Covalent Functionalization of Antimonene and Bismuthene Nanosheets

Abstract

Antimonene and bismuthene are promising members of the 2D pnictogen family with their tunable band gaps, high electronic conductivity, and ambient stability, making them suitable for electronic and optoelectronic applications. However, semi‐metal to semiconductor transition occurs only in the mono/bilayer regime, limiting their applications. Covalent functionalization is a versatile method for tuning materials’ chemical, electronic, and optical properties and can be explored for tuning the properties of pnictogens. In this work, emissions in liquid exfoliated antimonene and bismuthene are observed at ≈2.23 and ≈2.33 eV, respectively. Covalent functionalization of antimonene and bismuthene with p‐nitrobenzene diazonium salt proceeds with the transfer of lone pairs from Sb/Bi to the diazonium salt, introducing organic moieties on the surface attached predominantly via Sb/BiC bonds. Consequently, Sb/Bi signatures in Raman and X‐ray photoelectron spectra are blue‐shifted, implying lattice distortion and charge transfer. Interestingly, emission can be tailored upon functionalization to 2.18 and 2.27 eV for antimonene and bismuthene respectively, and this opens the possibility of tuning the properties of pnictogens and related materials. This is the first report on covalent functionalization of antimonene and bismuthene. It sheds light on the reaction mechanism on pnictogen surfaces and demonstrates tunability of optical property and surface passivation.

Antimonene: a tuneable post-graphene material for advanced applications in optoelectronics, catalysis, energy and biomedicine

“…Rao et al also covalently functionalized antimonene and bismuthine nanosheets using p -nitrobenzene diazonium salts. 183 The study of the reaction mechanisms demonstrated the transfer of lone pairs of electrons from the metallic Sb to the diazonium salts, forming a quaternary Sb+ species with organic moieties predominantly attached through Sb–C bonds. This functionalization led to lattice distorsion and charge transfer in the antimonene nanosheets, reducing their bandgap from 2.23 to 2.18 eV, demonstrating the tunability of the optical properties and surface passivation.…”

Recent Development Strategies for Bismuth‐Driven Materials in Sustainable Energy Systems and Environmental Restoration

“…[82,83] In addition to the Bi materials mentioned above, bismuthene (2D bismuth, 2D-Bi) is a promising material for use in energy storage and catalysis due to its tunable bandgap and high conductivity. [86,87] 2D-Bi is known to exhibit a high charge carrier mobility due to its 0.99 eV bandgap which, combined with its high air stability, means that it has a wide range of electronic and energy applications. [88,89] 2D-Bi is known to have three phases (α-, β-, and ξ-), but only the first two have been experimentally obtained and reported to have theoretical stability.…”

Single atom modified two-dimensional bismuthenes for toxic gas detection

“…The mechanism of covalent functionalization of bismuthene is also proposed to expand the ways of property modulation of bismuthene. 28 Altering the surface structure by anchoring or doping singleatom impurities is critical to obtain practical 2D-material based gas detectors. In this study, we investigated the detection performance of buckled honeycomb-like single atom modified two-dimensional bismuthene for the toxic gas H 2 S. We also compared the effects of different single-atom introduction methods (anchoring and doping) on the geometrical structure, electronic structure and gas sensing ability of bBi.…”

“…The mechanism of covalent functionalization of bismuthene is also proposed to expand the ways of property modulation of bismuthene. 28…”