查看更多>>摘要:The polysulfide shuttle and uncontrollable growth of lithium dendrites are the two fatal troubles that obstruct the practical process of lithium-sulfur batteries. Herein, a composite membrane consisting of metal-organic framework (MOF) Ce-based UiO-67 and glass fiber membrane (UiO-67-GF) is proposed as a dual-functional separator for these issues. On the one hand, the introduced Ce-UiO-67 crystals are capable of efficaciously adsorbing polysulfides and catalyzing their conversion, thereby restraining their shuttle. On the other hand, this MOF provides sufficient lithium-philic functional groups for ensuring the rapid and homogeneous transport of Li ions, and thus a stable Li plating and stripping process can be acquired. Consequently, this MOF-based separator is qualified for simultaneously resolving the challenges of polysulfide shuttle and Li dendrite. The battery with the proposed separator delivers an initial capacity of 919 mAh g(-1) and a limited decay rate of merely 0.04% per cycle for 500 cycles at 1 C. Moreover, even under a lean-electrolyte condition, a high area capacity of 6.0 mAh cm(-2) is still obtained under the increased sulfur loading of 7.0 mg cm(-2). (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要:To develop effective and low-cost enzyme-like nanomaterials in the antibacterial field, we designed an easily performed and highly specific approach to obtain novel ultrathin Ni-V mixed metal oxides (MMOs) with rich oxygen vacancy. Herein, a selenium (Se) doped novel ultrathin Ni-V MMOs were derived from Ni-V layered double hydroxide (LDHs) with Se powder in N-2 instead of direct calcination in the air successfully. After Se doped, the acquired Ni-V MMOs exhibited richer oxygen vacancy and more changeable elemental state, which can drastically promote the oxidase (OXD)/peroxidase (POD)-like activity increasing nearly 2 times compared with Ni-V MMOs. Se-doping endow 3NiV-Se-350 the unique 2D hierarchical nanostructure and the richest oxygen vacancy. More interesting, Se doped Ni-V MMOs calcinated at 350 ? with a Ni/V molar ratio of 3:1 show the best OXD/POD mimic activity among different Ni/V molar ratios, and possess a good reusability for 7 cycles. Mimic activity of 3NiV-Se-350 was attributed to the reactive oxygen species (ROS), such as center dot OH and center dot O-2(-). 3NiV-Se-350 also exhibit bactericidal rate of 71.04% without H2O2 and 98.89% in the presence of H2O2 against E. coli through generating center dot O-2(-). (C) 2022 Elsevier B.V. All rights reserved.