Lanthanide‐Coordinated Black Phosphorus

Abstract

Black phosphorus (BP) possesses unique physical properties and, owing to its intrinsic instability, the proper surface and chemical coordination is the key point in many applications. Herein, a facile and efficient surface lanthanide-coordination strategy based on lanthanide (Ln) sulfonate complexes is designed to passivate and functionalize different BP-based nanostructures including quantum dots, nanosheets, and microflakes. By means of Ln-P coordination, the lone-pair electrons of phosphorus are occupied, thus preventing oxidation of BP, and the LnL @BP exhibits excellent stability in both air and water. Furthermore, accompanied by the original photothermal performance of BP nanostructures, the Gd-coordinated BP has high R relativities in magnetic resonance (MR) imaging, and other Ln (Tb, Eu, and Nd) coordinated BP structures exhibit fluorescence spanning the visible to near-infrared regions. Not only is LnL surface passivation an efficient method to enhance the stability of BP, but also the MR or fluorescence derived from lanthanide ions extends the application of BP to optoelectronics and biomedical engineering.

Optical and Optoelectronic Properties of Black Phosphorus and Recent Photonic and Optoelectronic Applications

“…To improve the stability of BP upon ambient exposure, chemical modification and physical encapsulation are common schemes to protect BP from degradation. For the former, organic molecules or metal ions are usually employed to passivate the BP surface and meanwhile modify the optical/electrical properties of BP; for the latter, the atomic layer deposition of dielectric layer such as Al 2 O 3 , the spin coating of polymer, or the vdW capping with hBN layer has been developed to provide effective protection . In fact, the best mobility to date of few‐layer BP is observed from the h BN–BP– h BN heterostructure .…”

Black Phosphorous Nanosheets: A Novel Solar Vapor Generator

“…The low sign contrast between the substrate and BP nanosheets confirmed the thin‐layer structure, indicating the availability of water solution for the exfoliation of BP nanosheets (Figure d) . As highlighted by the red square and arrows (Figure d,e), some irregular holes in BP nanosheets were observed, which was due to the breaking of BP nanosheets by oxygen and water . In the high‐resolution TEM photographs (Figure f), both ordered lattice fringes (highlighted by black circles) and unordered lattice defects (highlighted by red circles) existed in the layer structure of BP nanosheets.…”

“…[46] As highlighted by the red square and arrows (Figure 2d,e), some irregular holes in BP nanosheets were observed, which was due to the breaking of BP nanosheets by oxygen and water. [17] In the high-resolution TEM photographs (Figure 2f ), both ordered lattice fringes (highlighted by black circles) and unordered lattice defects (highlighted by red circles) existed in the layer structure of BP nanosheets. This random dispersion of lattice defects indicates that the oxidation reaction was not confined to the special location of BP nanosheets, for instance, at layer edges, but in the whole lamella.…”

“…[14,15] As an emerging 2D nanomaterial, black phosphorous (BP) nanosheets are gradually receiving considerable attention, due to their thickness-tunable bandgap (0.3-2.0 eV), high electrical conductivity, biocompatibility, and excellent photothermal properties. [16][17][18][19][20] Zhang and coworkers reported a novel photodetector with hierarchical structure employing indium selenide and BP as vertical and basal components. [21] This prepared photodetector exhibited a wide response range from 405 to 1550 nm, and a relatively fast (%22 ms) response and high responsivity.…”

2D Elemental Nanomaterials Beyond Graphene

“…The Ag + modified BP of <10 nm thickness shows a significant increase in hole mobility from 796 to 1,666 cm 2 V −1 s −1 and on‐off ratio from 5.9×10 4 to 2.6×10 6 . BP nanostructures can be coordinated with sulfonates of magnetic resonance and fluorescence active lanthanide metal ions (Ln) (Ln=Tb, Eu, or Nd) . These lanthanide‐coordinated BP nanosheets show PL bands in the visible to NIR regions.…”