Optimized catalysts show great potential for renewable energy storage and conversion. Herein, we report metallic CuCo2S4 nanosheets (NSs) of atomic thickness as efficient bifunctional electrocatalysts for use in portable, flexible Zn-air batteries. The metallic CuCo2S4 NSs of atomic thickness with 4-atom-thick to 6-atom-thick layers are confirmed by temperature-dependent electrical resistance measurements and atomic force microscopy. Furthermore, extended X-ray absorption fine structure spectroscopy confirms that CuCo2S4 NSs with sulfur vacancies can further increase the OER activity. Due to high electrical conductivity and ultrathin nanosheet structure with abundant defects, CuCo2S4 NSs exhibit excellent reversible oxygen catalytic performance with an overpotential of 287 mV (at j = 10 mA cm-2) for the oxygen evolution reaction (OER) and an onset potential of 0.90 V for the oxygen reduction reaction (ORR). Additionally, the portable, flexible Zn-air battery using CuCo2S4 NSs as the air-cathode displays a high open circuit voltage and strong rechargeable capacity for 18 h. The present study highlights the importance of designing metallic catalysts having atomic thickness with surface defects for highly efficient and stable renewable energy storage and conversion.
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http://dx.doi.org/10.1039/c8nr01381k | DOI Listing |
Langmuir
January 2025
Univ. Rouen Normandie, Normandie Univ., SMS, UR 3233, F-76000 Rouen, France.
It has been shown that depositing ketoprofen as thin films on glass substrates has a stabilizing effect on the amorphous state of ketoprofen. Polyethylene glycol ( = 6000 g/mol) was mixed with ketoprofen in a wide range of concentrations. Amorphous thin films were prepared by spin coating and subjected to storage conditions with different levels of relative humidity.
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January 2025
Department of Physics and Chemistry, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Republic of Korea.
Magnetotransport of conventional semiconductor based double layer systems with barrier suppressed interlayer tunneling has been a rewarding subject due to the emergence of an interlayer coherent state that behaves as an excitonic superfluid. Large angle twisted bilayer graphene offers unprecedented strong interlayer Coulomb interaction, since both layer thickness and layer spacing are of atomic scale and a barrier is no more needed as the twist induced momentum mismatch suppresses tunneling. The extra valley degree of freedom also adds richness.
View Article and Find Full Text PDFNat Commun
January 2025
College of Materials Science and Technology; Key Laboratory of Material Preparation and Protection for Harsh Environment; Nanjing University of Aeronautics and Astronautics, Nanjing, 211100, China.
With the development of nanotechnology, nano-functional units of different dimensions, morphologies, and sizes exhibit the potential for efficient microwave absorption (MA) performance. However, the multi-unit coupling enhancement mechanism triggered by the alignment and orientation of nano-functional units has been neglected, hindering the further development of microwave absorbing materials (MAMs). In this paper, two typical ZIF-derived nanomaterials are self-assembled into two-dimensional ordered polyhedral superstructures by the simple ice template method.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, P. R. China.
Van der Waals interaction in multilayer structures was predicted to be of many-body character, almost in parallel with the establishment of Lifshitz theory. However, the diminishing interaction between layers separated by a finite-thickness intermediate layer prevents experimental verification of the many-body nature. Here we verify the substrate contribution at the adhesion between the atomic force microscopy tip and the supported graphene, by taking advantage of the atomic-scale proximity of two objects separated by graphene.
View Article and Find Full Text PDFNat Commun
January 2025
Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, USA.
Aqueous corrosion of metals is governed by formation and dissolution of a passivating, multi-component surface oxide. Unfortunately, a detailed atomistic description is challenging due to the compositional complexity and the need to consider multiple kinetic factors simultaneously. To this end, we combine experiments with a first-principles-derived, multiscale computational framework that transcends thermodynamic descriptions to explicitly simulate the kinetic evolution of surface oxides of Ni-Cr alloys as a function of composition, temperature, pH, and applied voltage.
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