查看更多>>摘要：? 2022 Elsevier B.V.Antimony (Sb) is attractive as a high-capacity anode for sodium-ion batteries, but undergoes structural degradation and instability of the solid-electrolyte interphase caused by the large volume change during cycling. Here, we demonstrate a unique Sb-based composite anode by embedding the Sb nanoparticles into the conductive hierarchical porous graphitic carbon (HPGC) that leaves enough room for volume change and is further encapsulated by a uniform conductive nitrogen-doped carbon (NC) layer to act as an electrolyte barrier. Such a design enables the Sb@HPGC/NC composite to exhibit a high capacity of 639 mAh g?1, stable cycling stability, and a commercial-level areal capacity of 3.11 mAh cm?2. In addition, full cells by coupling with sodium vanadium phosphate cathode deliver a high energy density of 223.4 Wh kg?1 with superior rate performance. This work provides a bright way for the rational design and construction of Sb-based anode materials for advanced SIBs.
查看更多>>摘要：? 2022 Elsevier B.V.The construction of heterostructures is an effective way of improving the photo-induced charge carrier migration rate of photocatalysts. In this study, a novel ZIF-derived CoFe2O4/Fe2O3@g-C3N4 (ZIF-CFO/FO@CN) composite was prepared using a feasible coprecipitation and high-temperature calcination approach. The separation of photo-induced charge carriers was effectively promoted due to the formation of Z-scheme heterostructure between g-C3N4 (CN) and ZIF-derived CoFe2O4/Fe2O3 (ZIF-CFO/FO). Meanwhile, combining ZIF-CFO/FO with CN could significantly boost the light response capability and reduce the bandgap of pure CN. Then, the obtained hybrid catalysts were used as an efficient mediator to activate peroxymonosulfate (PMS) for degrading levofloxacin (LVFX) under visible light illumination. The 15% ZIF-CFO/FO@CN composite exhibited the best photocatalytic performance for LVFX degradation, and LVFX of 95.1% was degraded within 40 min. Some factors influencing the degradation process in the 15% ZIF-CFO/FO@CN/Vis/PMS system are also discussed. Moreover, the mechanism of the LVFX degradation in this system was analyzed in detail based on the various characterization, LVFX degradation efficiency evaluation, radical species identification, and radical trapping results. The possible LVFX pathway was speculated based on the HPLC-MS measurement. This investigation explored the performance of photocatalysts coupled with PMS for degrading antibiotics from sewage and provided an efficient method for contaminated water treatment.
查看更多>>摘要：? 2022 Elsevier B.V.This work has prepared a series of CuO/g-C3N4 nanocomposites with CuO nanospindles anchoring on g-C3N4 nanosheets by facile ultrasonic treatment and impregnation method. The optimum 15%CuO/g-C3N4 sample exhibited higher efficiency, about 9 times and 20 times than pure g-C3N4 for photocatalytic degradation of Rhodamine B (RhB) and CO2 reduction respectively. Morphology of CuO and composition of CuO/g-C3N4 photocatalysts were fully characterized. The excellent performance of CuO/g-C3N4 nanocomposites is mainly attributed to novel morphology and its pivotal effect on light absorption, dynamics of charge carriers, and regulated band structure. We put forward a new combination method of CuO nanospindles with g-C3N4 nanosheets by simple and green preparation, which may pave the way for the synthesis of CuO/g-C3N4 heterojunctions and its photocatalysis application both in environment and energy.
查看更多>>摘要：? 2022 Elsevier B.V.Dielectric, piezoelectric and electrostrictive properties of antiferroelectric lead zirconate thin films, elaborated by sol gel on alumina substrates, have been studied as a function of the driving field magnitude EAC. Measurement of the displacement shows that the strain for applied fields below the antiferroelectric-ferroelectric transition is relatively small and that its main contribution arises from the electrostrictive effect. At the same time, due to the presence of a residual ferroelectricity, the piezoelectric effect also contributes to the displacement. At higher fields, a large strain is visible which comes mainly from the antiferroelectric to ferroelectric phase transition, the electrostrictive contribution however still being present. Similar to what has been shown for ferroelectric materials, strain versus the square of polarization loops S(P2) of the studied antiferroelectric material, exhibit hysteresis character due to the 180° domain walls which contribute to polarization but not to strain. Simultaneous measurement of polarization and displacement enables the extraction of the electrostrictive coefficient and a value Q = 0.082 ± 0.009 m4 C?2 has been obtained. Subtraction of the pure electrostrictive contribution from the displacement curve allows evidencing that the piezoelectric activity coexists with the electrostrictive effect at low fields. Maximum values of the equivalent piezoelectric coefficients are respectively 93 ± 3 pm V?1 and 100 ± 3 pm V?1 for the positive and the negative parts of the curve for a driving field magnitude EAC = 700 kV cm?1.
查看更多>>摘要：? 2022 The Author(s)This study presents the characteristics of hot deformation behavior of a Al0.3CoCrFeNi high–entropy alloy in the temperature and strain rate ranges of 1023–1423 K and 10–3–10 s–1, respectively. The constitutive flow behavior was modeled based on the hyperbolic–sinusoidal Arrhenius–type equations and a mathematical relation was used to observe the influence of true strain on material constants. To define the hot workability of the alloy, a processing map was developed based on the principles of the dynamic materials model. Accordingly, a dynamic recrystallization (DRX) domain was identified as prudent for processing in the temperature and strain rate ranges of 1273–1423 K and 10–2–2 × 10–1 s–1 respectively, with a peak efficiency of ~45% at 1423 K/6 × 10–2 s–1. At lower temperatures (1048–1148 K) and strain rates (10–3–3 × 10–3 s–1), a dynamic recovery (DRV) domain was identified with a peak efficiency of 38% at 1123 K/10–3 s–1. A large instability regime occurred above 3 × 10–1 s–1 with an increased tendency of adiabatic shear bands. It extended to lower strain rates 10–2–10?1 s?1 at temperatures< 1123 K, manifested by localized shear bands and grain boundary cracking. At low strain rates (5 × 10–3–10–3 s–1) and temperatures (1148–1298 K), particle stimulated nucleation of new DRX grains occurred at B2 precipitates, though the efficiency of power dissipation dropped sharply to ～9%.
查看更多>>摘要：? 2022 Elsevier B.V.Supercapacitors stand out among some traditional energy storage devices due to their advantages such as long cycle stability, fast charge-discharge performance and high-power density. Therefore, it is necessary to explore high-performance electrode materials for application in supercapacitors. Manganese dioxide (MnO2) has high theoretical capacitance and high energy density, however, the deterioration of volume expansion and low conductivity directly affect its wide application. Graphene has attracted great interest owing to its invention. The combination of graphene and MnO2 can not only highlight the low resistance, large specific surface area and thermal stability of graphene, but also solve the shortcomings of MnO2 alone as an electrode material. The proposal of composite materials has also promoted the development and application of electrode materials in supercapacitors. Hence, this review aims to summarize the synthetic strategies and research progress of MnO2-graphene based multi-element composites, including the combination of MnO2-graphene with various carbon materials, transition metal oxides and conducting polymers, respectively. Finally, the possible development directions of MnO2-graphene based composite electrode materials in the future are also prospected.
查看更多>>摘要：? 2022 Elsevier B.V.Exploration of efficient, inexpensive, and stable electrocatalysts for oxygen evolution reaction (OER) is of great signi?cance for energy conversion and storage. Currently, transition metal oxides (TMOs) show huge potential as electrode materials for OER due to their low-cost, rich redox chemistry and high chemical stability. In this work, we report a facile route for uniformly coating CeO2 nanoparticles (NPs) on the surface of nickel cobalt Prussian blue analogue (NiCo-PBA) derived Co3O4/NiO hollow porous nanocubes (Co3O4/NiO HPN). The accurate control of CeO2 content on the Co3O4/ NiO HPN (Co3O4/NiO@CeO2 HPN) surface can effectively alter the surface electronic states, which tunes the ratio of Co2+/Co3+ and Ni2+/Ni3+ for creating abundant oxygen vacancies. The large surface area of hollow nanocubes derived from NiCo-PBA with porous structure offers more active sites, resulting in the great promotion of OER activity. The prepared Co3O4/NiO@CeO2-2 HPN heterostructure exhibits remarkable OER performance with a low overpotential (290 mV at 10 mA·cm?2), small Tafel slope (66 mV dec?1) and excellent durability. The present method opens a new avenue to the preparation of low-cost and efficient electrocatalysts in OER.
查看更多>>摘要：? 2022 The AuthorsThe authors regret The authors regret for some errors in “Acknowledgements” of the above article. The corrected and final version of the mentioned section of the article is as follows. This work was supported by National Science Center Poland ( NCN) under project No. DEC-2017/27/B/ST5/02557. Karolina Trejgis would further like to thank the Foundation for Polish Science ( FNP) for its support. The authors would like to apologise for any inconvenience caused.
查看更多>>摘要：? 2022 The AuthorsInterest in nanocrystalline (nc) aluminum-lithium (Al-Li) alloys is motivated by the demand for lightweight and high-performance materials for light-weighting applications and superior fuel consumption. Nonetheless, nc metals, including Al are thermally unstable, which hinders their technological applications. In this study, we explore the effect of combining dilute amounts of strontium (1.0 at% Sr) and graphene nanoplatelets (1.0 wt% GNPs) to investigate the thermal stability of a nc Al-Li alloy. Ball milling was used to prepare four samples: Al-Li, Al-Li-Sr, Al-Li-GNPs, and Al-Li-Sr-GNPs, to systematically investigate the role of each added element. Isothermal annealing was conducted at different temperatures to investigate the thermal stability. Despite maintaining a nanometric grain size and high hardness of 70 nm and 1.1 GPa, respectively, after annealing at 773 K for 1 h, the Al-Li-Sr-GNPs sample suffered the most significant grain growth and the highest drop in hardness when compared to the Al-Li-Sr and Al-Li-GNPs samples. Microstructural investigations suggested that competing effects resulting from the spontaneous reaction of both Sr and GNPs with Al at higher temperatures resulted in a declining thermal stability efficiency. The formation and distribution of the rod-like Al4C3 phase at the grain boundaries stood in the way of proper Sr diffusion after annealing and caused the agglomeration of the Al4Sr phase.
查看更多>>摘要：? 2022 Elsevier B.V.VOSO4 is a promising cathode material for lithium-ion batteries owing to its polyanionic structure and the polyvalency of vanadium. In this study, carbon nanotubes (CNTs) and graphene oxide (GO) were adopted for modifying the microstructure and improving the overall performance of VOSO4. Before the chemical synthesis of VOSO4, the CNTs were firstly combined with precursor and CNT-VOSO4@C was formed via a one-step chemical synthesis. The results showed that CNTs could improve the charge–discharge performance of the VOSO4@C. The initial discharge specific capacity of CNT-VOSO4@C was up to 151.6 mAh·g?1 at 0.05 C, and even at 1 C the capacity could reach 66.06 mAh·g?1. The discharge–capacity retention rate is 100% after a long circulation. Secondly, CNTs and GO were composited with the synthesized VOSO4@C and the obtained composites VOSO4@C-CNT and VOSO4@C-GO exhibited good electrochemical properties with initial discharge specific capacities of 135.7 and 141.8 mAh·g?1 at 0.05 C, respectively. This may be attributed to the high specific surface areas and conductivities of CNTs and GO. When grinding the composites, CNTs and GO are uniformly distributed among the particles, forming bridges between the particles, that can increase the electrical conductivity between the particles and reduce the volume expansion of electrode materials. CNT-VOSO4@C exhibits the best modification effect. This study proposes a feasible approach for applying VOSO4 in lithium-ion batteries, particularly under weak currents.
NSTL
Elsevier