Stabilizing black phosphorus nanosheets via edge-selective bonding of sacrificial C60 molecules

Abstract

Few-layer black phosphorus (BP) with an anisotropic two-dimensional (2D)-layered structure shows potential applications in photoelectric conversion and photocatalysis, but is easily oxidized under ambient condition preferentially at its edge sites. Improving the ambient stability of BP nanosheets has been fulfilled by chemical functionalization, however this functionalization is typically non-selective. Here we show that edge-selective functionalization of BP nanosheets by covalently bonding stable C60 molecules leads to its significant stability improvement. Owing to the high stability of the hydrophobic C60 molecule, C60 functions as a sacrificial shield and effectively protects BP nanosheets from oxidation under ambient condition. C60 bonding leads to a rapid photoinduced electron transfer from BP to C60, affording enhanced photoelectrochemical and photocatalytic activities. The selective passivation of the reactive edge sites of BP nanosheets by sacrificial C60 molecules paves the way toward ambient processing and applications of BP.

Strain Enhanced Visible–Ultraviolet Absorption of Blue Phosphorene/MoX2 (X = S,Se) Heterolayers

“…In order to construct stable hybrid bP/MoS(Se) 2 vdW heterostructures, monolayer MoS 2 , MoSe 2 , and bP were relaxed firstly, and the values of lattice constants were, respectively, 3.169, 3.319, and 3.278 Å, which were in consistent with the previous reported data . Six possible stacking configurations of bP/MoS(Se) 2 vdW heterostructures, as shown in Figure (a)–(f) namely A1‐, A2‐, A3‐, B1‐, B2‐, and B3‐stacking, were considered.…”

“…Their VBMs and CBMs both located at the K point. The calculated electronic band structures of monolayer MoS 2 , MoSe 2 , and bP all agreed well with previous works . As shown in Figure (e) and (f), the bP/MoS(Se) 2 vdW heterostructures, indirect gap semiconductor could be found, because of the band structures preserved both the properties of bP and MoS(Se) 2 .…”

“…Phosphorus was reported as another class of 2D material beyond graphene and transition metal dichalcogenides . The transport properties of black phosphorus are prominent . For example, the electron carrier mobility of monolayer black phosphorus is high up to 1000 cm 2 V −1 s −1 , which is higher than the electron carrier mobility of semimetallic graphene and monolayer MoS 2 (10–200 cm 2 V −1 s −1 ).…”

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 .…”

Functionalized Hybridization of 2D Nanomaterials

“…[189] To this end, various effective approaches were developed for protecting BP nanosheets by surface modification with organic molecules. [191] Besides covalent modification, noncovalent functionalization on BP nanosheets is also effective for stabilizing BP nanosheets under ambient conditions. Meanwhile, this chemical modification spontaneously formed phosphorus-carbon bonds to optimize the electronic features of BP nanosheets, ultimately leading to a strong and controlled p-type doping to improve FET mobility and on/off current ratio.…”