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High acetic acid sensing performance of Mg-doped ZnO/rGO nanocomposites
摘要： Mg-doped ZnO/reduced graphene oxide (rGO) nanocomposites were synthesized using a facile and cost-effective sol-gel procedure to detect acetic acid vapor. Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy, and photoluminescence (PL) analysis were utilized to characterize morphologies, compositions of the nanocomposites, and optical properties of the synthesized nanostructures. The gas sensing measurements of spin-coated Mg-doped ZnO/rGO thin films were carried out for a temperature range of 150–350 oC at various acetic acid vapour concentrations. It was found that the Mg-doped sample with 20 wt. %/v of GO solution concentration exhibited the response/recovery time of 60 s/35 s with the best response of ~200% for 100 ppm of acetic acid at 250 oC.
关键词： Mg-doped ZnO/rGO,Gas sensor,Acetic acid,Nanoparticles
更新于2025-09-23 15:23:52
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TiO2 Modification with Transition Metallic Species (Cr, Co, Ni, and Cu) for Photocatalytic Abatement of Acetic Acid in Liquid Phase and Propene in Gas Phase
摘要： The commercial P25 titania has been modi?ed with transition metallic species (Cr, Co, Ni, and Cu), added by impregnation with aqueous solutions of the corresponding nitrates. The preparation procedure also includes a heat treatment (500 ?C) in argon to decompose the nitrates, remove impurities and to strengthen the metal–TiO2 interaction. The catalysts have been thoroughly characterized using N2 adsorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible diffuse-re?ectance spectroscopy (UV-vis DRS) and X-ray photoelectron spectroscopy (XPS), and have been tested in the aqueous phase decomposition of acetic acid and in the gas phase oxidation of propene, using an irradiation source of 365 nm in both cases. The photocatalytic activity of the four metal-containing catalysts varies with the nature of the metallic species and follows a similar trend in the two tested reactions. The effect of the nature of the added metallic species is mainly based on the electrochemical properties of the supported species, being Cu/P25 (the sample that contains copper) the best performing catalyst. In the photodecomposition of acetic acid, all the metal-containing samples are more active than bare P25, while in the gas phase oxidation of propene, bare P25 is more active. This has been explained considering that the rate-determining steps are different in gas and liquid media.
关键词： TiO2,P25,propene,photocatalysis,acetic acid,transition metals
更新于2025-09-23 15:22:29
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Design, Synthesis and Application of Imidazole-Based Organic Dyes in Dye Sensitized Solar Cells
摘要： Metal-free D–D–p–A type dyes (i.e., Car-Cy, Car-Rh, Dpa-Cy, and Dpa-Rh) were designed and synthesized for dye-sensitized solar cells (DSSCs). In the structure of the sensitized dyes, an imidazole ring is connected to a carbazole or diphenylamine moiety as a donor while cyanoacetic acid or rhodanine-3-acetic acid was introduced as an acceptor/anchor. The molecular structures of D–D–p–A type dyes were characterized using IR, NMR and MS spectral data. The optical, electrochemical, theoretical, light harvesting property, HOMO/LUMO levels, redox behavior, and photovoltaic properties of the synthesized dyes were evaluated. Among the fabricated photovoltaic devices based on the prepared dye, Dpa-Cy dye containing diphenylamine as a donor and cyanoacetic acid as an acceptor exhibited a high-power conversion efficiency of 1.70% with a short-circuit current density (JSC) of 4.48 mA cm?2, an open-circuit photovoltage (VOC) of 0.53 V and a fill factor of 72% under AM1.5 illumination (85 mW cm?2) in comparison with other dyes. Plane-wave calculations indicate that the dye binds reasonably strongly to the TiO2 surface, and the generated DOS picture shows an overlap of the molecular orbitals of the dye and the TiO2 bands. We conclude that the dyes have a promising role as sensitizers in DSSCs.
关键词： rhodanine-3-acetic acid,cyanoacetic acid,carbazole,DSSCs,diphenylamine
更新于2025-09-23 15:21:01
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Enhancement in Photovoltaic Properties of <i>N</i> , <i>N</i> a??diethylaniline based Donor Materials by Bridging Core Modifications for Efficient Solar Cells
摘要： The increasing demand of energy expedited the development of efficient photovoltaic materials.Herein, five push-pull donor materials (D1-D5) having N,N-diethylaniline as donor moiety and rhodanine-3-acetic as acceptor group are designed to be used as donor molecules in organic solar cells (OSCs). The bridging core modification of recently synthesized MR3 molecule (reference R) has been made with different π-spacers namely thiazole (B1), thieno[3,2-b]thiophene (B2), thiazolo[5,4-d] thiazole (B3), 2-(thiophen-2-yl)thiophene (B4) and 5-(thiazol-5yl)thiazole (B5). The structure–property relationship is studied and influence of bridging core modifications on photovoltaic, photophysical and electronic properties of D1-D5 are calculated and compared with reference R.The DFT and TDDFT calculations have been performed for the estimation of frontier molecular orbital (FMO) analysis, density of states (DOS) graphs, reorganization energies of electron and hole, open circuit voltage, photophysical characteristics, transition density matrix (TDM) surfaces and charge transfer analysis.Designed molecules exhibit better and comparable optoelectronic properties than synthesized reference molecules. Among all investigated molecules, D5 is proven as best candidate for OSCs application due to its promising photovoltaic properties including lowest band gap (2.24 eV), small electron mobility (λe = 0.0056 eV), small hole mobility (λh = 0.0046 eV), low binding energy (Eb = 0.21 eV), highest λmax values 610.76 nm (in gas) 670.22 nm (in acetonitrile) and high open circuit voltage (Voc = 1.17 V) with respect to HOMOdonor–LUMOPC61BM. This theoretical framework demonstrates that bridging core modification is a simple and effective alternative strategy to achieve the desirable optoelectronic properties. Furthermore, conceptualized molecules are superior and thus are recommended to experimentalist for out-looking future developments of highly efficient solar cells.
关键词： Rhodanine-3-acetic acid,Solar cells,Photovoltaic properties,Bridging core modifications,Density functional theory (DFT),N,N-diethylaniline
更新于2025-09-23 15:21:01
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A chemically modified laser-induced porous graphene based flexible and ultrasensitive electrochemical biosensor for sweat glucose detection
摘要： Porous laser-induced graphene (LIG) is an attractive and promising carbon material for electrochemical applications because it can immobilize various proteins, such as enzymes, antibodies, and receptors. However, poor inherent electrical properties caused by low surface conductivity is still a critical drawback for various applications. Here, we have proposed a surface modification method for the LIG electrode using acetic acid treatment via facile and practicable dipping technique. This simple acetic acid treatment dramatically increased the ratio of carbon-carbon bonds which effectively increased conductivity and decreased sheet resistance. Importantly, these unique properties also facilitated the stable and uniform dispersion of highly catalytic Pt nanoparticles (PtNPs) on LIG by avoiding the concentration of electric field on nanoparticles that can cause aggregation during electrodeposition. Finally, chitosan-glucose oxidase (GOx) composite was successfully immobilized onto the LIG/PtNPs electrode to fabricate a sweat glucose biosensor. The as-prepared LIG/PtNPs electrode exhibited a high sensitivity of 4.622 μA/mM as well as an ultra-low limit of detection (signal to noise ratio is 3) which was less than 300 nM and dynamic linear range up to 2.1 mM. Furthermore, we tested the variation of blood glucose level before and after meal using the amperometric response of the sensor which demonstrates the commercial potential of this unique sweat glucose biosensor.
关键词： Sweat glucose detection,Laser-induced graphene (LIG),Acetic acid treatment,Ultra-sensitive and -low detection limit,Electrochemical biosensor
更新于2025-09-23 15:19:57
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Drivers for the cracking of multilayer polyamidea??based backsheets in field photovoltaic modules: Ina??depth degradation mapping analysis
摘要： There is a lack of understanding on the root cause of cracking of photovoltaic (PV) backsheets due to the challenge of multilayer characterization and the complicated failure modes at the submodule level. In this work, the in-depth degradation mapping of field-exposed polyamide-based (PA-based) PV module backsheets was studied, with the major focus on the identification of underlying drivers for the through cracking (in between the solar cells). PV modules were retrieved from five different locations, comprising a variety of climates, including humid subtropical, hot-summer Mediterranean, tropical savanna climate, and hot arid. A suite of microscale cross-sectional characterizations, including chemical changes, fluorescence intensity, and modulus as a function of distance from the air surface of the backsheet, was performed. Results showed more advanced signs of degradation of the inner layer than the outer layer in the cracking region. Increases in the modulus were identified as the major indicator for the cracking. Moreover, a rudimentary test by immersion in acetic acid, which forms during photodegradation of the ethylene-vinyl acetate copolymer (EVA) encapsulant, showed the first-time direct evidence that acetic acid can largely accelerate the chemical degradation and facilitate the cracking of PA inner layer. This study suggests that the field cracking of PA-based backsheet can be attributed to the combined effects of chemical degradation and physical reorganization (chemi-crystallization) under cyclic thermomechanical stresses. Therefore, it is important to consider effects of local microclimates and interlayer infection to understand the heterogeneous nature of backsheet failures.
关键词： acetic acid,cross section,degradation,photovoltaic backsheet,cracking
更新于2025-09-19 17:13:59
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Molecular Engineering of a New Organic Chromophore with D-π-A Architecture for Dye-Sensitized Solar Cells
摘要： Herein, we report design and synthesis of a new metal-free organic dye N1 derived from (Z)-3-(9-hexyl-9H-carbazol-3-yl)-2-(thiophen-2-yl) acrylonitrile scaffold. In this design, the electron rich carbazole unit is connected to rhodanine-3-acetic acid via cyano vinyl thiophene as π-spacer. Its molecular structure was confirmed by FTIR, NMR, Mass spectral and elemental analyses. The dye was subjected to optical and electrochemical studies in order to investigate their absorption/emission behaviour as well as HOMO/LUMO energies. The DFT studies were performed using Turbomole 7.1V software and the results indicated the existence of proper charge separation between its HOMO and LUMO energy levels.
关键词： DFT,Rhodanine-3-acetic acid,DSSC,FMO level,Carbazole
更新于2025-09-16 10:30:52
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Microwave assisted sol–gel synthesis of titanium dioxide using hydrochloric and acetic acid as catalysts
摘要： Titanium dioxide (TiO2) was synthesized by microwave assisted sol–gel. The effect of the acid type used as catalyst on the phase transformation of TiO2 was investigated (hydrochloric or acetic acid). The samples obtained were characterized by scanning electron microscopy (SEM), this micrographs showed particles with irregular shapes. The results of Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) showed present signals of O and Ti. When hydrochloric acid was used as catalyst, three titania polymorphs were detected by X-ray diffraction (XRD), anatase, rutile and brookite, where the crystallite size was in the range of 9 and 16 nm. On the other hand, a single anatase phase was formed when acetic acid was used after only 15 min of reaction time. The anatase average crystallite size was obtained between 11 and 22 nm.
关键词： Microwave-assisted sol–gel,Acetic acid,Hydrochloric acid,Titanium dioxide
更新于2025-09-10 09:29:36