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Ahmad Lawrence opublikował 5 miesięcy, 1 tydzień temu
Moreover, In-situ High-resolution transmission electron microscope (HRTEM) and Geometrical phase analysis (GPA) evinces that the removal of the dislocated area in the Nano-dl-TNO leads to the contraction of the lattice, alleviation of the total volume expansion, causing the symmetrization and preserves structural stability. The present findings and designed approach reveal the rose-colored perspective of dislocation engineering into mixed transition metal oxides as next-generation anodes for advanced lithium-ion batteries and all-solid-state lithium-ion batteries.Transition metal phosphides hold great promise for high performance battery-type electrode materials due to their superb electrical conductivity and high theoretical capacity. Unfortunately, the electrochemical properties of single metal or bimetallic phosphides are unsatisfactory owing to their low energy density and poor cyclic stability, and one feasible approach is to introduce heteroatoms to form trimetallic phosphides. Here, novel Fe-Co-Ni-P nanosheet arrays are in situ synthesized on a flexible carbon cloth substrate via an electrodeposition method followed by a phosphorization treatment. Due to the presence of abundant redox active sites, large specific surface area with mesoporous channels, desirable electrical conductivity, modified electronic structure, and synergistic effect of Fe, Co, and Ni ions, the as-prepared Fe-Co-Ni-P electrode displays significantly enhanced electrochemical performance when compared to bimetallic phosphides Fe-Co-P and Fe-Ni-P. Remarkably, the Fe-Co-Ni-P electrode exhibits a large specific capacity of 593.0 C g-1 at 1 A g-1, exceptional rate performance (80.3% capacity retention at 20 A g-1), and good cycling stability (84.2% capacity retention after 5000cycles). Besides, an asymmetric supercapacitor device with Fe-Co-Ni-P electrode as a positive electrode and a hierarchical porous carbon as a negative electrode shows a high energy density of 57.1 Wh kg-1 at a power density of 768.5 W kg-1 as well as excellent cyclability with 88.4% of initial capacity after 10,000cycles. This work manifests that the construction of trimetallic phosphides is an effective strategy to solve the shortcomings of single or bimetallic phosphides for high-performance supercapacitors.
Polymeric anisotropic soft microparticles show interesting behavior in biological environments and hold promise for drug delivery and biomedical applications. However, self-assembly and substrate-based lithographic techniques are limited by low resolution, batch operation or specific particle geometry and deformability. Two-photon polymerization in microfluidic channels may offer the required resolution to continuously fabricate anisotropic micro-hydrogels in sub-10µm size-range.
Here, a pulsed laser source is used to perform two-photon polymerization under microfluidic flow of a poly(ethylene glycol) diacrylate (PEGDA) solution with the objective of realizing anisotropic micro-hydrogels carrying payloads of various nature, including small molecules and nanoparticles. The fabrication process is described via a reactive-convective-diffusion system of equations, whose solution under proper auxiliary conditions is used to corroborate the experimental observations and sample the configuration space.
By tunied morphology, stiffness, and surface properties for the sustained release of therapeutic agents.Many-body forces play a prominent role in structure and dynamics of matter, but their role is not well understood in many cases due to experimental challenges. Here, we demonstrate that a novel experimental system based on rotating electric fields can be utilised to deliver unprecedented degree of control over many-body interactions between colloidal silica particles in water. We further show that we can decompose interparticle interactions explicitly into the leading terms and study their specific effects on phase behaviour. We found that three-body interactions exert critical influence over the phase diagram domain boundaries, including liquid-gas binodal, critical and triple points. Phase transitions are shown to be reversible and fully controlled by the magnitude of external rotating electric field governing the tunable interactions. Our results demonstrate that colloidal systems in rotating electric fields are a unique laboratory to study the role of many-body interactions in physics of phase transitions and in applications, such as self-assembly, offering exciting opportunities for studying generic phenomena inherent to liquids and solids, from atomic to protein and colloidal systems.The development of a scalable strategy to prepare highly efficient and stable bifunctional electrocatalysts is the key to industrial electrocatalytic water splitting cycles to produce clean hydrogen. Here, a simple and quick one-step hydrothermal method was used to successfully fabricate a three-dimensional core chrysanthemum-like FeS/Ni3S2 heterogeneous nanoarray (FeS/Ni3S2@NF) on a porous nickel foam skeleton. Compared with the monomer Ni3S2@NF, the chrysanthemum-like FeS/ Ni3S2@NF heterostructure nanomaterials have improved catalytic performance in alkaline media, showing low overpotentials of 192 mV (η10) and 130 mV (η-10) for OER and HER, respectively. This study attests that integrated interface engineering and precise morphology control are effective strategies for activating the Ni3+/Ni2+ coupling, promoting charge transfer and improving the intrinsic activity of the material to accelerate the OER reaction kinetics and promote the overall water splitting performance. The scheme can be reasonably applied to the design and development of transition metal sulfide-based electrocatalysts to put into industrial practice of electrochemical water oxidation.At present, the magnetic metal/carbon composites have been widely explored for microwave absorption (MA), which effectively integrate the characteristics of magnetic and dielectric materials. As a typical material, metal-organic framework (MOF) shows tremendous potential as a precursor or template. However, its development is limited by the inferior impedance matching. Herein, a novel rod-like Fe/Fe3O4/FeN/N-doped carbon (FON/NC) composite was synthesized via dual-ligand strategy and following calcination. The outer polypyrrole (PPy) shell, obtained by a facile polymerization method, effectively optimized the impedance matching and observably enhanced the MA capacity. Both the multi-component loss mechanism and unique porous core-shell structures of MOF-derived composites were beneficial for microwave attenuation. The effects of filler loadings (20 wt%, 25 wt%, 30 wt% and 35 wt%) on electromagnetic (EM) properties of FON/NC@PPy composites were discussed. Remarkably, as-obtained composites exhibited a minimum reflection loss (RL) value of -60.08 dB at the layer thickness of merely 1.44 mm and the widest effective absorption bandwidth (EAB, RL ≤ -10 dB) of 5.06 GHz at 1.64 mm with 30 wt% filler loading. This work provides a great reference for designing MOF-derived absorbers with high MA performance.
Shear-thickening micelles were mostly made of cationic surfactants, but shear-thickening was rarely reported in the zwitterionic/anionic surfactants. Since wormlike micelles were essential in shear-thickening systems, it should be common for the hybrid wormlike micelles formed by zwitterionic/anionic surfactants, and their fundamental features need to be clarified.
The micellization of zwitterionic surfactant homologies alkyl dimethyl amidopropyl hydroxyl sulfobetaine (AHSB) and sodium dodecyl sulfate (SDS) in brine was studied, and various environmental factors were considered systematically. Light scattering, rheology, zeta potential,
H NMR and cryo-TEM techniques were employed to characterize the AHSB/SDS wormlike micelles.
AHSB/SDS hybrid wormlike micelles were formed in a wide x
region to endow them with apparent viscosities, in which the electrostatic and hydrophobic interactions between AHSB and SDS molecules were critical. AHSB with the longer tail, the higher c
and c
were advantageous ted by cryo-TEM. Moreover, the quantitative relationships on the critical shear rate ɣ̇c were established, and the activation energies were obtained from the temperature-dependent ɣ̇c.As a typical two-dimensional (2D) metal chalcogenides and visible-light responsive semiconductor, zinc indium sulfide (ZnIn2S4) has attracted much attention in photocatalysis. However, the high recombination rate of photogenerated electrons and holes seriously limits its performance for hydrogen production. In this work, we report in-situ photodeposition of Ni clusters in hierarchical ZnIn2S4 nanoflowers (Ni/ZnIn2S4) to achieve unprecedented photocatalytic hydrogen production. The Ni clusters not only provide plenty of active sites for reactions as evidenced by in-situ photoluminescence measurement, but also effectively accelerate the separation and migration of the photogenerated electrons and holes in ZnIn2S4. Consequently, the Ni/ZnIn2S4 composites exhibit good stability and reusability with highly enhanced visible-light hydrogen production. In particular, the best Ni/ZnIn2S4 photocatalyst exhibits an unprecedented hydrogen production rate of 22.2 mmol·h-1·g-1, 10.6 times that of the pure ZnIn2S4 (2.1 mmol·h-1·g-1). And its apparent quantum yield (AQY) is as high as 56.14% under 450 nm monochromatic light. Our work here suggests that depositing non-precious Ni clusters in ZnIn2S4 is quite promising for the potential practical photocatalysis in solar energy conversion.Zeolitic imidazolate framework-67 (ZIF67) derivatives are considered as promising active materials for energy storage owing to the possible formation of cobalt oxide and N-doped graphite. Cobalt oxide has multiple redox states for generating redox reactions for charge storage, while N-doped graphite can provide high electrical conductivity for charge transfer. In this study, it is the first time to synthesize binder-free electrodes composed of cobalt oxide and N-doped graphite derived from ZIF67 on carbon cloth (CC) for supercapacitor (SC). Successive oxidation and carbonization along with additional coverage of ZIF67 derivatives are applied to synthesize ZIF67 derivatives composed of cobalt oxide, N-doped graphite and cobalt oxide/N-doped graphite composites with different layer compositions. The highest specific capacitance (CF) of 90.0F/g at 20 mV/s is obtained for the oxidized ZIF67/carbonized ZIF67/carbon cloth (O67/C67/CC) electrode, due to the large surface area and high electrical conductivity benefitted from preferable morphology and growing sequence of Co3O4 and N-doped graphite. The symmetric SC composed of O67/C67/CC electrodes shows the maximum energy density of 2.53 Wh/kg at the power density of 50 W/kg. Cycling stability with CF retention of 70% and Coulombic efficiency of 65% after 6000 times repeatedly charge/discharge process is also obtained for this symmetric SC.Energy band structures greatly determine the charge separation and transfer properties in heterojunction photocatalysts and consequently their photocatalytic activities. Herein, a well-designed Z-scheme ZnIn2S4-S/CNTs/RP (ZIS-S/CNTs/RP) nanocomposite was fabricated according to an energy band alignment steering strategy to realize superior photocatalytic H2 evolution performance. The ZIS-S/CNTs/RP nanocomposite shows an efficient photocatalytic H2 evolution rate of 1639.9 μmol g-1h-1, which is noticeably higher than that of pristine red phosphorus (RP) and CNTs/RP and ZIS-S/RP composites, as well as those of the compared heterojunctions using bulk RP or ZnIn2S4. Owing to the modification of nanosized RP and the introduction of sulfur vacancies in ZnIn2S4, a tailored energy band alignment of the heterojunction with a higher reduction potential and larger Fermi level potential difference was achieved, which resulted in significantly increased photogenerated electron-hole separation efficiency and a more efficient Z-scheme charge transfer mechanism, thus promoting the photocatalytic activity of ZIS-S/CNTs/RP.