Articles
Journal of Materials Engineering and Performance (10599495)
In this study, transparent magnesium aluminate (MgAl2O4) spinel was fabricated from commercial MgO and Al2O3 nanopowders under controlled conditions using slip casting and spark plasma sintering (SPS). The slip casting parameters, including the pH of the alumina/magnesia slurry and the concentration of the dispersant (Dolapix CE64), were optimized to 12 and 1 wt.%, respectively. Dolapix CE64 was selected for its effectiveness in reducing slurry viscosity at low concentrations while minimizing impurities. The casting was performed with a solid loading of 75 wt.%, and the SPS process was conducted at 1450 °C under a pressure of 70 MPa for 15 min. The morpho-structural and optical properties of the fabricated spinel were analyzed using several techniques, including field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD), energy dispersive x-ray spectroscopy, Fourier transform infrared spectroscopy, and UV-visible spectroscopy. XRD patterns confirmed the formation of a single-phase, high-purity MgAl2O4. FESEM images estimated the grain size of the slip-casted and calcined sample at 800 °C to be approximately 200 nm with a non-spherical morphology. The minimum porosity in the as-cast alumina-magnesia nanocomposite was achieved through a stable slurry with a high solid loading and 1 wt.% Dolapix CE64, resulting in a transmission of 71% in the infrared region and 40-48% in the visible region after the SPS process. © ASM International 2025.
Progress in Organic Coatings (03009440)186
This study presents a novel method to create a UV-curable nanocomposite coating composed of fluorinated polyurethane acrylate (FPUA) and modified graphene oxide (MGO) with exceptional corrosion resistance. The graphene oxide (GO) nanosheets were chemically modified with methacryloxy propyl trimethoxy silane to improve their dispersibility and interactions with the FPUA resin, which was used as the matrix of the prepared coatings. The modification was verified by various techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Different amounts of MGO were added to the FPUA resin to prepare the UV-curable coatings. The physicochemical interactions between the MGO and the binder were investigated by measuring the gel contents, adhesion strength, and thermal stability of the coatings. The corrosion resistance of the nanocomposite was assessed by different methods, and the results showed that adding 2 wt% MGO reduced the film porosity by more than six orders of magnitude. The results also indicated a significant improvement in the resistance to ionic current and charge transfer due to the good dispersion, barrier properties, and strong bonding of the MGO with the polymer matrix. Nevertheless, the excessive loading of MGO could potentially harm the anticorrosion properties of the coating by forming aggregates and corrosive elements diffusion routes. The obtained results revealed that the prepared UV-curable nanocomposite coatings could open up a new avenue for designing anticorrosive nanocomposite coatings based on graphite derivatives. © 2023
Renewable Energy (09601481)226
Photocatalytic fuel cell (PFC) systems can be a new generation of energy production by simultaneously producing electricity and removing organic pollutants from aqueous solutions. A baffling photoreactor is developed for application in a PFC, and the continuous system consists of a light-responsive photoanode (ZnO/Bi2MoO6/MIL-101; ZnO/Bi2MoO6; ZnO) and a photocathode (Cu/CuO/Cu2O). A response surface method (RSM) is presented to characterize the process factors (pH, immobilized catalyst dosage (mg/cm2), and tetracycline concentration (ppm)) on the performance of a reactor designed to optimize degradation efficiency and maximum power generation. The optimal conditions are determined at pH = 7, Catalyst dosage = 0.87 mg/cm2, and tetracycline concentration = 80 ppm. In optimal conditions, other parameters for degradation efficiency (88.8%), open circuit voltage (1.03 V), short circuit current (2.5 mA/cm2), and maximum power generation (0.87 mW/cm2) are obtained. The performance of different photoanodes by linear sweep voltammetry shows a current density of 2.5 mA/cm2 for ZnO/Bi2MoO6/MIL-101, which is 7.8 and 1.8 times higher than ZnO and ZnO/Bi2MoO6 photoanodes, respectively. The flow regime is determined by residence time distribution (RTD) in the novel reactor with the experimental data of 6 tanks-in-series. © 2024 Elsevier Ltd
Journal of Alloys and Compounds (09258388)984
Herein, as a novel idea, a microwave (MW) post-treatment strategy is proposed to modify the structure and surface characteristics of already prepared activated carbons (ACs) for application in non-aqueous Electric Double-Layer Capacitors. Pistachio nutshell-derived carbon is first KOH-activated and then subjected to MW irradiation for 0, 2, 5, and 10 minutes. X-ray Diffraction and Raman analyses show that MW post-treatment leads to structural modifications, and FTIR and XPS analyses reveal relative elimination of surface functional groups which results in subsequent enhancement in water contact angle and renders more favorable surface wetting of carbon by non-aqueous organic electrolyte. The performance characteristics of symmetrical non-aqueous supercapacitors incorporated with the prepared ACs show a significant positive effect of MW irradiation in such a way that 0 and 10-minute-irradiated ACs demonstrate 152 and 392 F g−1 capacities, respectively, at 1.75 A g−1, with the corresponding specific energies and powers of 340 Wh kg−1 and 11 kW kg−1 for AC-10, respectively. This remarkable enhancement in the electrochemical performance is attributed to the effective role of the MW post-treatment in modifying the AC structure as well as providing AC surfaces that have better wettability with less polar non-aqueous electrolyte. Moreover, this strategy is additionally applicable to make hydrophobic activated carbons for other applications as the absorption of less polar contaminants from liquid or gaseous environments. © 2024 Elsevier B.V.
Torabi, M.,
Karimi shervedani, R.,
Shahrokhi, S.M.,
Khosravi, M.,
Mohagheghnia, M.,
Hakami shalamzari, Y. Journal of Energy Storage (2352152X)102
This research introduces the supercapacitive behavior of porous coral-like nickel-cobalt-phosphide composited with reduced graphene nanosheets (RGNs) using a straightforward one-step hydrothermal process. Several surface and electrochemical methods were used to follow the fabrication and study the electrochemical behavior and supercapacitive charge storage performance of the composite (NiCoP/RGNs) and its ancestors (NiP, CoP, NiP/RGNs, and CoP/RGNs). The effects of each component, NiP, Co, and graphene, on the performance of the composite were studied. In the composite with the optimum proportion of ingredients, the presence of NiP contributed to the high specific capacity, Co enhanced the intrinsic conductivity and electrochemical activity, and graphene significantly increased the surface area and electrical conductivity, leading to improved overall performance of the NiCoP/RGNs composite. The NiCoP/RGNs composite exhibited a uniformly shaped porous nanostructure with coral-like morphology and superior specific capacity of 982 C g−1 at 1 A g−1 (2455.6 F g−1), which can be attributed to its substantial specific surface area, notable intrinsic conductivity, and fleeting reversible faradic reaction properties. The asymmetric supercapacitor (ASC), made up of stainless steel modified with NiCoP/RGNs as a positive electrode and industrial active carbon as a negative electrode, revealed a high energy density of 54.63 W h kg−1 at a power density of 749.49 W kg−1 with 81 % capacity retention after 4000 cycles. The research may open up possibilities for the one-step, straightforward production of highly porous bimetallic phosphide materials, combined with graphene nanosheets, to store electrochemical energy. © 2024 Elsevier Ltd
