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An inorganic/organic hybrid composite of CuS nanoparticles (NPs) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) was prepared via a facile mixing process. Counter electrodes (CEs) of quantum dot sensitized solar cells (QDSSCs) were prepared by coating the hybrid CuS-PEDOT:PSS composite on fluoride-doped tin oxide (FTO) substrates using simple drop-casting technique. The SEM micrographs of CuS-PEDOT:PSS CEs revealed three-dimensional surface morphology and homogeneous dispersion of CuS NPs on the PEDOT:PSS. The electrochemical measurements of the hybrid CEs showed high electrocatalytic activity towards polysulfide electrolyte resulted from embedding the catalytic active CuS NPs into the continuous PEDOT:PSS conducting matrix. The CdS-QDSSC fabricated with CuS- PEDOT:PSS CE exhibited an remarkable stable power conversion efficiency (PCE) of 1.04%, that is higher than that of Pt CE (0.48%) measured under one-sun illumination. The enhancements in the photovoltaic performance of QDSSCs fabricated with hybrid CEs are discussed based on the analysis of electrochemical results. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to present an efficient and reliable graphene nanoplatelets (GNPs)-based temperature sensor. Design/methodology/approach: A high-quality dispersion of GNPs was dropped by casting method on platinum electrodes deposited on a polyethylene terephthalate (PET) substrate. The GNPs were characterized by scanning electron microscope, Raman spectroscopy and X-ray diffraction spectra to ensure its purity and quality. The temperature sensing behavior of the fabricated sensor was examined by subjecting it to different temperatures, range from room temperature (RT) to 150 °C. Findings: Excellent resistance linearity with temperature change was achieved. Temperature coefficient of resistance of the fabricated sensor was calculated as 1.4 × 10–3°C. The sensor also showed excellent repeatability and stability for the measured temperature range. Good response and recovery times were evaluated at all the measured temperatures. With measuring the sensor response, the ambient temperature can be determined. Originality/value: The present work presents a new simply and low cost fabricated temperature sensor based on GNPs working at a wide temperature range. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the possible radioprotective effect of Costus speciosus and carnosine as natural antioxidants in order to control the hyperglycemia developed in male albino rats exposed to acute oxidative stress induced by gamma radiation. Methods: Twenty-eight adult male albino rats were divided into four groups. The first group was taken as a control group, while the three other groups were exposed to γ irradiation at a single 7.5 Gy dose. Furthermore, the rats in the second and third groups were i.p. injected with Costus speciosus root powder and carnosine, respectively. On the 3rd day, after irradiation, the serum levels of glucose, insulin, C peptide, copper, iron, calcium, total antioxidant capacity (TAC) and malondialdehyde (MDA) were measureded. Results: The results revealed that exposure to γ irradiation induced significant increases in serum glucose, iron, and malondialdehyde. However, the levels of serum calcium, copper, total antioxidant capacity and insulin significantly decreased (p < 0.05). A significant decrease was observed in C peptide in the exposed group, compared to control group. All the test parameters indicate improvement after treatment with Costus speciosus and carnosine (p < 0.05). Conclusion: Costus speciosus and carnosine ameliorate the effect of gamma radiation, indicating their role as antidiabetic agents and radioprotectors; however, Costus speciosus was critically more efficient than carnosine. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ fast processing technique for heteroatom doping of flexible GO films. • Pristine, N, and SN doped laser reduced graphene oxide for planar supercapacitors. • SN-LrGO interdigitated planar SC exhibits an areal capacitance of 13.8 mFcm−2. • Fabricated SCs show long lifespan with more than 90% retention after 2000 cycles. • Series and parallel combinations of SN-LrGO PSCs are investigated. A novel, scalable, single-step and low-synthesis temperature fabrication approach is proposed for real-time doping, reduction, and patterning of graphene oxide-based films supported on flexible polyethylene terephthalate (PET) substrate using a CO2 Laser system. Laser reduced graphene oxide (LrGO), nitrogen-doped laser reduced graphene oxide (N-LrGO), and sulfur-nitrogen co-doped laser reduced graphene oxide (SN-LrGO) planar supercapacitors (PSCs) are readily fabricated with the proposed approach. Structural and elemental characterizations prove the successful integration of nitrogen and sulfur atoms into the graphene framework with high contents up to 3.71 at% N and 1.82 at% S, and at a low density of structural defects. An areal capacitance as high as 13.8 mF cm−2 at 10 mV s−1 and a maximum power density of 151.7 mW cm−3 at an energy density of 0.152 mWh cm−3 is achieved by SN-LrGO PSC composed of 10 interdigitated fingers with an excellent retention rate after 2000 charging/discharging cycles at 0.125 mA cm−2. Furthermore, higher operating voltage window and current ratings are easily achieved via series and parallel combinations of SN-LrGO PSCs directly on the same substrate. This manifests the versatility of the proposed approach for producing flexible and high-performance graphene-based electrochemical storage devices. [ABSTRACT FROM AUTHOR]

This reported work aims to fabricate an eco-friendly Zr bio-based MOF and assessment its adsorption efficiency towards the cationic and anionic dye pollutants including methylene blue (MB) and direct red 81 (DR-81), respectively. Also, its adsorption tendency for the highly toxic heavy metal of hexavalent chromium (Cr(VI)) was compared with dyes. The adsorption performance of bio-MOF showed that the maximum monolayer adsorption capacities were recorded as 79.799 mg/g for MB, 36.071 mg/g for DR-81, and 19.012 mg/g for Cr(VI). Meanwhile, the optimum dosage of as-synthesized MIP-202 bio-MOF was 0.5, 1, and 2 g L−1 for MB, DR-81, and Cr(VI), respectively. Thermodynamic analysis demonstrated the spontaneous, thermodynamically, and endothermic nature of the decontamination processes onto the fabricated Zr bio-based MOF. The adsorption data were fitted by Langmuir isotherm model compared with Freundlich and Temkin models for all studied water pollutants. Pseudo-second-order kinetic model was a fit model for description of the adsorption kinetics of the different cationic and anionic pollutants onto Zr bio-based MOF. These outcomes indicated that Zr bio-based MOF has potential application for adsorption of different types of industrial water pollutants including cationic and anionic dyes and heavy metals. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Fe-MOF was prepared using a simple, green, inexpensive synthesis strategy. • CO conversion was augmented with low methane selectivity. • The catalyst is highly selective for gasoline and light olefin. • The produced gasoline is equivalent to Fluid Catalytic Cracking gasoline. • Pore volume significantly influences the olefin productivity and C 5+ selectivity. The global trend toward sustainability is due to the growing demand for synthetic chemicals and fuels relying on fossil crude oil with the associated concerns of climate change. The Fischer-Tropsch synthesis (FTS) process is a key sustainable pathway for supplying light olefins, gasoline, and other petrochemicals using green hydrogen and energy. Here we report a simple, green, cost-effective synthesis strategy to prepare an iron-based metal–organic framework (Fe-BTC MOF) at room temperature with a remarkable porous structure analogous to the commercially available Basolite F300. The catalyst shows a 97% syngas conversion to gasoline-range hydrocarbons (C 5 -C 12) at high temperatures, with a selectivity of 48.3%, yield of 28%, low methane selectivity (15.5%) and low C 13+ selectivity (1%). In addition, the catalyst is 29% selective to light olefin (C 2 -C 4 =), yielding 17%, besides an olefin/paraffin ratio (O/P) of 4.3 with 81% olefin selectivity of the C 2 -C 4 fraction. The resulting gasoline is equivalent to gasoline produced by Fluid Catalytic Cracking (FCC) of crude oil. The highest C 5 -C 12 selectivity reached 63.6%, yielding 12% at 29% CO conversion. The Fe-BTC/C catalyst showed excellent stability for time on stream >100 h and a high gas hourly space velocity (GHSV) value of 20000 mL g-1 cat h−1 with an Fe-time yield of 165 µmol CO g-1 Fe s−1. The prepared Fe-BTC catalyst, with a 2-fold larger pore volume than the previously prepared Fe-MIL-88B catalyst, has a higher olefin production capability by 2-fold, 7-fold higher O/P for the light fraction and 2.3-fold higher C 5+ selectivity. The sustainable synthesis of catalysts with improved porous structure may significantly foster FTS technology for being economically practical to be scaled up and commercialized for national fuel and olefin production projects. [ABSTRACT FROM AUTHOR]

This study introduces a practical methodology for modeling of self-healing microcapsules-based composites elasticity with experimental verification. The elastic modulus of the matrix material was determined using dynamic mechanical analysis (DMA). In addition, single-microcapsule micromanipulation compression was performed accompanied by 2D finite element modeling (FEM) to extract the elastic modulus of single-microcapsule. Detailed 3D FEMs were constructed to predict the effective elastic properties of the microcapsules-based composites. To define the material properties of these FEMs, both of the elastic moduli of the matrix and the microcapsules were used. Microstructures having packing arrangement of simple cubic (SC), body-centered cubic (BCC), face-centered cubic (FCC), and random-monodispersed (RM) microcapsules were investigated. The microcapsules size and shell wall thickness reflect the microstructural geometry at definite volume fractions. Dynamic mechanical analysis was performed to determine the elastic modulus of prepared composites containing 5, 10, and 20 vol% microcapsules. Finally, experimental verification was obtained by comparing the experimental work to the FEM results. Good agreement was achieved. It was found that the volume fraction and the packing arrangement of the microcapsules in the composite were the only parameters that affect the composite effective elastic modulus, while the size and shell thickness of the microcapsules are not effective. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to develop a new simple technique to synthesize graphene film on a flexible polyethylene terephthalate (PET) substrate and applied as a strain sensor. Design/methodology/approach – Graphene film was synthesized using laser treatment of graphene oxide (GO) film deposited on PET substrate. A universal laser system was used to simultaneously reduce and pattern the GO film into laser reduced graphene oxide (LRGO) film. Findings – The laser treatment synthesizes a multilayer graphene film with overlapped flakes, which shows structure integrity, mechanical flexibility and electrical conductivity of 1,330 S/m. The developed LRGO/PET film was used to fabricate a high sensitivity strain sensor. The sensitivity and temperature dependency of its gauge factor (GF) was examined at applied strains up to 0.25 per cent and operating temperatures up to 80°C. The fabricated sensor shows stable GF of approximately 78 up to 60°C with standard error of the mean not exceeding approximately ± 0.2. Originality/value – The proposed method offers a new simple and productive technique of fabricating large-scale graphene-based flexible devices at a low cost. [ABSTRACT FROM AUTHOR]