Exploring novel versatile electrode materials with outstanding electrochemical performance is the key to the development of advanced energy conversion and storage devices.In this work,we aim to construct new-fangled o...Exploring novel versatile electrode materials with outstanding electrochemical performance is the key to the development of advanced energy conversion and storage devices.In this work,we aim to construct new-fangled one-dimensional(1D)quasi-layered patronite vanadium tetrasulfide(VS_(4))nanostructures by using different sulfur sources,namely thiourea,thioacetamide,and L-cysteine through an ethyleneaminetetraacetic-acid(EDTA)-mediated solvothermal process.The as-prepared VS4exhibits several unique morphologies such as urchin,fluffy nanoflower,and polyhedron with appropriate surface areas.Among the prepared nanostructures,the VS_(4)-1@NF nanostructure exhibited excellent electrochemical properties in 6 M KOH solution,and we explored its redox electrochemistry in detail.The asprepared VS_(4)-1@NF electrode exhibited battery-type redox characteristics with the highest capacity of280 C g^(-1)in a three-electrode assembly.Moreover,it offered a capacity of 123 F g^(-1)in a hybrid twoelectrode set-up at 1 A g^(-1)with the highest specific energy and specific power of 38.5 W h kg^(-1)and750 W kg^(-1),respectively.Furthermore,to ensure the practical applicability and real-world performance of the prepared hybrid AC@NF//VS_(4)-1@NF cell,we performed a cycling stability test with more than 5,000galvanostatic charge–discharge cycles at 2 A g^(-1),and the cell retained around 84.7%of its capacitance even after 5,000 cycles with a CE of 96.1%.展开更多
Two-dimensional asymmetric chalcogen atoms attached to Janus nanoparticles have fascinated research attention owing to their distinctive properties and characteristics for various applications.This paper proposed a fa...Two-dimensional asymmetric chalcogen atoms attached to Janus nanoparticles have fascinated research attention owing to their distinctive properties and characteristics for various applications.This paper proposed a facile synthesis to produce efficient molybdenum-based symmetric and asymmetric chalcogens bounded by X Mo X and TeMo X nanostructures.Subsequently,the fabricated X Mo X and TeMo X nanostruc-tures were employed as anodes for lithiumion batteries(LIBs).Assembled LIBs using TeMoS and TeMoSe Janus anodes achieved 2610 and 2073 mAh g^(-1)reversible capacity at 0.1 A g^(-1),respectively for the halfcell configuration,which is outstanding performance compared with previous reports.Superior rate capability performances at 0.1-20 A g^(-1)and exceptional cycling solidity confirmed high charge and discharge capacities for TeMo X Janus lithium-ion battery anodes.In addition,the full cell device with TeMoS//LiCoO_(2)configuration explored the discharge capacity of 1605 mAh g^(-1)at 0.1 A g^(-1)which suggests their excellent electrochemical characteristics.The density functional theory approximations established the significance of assembled symmetric and asymmetric chalcogen atoms interacted with X Mo X and TeMo X anode materials for LIBs.Thus,the present investigation supports a new approach to creating two-dimensional materials based on asymmetric chalcogen atoms with core metal to effectively increase desirable energy storage characteristics.展开更多
Highly surface active super paramagnetic colloidal suspensions of nano crystalline ferrofluid have been synthesized through wet-chemical route. Entrapment of magnetic domains presented in the nano ferrofluid in a poly...Highly surface active super paramagnetic colloidal suspensions of nano crystalline ferrofluid have been synthesized through wet-chemical route. Entrapment of magnetic domains presented in the nano ferrofluid in a polymer matrix like poly vinyl alcohol film was accomplished by developing polymer composite film in between two magnetic poles by solvent casting method. Similarly poly vinyl alcohol-ferrofluid composite films were also developed in the absence of magnetic field. Atomic force microscopy image of nano-composite film makes it clear that the film developed in the absence of magnetic field possesses randomly oriented domains, whereas film developed with magnetic field shows well aligned flux lines. The characteristics and nature of forces acting between magnetic domains along the magnetic flux lines were explored from magnetic force microscopy imaging. The number of flux lines developed in the polymer matrix was observed to be directly proportional to applied external magnetic field. Approximate number of magnetic lines passing through unit area of composite film was evaluated from line profile data analysis of atomic force microscopy image. The particle sizes of the nanoparticles encapsulated in the polymer matrix were found to be in the range of 10- 20 nm. Scanning electron microscopy micrographs confirm aggregation of ferrofluid particles of ribbon like morphology along the magnetic flux lines. Magnetic properties of the entrapped nanoparticles in polymer matrix film were analyzed using vibrating sample magnetometer at room temperature. The super paramagnetic nature and other magnetic properties were evaluated from the hysteresis loop.展开更多
基金supported by the Research Program of Dongguk University in 2022(No.S-2022-G0001-00016)。
文摘Exploring novel versatile electrode materials with outstanding electrochemical performance is the key to the development of advanced energy conversion and storage devices.In this work,we aim to construct new-fangled one-dimensional(1D)quasi-layered patronite vanadium tetrasulfide(VS_(4))nanostructures by using different sulfur sources,namely thiourea,thioacetamide,and L-cysteine through an ethyleneaminetetraacetic-acid(EDTA)-mediated solvothermal process.The as-prepared VS4exhibits several unique morphologies such as urchin,fluffy nanoflower,and polyhedron with appropriate surface areas.Among the prepared nanostructures,the VS_(4)-1@NF nanostructure exhibited excellent electrochemical properties in 6 M KOH solution,and we explored its redox electrochemistry in detail.The asprepared VS_(4)-1@NF electrode exhibited battery-type redox characteristics with the highest capacity of280 C g^(-1)in a three-electrode assembly.Moreover,it offered a capacity of 123 F g^(-1)in a hybrid twoelectrode set-up at 1 A g^(-1)with the highest specific energy and specific power of 38.5 W h kg^(-1)and750 W kg^(-1),respectively.Furthermore,to ensure the practical applicability and real-world performance of the prepared hybrid AC@NF//VS_(4)-1@NF cell,we performed a cycling stability test with more than 5,000galvanostatic charge–discharge cycles at 2 A g^(-1),and the cell retained around 84.7%of its capacitance even after 5,000 cycles with a CE of 96.1%.
基金supported by the Mid-career Researcher Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(No.2019R1A2C2086747)and the research program of Dongguk University in 2022(No.S-2022-G0001-00016).
文摘Two-dimensional asymmetric chalcogen atoms attached to Janus nanoparticles have fascinated research attention owing to their distinctive properties and characteristics for various applications.This paper proposed a facile synthesis to produce efficient molybdenum-based symmetric and asymmetric chalcogens bounded by X Mo X and TeMo X nanostructures.Subsequently,the fabricated X Mo X and TeMo X nanostruc-tures were employed as anodes for lithiumion batteries(LIBs).Assembled LIBs using TeMoS and TeMoSe Janus anodes achieved 2610 and 2073 mAh g^(-1)reversible capacity at 0.1 A g^(-1),respectively for the halfcell configuration,which is outstanding performance compared with previous reports.Superior rate capability performances at 0.1-20 A g^(-1)and exceptional cycling solidity confirmed high charge and discharge capacities for TeMo X Janus lithium-ion battery anodes.In addition,the full cell device with TeMoS//LiCoO_(2)configuration explored the discharge capacity of 1605 mAh g^(-1)at 0.1 A g^(-1)which suggests their excellent electrochemical characteristics.The density functional theory approximations established the significance of assembled symmetric and asymmetric chalcogen atoms interacted with X Mo X and TeMo X anode materials for LIBs.Thus,the present investigation supports a new approach to creating two-dimensional materials based on asymmetric chalcogen atoms with core metal to effectively increase desirable energy storage characteristics.
文摘Highly surface active super paramagnetic colloidal suspensions of nano crystalline ferrofluid have been synthesized through wet-chemical route. Entrapment of magnetic domains presented in the nano ferrofluid in a polymer matrix like poly vinyl alcohol film was accomplished by developing polymer composite film in between two magnetic poles by solvent casting method. Similarly poly vinyl alcohol-ferrofluid composite films were also developed in the absence of magnetic field. Atomic force microscopy image of nano-composite film makes it clear that the film developed in the absence of magnetic field possesses randomly oriented domains, whereas film developed with magnetic field shows well aligned flux lines. The characteristics and nature of forces acting between magnetic domains along the magnetic flux lines were explored from magnetic force microscopy imaging. The number of flux lines developed in the polymer matrix was observed to be directly proportional to applied external magnetic field. Approximate number of magnetic lines passing through unit area of composite film was evaluated from line profile data analysis of atomic force microscopy image. The particle sizes of the nanoparticles encapsulated in the polymer matrix were found to be in the range of 10- 20 nm. Scanning electron microscopy micrographs confirm aggregation of ferrofluid particles of ribbon like morphology along the magnetic flux lines. Magnetic properties of the entrapped nanoparticles in polymer matrix film were analyzed using vibrating sample magnetometer at room temperature. The super paramagnetic nature and other magnetic properties were evaluated from the hysteresis loop.
