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Water purification is an important issue in our daily life. Various pollutants, from micrometer-sized microorganisms to molecular- or atomic-sized pollutants, need to be efficiently removed from water. Unlike traditional cascade-stage techniques, we report a one-step water purification method based on a ceramic aerogel composed of porous BN fibers, which realizes >99% Microcystis and >98% E. coli cell removals from water and high-capacity adsorptions of pesticide, oils, organic compounds, metal ions, etc. The adsorption capacities for metal ions are about one order of magnitude higher than those achieved by the reported porous/activated carbons. Our studies show the importance of the unique hierarchical structure of the BN aerogel to realize remarkable water purification performances; micrometer-sized pores constructed by high-dense fibers, the porous structures and rich surface functional groups of the BN fibers all contribute to the efficient removals of different types of the pollutants. These results suggest the potential applications of the BN aerogels toward one-step and comprehensive water purifications.

The lithium-sulfur battery (Li–S) is a promising energy storage system with many advantages over the commercialized lithium-ion battery. It has a high theoretical capacity of 1675 mAh g−1, a high theoretical energy density (2600 Wh kg−1), and is eco-environmentally friendly. Although only a small amount is used (

2D coordination nanosheets (CONASHs) have gained considerable attention due to their highly flexible structures, which favor tailoring band gaps and optical and optoelectrical properties of the materials. The development of this type of 2D materials may generate advanced core materials used in electronic and optoelectronic devices. In this study, for the first time, we report the synthesis of a free-standing CONASH from a two-armed ligand and Zn via simple liquid–liquid interfacial reactions. The 2D structure was achieved by a rational design through incorporating cyanostilbene functionality into the ligand, which not only assisted in the side-by-side self-assembly of 1D polymers through hydrogen bonds but also endowed excellent photophysical characteristics. The as-synthesized nanosheets exhibited semiconducting properties with an optical band gap of 1.66 eV and strong yellow photoluminescence, which were found to label the lysosomes of mouse 4T1 cells with high brightness, specificity, and photostability. Furthermore, photodetectors fabricated based on the CONASH showed excellent photodetecting properties in a wide visible light region with the detectivity up to 6.09 × 1011 Jones and quick responses. This study should motivate the future engineering of diversifying 2D CONASHs based on nonclassical two-arm building blocks with adjustable structural and band properties for broad optical, electrical, and optoelectrical applications.

The main challenge associated with sodium-ion battery (SIB) anodes is a search for novel candidate materials with high capacity and excellent rate capability. The most commonly used and effective route for graphene-based anode design is the introduction of in-plane “hole” defects via nitrogen-doping; this creates a spacious reservoir for storing more energy. Inspired by mountains in nature, herein, we propose another way – the introduction of blistering in graphene instead of making “holes”; this facilitates adsorbing/inserting more Na+ ions. In order to properly answer the key question: ““protrusions” or “holes” in graphene, which is better for sodium ion storage?”, two types of anode materials with a similar doping level were designed: a phosphorus-doped graphene (GP, with protrusions) and a nitrogen-doped graphene (GN, with holes). As compared with GN, the GP anode perfectly satisfies all the desired criteria: it reveals an ultrahigh capacity (374 mA h g−1 after 120 cycles at 25 mA g−1) comparable to the best graphite anodes in a standard Li-ion battery (∼372 mA h g−1), and exhibits an excellent rate capability (210 mA h g−1 at 500 mA g−1). In situ transmission electron microscopy (TEM) experiments and density functional theory (DFT) calculations were utilized to uncover the origin of the enhanced electrochemical activity of “protrusions” compared to “holes” in SIBs, down to the atomic scale. The introduction of protrusions through P-doping into graphene is envisaged to be a novel effective way to enhance the capacity and rate performance of SIBs.

Fuel cell vehicles powered by hydrogen are particularly attractive and competitive among rapidly developing new energy-driven automobiles. One critical problem for this type of vehicles is the high cost for hydrogen storage due to the lack of efficient and low-pressure hydrogen storage technologies. In the frame of development of hydrogen physisorption-relied materials, attention has mostly been paid to the textural designs of porous materials, including specific surface area, pore volume, and pore size. However, based on the hydrogen physisorption mechanism, hydrogen adsorption energy on a material surface is another key factor with regard to hydrogen uptake capacity. Herein, solid experimental evidences are provided and it is also proven that the chemical states of porous boron nitride (BN) materials remarkably affect their hydrogen adsorption performances. The developed carbon and oxygen co-doped BN microsponges exhibit the hydrogen uptake capacity per specific surface area of 2.5–4.7 times larger than those of undoped BN structures. These results show the importance of chemical state modulations on the future designs of high-performance hydrogen adsorbents based on physisorption approaches.

Functionalization is an important way to breed new properties and applications for a material. This review presents an overview of the progresses in functionalized hexagonal boron nitride (h-BN) nanomaterials. It begins with an introduction of h-BN structural features, physical and chemical properties, followed by an emphasis on the developments of BN functionalization strategies and its emerging properties/applications, and ends with the research perspectives. Different functionalization methods, including physical and chemical routes, are comprehensively described toward fabrication of various BN derivatives, hetero- and porous structures, etc. Novel properties of functionalized BN materials, such as high water solubility, excellent biocompatibility, tunable surface affinities, good processibility, adjustable band gaps, etc., have guaranteed wide applications in biomedical, electronic, composite, environmental and "green" energy-related fields.

Development of microsized on-chip batteries plays an important role in the design of modern micro-electromechanical systems, miniaturized biomedical sensors, and many other small-scale electronic devices. This emerging field intimately correlates with the topics of rechargeable batteries, nanomaterials, on-chip microfabrication, etc. In recent years, a number of novel designs are proposed to increase the energy and power densities per footprint area, as well as other electrochemical performances of microsized lithium-ion batteries. These advances may guide the pathway for the future development of microbatteries.

Construction of cellular architectures has been expected to enhance materials' mechanical tolerance and to stimulate and broaden their efficient utilizations in many potential fields. However, hitherto, there have been rather scarce developments in boron nitride (BN)-type cellular architectures because of well-known difficulties in the syntheses of BN-based structures. Herein, cellular-network multifunctional foams made of interconnective nanotubular hexagonal BN (h-BN) architectures are developed using carbothermal reduction-assisted in situ chemical vapor deposition conversion from N-doped tubular graphitic cellular foams. These ultralight, chemically inert, thermally stable, and robust-integrity (supporting about 25,000 times of their own weight) three-dimensional-BN foams exhibit a 98.5% porosity, remarkable shape recovery (even after cycling compressions with 90% deformations), excellent resistance to water intrusion, thermal diffusion stability, and high strength and stiffness. They remarkably reduce the coefficient of thermal expansion and dielectric constant of polymeric poly(methyl methacrylate) composites, greatly contribute to their thermal conductivity improvement, and effectively limit polymeric composite softening at elevated temperatures. The foams also demonstrate high-capacity adsorption-separation and removal ability for a wide range of oils and organic chemicals in oil/water systems and reliable recovery under their cycling usage as organic adsorbers. These created multifunctional foams should be valuable in many high-end practical applications.

Boron, carbon, nitrogen, and oxygen atoms can form various building blocks for further construction of structurally well-defined 2D materials (2DMs). Both in theory and experiment, it has been documented that the electronic structures and optical properties of 2DMs are well tunable through a rational design of the material structure. Here, the recent progress on 2DMs that are composed of B, C, N, and O elements is introduced, including borophene, graphene, h-BN, g-C3 N4 , organic 2D polymers (2DPs), etc. Attention is put on the band structure/bandgap engineering for these materials through a variety of methodologies, such as chemical modifications, layer number and atomic structure control, change of conjugation degree, etc. The optical properties, such as photoluminescence, thermoluminescence, single photon emission, as well as the associated applications in bioimaging and sensing, are discussed in detail and highlighted.

Three-dimensional graphene architectures in the macroworld can in principle maintain all the extraordinary nanoscale properties of individual graphene flakes. However, current 3D graphene products suffer from poor electrical conductivity, low surface area and insufficient mechanical strength/elasticity; the interconnected self-supported reproducible 3D graphenes remain unavailable. Here we report a sugar-blowing approach based on a polymeric predecessor to synthesize a 3D graphene bubble network. The bubble network consists of mono- or few-layered graphitic membranes that are tightly glued, rigidly fixed and spatially scaffolded by micrometre-scale graphitic struts. Such a topological configuration provides intimate structural interconnectivities, freeway for electron/phonon transports, huge accessible surface area, as well as robust mechanical properties. The graphene network thus overcomes the drawbacks of presently available 3D graphene products and opens up a wide horizon for diverse practical usages, for example, high-power high-energy electrochemical capacitors, as highlighted in this work., Three-dimensional graphene offers an ideal sheet-to-sheet connectivity of assembled graphenes, but often suffers from poor electrochemical performance. Wang et al. present a sugar-blowing technique to prepare a 3D graphene, which overcomes such problems and shows potential in supercapacitor applications.

Nanostructured active materials with both high-capacity and high-rate capability have attracted considerable attention, but they remain a great challenge to be realized. Herein, we report a new route to fabricate a bicontinuous Cu/Li4Ti5O12 scaffold that consists of Li4Ti5O12 nanoparticles (LTO NPs) with highly exposed (111) facets and nanoporous Cu scaffolds, which enable simultaneous high-capacity and high-rate lithium storage. It is a ‘one stone, two birds’ strategy. When tested as the anode in lithium-ion batteries LIBs, Cu/LTO showed superior performance, such as a lifespan greater than 2000 cycles and an ultrafast charging time (

Two-dimensional (2D) boron nitride (BN) nanosheets, the rising material stars, have unique properties and amazing functionalities. The concise history of diverse synthesis routes of BN nanosheets is briefly summarized here; and the recent development towards mass production of BN nanosheets, i.e. chemical blowing technique relying on blowing molten polymer precursors into large polymeric bubbles and subsequent annealing into BN bubbles/nanosheets, is focused on. The abundant BN nanosheets enable their applications, especially in the representative polymeric composites with BN nanosheet additives, as particularly highlighted in this review. The highly thermoconductive insulating BN-filled composites are thus envisaged as high-performance packaging materials for electrical circuits.

High-throughput few-layered BN nanosheets have been synthesized through a facile chemical blowing route. They possess large lateral dimensions and high surface area, which are beneficial to fabricate effectively reinforced polymeric composites. The demonstrated composites made of polymethyl methacrylate and BN nanosheets revealed excellent thermal stability, 2.5-fold improved dielectric constant, and 17-fold enhanced thermal conductivity. The results indicate multifunctional practical applications of such polymeric composites in many specific fields, such as thermoconductive insulating long-lifetime packaging for electrical circuits.