Two-dimensional (2D) metal–organic framework nanosheets (MONs) or membranes are classes of periodic, crystalline polymeric materials that may show unprecedented physicochemical properties due to their modular structures, high surface areas, and high aspect ratios. Yet preparing 2D MONs from multiple components and two different types of polymerization reaction remains challenging and less explored. Here, we report the synthesis of MOF films via interfacial polymerization, which involves three active monomers for simultaneous polycondensation and polycoordination taking place in a confined interface. The well-defined lamellar structure of the MOF films allowed feasible and scalable exfoliation to produce free-standing 2D MONs with high aspect ratio up to 2000:1 and ultrathin thickness (∼1.7 nm). The pore structure was revealed by high-resolution TEM images with near-atomic precision. The imide-linkage of MONs provided superior thermal (up to 530 °C) and good chemical stability in the pH range from 3 to 12. More importantly, the MONs exhibited exceptional catalytic activity and superior reusability for the hydroboration reactions of alkynes, in which the turnover frequency (TOF) reached 41734 h–1, which is 2–4 orders of magnitude greater than that reported for homogeneous and heterogeneous catalysts.

Covalent organic framework (COF) materials with porous character and robust structure have significant applied implications for Kion battery (KIB) anodes, but they are limited by the low reversible capacity and inferior rate capability. Here, based on theoretical calculations, we identified that a porous bulk COF featuring numerous pyrazines and carbonyls in the π-conjugated periodic skeleton could provide multiple accessible redox-active sites for high-performance potassium storage. Its porous structure with a surface-dominated storage mechanism enabled the fast and stable storage of K-ions. Its insolubility in organic electrolytes and small volumetric change after potassiation ensured a robust electrode for stable cycling. As a KIB anode, this bulk COF demonstrated an unprecedentedly outstanding combination of reversible capacity (423 mAh g −1 at 0.1 C), rate capability (185 mAh g −1 at 10 C), and cyclability. The theoretical simulation and comprehensive characterizations confirmed the active sites are contributed by C�O, C�N, and the cation−π effect.

The design of adsorbents for rapid, selective extraction of ultra-trace amounts of gold from complex liquids is desirable from both an environmental and economical point of view. However, the development of such materials remains challenging. Herein, we report the fabrication of two vinylene-linked two-dimensional silver(I)-organic frameworks prepared via Knoevenagel condensation. This material enables selective sensing of gold with a low limit of detection of 60 ppb, as well as selective uptake of ultra-trace gold from complex aqueous mixtures including distilled water with 15 competing metal ions, leaching solution of electronic waste (e-waste), wastewater, and seawater. The present adsorbent delivers a gold adsorption capacity of 954 mg g−1, excellent selectivity and reusability, and can rapidly and selectively extract ultra-trace gold from seawater down to ~20 ppb (94% removal in 10 minutes). In addition, the purity of recovered gold from e-waste reaches 23.8 Karat (99.17% pure).

Micro/nanoplastic (MNP) contamination in nonmarine waters has evolved into a notable ecotoxicological threat to the global ecosystem. However, existing strategies for MNP removal are typically limited to chemical flocculation or physical filtering that often fails to decontaminate plastic particulates with ultrasmall sizes or ultralow concentrations. Here, we report a self-driven magnetorobot comprising magnetizable ion-exchange resin sphere that can be used to dynamically remove or separate MNPs from nonmarine waters. As a result of the long-range electrophoretic attraction established by recyclable ion-exchange resin, the magnetorobot shows sustainable removal efficiency of >90% over 100 treatment cycles, with verified broad applicability to varying plastic compositions, sizes, and shapes as well as nonmarine water samples. Our work may facilitate industry-scale MNP removal with affordable cost and minimal secondary pollution and suggests an appealing strategy based on self-propelled micro/nanorobots to sample and assess nanoplastics in aqueous environment.

Covalent organic frameworks (COFs) with one-dimensional (1D) pores are capable of sulfur encapsulation; however, the physical absorption leads to an insufficient suppression on the shuttle of lithium polysulfides that ultimately cripples the performance of lithium–sulfur batteries (LSBs). Here, we prepared two vinylene-linked COFs bearing different pores, denoted as COF-1 and COF-2. Interestingly, COF-1 can only physically isolate sulfur to give S-COF-1, while the polysulfide chains can be covalently linked to the framework of COF-2 via inverse vulcanization to produce S-COF-2. S-COF-1 and S-COF-2 deliver superior capacities of 1179 and 1293 mAh g–1 at 0.2C, an outstanding rate performance (331 and 692 mA h g–1 at 3C), and a prolonged cycling life span (a low declining value of 0.09% per cycle at 1C for S-COF-2). Due to the synergistic effect of covalent linking and physical confinement of sulfur, S-COF-2 features a superior LSBs performance compared to S-COF-1. Our studies provide a strategy for improving the performances of LSBs by combining the chemical and physical installation of sulfur.

were proposed to be mainly responsible for the adsorption and activation of CO. [5] Meanwhile, the TiO 2 support was also demonstrated to play a crucial role in determining the catalytic activity. In addition to stabilize the gold particles, it participates in the activation of O 2 , which acts as the most crucial step during CO oxidation. [6] Based on experimental observations that the activity of Au/TiO 2 catalysts for CO oxidation was almost proportional to the total length of the interfacial perimeter, the active sites are now popularly viewed to locate at the gold-support interfacial perimeter. [7] The interface Au-Ti 4+ site is largely responsible for activating O 2 via an Au-assisted Mars-van Krevelen mechanism. [2a] This is intimately associated with the size of gold particles; smaller particles result in a larger length of interfacial perimeter and therefore a higher activity. [8] It should be noted that elaboration of the size effect of gold particles and identification of the active sites on Au/ TiO 2 catalysts for CO oxidation, also strongly depend on the reaction conditions, especially the temperature that may alter the reaction pathways. [9] At room temperature and above, CO oxidation proceeds via the typical Mars-van Krevelen mechanism; the lattice oxygen in TiO 2 at Au-TiO 2 interface is reactively removed by CO, resulting in the reduction of the catalyst surface that is replenished by O 2 in the feed gas. [10] As such, the amount of reactive oxygen species coincides with the number of the active sites around Size-controlled Au colloids in the range of 2-5 nm are synthesized in aqueous phase solution and deposited on TiO 2 , yielding Au/TiO 2 catalysts containing relatively uniform gold particles with mean sizes of 2.2, 3.4, and 4.8 nm. Detailed structural analyses verify that the shape of Au particles evolve from a flat polyhedral to a rounded truncated-octahedron when increasing the size from 2.2 to 4.8 nm because smaller gold particles have a higher adhesion energy on TiO 2 . The atomic configurations of Au particles and the Au-TiO 2 interfacial perimeters are quantitatively analyzed as a function of Au particle size. Smaller gold particles show apparently much higher activity for lowtemperature oxidation of CO than the big ones, primarily because of the rich number of active sites at the interfaces. Specific reaction rates, normalized with the total length of the interfacial perimeters in the catalysts, however, are essentially identical. This suggests that the size effect of Au particles, in the range of 2-5 nm, originates from the bonding strength between Au nanoparticles and TiO 2 surfaces. Au/TiO 2 CatalystsThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.

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The efficient separation of acetylene (C2H2) from its mixture with carbon dioxide (CO2) remains a challenging industrial process due to their close molecular size/shapes and similar physical properties. Herein, we...