查看更多>>摘要：? 2022 Elsevier B.V.In this study, laser shock peening (LSP) was used to treat NiCoCrAlY coating prepared via arc ion plating (AIP), which is to improve the high temperature oxidation resistance of NiCoCrAlY coating. The oxidation condition is continuous oxidation at 1100 ℃. The results showed that after 150 h oxidation, the samples without LSP treatment had oxide film damage and large-area internal oxidation, and the coating nearly failed. The samples treated by LSP had intact oxide film and strong antioxidant properties. This is attributed to the fact that LSP helps to eliminate large particle clusters on the sample surface, which provides a prerequisite for the uniform growth of thermally grown oxide (TGO). Furthermore, LSP introduces high density dislocations, high density stacking faults and twins, which refines the grains of the coating and provides more diffusion channels for the selective oxidation of Al elements. Due to above reasons, LSP treated sample can form a continuous and uniform Al2O3 oxide scale faster at the initial stage of oxidation, which hinders the diffusion reaction of other elements and keeps TGO in a stable growth stage for a long time. It is proved that LSP is a potential technology for improving the oxidation resistance of NiCoCrAlY coating.
查看更多>>摘要：? 2022Multi-walled carbon nanotube (MWCNT)/Ni-Mn-S composites are derived from MWCNT/Ni/Mn bimetallic metal-organic framework (MOF) for supercapacitor electrodes. Electroconductive MWCNT is introduced into Ni-Mn-S to form a three-dimensional interconnected structure due to the covalent interaction between Ni atoms and C atoms. During energy storage, MWCNT serves as miniature current collector to shorten pathway of electron collection and transmission. In addition, S2- etching agent with Kirkendall effect makes edges and surfaces of the resulted sulfide structures rougher provide more active sites and improves electrochemical performance compared with precursors. By finely adjusting Ni/Mn molar ratio, the prepared MWCNT/Ni-Mn-S composite achieves excellent properties. As-prepared MWCNT/Ni-Mn-S(3:2) exhibits high specific capacitance of 1041 mAh g?1 at 1 A g?1 and good cyclic stability. The capacitance retention reaches 83.3% after 10,000 cycles. The assembled MWCNT/Ni-Mn-S(3:2)//AC hybrid supercapacitor (HSC) also shows high energy density of 25.33 Wh Kg?1 at power density of 829 W Kg?1 and outstanding cycling stability (93.3% after 20,000 cycles), which illustrates MWCNT/Ni-Mn-S(3:2) has important potential in supercapacitor.
查看更多>>摘要：? 2022In many wastewater treatment processes, the discovery of cost-effective electrocatalysts is very important for photoelectrocatalytic reactions. This paper reports a suitable method for the synthesis of high efficiency hybrid photoelectrocatalyst consisting of NiCo layered double hydroxide and CdS, called CdS@NiCo-LDH. 3-D CdS@NiCo-LDH electrode was fabricated on a nickel foam using hydrothermal synthesis. The synthesized electrode showed high specific surface area, efficient electron transportation, and long-term stability. The pH, bias potential, reaction temperature, and dye concentration were evaluated for the degradation of Allura Red in aqueous solution using the synthesized photoelectrocatalyst. TOC and COD of the dye solution were also investigated. The layered architecture of the CdS@NiCo-LDH composite provided more accessible surface for the diffusion of dye and gaseous molecules. The photoelectrocatalyst exhibited excellent stability in the degradation process and the results proved the efficiency of the suggested procedure for dye degradation.
查看更多>>摘要：? 2022 Elsevier B.V.For photocatalytic films, the low degradation efficiency has become an urgent problem to be solved due to the less amount of photocatalytic component. Therefore, it is particularly important to control the matching of interaction effect between each layer by adjusting the photonic crystal and doping, so as to achieve the best photocatalytic performance. Herein, Cu2+ doped TiO2-SiO2 (CTS) layer was deposited on SiO2 photonic crystal layer to construct multilayer structured films via vertical deposition method and calcination process. The photonic crystal/Cu2+ doped TiO2-SiO2 (PC/CTS) film shows the best photocatalytic performance although the amount of catalytic material is little, that is, the degradation rate of RhB by PC/CTS can reach 48.21% after 180 min of visible light irradiation, which is nearly 5 times than that of single-layer CTS film (10.97% after 180 min). Furthermore, a layer of amorphous SiO2 was deposited between SiO2 photonic crystal film and photocatalyst CTS layer to investigate the optical local interaction range of SiO2 photonic crystal. Finally, the mechanism of multilayer structured PC/CTS composite film is discussed, indicating that the synergistic effect between different layers is a decisive factor for effectively improving the visible photocatalytic performance of thin films.
查看更多>>摘要：? 2022The caCTF-1 derived from CTF-1 by carbonization is introduced into the multi-step heat treatment carbon repaired pC-C3N4 to form a 3D interconnected nitrogen-rich carbon structure (caC@pC). Through carbon repairing process, the obtained pC-C3N4 has an extended π-conjugate plane and it is closely interconnected with the nitrogen-rich caCTF-1, thereby accelerating charge transfer, improving energy storage, and exhibiting high specific capacitance (535.8 F·g?1 under 1 A·g?1) and good rate performance. In addition, by employing MOF with diphenyl semicarbazide structural unit as a precursor, NiCoTe2 is prepared by a simple hydrothermal process, which exhibits high redox activity with a high specific capacitance of 2006.0 F·g?1 at 1 A·g?1 and good cycle stability. The hybrid supercapacitor NiCoTe2//caC@pC HSC is assembled with caC@pC as the negative electrode and NiCoTe2 as the positive electrode. When the power density is 790.05 W·kg?1, it exhibits a high energy density of 50.84 Wh·kg?1 and high cycle stability. After 25,000 cycles, the capacitance retention rate is 87.88%.
查看更多>>摘要：? 2022 Elsevier B.V.Two-dimensional (2D) materials can serve as a platform for developing novel spintronic devices and circuits for low-power electronics. In particular, inducing magnetism and injecting spins in graphene have promised the emerging field of graphene spintronics. This review focuses on magnetic proximity effects at the interface of 2D materials and magnetic oxide insulators. We highlight unique spin-related phenomena arising from magnetic exchange interaction and spin-orbital coupling in 2D materials coupled with magnetic oxides. We also describe the fabrication of multifunctional hybrid devices based on spin transport. We conclude with a perspective of the field and highlight challenges for the design and fabrication of 2D spintronic devices and their potential applications in information storage and logic devices.
查看更多>>摘要：? 2022 Elsevier B.V.Based on a microwave-assisted hydrothermal reaction, a new route is proposed to prepare highly pure true nanoparticles (≤15 nm) of the single-phase spinel LiMn2O4 (LMO) at a low temperature (140 °C) and short reaction time (5 min), using exclusively water-soluble reagents. The obtention of this material was confirmed by using different techniques such as X-ray diffractometry, Rietveld crystal structure refinement, inductively coupled plasma-atomic emission spectroscopy and high-resolution transmission electron microscopy. Electrochemical evaluations were performed by using cyclic voltammetry and galvanostatic charge and discharge tests. Only electrodes prepared from spinel LMO nanoparticles with an average size of ~15 nm showed electrochemical activity. From charge and discharge tests at a constant rate of C/5, the electrodes prepared from this active material exhibited an initial specific capacity of 128 mA h g–1 with a capacity retention of 95% after the 27th cycle. The hallmark of the synthesis route here described is the saving of energy while preparing truly nanoparticulate LMO with excellent chemical, structural and promising electrochemical properties.
查看更多>>摘要：? 2022 Elsevier B.V.A novel Ni(OH)2/ZnO hydrangea-like structure is prepared via a facile electrodeposition strategy with the Ni(OH)2 flower-like particles growing on the ZnO layered carrier. This flower-like structure can take advantage of both ZnO and Ni(OH)2, leading to a fast ion/electron transport speed and structural stability, finally, attaining an outstanding specific capacitance (2264.55 F g?1 at 0.5 A g?1), excellent rate performance (601.09 F g?1 at 30 A g?1) and cycle stability (maintain 94.9% specific capacitance after 5000 cycles). The Ni-OH/ZnO//AC asymmetric supercapacitor device achieves a high energy density of 68.44 Wh kg?1 at a power density of 400 W kg?1, demonstrating great potential as an electrode material for energy storage devices. The mechanism of synergistic effect of Ni(OH)2 and ZnO mutually supporting composite structure to improve electrochemical properties is innovatively proposed.
查看更多>>摘要：? 2022 Elsevier B.V.In this paper, we show various memory characteristics of the Ag/AlN/TiN devices for neuromorphic systems. We verified the thickness and the components of the device stack by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). We investigated the long-term memory (LTM) characteristics, and short-term memory (STM) characteristics can be determined by compliance current (CC). It shows LTM characteristics when CC is high and STM characteristics when CC is low. I-V curves for each characteristic were investigated, and potentiation and depression for LTM characteristics. The switching and conduction mechanisms of Ni/Ag/AlN/TiN devices are studied using the schematic drawing of the conducting filament and the energy band diagram, including the work function, electron affinity, and bandgap energy of each layer. The linearity of potentiation and depression was compared for an identical pulse and an incremental pulse. Finally, we investigated Modified National Institute of Standards and Technology (MNIST) pattern accuracy depending on the linearity of potentiation and depression.
查看更多>>摘要：? 2022 Elsevier B.V.Nowadays metal oxide coatings become one of the dominant ways to suppress electrolyte decomposition and consequantly improve cyclicability of high-voltage cathode materials for high energy-density batteries. However electrochemically inert nature and relatively high density of the metal oxides inevitably reduce cathode capacities. Meanwhile weak interfacial binding may induce desorption of the metal oxides during charge/discharge cycling. Herein a new strategy of light-weight g-C3N4/carbon coordinative modification of 5 V cathode material graphite flakes (GF) for dual-ion batteries is provided with aim to maintain graphite capacity and enhance interfacial binding strength simultaneously. Liquid-solid phase separation is utilized to generate multifunctional unique structure of the modification layer consisting of ultrafine g-C3N4 particles embedded homogeneously in carbon matrix, endowing the modified GF with high capacity and cyclicability for anion PF6─ storage simultaneously. A capacity enhancement of ~11% (1 C) is realized compared with that of TiO2/carbon modified GF, demonstrating superiority of the light-weight modification. Meanwhile capacity retention reaches 87% after 1500 charge/discharge cycles (5 C), exhibiting excellent cyclicability. The liquid-solid phase separation is an efficient way to generate homogeneous mixtures. Furthermore, the strategy of light-weight g-C3N4/carbon modification may provide a general way to improve capacity and cyclicability of other high-voltage cathode materials simultaneously.
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