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        검색결과 859

        6.
        2025.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To improve the proton conductivity of the proton exchange membranes (PEM), an amino derivative with sulfonic acid groups was used to modify graphene oxide (GO), resulting in sulfonated graphene oxide (S-GO), which was then incorporated into a perfluorinated sulfonic acid (PFSA) matrix to fabricate a PFSA/S-GO composite membranes. Elevating the doping concentration of S-GO within the composite membrane has resulted in enhanced proton conductivity, outperforming the baseline PFSA membrane across a range of temperatures. Notably, this conductivity ascended to 291.89 mS/cm when measured at 80 °C under conditions of 100% RH. Furthermore, the strong interface interaction between sulfonated graphene oxide and perfluorinated sulfonic acid polymer endowed the composite proton exchange membrane with excellent thermal stability and mechanical strength.
        4,000원
        7.
        2025.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Wearable thermoelectric devices offer a transformative approach to energy harvesting, providing sustainable solutions for powering next-generation technologies. In pursuit of efficient, flexible, biocompatible, and cost-effective thermoelectric materials, zinc oxide (ZnO) has emerged as a distinctive candidate due to its unique combination of favorable properties. This study explores the growth and optimization of ZnO nanorods on conductive carbon fabric (CF) using a simple microwave-assisted solvothermal technique. This method circumvents traditional complex processes that typically involve high temperatures or lengthy growth times, offering advantages such as rapid, uniform, and controllable volumetric heating. By systematically varying growth parameters, including microwave power and reaction time, we established conditions that promote the vertical alignment of ZnO nanorods, essential for enhancing thermoelectric performance. Structural and morphological analyses highlight the pivotal influence of the seed layer and growth parameters in achieving dense, uniform growth of ZnO nanorods. Interestingly, at higher microwave power levels, a transformation from nanorod structures to sheetlike morphologies was observed, likely due to Ostwald ripening, where larger particles grow at the expense of smaller ones. The optimized growth conditions for achieving superior growth and thermoelectric performance were identified as 15 min of growth at 100 W microwave power. Under these conditions, ZnO nanorods exhibited enhanced crystallinity and a higher growth rate, contributing to an improved thermoelectric power factor of 777 nW/mK2 at 373 K. This work underscores the importance of precise parameter control in tailoring ZnO nanostructures for wearable thermoelectric applications and demonstrates the potential of scalable, low-cost methods to achieve high-performance energy-harvesting materials.
        4,800원
        8.
        2025.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Enhancing the energy storage capabilities of supercapacitors (SCs) while preserving their electrochemical performance is crucial for their widespread application. Our research focuses on developing Sb-modified tin oxide (ATO) nanoparticles via a scalable hydrothermal process, offering substantial potential in this domain. The tetragonal nanoparticle structure provides abundant active sites and a highly porous pathway, facilitating rapid and efficient energy storage. Additionally, tin's varied oxidation states significantly enhance redox capacitance. Electrochemical measurements demonstrate ATO's promise as an advanced SC electrode, achieving a peak specific capacitance of 332 F/g at 3 mA/cm2, with robust redox capacitance confirmed through kinetic analysis. Moreover, the ATO electrode exhibits exceptional capacitance retention over 2000 cycles. This study establishes ATO as a leading candidate for future energy storage applications, underscoring its pivotal role in advancing energy storage technologies.
        4,600원
        9.
        2025.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Researchers have made significant strides in developing high-performance anode-supported tubular solid oxide fuel cells (SOFCs). These cells feature a thin, dense electrolyte made of Ba(Zr0.1Ce0.7Y0.2)O3-δ (BZCY). The fabrication process involved several key steps. First, fine BZCY powder was prepared using a co-precipitation method. Next, Ni-BZCY anode tubes were created via an extrusion process, boasting a 34 % porosity and an average pore size of 0.381 μm. To optimize cell performance, a Ni-BZCY/BZCY nanocomposite slurry was applied as an anode functional layer (AFL) using a dip-coating method. The BZCY electrolyte itself was then coated with a vacuum slurry coating, and finally, an LSCF-BZCY cathode was added, prepared with dip-coating methods. Impedance analysis, conducted under open-circuit conditions at 700 °C, revealed impressive electrical characteristics. The BZCY electrolyte showed an ohmic resistance of approximately 0.79 Ωcm-2 and a very low polarization resistance of about 0.036 Ωcm-2. When tested in a humidified hydrogen atmosphere (3 % H2O) at temperatures ranging from 600 °C to 700 °C, these tubular BZCY cells delivered outstanding power output. Specifically, they achieved a remarkable maximum power density of roughly 0.51 Wcm-2 at 700 °C. This research highlights the potential of these advanced tubular solid oxide fuel cells based on the BZCY as a proton conductor for efficient energy conversion.
        4,000원
        10.
        2025.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Lithium- and manganese-rich layered oxide (LMRO) is considered a promising cathode material for lithium-ion batteries owing to its high capacity and energy density. However, operation at a high voltage of 4.8 V leads to several issues including low Coulombic efficiency, poor cycle life, slow kinetics, and voltage decay due to spinel phase transition, hindering commercialization. Herein, we synthesized a cobalt-free LMRO cathode and studied the effect of Nb2O5 and Sb2O3 coating layers on electrochemical performance. The Nb2O5 coating facilitated the formation of a LiNbO3 layer, which enhanced the initial electrochemical performance, including Coulombic efficiency and energy density. Meanwhile, Sb2O3 not only coated the surface but also doped into the bulk structure, thereby increasing capacity and improving rate capability. Comparative analysis using materials with different structural solubility revealed how oxide coatings influenced lithium-ion transport and electrochemical behavior. This study highlights the importance of interfacial engineering for optimizing LMRO cathodes for high-performance lithium-ion batteries.
        4,000원
        11.
        2025.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Zinc oxide has attracted attention due to its high functionality, including chemical stability, high biocompatibility, and excellent optical properties. In particular, when the particles are nano-sized, they exhibit new characteristics, making them suitable for application in UV-filters, photo-catalysts and cosmetics. This paper provides an overview of nano zinc oxide used for UV filters, and summarizes domestic and international production technology and the industrial status of zinc oxide nano-powder. First, the concept and principle of the nano-sized zinc oxide manufacturing process is provided, and various types of manufacturing methods are analyzed, namely, wet process, dry process, and powder process. Next, the results of an analysis of the domestic sunscreen market size and company status are provided. The production processes of major domestic companies and their product characteristics, such as particle size, purity, surface treatment, and transparency of the zinc oxide powder being produced, are analyzed and provided. The characteristics of zinc oxide produced for use in sunscreens, both domestically and internationally, can be summarized as follows. Manufactured zinc oxide powder is white or transparent, and particle size typically ranges from 30 to 200 nm on average, although non-nano sized powders have also been developed in recent years. When used as a coating, the surface to be coated is typically treated with substances such as silicone oil or silane, and the powder is formulated into products by dispersing it in oil- or water-based systems.
        4,000원
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