查看更多>>摘要:? 2022 The Author(s)The experimental investigations of multi-component alloy systems require considerable time and effort in terms of sample preparation; in particular, when studying numerous material compositions, the melting, processing, and machining of each specimen at each composition are significantly time- and effort-intensive. To overcome this challenge, the high-throughput evaluation of the stress–strain curves associated with the chemical compositions and microstructures of a Ni–Co–Cr ternary system was performed by estimating the yield stress and tangent modulus via indentation testing. Four diffusion couples (involving the diffusion of Ni and Co) with different nominal Cr contents were prepared, and more than 570 stress-strain curves at the points with different chemical compositions and microstructures were measured. The addition of Cr solute increased the elastic modulus and hardness and decreased the normalized pile-up height, indicating a low strain hardening behavior. The estimated yield stress was strongly dependent on the Cr content, whereas the Co content did not sufficiently affect the strength. Moreover, the effects of crystal orientation on the indentation testing of the face-centered cubic and hexagonal close-packed phases are discussed. The proposed technique can facilitate the evaluation of elastoplastic behavior in multi-component systems in single phase (fcc), which can help achieve the statistical data-driven material development of Ni-based superalloys.
查看更多>>摘要:? 2022 Elsevier B.V.Using clean and renewable solar energy to convert nitrogen to ammonia is promising, however the low utilization of light and the high cost of catalyst restrain its application. Herein, novel two-dimensional(2D) silicate CaCuSi4O10 nanosheet was prepared by high-temperature solid state method using silica derived from palygorskite clay (Pal) and calcium carbonate derived from egg shells, respectively. The photocatalytic nitrogen fixation was performed using CaCuSi4O10 compound as catalyst. The effect of flux content on the ammonia generation rate was investigated. Results demonstrated that the 2D CaCuSi4O10 nanosheet can chemically adsorb and activate N2 due to the high surface area along with abundant oxygen vacancies. The ammonia evolution rate of CaCuSi4O10 can reach up to 60.3 μmol·g?1·h?1 and 15.6 μmol·g?1·h?1 under simulated solar light and near infrared (NIR) light irradiation, respectively. The enhanced photocatalytic nitrogen fixation can be ascribed to the up-conversion capability of CaCuSi4O10, which converts NIR into visible and UV light improving the utilization efficiency of full solar spectrum. Current study may offer a promising strategy for cost-effective photocatalytic nitrogen fixation under full spectrum.
查看更多>>摘要:? 2022 Elsevier B.V.Aqueous Zn ion batteries with cost-effectiveness, high safety, and eco-friendliness have a great potential as an excellent substitute for non-aqueous cells for large-scale energy storage. However, the intercalation of Zn2+ ions in the cathode materials is challenging and complex due to the sluggish diffusion kinetics of Zn2+ ions. Herein, the highly reversible Zn ion battery based on vanadium oxide nanobelts has been developed by using pre-inserted bimetallic ions (Na+ and Ca2+ ions) within the vanadium oxide layer (NCVO) as the cathode and Zn(CF3SO3)2 solution as an electrolyte. Vanadium oxide nanobelts which were calcined at 350 °C (NCVO-350) deliver the superior cycle stability with a capacity retention rate close to 100% after 200 cycles at 0.5 A g?1, and 92% retention is also achieved after 3000 cycles at 10 A g?1. The ultrahigh capacity retentions at low/high current densities are attributed to the pre-inserted bimetallic ions within the layers to enhance the structural stability of the vanadium oxide nanobelts. Moreover, the low-cost electrode material preparation process will accelerate the industrialization of aqueous Zn ion batteries.
查看更多>>摘要:? 2022 Elsevier B.V.A novel three dimensional (3D) N-doped Li4Ti5O12 (LTO) nanoribbon (N-LTONR) network electrode is synthesized by hydrothermal process and subsequent gas-solid reaction. The presence of self-doped Ti3+ and oxygen vacancies in LTO lattice further enhances the intrinsic conductivity. The thin nanoribbons (70 nm in width and 20 nm in thickness) are twisted and intertwined to form a 3D conductive network, and can be directly served as flexible electrode for Li ion batteries (LIB) without using any binder and conductive additives. The optimized N-LTONR electrode exhibits excellent high-rate capability, low-temperature performance and cycle stability. It delivers a areal capacity of 0.26 mAh cm?2 at a high current density of 10 mA cm?2, and has a capacity retention rate of 85.2% after 1000 cycles at 3 mA cm?2. It also displays excellent low-temperature adaptability and retains 78.3% room temperature-capacity even under ? 30 °C, exhibits a low capacity loss (2%) after 100 cycles at 1 mA cm?2 under ? 20 °C. In addition, the 3D nanoribbon network electrode possesses good flexibility and has promising potential to be used for flexible and bendable LIBs.
查看更多>>摘要:? 2022 Elsevier B.V.The ovality variation and texture evolution with annealing temperature of GH4145 alloy tubes that were cold rolled through 2 passes, 3 passes, and 6 passes (from ?32 mm × 3 mm to ?26 mm × 1 mm) were studied. The mechanism of ovality variation was determined by laser scanning confocal microscopy, electron backscattered diffraction, and X-ray diffraction. The best rolling process for GH4145 alloy tubes was identified: cold rolling through 3 passes, which resulted in an area reduction of approximately 24% per pass, followed by annealing at 920 °C for 30 min, via which the lowest ovality could be obtained. In terms of texture evolution, mainly S, copper, and brass textures were distributed in all cold-rolled tubes, and Goss texture was only observed in 2-pass tubes. With increasing annealing temperature, the texture strength first decreased and then increased, and the type of recrystallization texture was the same as that of cold-rolling texture, which was dominated by oriented nucleation. The higher residual stress in the cold rolling process resulted in higher ovality of the tube due to the higher energy storage. The release of residual stress during heat treatment reduced the ovality, while the enhancement of recrystallization texture led to a slight increase in ovality.
查看更多>>摘要:? 2022 Elsevier B.V.Owing to the low cost and renewability, biomass-derived hard carbons (B-HCs) are attractive anode candidates for sodium-ion batteries (SIBs). Although the specific capacity of B-HCs can be further improved by incorporating transition metal sulfides, it also brings out other issues, including the sluggish kinetics, “shuttle effect” of sodium polysulfides and voltage failure. Herein, a facile in-situ synthesis strategy for Fe7S8 inserted N,S co-doped carbon nano-aggregates (Fe7S8-NS/C) is developed. The strong adsorption of sericin to Fe3+ ensures the dispersive distribution of Fe7S8 nanoparticles in carbon matrix, contributing to fast Na+ transport kinetics. The first principles calculations demonstrate the self-doped pyridine N (3.45 at%) and pyrrolic N (7.91 at%) is conducive to Na adsorption, which promotes sodium storage. More importantly, the polar C-S and C-N bonds in the carbon matrix can effectively immobilize sodium polysulfides and inhibit abnormal voltage failure. As an anode material for SIBs, the elaborate Fe7S8-NS/C composite offers high reversible capacity (477 mAh g?1 at 1 A g?1 over 500 cycles) and excellent rate capability (326 mAh g?1 at 5 A g?1). The simple synthesis method and outstanding electrochemical performances make the Fe7S8-NS/C an attractive candidate for SIBs.
查看更多>>摘要:? 2022 Elsevier B.V.Aqueous zinc-ion batteries (ZIBs) have received widespread attention due to their high specific capacity (820 mA h g?1), high safety and low cost. Manganese (Mn)-based oxides show great potential as cathode materials for aqueous ZIBs, but they also face problems of low conductivity and poor rate performance. The introduction of carbon nanotubes (CNTs) can improve the hydrophilicity, enhance the conductivity of Mn-based oxides, and further improve the cycling performances of the ZIBs at high current density. Therefore, in this paper, Mn-based metal-organic-framework (Mn-MOF) is chosen as a template, while carboxylic CNTs are introduced during the synthesis process of Mn-MOF, finally after further calcination, composite material of Mn-based oxides, MOF-derived carbon and CNTs (MnOx@C@CNT) is prepared as the cathode for aqueous ZIBs. After 5000 cycles at a current density of 3 A g?1, the capacity retains 96.7 mA h g?1, while the capacity decay rate is 2% only. This work provides a solution to the challenges of Mn-based oxides for aqueous ZIBs cathode, thus achieve better electrochemical performances.
查看更多>>摘要:? 2022 Elsevier B.V.The development of electrocatalysts that show multifunctionality towards efficient sensing and energy applications are of great significance. Herein, we report a rational design of photochemical deposition of Ag nanoparticles (Ag NPs) on ZIF-67-decorated carbon nanotube (Ag NPs/ZIF-67 @CNT) hybrid, which exhibits dual-functional capabilities for both effective enzymeless glucose detection and electrocatalytic water oxidation. The distribution of Ag NPs on the ZIF-67-functionalized CNT can be optimized by adjusting the concentration of Ag+ aqueous solution during the light illumination process. The optimized Ag NPs/ZIF-67 @CNT composite showed superior glucose-sensing capability with a low determination limit of 0.46 μM (S/N = 3), high sensitivity of 469.4 μA·mM?1·cm?2, wide linearity detection range (0.010–7.0 mM) and short response time (less than 5 s). Also, the Ag NPs/ZIF-67 @CNT composite acting as potential electrocatalyst possessed an overpotential of 286 mV with a Tafel-slope of 80.75 mV dec?1 at 10 mA·cm?2 for high durability water-oxidation reaction. This work provided a feasible way to prepare Ag NPs decorated ZIF-67/CNT with modulated bifunctional catalytic performances via photochemical reduction strategy, which can also provide effective guidance for designing other multifunctional electrocatalysts.
查看更多>>摘要:? 2022 Elsevier B.V.Water splitting is a promising hydrogen production technology limited by the slow kinetic oxygen evolution reaction (OER). The development of highly active and robust OER catalysts is in high demand. A series of three-dimensional (3D) self-supported FeOOH@Ni(OH)2 heterostructures supported on nickel foam are synthesized and used as efficient OER catalysts using a simple hydrothermal method. The benefits of the appropriate 3D nanoflower morphology, the large number of FeOOH nanosheets adhered on the nanoflower surface, the formation of heterogeneous interfaces, and the synergistic effect of Ni(OH)2 and FeOOH significantly improve the OER catalytic performance of the material. The optimal catalyst in 1 M KOH, alkaline artificial seawater (1 M KOH + 1 M NaCl), and alkaline nature seawater (1 M KOH + seawater) require only 285, 286, and 325 mV overpotential, respectively, to achieve 100 mA cm?2 current density and has robust stability. This study contributes to the rational design of interface-engineered heterostructures for seawater splitting by synthesizing high catalytic activity catalysts.
查看更多>>摘要:? 2022 Elsevier B.V.The development of efficient, stable and low-cost bifunctional electrocatalyst for water splitting is of great practical significance for the industrial application of hydrogen production. In this paper, a well-aligned columnar nickel sulfide and NiAl layered double hydroxides composite (NiAl-LDH/Ni3S2) supported on Ni-foam substrate was successfully designed and prepared by successive hydrothermal processes. Ni3S2 nanorod arrays attached to Ni-foam could provide large open space and short ions diffusion path, and NiAl-LDH provides large contact area with electrolyte, thus enabling fast and reversible redox process, which together could promote electrocatalytic activity. Accordingly, the NiAl-LDH/Ni3S2/NF electrode shows excellent HER and OER performance, in which the low overpotentials of 53.6, 90.2 and 209.2 mV are needed to drive the current density of 10, 20 and 100 mA/cm2 for HER, and similarly for OER, it needs 350.4 mV low overvoltage to reach 100 mA/cm2. In the self-assembled device, the overall water splitting reaction can be driven at a cell voltage of 1.56 V when NiAl-LDH/Ni3S2/NF electrode used as cathode and anode, to achieve the current density of 10 mA/cm2, and the loss voltage is only 16.5 mV within 10 h, showing the excellent stability. The well-constructed NiAl-LDH/Ni3S2/NF is a promising material in the area of electrocatalytic water splitting, which is of practical significance to realize the industrial development of hydrogen production.