investigation reports the morphological and structural properties of ZnO doped with the Al, In and Ga elements and its utilization as redox material to improve the capacitance and energy density of graphene supercapacitors (SCs). All the ZnO nanoparticles doped with these elements presented a plate-like morphology with irregular edges and had hexagonal wurtzite phase. Moreover, the values of band gap were obtained for the ZnO nanoparticles and they are reduced with the order of: ZnO:Ga (3.2 eV)>ZnO:In (3.0 eV)>ZnO:Al (2.95 eV). The results of electrochemical characterization revealed that the graphene SCs made without ZnO presented a maximum capacitance and energy density of 97.2 F g?1 and 19.4 Wh kg?1, respectively. After the deposition of the Al, In or Ga-doped ZnO nanoparticles to the SC electrodes, the capacitance and energy density are enhanced by 22–193%. The maximum values of capacitance and energy density of 284.6 F g?1 and 56.9 Wh kg?1 were observed for the SC made with ZnO:Al. Moreover, the analysis by Raman and photoluminescence demonstrated the presence of Zinc interstitials, oxygen vacancy and oxygen interstitials defects, which served as redox centers for the charge storage in the solid state SCs. In general, this research confirmed that adding doped ZnO into the SCs is a good strategy to increment their performance, which is of interest for energy storage applications.
查看更多>>摘要：? 2022The energy gap between 6,6-phenyl-C61-butyric acid methyl ester (PCBM) and silver (Ag) is disadvantage to the electron collection of perovskite solar cells (PSCs). In this work, solvent treatment is applied on the surface of PCBM by using ethanol, acetonitrile and ethanol:5 vol% acetonitrile, respectively. Experimental results showed that solvent treatment greatly enhanced the power conversion efficiency (PCE) of PSCs. After ethanol:5 vol% acetonitrile treatment, the PCE of PSC increased from 14.03 ± 0.23 % to 17.03 ± 0.13 % due to the simultaneously enhancement of VOC, JSC and FF. Electronic energy level at the surface of PCBM, electron mobility of PCBM film and the dark current density of PSCs were analysed to investigate the work mechanism of solvent treatment.
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