Intergrating Hollow Multishelled Structure and High Entropy Engineering toward Enhanced Mechano-Electrochemical Properties in Lithium Battery.

Hollow multishelled structures (HoMSs) are attracting great interest in lithium-ion batteries as the conversion anodes, owing to their superior buffering effect and mechanical stability. Given the synthetic challenges, especially elemental diffusion barrier in the multimetal combinations, this complex structure design has been realized in low- and medium-entropy compounds so far. It means that poor reaction reversibility and low intrinsic conductivity remain largely unresolved. Here, a hollow multishelled (LiFeZnNiCoMn)3O4 high entropy oxide (HEO) is developed through integrating molecule and microstructure engineering. As expected, the HoMS design exhibits significant targeting functionality, yielding satisfactory structure and cycling stability. Meanwhile, the abundant oxygen defects and optimized electronic structure of HEO accelerate the lithiation kinetics, while the retention of the parent lattice matrix enables reversible lithium storage, which is validated by rigorous in situ tests and theoretical simulations. Benefiting from these combined properties, such hollow multishelled HEO anode can deliver a specific capacity of 967 mAh g-1 (89% capacity retention) after 500 cycles at 0.5 A g-1. The synergistic lattice and volume stability showcased in this work holds great promise in guiding the material innovations for the next-generation energy storage devices.

A novel insight into the microwave induced catalytic reduction mechanism in aqueous Cr(VI) removal over ZnFe2O4 catalyst.

Aqueous Cr(VI) pollution is an emerging environmental issue. Herein, a sphere-like ZnFe2O4 catalyst with a size of ∼430 nm was prepared by a solvothermal method, by which the aqueous Cr(VI) in a 50 mL solution with concentration of 50 mg/L was completely removed after 10 min-microwave (MW) irradiation. "Surface temperature visualization" tests and COMSOL simulations showed that the surface temperature of the as-prepared ZnFe2O4 catalysts could be as high as > 1000 °C only after 300 s MW irradiation, and the work function calculations and scavenging experiments demonstrated that the excited electrons derived by the "hot spots" effect of the ZnFe2O4 catalysts reduced the Cr(VI) to Cr(III). Kinetic reaction process of the reduction of *Cr2O72- to *CrO3H3 over the ZnFe2O4 catalysts was clarified by using DFT calculation, and the results indicated that *Cr2O72- adsorbed on the Fe atoms was more easily to be reduced, and that Fe atoms played more significant roles than the Zn and O atoms in ZnFe2O4 catalysts. The present study not only proves that the MW induced ZnFe2O4 catalytic reduction was promising for ultrafast remediation of toxic Cr(VI), but also provides a new insight into the corresponding mechanism.

Thermal development of the endoparasitoid Aphelinus maculatus Yasnosh (Hymenoptera: Aphelinidae) parasitizing Myzus persicae Sulzer (Homoptera: Aphididae).

The aphid parasitoid, Aphelinus maculatus Yasnosh, was first documented in China in 2016. It is important to make clear of the effects of temperatures on the development of this aphid parasitoid for the future using as a aphid biological control agent. So the thermal requirements, lower developmental threshold (t), thermal constant (K), upper developmental threshold (Tm) and optimum developmental temperature (To) for the egg-mummy, mummy-adult and egg-adult periods of A. maculatus were established under the laboratory conditions. The studies were conducted at five constant temperatures (13, 18, 23, 28, and 33 °C) and with a 16 L: 8D photoperiod. Lower developmental threshold (t) and thermal constant (K) were estimated by fitting linear model. Upper developmental threshold (Tm) and optimal developmental temperature (To) were estimated by fitting Logan I non-linear model. The results turned out that the lower (t) and the upper developmental thresholds (Tm) for egg-adult period were 5.59 °C and 28.17 °C, respectively. The thermal constants (K) for egg-mummy, mummy-adult, and egg-adult periods were estimated at 121.51, 127.88, and 243.90 degree-days, respectively. The optimal developmental temperature (To) for egg-adult period was 27.45 °C calculated by the model, but the survival rate was only 40.68% at the temperature of 28 °C. The highest survival rate was 74.32% at temperature of 23 °C, implying that A. maculatus preferentially developed at the temperate regions of temperature.

Preparation and Photocatalytic Performance for Degradation of Rhodamine B of AgPt/Bi4Ti3O12 Composites.

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min-1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.

Catalytic Preparation of Carbon Nanotubes from Waste Polyethylene Using FeNi Bimetallic Nanocatalyst.

In this work, carbon nanotubes (CNTs) were synthesized by catalytic pyrolysis from waste polyethylene in Ar using an in-situ catalyst derived from ferric nitrate and nickel nitrate precursors. The influence factors (such as temperature, catalyst content and Fe/Ni molar ratio) on the formation of CNTs were investigated. The results showed that with the temperature increasing from 773 to 1073 K, the carbon yield gradually increased whereas the aspect (length-diameter) ratio of CNTs initially increased and then decreased. The optimal growth temperature of CNTs was 973 K. With increasing the Fe/Ni molar ratio in an FeNi bimetallic catalyst, the yield of CNTs gradually increased, whereas their aspect ratio first increased and then decreased. The optimal usage of the catalyst precursor (Fe/Ni molar ratio was 5:5) was 0.50 wt% with respect to the mass of polyethylene. In this case, the yield of CNTs reached as high as 20 wt%, and their diameter and length were respectively 20-30 nm, and a few tens of micrometers. The simple low-cost method developed in this work could be used to address the environmental concerns about plastic waste, and synthesize high value-added CNTs for a range of future applications.