查看更多>>摘要：? 2022 Elsevier B.V.In this report, the Polyaniline (PANi) nanoparticles (NPs) were synthesized by in-situ polymersation method. These PANi NPs were characterized by various standard techniques. The crystal structure study were done by Powder X-Ray diffraction (XRD) technique and confirms its amorphous structure. Scanning Electron Microscopy (SEM) images showed that this material shows micron size microfibers made up of NPs with less porosity. The Fourier Transform Infrared (FT-IR) spectroscopy confirms PANi NPs formation and dominant vibrations corresponding to its Quinone and benzene rings were very much visible in the data. From the UV-Visible spectroscopy data, the absorption data confirms the transitions related to its Quinone ring and pyran rings. The optical band gap was estimated to be around 2.47 eV and this material follows indirect allowed transition. From the Photoluminescence (PL) data, it showed various emission line in visible region after exciting it by various UV photons. PL data also confirms defects and bipolaron formation in it. The Cyclic Voltammetry (CV) of PANi was also studied and the parameters like specific capacitance (CP), energy density (ED),and power density (PD) were estimated. For the current material, the value of CP, ED, PD were calculated to be around 72F/g, 144 J/cm3, and 0.9 W/m3 respectively. Further the energy bands like highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of this material was determined by employing CV and the value obtained goes well as calculated by optical absorption techniques. The Electrochemical Impedance Spectroscopy (EIS) carried on PANi NPs (under different studied conditions) also reveals the formation of defects or the play of existing defects with the incident light photons. From practical application point of view, a diode like structure of this material was also fabricated. To this diode, current-voltage (I-V) and dielectrics spectroscopy measurements was carried out in dark and with photons of various wavelengths. Under different measured conditions, the I-V characteristics showed non-linear behavior. Under above experimental situations, the various parameters related with I-V characteristics were also calculated. Also this material show self-powered phenomenon, one of the essential conditions for photo detector/sensor applications. Further this device was also subjected to transient measurements. The reverse recovery time for this diode was calculated to be around 3.04 μs. The capacitance and loss studied on this device shows well dispersion with applied frequency. The observed capacitance and loss also show some changes in presence of different color of photons. The experimental data and overall properties shown by this material correlate with each other. The various properties shown by this material projects it a good candidate for future flexible optoelectronics applications.
查看更多>>摘要：? 2022 Elsevier B.V.Diketopyrrolopyrrole (DPP), typically flanked with thiophene rings as π-spacers, has been regarded as a promising electron-acceptor unit for constructing donor-acceptor-donor (D-A-D) type small molecule organic semiconductors. Exploring the relationships between its conjugation structure and semiconducting property is of great importance for both molecular design and device fabrication of such DPP materials. Herein we describe the synthesis, self-assembly, and transistor characteristics of two novel N- and N′? 2-octyldodecylated DPP derivatives which were modified with native anthracene (An) and brominated anthracene (Br-An) at 5-, 5′-position of the flanked thiophenes, respectively, namely An-DPP and Br-An-DPP. Attributing to the self-assembly behaviors, they exhibit enormous difference in hole transport characteristics on interdigitated-electrode based organic field-effect transistor (OFET) devices even though there is only two atoms’ discrepancy in accordance with their molecular structures. The characterization of OFETs with interdigitated-electrodes based on Br-An-DPP reveals p-channel operation with highest ?eld-effect mobility of 0.2 cm2·V?1·s?1, which is 107 times higher than that of An-DPP (4.8 × 10?8 cm2·V?1·s?1), and with a threshold voltage of - 2.5 V. X-ray diffraction, atomic force microscopy, scanning electron microscopy, and optical absorption studies reveal the presence of crystalline films caused by bromination on anthracene-modified alkylated DPP (i.e., Br-An-DPP), while An-DPP exhibits completely amorphous phase.
查看更多>>摘要：? 2022 Elsevier B.V.The solution casting approach was used to successfully manufacture polyvinylidene fluoride-barium titanate (PVDF-BT) films doped with varied ratios of polyaniline (PANI) (0, 0.5, 1, 2% wt.). The structural and dielectric properties of different prepared films and a selected film irradiated with 0, 10, 20, and 30 kGy from an electron beam accelerator (EB) are investigated. Incorporating PANI into PVDF-BT resulted in a higher β-phase, as evidenced by XRD and FTIR. Besides the amorphization of BT particles inside the irradiated film, EB induces the transition of α-phases into β-phases. Adding PANI, the dielectric constant (ε‘) and loss tangent (tanδ) of the PVDF-BT composites increased. In contrast, EB irradiation causes a reduction of ε‘and tanδ values of the irradiated sample. Because of the reduced polarization level, the ac conductivity (σac) rose with increasing PANI content in PVDF-BT composite, but it decreased with increasing EB doses. Furthermore, adding PANI to PVDF-BT composite and irradiating with EB generated structural alterations in the material. Incorporating PANI into PVDF-BT and EB irradiation decreased mobile ions and lattice strain inside samples.
查看更多>>摘要：? 2022 Elsevier B.V.Recently, the demand for energy storage devices and the role of supercapacitors are increasing rapidly. Therefore, fabrication and designing of an electrode material for supercapacitor with superior performance, excellent structure, easy synthetic procedure, and highly abundant are mandatory for commercialization. In this point of view, Zinc metal-organic frameworks (Zn-MOF) and reduced graphene oxide (rGO) hybrid composites with attractive wrinkled nanosheet-like topographical electrodes are fabricated with various composites of rGO by hydrothermal technique. The as-synthesized Zn-MOF-rGO nanocomposite shows wrinkled nanosheet-like structures which revealed notable supercapacitor performance. The optimized Zn-MOF-rGO20 electrode shows the highest specific capacity of 205 C·g?1 at a current density of 1 A·g?1, as compared to Zn-MOF-rGO10 (153 C·g?1) and pure Zn-MOF (54 C·g?1) respectively. Additionally, the symmetric device of the Zn-MOF-rGO20 electrode exhibits a specific capacitance of 82.5 F·g?1 and 7.1 Wh·kg?1 of energy density at 0.4 kW·kg?1 of power density. Therefore, the optimum rGO added to the Zn-MOF electrode is shown as a promising candidate for supercapacitor applications.
查看更多>>摘要：? 2022 Elsevier B.V.High-quality PEDOT:PSS layer plays an important role in achieving efficient FASnI3 perovskite solar cells. To overcome the defects of the conventional PEDOT:PSS layer, edetate disodium (EDTA-2Na) was applied as the dopant into the PEDOT:PSS solution to modify the film quality. By characterizing the surface morphology and the analysis of the bulk crystallization, it reveals that the incorporation of EDTA-2Na can efficiently optimize the surface morphology, surface energy state and the grain size of the perovskite crystals. Therefore the open-circuit voltage of the perovskite devices can be improved, which as a result leads to the enhancement of the overall device performance as long as the doping concentration of EDTA-2Na was optimized.
查看更多>>摘要：? 2022 The AuthorsPoly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is an emerging biomaterial that – due to its stability and conductivity - has been adopted for diverse biomedical technologies, such as biosensors, coatings for electrodes, and substrates for tissue engineering. Currently, some researchers are focusing on the processing of this biomaterial into three-dimensional (3D) scaffolds, either in the form of fibrous structures, porous sponge-like constructs or hydrogels. However, due to its instability in aqueous environments, challenges occur when applying manufacturing techniques to PEDOT:PSS. Moreover, the standardised use of covalent crosslinking via glycidoxypropyltrimethoxysilane (GOPS) negatively impacts the conductive properties of the material. In this work, poly(ethylene glycol) diglycidyl ether (PEGDE) – which was previously demonstrated to stabilise PEDOT:PSS films - has been used as crosslinking reagent to generate 3D electroconductive porous biomaterial sensors via lyophilization. Both isotropic and anisotropic porous scaffolds were obtained, and although macroscopically similar to GOPS-crosslinked samples, these constructs exhibited unique mechanical electrical features. PEGDE crosslinking of 3D PEDOT:PSS sponges enhanced material hydrophilicity, softness, and electrical conductivity. Finally, biphasic electroactive sponges were manufactured via the inclusion of an elastomeric matrix into these constructs to prolong their longevity and achieve varying degrees of bulk stiffness. These were evaluated as piezoresistive sensors and demonstrated a high strain gauge factor with potential for biometric sensing and biomonitoring.
查看更多>>摘要：? 2022 Elsevier B.V.In this paper, we present a theoretical evaluation and explanation of the adsorption mechanisms of methylene blue or malachite green dyes on a metalloporphyrin [CoII(TMPP)]. This theoretical investigation was carried out by a dual-energy monolayer adsorption model that was developed using statistical physics. The modeling findings show that the adsorption of the dyes studied is due to a molecular aggregation process in aqueous solution, which is dependent the temperature of adsorption. These MG or MB molecules were linked or adsorbed onto the [CoII(TMPP)] surface by a non-flat deposition under the observed the conditions of utilization with thermal stirring and steric hindrance, which may have an important role during adsorption. Similarly, [CoII(TMPP)] metalloporphyrin exhibited the strongest adsorption for methylene blue dyes, particularly at 318 K. Similarly, the adsorption capacities ranged from 96.12 to 110.53 mg/g for methylene blue and from 91.54 to 101.67 mg/g for malachite green, respectively. The endothermic energies of adsorption were investigated for the studied adsorbate molecules, and ranged from 17.67 to 24.17 kJ/mol, showing that physical forces are used to remove of these two dyes from water pollutants. This study facilitates the understanding of the physico-chemical param6eters which govern organic molecules adsorption on the surface of [CoII(TMPP)], an alternative method used for water treatment and purity.
查看更多>>摘要：? 2022 Elsevier B.V.The development of small molecule-based (SMs) organic photovoltaic (PV) materials is under intense attention by the researchers for organic solar cells (OSCs) to constantly revise their power conversion efficiencies (PCEs). Therefore, we have designed a series of Z-shaped non-fullerene acceptors (NFAs) (SNAA1-SNAA6), and characterized them theoretically for the possible use of in efficient OSCs devices. We have designed this Z-shaped series after employing several end-capped modifications over reference molecule (COi5DFIC (R)) to enhance their photovoltaic parameters further. We have extensively characterized these Z-shaped NFAs and explored their optoelectronic, photovoltaic and structure-property relationship with density functional theory (DFT) and time-dependent (TD-DFT). As a result, this Z-shaped NFA series (SNAA1-SNAA6) showed attractive narrower bandgaps (Eg) compared to parent molecule R, and all are extremely red-shifted in the UV-Visible absorption spectrum. Moreover, we have also performed a complex study of donor:acceptor (D:A) blend (SNAA1:PTB7-Th) to show their compatibility in fabricating highly efficient OSCs devices.
查看更多>>摘要：? 2022Polypyrrole (PPy) has aroused great interest due to its excellent physicochemical properties in recent years, especially in the area of electromagnetic wave absorption (EMA). A large number of researches have shown that the regulation of micromorphology has great influence on the EMA performance. Compared with other micromorphology, the hollow structure can significantly promote the EMA performance. In this study, we fabricated hollow PPy (HPPy) nanorods using self-assembly template that can be removed easily. The results show that the dielectric constant of HPPy can be controllably adjusted by tuning the wall thickness, and the HPPy exhibits better EMA performance than the shapeless PPy. Specifically, the minimum reflection loss (RL) can reach ? 54.94 dB, and the largest effective absorption bandwidth (EAB) reaches 7.36 GHz under filler loading ratio of 10 wt%. Impedance matching and multiple scattering are considered to be major factors for the improvement of EMA property. This research gives a general method for the preparation of novel hollow electromagnetic absorbing materials.
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