In preclinical and clinical research, to destroy cancers, particularly those located in deep tissues, is still a great challenge. Photodynamic therapy and photothermal therapy are promising alternative approaches for tissue cancer curing. Black phosphorus (BP)-based nanomaterials, with broad UV-vis near-infrared absorbance and excellent photothermal effect, have shown great potential in biomedical applications. Herein, a biocompatible therapeutic platform, chlorin e6 (Ce6)-decorated BP nanosheets (NSs), has been developed for fluorescence and thermal imaging-guided photothermal and photodynamic synergistic cancer treatment. Taking advantage of the relatively high surface area of exfoliated BP NSs, the PEG-NH-modified BP NSs (BP@PEG) are loaded with a Ce6 photosensitizer. The resulted BP@PEG/Ce6 NSs not only have good biocompatibility, physiological stability, and tumor-targeting property but also exhibit enhanced photothermal conversion efficiency (43.6%) compared with BP@PEG NSs (28.7%). In addition, BP@PEG/Ce6 NSs could efficiently generate reactive oxygen species because of the release of the Ce6 photosensitizer, which is also verified by in vitro studies. In vivo fluorescence imaging suggests that BP@PEG/Ce6 NSs can accumulate in the tumor targetedly through the enhanced permeability and retention effect. Both in vitro and in vivo studies suggest that BP@PEG/Ce6 can be a promising nanotheranostic agent for synergetic photothermal/photodynamic cancer therapy.

A mitochondria-targeting nanosystem, BP@PDA–Ce6&TPP NSs, has been constructed, and exhibit excellent performance in imaging-guided synergistic photothermal and photodynamic cancer therapy.

The shuttle of polysulfide and severe volume change of sulfur cathodes, are the bottlenecks in the practical application of lithium–sulfur batteries, and need to be solved through further exploration of simple and scalable strategies. Herein, an elastic and conductive coating layer is designed and synthesized, by combining water soluble conducting polymer modified carbon nanotubes (PASANTs) with crosslinked waterborne polyurethane (cWPU). It shows high electronic conductivity and excellent resilience. As a result, a lithium–sulfur battery with cWPU/PASANTs coated cathode is able to achieve an outstanding cycle stability with a capacity of 70.8% after 500 cycles at 0.5C and an excellent rate performance (specific capacity of 1130 mAh g−1 at 0.1C and maintain 68.2% at 2C). This work embodies a systematic design concept, which shows the application prospects of large‐scale production, and is expected to be further applied to other easily pulverized high‐specific‐capacity materials such as silicon and tin.

semimetals (Si and Ge) to transition metal dichalcogenides (TMDs), which can be tuned from semiconductors to superconductors, have been intensively investigated. [8] Despite the recent advances in 2D materials, it is still challenging to obtain 2D materials with desired layers and size in facile and controllable manners.Indeed, continuous research has been carried out on the synthesis of 2D materials. [9] Generally, two synthetic strategies, known as top-down and bottom-up, are applied to obtain 2D materials. In the common top-down strategy, 2D materials are exfoliated from their bulk counterparts. Differently, using the bottom-up strategy, 2D materials with a few thin layers, even an atomically thin layer, can be directly synthesized from small building blocks such as molecules and atoms. [10] In these synthetic strategies for 2D materials, chemical vapor transport (CVT) reaction, an old yet powerful technology, plays an important role because CVT reactions can be used for both topdown and bottom-up syntheses of 2D materials. [11] CVT reactions represent a category of reactions with one common feature: a condensed phase, typically a solid, sublimes in the presence of a gaseous reactant (the mineralizer), and then deposits elsewhere usually in the form of crystals. [12] Notably, CVT is different from chemical vapor deposition (CVD), another chemical vapor-based approach for synthesizing 2D materials. Specifically, the main difference between CVT and CVD lies in the source materials for synthesizing products, where solid reactants are typically used in CVT and gaseous precursors are usually applied in CVD. The difference induces consequent differences in reactor design, operational control, and product features, thus bringing strengths and drawbacks for each approach. Since the discovery of CVT reaction by Bunsen in 1851, comprehensive understanding of CVT reactions in both experimental exploration and theoretical modeling has been established. [13] Furthermore, thousands of CVT reactions have been applied till now, producing a great variety of pure and crystalline solids, including metals, metalloids, intermetallic phases, metal oxides, halides, chalcogen halides, chalcogenides, and pnictides. [13,14] The knowledge about CVT reactions, together with the large number of applicable reactions, can offer opportunities for the controllable synthesis of 2D materials and the exploration of new 2D materials. Unfortunately, for the preparation of 2D materials, in stark contrast to the wide application of CVD, 2D materials, namely thin layers of layered materials, are attracting much attention because of their unique electronic, optical, thermal, and catalytic properties for wide applications. To advance both the fundamental studies and further practical applications, the scalable and controlled synthesis of large-sized 2D materials is desired, while there still lacks ideal approaches. Alternatively, the chemical vapor transport reaction is an old but powerful technique, and is recently adopted for synthesizing 2D material...

Black phosphorus, an emerging layered material, exhibits promising applications in diverse fields, ranging from electronics to optics. However, controlled synthesis of black phosphorus, particularly its few-layered counterparts, is still challenging, which should be due to the unclear growth mechanism of black phosphorus. Here, taking the most commonly used Sn-I assisted synthesis of black phosphorus as an example, we propose a growth mechanism of black phosphorus crystals by monitoring the reactions and analyzing the as-synthesized products. In the proposed mechanism, Sn24P19.3I8 is the active site for the growth of black phosphorus, and the black phosphorus crystals are formed with the assistance of SnI2, following a polymerization-like process. In addition, we suggest that all Sn-I assisted synthesis of black phosphorus should share the same reaction mechanism despite the differences among Sn-I containing additives. Our results shown here should shed light on the controlled synthesis of black phosphorus and facilitate further applications of black phosphorus.