Fabrication and Catalytic Performance of Highly Stable Multifunctional Core–Shell Zeolite Composites

Multifunctional Fe₃O₄@SiO₂–Au@silicalite-1 core–shell magnetic zeolite composites were fabricated by combining a series of sol–gel process and vapor-phase transfer of silicalite-1 zeolite nanocrystal-seeded silica shells. The obtained composite has high magnetization (32.00 emu/g), stably confined and active gold nanoparticles (ca. 15 nm), and a hierarchical silicalite-1 outer shell. The core–shell composite exhibits a high efficiency of magnetic separability, excellent catalytic performance, and reusability for the reduction of 4-nitrophenol with conversion of 98% in 12 min. Moreover, it preserves a good stability after a high-temperature hydrothermal treatment

Mapping and evaluating global urban entities (2000–2020): A novel perspective to delineate urban entities based on consistent nighttime light data

The differences in the definition of urban areas lead to our contrasting or inconsistent understanding of global urban development and their corresponding socioeconomic and environmental impacts. The existing urban areas were widely identified by the boundaries of built-environment or social-connections, rather than urban entities that are essentially the spatial extents of human activity agglomerations. Thus, this study has attempted to map and evaluate global urban entities (2000–2020) from a perspective of an updated urban concept of urban entities based on the consistent remotely sensed nighttime light data. First, a K-means algorithm was developed to cluster urban and non-urban pixels automatically in consideration of global region division. Then, a post-processing was conducted to enhance the temporal and logical consistency of urban entities during the study period. Rationality assessment indicates that urban entities derived from remotely sensed nighttime light data more effectively reflect the spatial agglomeration extents of human activities than those of physical urban areas. Global urban entities increased from 157,733 km2 in 2000 to 470,632 km2 in 2020 accompanied by a differentiated urban expansion at global, continental, and national levels. Our study provides long-time series and fine-resolution datasets (500 m) and new research avenues for spatiotemporal analysis of global urban entity expansion with the improvement of the understanding of urbanization and the emergence of effective urban mapping theories and approaches.</p

AIEgen-Functionalized Mesoporous Silica Gated by Cyclodextrin-Modified CuS for Cell Imaging and Chemo-Photothermal Cancer Therapy

A novel multifunctional drug delivery system has been constructed by assembling per-6-thio-β-cyclodextrin-modified ultrasmall CuS nanoparticles (CD-CuS) onto fluorescent AIEgen-containing mesoporous silica nanoparticles (FMSN). The CD-CuS nanoparticles are anchored on the surface of benzimidazole-grafted FMSN, acting as a gatekeeper and photothermal agent. The prepared blue-emitting nanocomposite (FMSN@CuS) exhibits good biocompatibility and cell imaging capability. Anticancer drug doxorubicin hydrochloride (DOX) molecules are loaded into FMSN@CuS, and zero prerelease at physiological pH (7.4) and on-demand drug release at an acidic environment can be achieved due to the pH-responsive gate-opening of CD-CuS only at an acidic condition. The FMSN@CuS nanocomposite can generate obvious thermal effect after the exposure of 808 nm laser, which can also accelerate the DOX release. Meanwhile, the fluorescence intensity of DOX-loaded FMSN@CuS increases with the release of DOX, and the intracellular drug release process can be tracked according to the change of luminescence intensity. More importantly, DOX-loaded FMSN@CuS displays efficient anticancer effects in vitro upon 808 nm laser irradiation, demonstrating a good synergistic therapeutic effect via combining enhanced chemotherapy and photothermal therapy

Enhancing Gas Sorption and Separation Performance via Bisbenzimidazole Functionalization of Highly Porous Covalent Triazine Frameworks

In this paper, a series of bisbenzimidazole-functionalized highly porous covalent triazine frameworks (<b>CTF-BIBs</b>) has been constructed from a new organic building block, 1,4-bis­(5-cyano-1<i>H</i>-benzimidazole-2-yl)­benzene, via ionothermal polymerization. The physical porosity and gas adsorption properties of these <b>CTF-BIBs</b> were characterized, and the resulting <b>CTF-BIBs</b> exhibit significantly high Brunauer–Emmett–Teller surface areas (1636–2088 m² g^–1) and notable CO₂ uptakes (86.4–97.6 cm³ g^–1 at 273 K and 1 bar; 48.5–56.8 cm³ g^–1 at 298 K and 1 bar). More importantly, these <b>CTF-BIBs</b> exhibit excellent selective separation abilities for CO₂/N₂, CO₂/CH₄, C₂H₆/CH₄, and C₃H₈/CH₄, particularly for equimolar mixtures C₃H₈/CH₄ (386.6 for <b>CTF-BIB-1</b> under 1 bar and 298 K). Furthermore, transient breakthrough simulations were carried out for equimolar CO₂/C₃H₈/C₂H₆/CH₄ mixtures, and <b>CTF-BIBs</b> display good separation performance in industrial fixed bed adsorbers. These results clearly demonstrate that the synthesized <b>CTF-BIBs</b> may serve as potential materials for CO₂ capture and adsorptive separation for small hydrocarbons