Boron Nitride Ultrathin Fibrous Nanonets: One-Step Synthesis and Applications for Ultrafast Adsorption for Water Treatment and Selective Filtration of Nanoparticles

Novel boron nitride (BN) ultrathin fibrous networks are firstly synthesized via an one-step solvothermal process. The average diameter of BN nanofibers is only ∼8 nm. This nanonets exhibit excellent performance for water treatment. The maximum adsorption capacity for methyl blue is 327.8 mg g^–1. Especially, they present the property of ultrafast adsorption for dye removal. Only ∼1 min is enough to almost achieve the adsorption equilibrium. In addition, the BN fibrous nanonets could be applied for the size-selective separation of nanoparticles via a filtration process

Highly Sensitive Fluorescence Imaging of Zn²⁺ and Cu²⁺ in Living Cells with Signal Amplification Based on Functional DNA Self-Assembly

Intracellular trace Zn²⁺ and Cu²⁺ play important roles in the regulation of cell function. Considering the limitations of existing metal ion detection methods regarding sensitivity and applicability to living cells, an amplification strategy based on functional DNA self-assembly under DNAzyme catalysis to improve the sensitivity of intracellular Zn²⁺ and Cu²⁺ imaging is reported. In this process, metal ions as cofactor can activate the catalysis of DNAzyme to shear substrate chains, and each broken substrate chain can initiate consecutive hybridizations of hairpin probes (Hx) labeled with fluorophore, which can reflect the information on a single metal ion with multiple fluorophores. The detection limit can reach nearly 80 pM and high-sensitivity fluorescence imaging of intracellular Zn²⁺ and Cu²⁺ can be achieved. The results are important for research on cell function regulation associated with trace Zn²⁺ and Cu²⁺. This approach is also a new way to improve the sensitivity of other trace metal ion imaging

Pressure-Induced Oriented Attachment Growth of Large-Size Crystals for Constructing 3D Ordered Superstructures

Oriented attachment (OA), a nonclassical crystal growth mechanism, provides a powerful bottom-up approach to obtain ordered superstructures, which also demonstrate exciting charge transmission characteristic. However, there is little work observably pronouncing the achievement of 3D OA growth of crystallites with large size (<i>e.g.</i>, submicrometer crystals). Here, we report that SnO₂ 3D ordered superstructures can be synthesized by means of a self-limited assembly assisted by OA in a designed high-pressure solvothermal system. The size of primary building blocks is 200–250 nm, which is significantly larger than that in previous results (normally <10 nm). High pressure plays the key role in the formation of 3D configuration and fusion of adjacent crystals. Furthermore, this high-pressure strategy can be readily expanded to additional materials. We anticipate that the welded structures will constitute an ideal system with relevance to applications in optical responses, lithium ion battery, solar cells, and chemical sensing

Synthesis of Few-Atomic-Layer BN Hollow Nanospheres and Their Applications as Nanocontainers and Catalyst Support Materials

In this work, few-atomic-layer boron nitride (BN) hollow nanospheres were directly synthesized via a modified CVD method followed by subsequent high-temperature degassing treatment. The encapsulated impurities in the hollow nanospheres were effectively removed during the reaction process. The BN shells of most nanospheres consisted of 2–6 atomic layers. Because of the low thickness, the obtained BN hollow nanospheres presented excellent performance in many aspects. For instance, they were demonstrated as useful nanocontainers for controllable multistep release of iodine, which could diffuse and be encapsulated into the few-layer BN hollow nanospheres when heating. They were also promising support materials that could markedly increase the photocatalytic activity of TiO₂ nanocrystals

Pressure-Induced Synthesis and Evolution of Ceria Mesoporous Nanostructures with Enhanced Catalytic Performance

Evaluating the effect of pressure for the formation of nanomaterials is significant in solvothermal methods. In this study, a pressure-dependent template-free solvothermal method is developed to controllably synthesize four kinds of uniform CeO₂ mesoporous nanostructures in a single reaction system, i.e., mesoporous nanospheres, nanoporous mesocrystals, hollow nanospheres, and nanowires. They all comprise small nanoclusters (3–5 nm). Properly adjusting the reaction pressure allows for achieving the transition between them. Furthermore, the corresponding pressure-induced self-assembly (Ostwald ripening, reconstruction) mechanisms are proposed to illustrate the morphological evolution process. In addition, they also display large specific surface area and excellent catalytic activity for CO oxidation

Large-Scale Synthesis of Few-Layer F‑BN Nanocages with Zigzag-Edge Triangular Antidot Defects and Investigation of the Advanced Ferromagnetism

Investigation of light-element magnetism system is essential in fundamental and practical fields. Here, few-layer (∼3 nm) fluorinated hexagonal boron nitride (F-BN) nanocages with zigzag-edge triangular antidot defects were synthesized via a facile one-step solid-state reaction. They are free of metallic impurities confirmed by X-ray photoelectron spectroscopy, electron energy loss spectroscopy, and inductively coupled plasma atomic emission spectroscopy. Ferromagnetism is obviously observed in the BN nanocages. Saturation magnetization values of them differed by less than 7% between 5 and 300 K, indicating that the Curie temperature (<i>T</i>_c) was much higher than 300 K. By adjusting the concentration of triangular antidot defects and fluorine dopants, the ferromagnetic performance of BN nanocages could be effectively varied, indicating that the observed magnetism originates from triangular antidot defects and fluorination. The corresponding theoretical calculation shows that antidot defects and fluorine doping in BN lattice both favor spontaneous spin polarization and the formation of local magnetic moment, which should be responsible for long-range magnetic ordering in the sp material