Structure and Properties of Violet Phosphorus and Its Phosphorene Exfoliation

Abstract

Black phosphorene has attracted much attention as a semiconducting two‐dimensional material. Violet phosphorus is another layered semiconducting phosphorus allotrope with unique electronic and optoelectronic properties. However, no confirmed violet crystals or reliable lattice structure of violet phosphorus had been obtained. Now, violet phosphorus single crystals were produced and the lattice structure has been obtained by single‐crystal x‐ray diffraction to be monoclinic with space group of P2/n (13) (a=9.210, b=9.128, c=21.893 Å, β=97.776°). The lattice structure obtained was confirmed to be reliable and stable. The optical band gap of violet phosphorus is around 1.7 eV, which is slightly larger than the calculated value. The thermal decomposition temperature was 52 °C higher than its black phosphorus counterpart, which was assumed to be the most stable form. Violet phosphorene was easily obtained by both mechanical and solution exfoliation under ambient conditions.

Crystalline Red Phosphorus Nanoribbons: Large‐Scale Synthesis and Electrochemical Nitrogen Fixation

“…The Raman spectra of bulk cRP and cRP NRs present complex vibration modes caused by the low symmetry of the triclinic crystal and diverse atomic coordination. [11,28] The sharp peaks around 353 and 368 cm À1 are related to phosphorus cage stretching vibrations in the tube-like substructure of cRP. [28,29] Compared with bulk, the Raman signals of cRP NRs are slightly shifted to high wavenumber direction (Supporting Information, Figure S5).…”

A general-purpose machine-learning force field for bulk and nanostructured phosphorus

“…White P, known since alchemical times, is formed of weakly bound P 4 molecules 2 , red P is an amorphous covalent network [3][4][5] and black P can be exfoliated to form monolayers, referred to as phosphorene 6,7 , which have promise for technological applications 8 . Other allotropes include Hittorf's violet and Ruck's fibrous forms, consisting of cage-like motifs that are covalently linked in different ways [9][10][11] , P nanorods and nanowires [12][13][14] and a range of thus far hypothetical allotropes [15][16][17][18] . Finally, liquid P has been of fundamental interest due to the observation of a first-order transition between low-and high-density phases [19][20][21] .…”

Crystalline Red Phosphorus Nanoribbons: Large‐Scale Synthesis and Electrochemical Nitrogen Fixation

“…These advantages may be attributed to the more obvious anisotropy and the quasi-onedimensional morphology of cRP NRs, which benefit to the more efficient charge transfer and more exposed-edge sites. [11,20] The possible byproduct of N 2 H 4 is also considered by the Watt-Chrisp method but no N 2 H 4 is observed at any potentials (Supporting Information, Figure S12).…”

“…Recently, BP has been proved to be an active electro- [9] or photo-electrocatalyst [10] for NRR. Besides BP, other 2D phosphorus materials such as violet phosphorus [11] and blue phosphorus [12,13] have great potential in photo-electronics, [14] batteries, [15,16] and catalysis. [17,18] However, it is difficult to produce these 2D phosphorus materials including BP on a large scale thus hampering the development of 2D phosphorus nanoribbons.…”

“…The reaction temperature and annealing time are much less than those described in previous publications (typical temperature of 550 8C to 650 8C and annealing time of days to weeks). [11,15,22,23] After cooling to room temperature, the dark red lumps of cRP attach to the quartz tube wall (Supporting Information, Figure S1a). The cRP lumps are then ground and washed with acetone and ethanol to remove I 2 and orange-red powder is obtained after drying (Supporting Information, Figure S1b).…”