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Black phosphorus (BP), a burgeoning elemental 2D semiconductor, has aroused increasing scientific and technological interest, especially as a channel material in field-effect transistors (FETs). However, the intrinsic instability of BP causes practical concern and the transistor performance must also be improved. Here, the use of metal-ion modification to enhance both the stability and transistor performance of BP sheets is described. Ag spontaneously adsorbed on the BP surface via cation-π interactions passivates the lone-pair electrons of P thereby rendering BP more stable in air. Consequently, the Ag -modified BP FET shows greatly enhanced hole mobility from 796 to 1666 cm V s and ON/OFF ratio from 5.9 × 10 to 2.6 × 10 . The mechanisms pertaining to the enhanced stability and transistor performance are discussed and the strategy can be extended to other metal ions such as Fe , Mg , and Hg . Such stable and high-performance BP transistors are crucial to electronic and optoelectronic devices. The stability and semiconducting properties of BP sheets can be enhanced tremendously by this novel strategy.

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Heterostructures composed of two-dimensional black phosphorus (2D BP) with unique physical/chemical properties are of great interest. Herein, we report a simple solvothermal method to synthesize in-plane BP/Co P heterostructures for electrocatalysis. By using the reactive edge defects of the BP nanosheets as the initial sites, Co P nanocrystals are selectively grown on the BP edges to form the in-plane BP/Co P heterostructures. Owing to disposition on the original defects of BP, Co P improves the conductivity and offers more active electrocatalytic sites, so that the BP/Co P nanosheets exhibit better and more stable electrocatalytic activities in the hydrogen evolution and oxygen evolution reactions. Our work not only extends the application of BP to electrochemistry, but also provides a new idea to improve the performance of BP by utilization of defects. Furthermore, this strategy can be extended to produce other BP heterostructures to expand the corresponding applications.

Nanomedicines intergrating both therapy and diagnosis functions provide a promising strategy for anticancer treatment. As novel two-dimensional materials, black phosphorus nanosheets (BPs) possess unique properties for biomedical applications, pratically for photothermal therapy (PTT) of cancer, but their lack of air and water stability may hinder their application. Herein, a covalent functionalization strategy based on Nile Blue (NB) dye via diazonium chemistry is established to modify BPs, not only enhancing the stability of BPs but also rendering BPs via nearinfrared (NIR) fluorescence, forming a novel multifunctional nanomedicine with both PTT and NIR imaging capabilities. In vitro tests demonstrate that the dye-modified BPs (named NB@BPs) have good biocompatibility and exhibit strong PTT and NIR imaging efficiency. In vivo experiments show that the NB@BPs can mark the tumor site with red fluorescence and lead to efficient tumor ablation under NIR irradiation. These results reveal a potential BP-based nanomedicine with multiple functionalities that bode well for anticancer applications.

Poly(vinylpyrrolidone)-encapsulated Bi2 Se3 nanosheets with a thickness of 1.7 nm and diameter of 31.4 nm are prepared by a solution method. Possessing an extinction coefficient of 11.5 L g(-1) cm(-1) at 808 nm, the ultrathin Bi2 Se3 nanosheets boast a high photothermal conversion efficiency of 34.6% and excellent photoacoustic performance. After systemic administration, the Bi2 Se3 nanosheets with the proper size and surface properties accumulate passively in tumors enabling efficient photoacoustic imaging of the entire tumors to facilitate photothermal cancer therapy. In vivo biodistribution studies reveal that they are expelled from the body efficiently after 30 d. The ultrathin Bi2 Se3 nanosheets have large clinical potential as metabolizable near-infrared-triggered theranostic agents.

Salinity is one of the most important abiotic stress affecting the world rice production. The cultivation of salinity-tolerant cultivars is the most costeffective and environmentally friendly approach for salinity control. In recent years, CRISPR/Cas9 systems have been widely used for target-site genome editing; however, their application for the improvement of elite rice cultivars has rarely been reported. Here, we report the improvement of the rice salinity tolerance by engineering a Cas9-OsRR22-gRNA expressing vector, targeting the OsRR22 gene in rice. Nine mutant plants were identified from 14 T 0 transgenic plants. Sequencing showed that these plants had six mutation types at the target site, all of which were successfully transmitted to the next generations. Mutant plants without transferred DNA (T-DNA) were obtained via segregation in the T1 generations. Two T2 homozygous mutant lines were further examined for their salinity tolerance and agronomic traits. The results showed that, at the seedling stage, the salinity tolerance of T2 homozygous mutant lines was significantly enhanced compared to wild-type plants. Furthermore, no significantly different agronomic traits were found between T2 homozygous mutant lines and wild-type plants. Our results indicate CRISPR/ Cas9 as a useful approach to enhance the salinity tolerance of rice.