查看更多>>摘要：? 2022 Elsevier B.V.Herein, a series of superhydrophobic thin polyacrylic resin-coated carbon black (CB)/hexagonal boron nitride (h-BN)@Fe3O4/cellulose composite papers with good flexibility, low density (~0.67 g/cm3), high electrical conductivity (~0.065 S/cm), good thermal conductivity (0.462 W.m?1. K?1), and with water contact angle (WCA) of 153° were successfully fabricated by a facile dip-coating/spraying method. The CB-BN@Fe3O4 distribution in cellulose matrix provided high electrical conductivity in the in-plane and thickness directions. The electrical conductivity in both in-plane and thickness directions increased by increasing the number of vacuum-assisted dip-coating cycles. Moreover, these composites exhibited excellent electromagnetic interference shielding effectiveness (EMI SE) in the frequency range of 8.2–12.4 GHz. The absorption was the main mechanism for attenuation of EM waves for this composite paper. A multilayer of this composite with 12 wt% filler exhibited a higher EMI SE of 68.2 dB compared to its monolayer composite. The composites showed good thermal stability and excellent stability against washing and 150 times bending tests. Overall, this study proposes that polyacrylic resin-coated CB/BN@Fe3O4/cellulose papers can be used as wallpaper in buildings such as hospitals and antenna rooms that are exposed to electromagnetic waves.
查看更多>>摘要：? 2022 Elsevier B.V.Todays, metal-organic frameworks (MOFs) and their derived structures are extensively investigated as the novel electrode materials for supercapacitors applications due to their stable porous architectures and exceptionally large specific surface areas. In this study, bimetallic Ni,Zn-MOF is first synthesized onto Ni foam via a novel indirect cathodic electrodeposition method for the first time. The fabricated Ni,Zn-MOFs onto Ni foam was converted to corresponding bi-metal hydroxide@C/Ni foam through direct chemical treating with 6 M KOH solution. The obtained Ni,Zn-MOFs/NF and Ni2-xZnx (OH)2 @C/NF electrodes were characterized through XRD, FT-IR, FE-SEM, AFM and EDS analyses. The results confirmed deposition of well-defined crystalline porous sheet-like structures of Ni3-xZnx(BTC)2 onto Ni foam, where its derived hydroxide@C electrode also exhibited similar morphology. In three-electrode system, the prepared Ni,Zn-MOF/Ni foam exhibited the superior storage capacities of 356.1 mAh g–1 and 255.5 mAh g–1 and capacity retentions of 94.2% and 84.5% after 6000 cycles at 5 and 15 A g–1, respectively. On the other hand, Ni,Zn-MOF derived hydroxide-C/Ni foam presented the superior capacities of 545 mAh g–1 and 406 mAh g–1 as well as proper cycling stabilities of 91.8% and 78.3% after 6000 cycling at the applied loads of 5 and 15 A g–1, respectively. The fabricated Ni,Zn-hydroxide-C/NF//N-PG/NF ASC device can deliver an of 34.5 W h kg?1 at a power density of 624 W kg?1. Based on these findings, both of these fabricated battery-type electrodes are introduced as the promising candidates for use in energy storage devices.
查看更多>>摘要：? 2022 Elsevier B.V.We report the synthesis of low bandgap polymers containing a difluoroquinoxaline unit by Stille polymerization for use in organic solar cells (OSCs). A new series of copolymers were synthesized with 2, 3- didodecyl-6, 7- difluoro-quinoxaline and pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione as electron-deficient units and thiophene or bithiophene as the electron-rich unit. The bithiophene moiety in one of the polymers was associated with reduced electron density because of a weak push-pull effect and an increase in the highest occupied molecular orbital (HOMO) energy level. Efficient polymer solar cells were fabricated by blending the synthesized copolymers with the fullerene PC71BM, and the PCE was measured to be 3.41% under 100 mW/cm2 AM 1.5 G illumination. These results demonstrate that the careful design of a balanced chemical structure is crucial for high performance polymer solar cells.
查看更多>>摘要：? 2022Polypyrrole and aniline 2- sulfonic acid (CFt/PPy/ASA(0.03) composite was synthesized on carbon felt (CFt) under acid conditions. Here, we report investigated in concentration of ASA on the electropolymerization of the PPy, to improve performance of supercapacitor by a facile and effective one-step electropolymerization method. To form a 3D carbon felt, homogeneous and large grains are grown on the surface with the addition of ASA, which provides high active mass and potential redox materials of pseudocapacitive supercapacitor. The flexible electrode shows a high specific areal capacitance 4000 mF.cm?2 at the scan rate of 10 mV.s?1 and excellent rate capability. A symmetric supercapacitor was also assembled with 1 M H2SO4 electrolyte which delivers a maximum energy density of 18.8 Wh.kg?1 at a power density of 312.5 kW.kg?1, and a maximum power density of 1875 kWh.kg?1 can be reached up while delivering a energy density 2.2 Wh.kg?1. The device displays retention of capacitance performance 82.7% even after 2500 cycles in aqueous electrolyte on the PPy-based materials. Therefore, (CFt/PPy/ASA(0.03) electrode has an important role in practical applications of flexible, wearable and portable electronics.
查看更多>>摘要：? 2022The performance and hence pragmatic use of organic humidity sensors requires various factors to be addressed outside of progress in high-performance organic-based sensing materials. While important, evaluation of fabrication techniques also requires attention to optimise performance. Herein we report the effect of different application techniques on the humidity sensing performance of poly[N-90-heptadecanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)] (PCDTBT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) organic composites. Spin-coating, immersion and drop-casting techniques have been applied to prepare sensors. Field-emission scanning electronic microscopy (FESEM) analysis of the prepared films revealed different types of self-assembled nanorods and nanotubes to be formed. The morphological and self-assembled differences could be attributed to various crystallisation processes as a result of different deposition techniques. Capacitive responses of all three sensors have been studied as a function of relative humidity at room temperature. PCDTBT:PC71BM composites prepared through the immersion technique showed superior sensing performance including higher sensitivity (62.34 pF/%RH) than sensors prepared through the spin coating (0.2 pF/%RH) and drop-casting (7.5 pF/%RH) techniques. The superior sensing performance of the sensor prepared through the immersion technique can be ascribed to both the nanotube and porous morphology exhibited.
查看更多>>摘要：? 2022 Elsevier B.V.Herein, a new strategy for the fabrication of emerging MgCo2O4 @Ni3S2 heterostructure array for asymmetric supercapacitors through hydrothermal and subsequent calcination technique is reported. The MgCo2O4 micron flakes are full covered by ultrathin Ni3S2 nanosheets and the comparison of morphology for MgCo2O4 and MgCo2O4 @Ni3S2 electrode has been investigated by scanning electron microscope and transmission electron microscope. The porous structure of MgCo2O4 combined with Ni3S2 causes the composite electrode to have a short ion diffusion path, fast ion/electron transfer with maximized use of active material, resulting in high specific capacitance. When the prepared MgCo2O4 @Ni3S2 core-shell-like structure compound is employed as binder-free electrode for supercapacitors, it shows a prominent specific capacitance (1123.9 F g?1) under 1 A g?1 current density. In addition, high capacitance retention (90.7% after 2000 cycles) can be obtained. Most notably, the asymmetry supercapacitor was fabricated by using the carbon activated as negative electrode and MgCo2O4 @Ni3S2 as positive electrode. This resulting MgCo2O4 @Ni3S2/NF // AC device exhibits a great energy density of 28.37 Wh kg?1 under the condition of 159.6 W kg?1 and 82.9% capacity retention after 8000 cycles.
查看更多>>摘要：? 2022 Elsevier B.V.[1]benzothieno[3,2-b]benzo-thiophene (BTBT)-based compounds with different side chains, 2-(2-ethylhexyl)benzo[b]benzo[4,5]thieno[2,3-d]thiophene (compound 1), 2-(2-ethylhexyl)?7-(thiophen-2-yl)benzo[b]benzo[4,5]thieno[2,3-d]thiophene (compound 2), 2-(2-ethylhexyl)?7-(5-octylthiophen-2-yl)benzo[b]benzo[4,5]thieno[2,3-d]thiophene (compound 3), and 2-(2-ethylhexyl)?7-(5-(2-ethylhexyl)thiophen-2-yl)benzo[b]benzo[4,5]thieno[2,3-d]thiophene (compound 4), were synthesized and characterized as solution-processable small molecular organic semiconductors for organic field-effect transistors (OFETs). The corresponding compounds were employed as active layers for top-contact/bottom-gate OFETs via solution-shearing method and the electrical properties were investigated. The resulting devices exhibited p-channel activity and, especially, thin films of monoalkylated BTBT with additional thiophene ring showed the highest hole mobility up to 0.12 cm2/Vs and current on/off ratio over 107. The analysis of atomic force microscopy (AFM) and X-ray diffraction (XRD) were carried out to correlate surface morphology and microstructure of thin films with the device performance.
查看更多>>摘要：? 2022 Elsevier B.V.The sensitive detection of Hg(II) is a huge consequence for safe environment monitoring and industrial processing. Herein, a sensitive and environment-friendly electrochemical sensor was fabricated using Ag nanoparticles anchored Pani-based bio-nanocomposite. In a simple one-step process AgNPs were prepared using Syzygium aromaticum extract followed by incorporating polyaniline nanostructural array (Pani/Ag/CL) at room temperature through in-situ oxidative polymerization using K2S2O8. The glassy carbon electrode (GCE) was modified with Pani/Ag/CL for the selective electrochemical determination of trace amounts of Hg(II) from different aqueous samples. The electrochemical sensing behavior of the Pani/Ag/CL modified GCE was examined through cyclic voltammetry. The electrochemical impedance analysis of Pani/Ag/CL modified GCE displays favorable kinetic charges for transport. The best reactivity performance for electro-catalytic reduction reactions was observed in a phosphate buffer solution of pH = 5.7. The proposed PANI/Ag/CL modified GCE attains a high sensitivity of 256 μA μM?1 cm?2, a very low limit of detection (0.382 nM), and the limit of quantification (1.27 nM). The practical feasibility and selectivity of the PANI/Ag/CL/GCE were investigated in the sea, tap and wastewater samples with the adequate recovery of Hg(II) added. In addition, the proposed Pani/Ag/CL modified GCE also displayed attractive features such as fast response, simple preparation, repeatability, good stability, as well as detection of the Hg(II) in the occurrence of potential interferences metal cations.
查看更多>>摘要：? 2022 Elsevier B.V.Organic solar cells (OSCs) have attracted great interest in recent years owing to such features as low cost, light weight, and flexibility. The top electrodes of OSCs are generally fabricated by vapor deposition on organic layers. Recently, electrode lamination has emerged as a cost-effective process for the fabrication of top electrodes of OSCs because it does not damage organic thin layers. However, problems abound, including the low short-circuit current density (JSC) and the poor device durability of the resulting OSCs, which are due to the weak contact between the laminated electrode films and the organic layers. Herein we report an electrode sticker that can be firmly attached to an organic layer by thermocompression to realize electrode sticker-laminated OSCs with good JSC and device durability. The electrode sticker-laminated OSCs showed high JSC that approached that of electrode-sublimated OSCs, and their PCE values remained unchanged and were 98% of the maximum value after continuous photo-irradiation for 100 h under ambient conditions. The electrode sticker can be used to fabricate low-cost OSCs with good performance and durability for practical applications.
查看更多>>摘要：? 2022 Elsevier B.V.The coupling between semiconductor/ polymer compositions is one of the unique trials to attain outstanding nanocomposite thermoelectric materials. Herein, Bi2Te3/PANI composites prove their ability to achieve the physical properties of the thermoelectrics by the variation of stoichiometric concentrations. The in-situ polymerization method was utilized to obtain Bi2Te3/PANI compositions. The structural characteristics of the materials were investigated by X-ray diffraction (XRD). XRD, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) confirm the homogeneous growth of PANI over the surface of Bi2Te3 nanoparticles, affect on the order structure with low crystallinity during the polymerization. Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) analyses illustrate the π-π interactions of uniform PANI on Bi2Te3 nanoparticles. The other strong interactions, including electrostatic and hydrogen bonding between Bi2Te3 and PANI may construct a route to enhance the order of the structure of the chains and improve the thermoelectric performance. Distinctive revolutionize the electrical resistivity, Seebeck Coefficient, and the power factor with increased PANI concentrations, which improves thermoelectric performance. The spin concentration charge carriers were determined from Electron Spin Resonance (ESR) dependent on the PANI doping levels. The formation of polarons and bi-polarons were produced during the doping process represent the carriers in these systems.
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