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A carbon nanotube-iron (III) oxide nanocomposite as a cathode in dye-sensitized solar cells: Computational modeling and electrochemical investigations
摘要： Here is the evaluating result on the applicability of the multi-walled carbon nanotube (MWCNT) and a-iron (III) oxide (a-Fe2O3) nanocomposite as a cathode material in dye-sensitized solar cells (DSCs). The morphology and the structure of the MWCNT/a-Fe2O3 nanocomposite have characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray elemental mapping analysis. Moreover, the electrochemical performance of the nanocomposite has studied toward the activity of Iˉ/I3ˉ redox couple which represents high current density, low peak-to-peak separation, low charge-transfer resistance, and almost 100% stable response signal. Furthermore, the computational modeling employing the molecular mechanics (MM) and the restricted-Hartree Fock/semiempirical parameterization (RHF/PM6) methods reveals that the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and the HOMO-LUMO energy gap of the modeled nanocomposite are as (cid:1)6.88, (cid:1)3.62, and 3.26 eV, respectively. These properties match with the electronic-level domino of the DSC structure. Finally, the DSC device has fabricated using N719-sensitized TiO2 photoanode and MWCNT/a-Fe2O3 counter electrode, presenting the open-circuit potential, the short-circuit current density, and the power-conversion ef?ciency of 0.7 V, 20.37 mA cmˉ2, and 6.0%, respectively. This study successfully approves the potential of the nanocomposite as a cathode material in iodine-based dye-sensitized solar cells.
关键词： Dye-sensitized solar cell,Nanocomposite,Carbon nanotube,Molecular mechanics,RHF/PM6,Iron (III) oxide
更新于2025-11-21 11:18:25
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Kinetic stabilization of cellulose nanocrystals in a photocurable prepolymer for application as an adhesion promoter in UV-curable coatings
摘要： Cellulose nanocrystals (CNC) at low loading levels were shown to reinforce a photocurable coating resulting in improved adhesion. A polyether polyol containing CNC at loading levels of up to 1.8 wt% was grafted with 3-isopropenyl-α,α-dimethylbenzyl isocyanate to functionalize it with a photocurable group. The nanoparticles were kinetically stabilized in the rapidly forming prepolymer of high viscosity. Photoinitiators and a difunctional reactive diluent were added to produce optically transparent coatings and free films upon irradiation by ultraviolet (UV) light. This allowed evaluation of the effects of CNC at low loading levels in a glassy polymer matrix obtained through a rapid cure system. Incorporation of CNC nanoparticles in the polymer matrix resulted in an average improvement in adhesive strength of 154% while enhancing tensile strength by an average of 16%. The technique described could be used as a new approach to reduce adhesive failure in UV-curable coatings without sacrificing their mechanical strength.
关键词： Coatings,Nanoreinforcement,UV curing,Nanocomposite,Adhesion promoter,Cellulose nanocrystals
更新于2025-11-21 11:01:37
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Synergistic effect of g-C3N4, Ni(OH)2 and halloysite in nanocomposite photocatalyst on efficient photocatalytic hydrogen generation
摘要： Here, we develop a strategy to improve the visible-light-driven photocatalytic hydrogen evolution activity of g-C3N4 by compositing it with low-cost Ni(OH)2 nanoplatelets and inexpensive and earth-abundant halloysite nanotubes. The Ni(OH)2@g-C3N4/halloysite nanocomposite photocatalyst with different amounts of Ni(OH)2 (0.5–10 wt%) were prepared, and a synergistic effect of Ni(OH)2 platelets and halloysite nanotubes on physicochemical properties and photocatalytic hydrogen evolution activity of g-C3N4 was investigated. As expected, the Ni(OH)2@g-C3N4/halloysite nanocomposite photocatalyst prepared with 1 wt% Ni(OH)2 exhibited the highest photocatalytic hydrogen evolution rate (18.42 μmol·h–1) which is much higher than that of g-C3N4 (0.43 μmol·h–1) and Ni(OH)2@g-C3N4 (9.12 μmol·h–1). Such enhancement in photocatalytic activity of Ni(OH)2@g-C3N4/halloysite nanocomposite photocatalyst is attributed to efficient transfer of photogenerated electrons from the g-C3N4 to Ni(OH)2 cocatalyst interface and trapping of photogenerated holes on the negatively charged surfaces of halloysite nanotubes. In addition, adsorption affinity of the water and methanol molecules was modeled using different surfaces of Ni(OH)2, halloysite-7?, and g-C3N4 and it is found that combining the g-C3N4 with halloysite-7? and Ni(OH)2 can significantly improve the adsorption of water and methanol molecules on the surface of the developed nanocomposite. This study offers a simple approach for developing an efficient and inexpensive nanocomposite for effective and applied photocatalytic water splitting methodology for hydrogen production and other possible optoelectronic and photocatalytic applications.
关键词： Halloysite,g-C3N4,Water splitting,Nanocomposite,Hydrogen production,Ni(OH)2
更新于2025-11-19 16:51:07
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Aqueous synthesis of glutathione-capped CuInS2/ZnS quantum dots-graphene oxide nanocomposite as fluorescence a??switch OFFa?? for explosive detection
摘要： This work reports a simple and fast aqueous preparation of CuInS2/ZnS-graphene oxide (CIS/ZnS-GO) nanocomposite as a fluorescence "switch OFF" probe for the fluorescence detection of 2, 4, 6-trinitrophenol (TNP.) – a raw material for various explosive devices. The as-synthesized nanocomposites was characterised using Ultraviolet–visible (UV–Vis) spectroscopy, photoluminescence (PL) spectroscopy, high resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Raman scattering. The PL studies revealed that the adsorption of TNP onto GO via p-p stacking enhanced the charges transfer from CuInS2/ZnS-GO to the analyte. The limit of detection (LOD) for the analyte is 57 lΜ.
关键词： Nanocomposite,Explosive,Quenching,Trinitrophenol,Fluorescence,Detection
更新于2025-11-19 16:46:39
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A magnetically recoverable CaTiO<sub>3</sub>/reduced graphene oxide/NiFe<sub>2</sub>O<sub>4</sub> nanocomposite for the dye degradation under simulated sunlight irradiation
摘要： In this work, ternary CaTiO3/reduced graphene oxide (rGO)/NiFe2O4 nanocomposite was successfully prepared using polyacrylamide gel route followed by hydrothermal method. It is observed that NiFe2O4 and CaTiO3 nanoparticles are assembled on the surface of rGO. Furthermore, the formation of chemical bonding between the nanoparticles and rGO is confirmed. The photocatalytic activities of the samples were evaluated through the degradation of methylene blue and rhodamine B under the simulated sunlight irradiation. The results indicate that the ternary nanocomposite exhibits remarkable enhanced photocatalytic activity compared with bare CaTiO3 and NiFe2O4. In this nanocomposite, the photogenerated electrons of CaTiO3 and NiFe2O4 can be captured by rGO, leading to an increased separation and availability of electrons and holes for the photocatalytic reaction. Moreover, this nanocomposite exhibits obvious ferromagnetism and can be readily recovered by external magnetic field. The recycling photocatalytic experiment demonstrates that the nanocomposite possesses good photocatalytic reusability.
关键词： Nanocomposite,CaTiO3,Graphene,NiFe2O4,Photocatalysis
更新于2025-11-19 16:46:39
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Tailored nanocomposite energy harvesters with high piezoelectric voltage coefficient through controlled nanowire dispersion
摘要： Composites composed of piezoelectric nanomaterials dispersed in a flexible polymer have emerged as promising materials for highly durable and flexible energy harvesters and sensors. Although piezoelectric materials in their bulk form have a high electromechanical coupling coefficient and can efficiently convert mechanical energy to electrical energy, the ceramic form has low fracture toughness and thus they are limited in certain applications due to difficulty in machining and conforming to curved surfaces. Recently, additive manufacturing processes such as direct write, have been developed to incorporate piezoelectric nanowires into a polymer matrix with controlled alignment to realize printed piezoelectrics. Given the multiphase structure of a nanocomposite, it is possible to control the material structure such that the piezoelectric coupling and dielectric properties can be varied independently. In this paper, experimentally validated finite element (FE) and micromechanics models are developed for calculation and optimization of the piezoelectric voltage coefficient, g31, of a nanocomposite. It is shown that by using high aspect ratio nanowires with controlled alignment, the piezoelectric coupling can be disproportionately increased with respect to the dielectric constant which yields a g31 coefficient that can be enhanced more than seven times compared to the bulk piezoelectric material. Moreover, it is demonstrated that the use of high aspect ratio nanowires in the energy harvester resulted in significant improvement on the output electrical power of an energy harvester.
关键词： Energy harvesting,Nanowires,Finite element modeling (FEM),Voltage coefficient,Piezoelectric,The Mori-Tanaka method,Direct write,Nanocomposite
更新于2025-11-14 17:28:48
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Preparation of ellipsoidal rod-shaped silica nanocomposite abrasives by Chromium ion/PEG200 induced method for sapphire substrates chemical mechanical polishing
摘要： Abrasive is vital to sapphire substrates chemical mechanical polishing and provides the most critical support for ?attening of sapphire. This work proposed a method to prepare ellipsoidal rod-shaped silica nanocomposite abrasives in order to increase the material removal rate and improve the surface roughness, which were applied to chemical mechanical polishing on sapphire substrates. Ellipsoidal rod-shaped silica nanocomposite abrasives were prepared by Chromium ion/PEG200 induced method. In this work, the synthesis process of ellipsoidal rod-shaped silica nanocomposite abrasives was discussed. As an inducing agent, Chromium compounds were bonded with two SiO2 particles via chemical bonds. And ellipsoidal rod-shaped silica nanocomposite abrasives were coated by PEG200 via hydrogen bonds. Results from X-ray photoelectron spectroscopy and time-of-?ight secondary ion mass spectroscopy revealed the occurrence of solid-state chemical reactions. The contact angle tests indicated the polishing liquid containing ellipsoidal rod-shaped silica nanocomposite abrasives had a good wettability. Ellipsoidal rod-shaped silica nanocomposite abrasives showed an excellent chemical mechanical polishing performance with a higher material removal and a lower surface roughness due to an excellent combination of chemical effect and mechanical effect occurred between ellipsoidal rod-shaped silica nanocomposite abrasives and sapphire substrates. A material removal model was built to describe the polishing behavior of ellipsoidal rod-shaped silica nanocomposite abrasives.
关键词： Polishing mechanism,Sapphire substrates,Ellipsoidal rod-shaped silica nanocomposite abrasives,Chemical mechanical polishing
更新于2025-11-14 15:27:09
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Facile synthesis of yellow emissive carbon dots with high quantum yield and their application in construction of fluorescence-labeled shape memory nanocomposite
摘要： Synthesizing carbon dots (CDs) with efficient long-wavelength emissions (i.e., yellow- to red light) generally suffer from sophisticated approaches, time-consuming process, harsh conditions, and requirement of organic solvent; also, a further limitation of the resulting CDs is relatively low quantum yield (QY) in aqueous solution. Herein, novel yellow emitting CDs (Y-CDs) with a considerable QY of 62.8% were synthesized from a precursor comprising resorcinol and o-phenylenediamine via a facile microwave method. To probe the fluorescence mechanism, another typical resorcinol-derived CDs using ethylenediamine as dopant were fabricated as well, showing strong green emission with an absolute QY of 60.6%. Spectroscopic and structural characterizations indicated that the distinct redshift of green to yellow emission depended on the dimension of conjugated sp2-domain and the content of graphitic N heavily, while the excellent QY was highly related to the low proportion of defective sp2 carbon cluster and high nitrogen content within CDs. Moreover, the Y-CDs were confirmed to be capable of introducing additional crosslinking points in poly(vinyl alcohol) (PVA) polymer, which resulted in the Y-CDs-contained nanocomposite behaving superior and tunable water-induced shape recovery performances. Importantly, since being labeled with long-wavelength emission, the responsiveness of PVA/Y-CDs composite will contribute to its versatile utilization in biology-relevant fields.
关键词： shape recovery,fluorescence mechanism,yellow emission,carbon dots,nanocomposite
更新于2025-11-14 15:23:50
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Influence of Electrochemical Hydrogenation on the Circular Photocurrent in the Ag/Pd Nanocomposite
摘要： This work reports on a circular photocurrent in Ag/Pd nanocomposite films. The films, containing metal (Ag-Pd) and semiconductor (PdO) nanocrystallites in amorphous lead-silicate glass, are modified by electrochemical hydrogenation in a sulfuric acid solution. The photocurrent in the modified nanocomposite films is excited by nanosecond laser pulses at wavelengths of 532, 1064, and 1550 nm. In order to determine the circular and linear contributions in a transverse photocurrent, the dependences of the photocurrent on the degree of circular polarization of the exciting radiation are investigated. It is found that the electrochemical hydrogenation modification leads to a significant decrease of the electrical resistance and the polarization-sensitive transverse photocurrent in the films. It is also found that electrochemical hydrogenation significantly affects the ratio of the circular and the linear photocurrent components. The photocurrent is found to be generated on the subsurface layer of the films in the absence of crystalline phase component PdO.
关键词： circular photocurrent,Ag/Pd nanocomposite,electrochemical hydrogenation
更新于2025-11-14 15:13:28
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Growth and characterization of hybrid (HoGO/P3HT) graphene-based nanostructures for photovoltaic (PV) applications.
摘要： Herein, we present a comparative study between nanostructures of poly(3-hexylthiophene) (P3HT), Holmium-Graphene Oxide (HoGO) nanocomposite and hybrid HoGO/P3HT thin-film nanostructures in terms of structural, morphological and spectroscopic properties. Specifically, the graphene based GO nanostructure was functionalized with rear earth ion Ho(III) to improve its mobility. Furthermore, semiconducting P3HT nanostructure was successfully grown with HoGO nanocomposite creating hybrid HoGO/P3HT nanostructure for energy materials. The nanostructures were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), (FTIR) and UV/VIS/NIR spectroscopy. The interaction between HoGO and HoGO/P3HT nanostructures is evidenced through substantial variations in nanoparticle morphologies. FTIR results provided the evidence of the presence of different types of carbon functionalities in the nanostructures. From the absorption spectra, growth of hybrid HoGO/P3HT nanostructure broadened the absorbance with a slight decrease in %. These nanostructures open a promising direction on growth of hybrids for photovoltaic applications because of their interesting optical properties.
关键词： nanostructures,Hybrid,nanocomposite,thin-film,photovoltaics
更新于2025-10-22 19:40:53