2D Xenes possess various physical and chemical properties, such as flexibility, layer-dependent semiconducting, high carrier mobility, molecule and light sensitivity, topologically nontrivial band structures, etc. In order to utilize 2D Xenes more effectively, surface modifications become particularly important to tune the properties of 2D Xenes. 2D Xenes have become promising for applications in different fields, such as spintronics, electronics, optoelectronics, superconducting, photovoltaics, sensors, catalysis, and biomedicines. For instance, the FET of acene-type graphene nanoribbons exhibits excellent semiconductor characteristics with an on/off ratio of 88
[55]. To enhance the mid-infrared (MIR) absorption of graphene, the localized surface plasmon resonance of B-doped Si quantum dots (QDs) results in a QD/graphene hybrid photodetector with ultrahigh responsivity, gain, and specific detectivity in the UV-to-MIR region
[56]. A 2D bismuthene/Si(111) heterostructure exhibits excellent photodetection performance in the Vis-MIR region due to the promoted generation and transportation of charge carriers in the heterojunction
[57]. Solution-exfoliated black phosphorene flakes, as an electron transport layer, can enhance the performance of organic solar cells
[58]. In addition, layered black phosphorene exhibits the selective detection of methanol
[59]. The thermoelectric power (S) in black phosphorene can be effectively controlled with ion-gating. In the hole-depleted state, the S of black phosphorene can reach +510 μV/K at 210 K, much higher than the bulk single crystal value of +340 μV/K at 300 K
[60]. Under the proper electron-doping and biaxial tensile strain, buckled arsenene shows superconductivity with a high T
c of 30.8 K
[61]. Iodine-decorated stanene exhibits a topologically nontrivial band structure with a larger gap of ~320 meV than that of pristine stanene (~100 meV)
[62]. Graphene/Pt(111) surfaces can cause CO adsorption/desorption and CO oxidation surface reactions
[63]. MoS
2/graphene hybrids decorated by CdS nanocrystals can act as high-performance photocatalysts for H
2 evolution under visible light irradiation
[64]. Moreover, 2D Xenes are also regarded as promising agents for biomedical applications
[65]. For example, an ultrathin bismuthene can act as a sensing platform to detect microRNA with a detection limit of 60 PM
[66]. Polyethylene-coated antimonene quantum dots can be used as photothermal agents with a high photothermal conversion efficacy of 45.5% for photothermal therapy in cancer theranostics
[67]. Overall, thanks to surface modifications, 2D Xenes show great potential for applications in plenty of fields.