Tunable Electronic and Optical Properties of 2D Monoelemental Materials Beyond Graphene for Promising Applications

Abstract

As a new type of two‐dimensional (2D) materials, monoelemental 2D materials have the atomic structure similar to graphene, and their excellent optical and electronic properties have potential applications in many fields. To date, many studies based on monoelemental 2D materials have been reported, and excellent performance has been demonstrated in various fields. The monoelemental 2D materials that have been reported so far are mainly distributed in the group IIIA, IVA, VA, and VIA. Because of their structural similarities to graphene, they are commonly referred to as "Xenes." Here, we have comprehensively reviewed the research progress of monoelemental 2D materials. In this review, we explore the structure, properties, and practical applications of these monoelemental 2D materials. First, the classification, structural features, optical properties, electronic characteristics, and regulating mechanism of these monoelemental 2D materials are introduced. Then, the practical application and research progress of monoelemental 2D materials in various fields are reviewed comprehensively, especially including photoelectric catalysis, solar cells, and other energy fields. This review will give readers a more all‐sided understanding of monoelemental 2D materials and have some guiding significance for their further development.

Electrochemical Exfoliation of Two‐Dimensional Phosphorene Sheets and its Energy Application

“…Moreover, few-layered phosphorene has the characteristics of supercapacitor-type materials owing to its large specific surface area, durable mechanical strength ( � 94 GPa), and high carrier mobility. [61,62] For instance, Zhi et. al developed a phosphorene-based zinc ion hybrid capacitor with an expanded operating potential reach to 2.2 V in a novel "water in salt" (WIS) electrolyte, which exhibits 105.9 F g À 1 even after 9500 cycles.…”

“…Moreover, few‐layered phosphorene has the characteristics of supercapacitor‐type materials owing to its large specific surface area, durable mechanical strength (≈94 GPa), and high carrier mobility [61,62] . For instance, Zhi et.…”

Promoted photocarrier separation by dipole engineering in two-dimensional perovskite/C2N van der Waals heterostructures

“…[15][16][17][18][19] Owing to the resultant quantum effects from their reduced dimensions, 2D materials show many intriguing physical and chemical properties that are different from their bulk counterparts. 20,21 Meanwhile, 2D materials show great potential for photocatalytic water splitting because of the high specific surface area, which may provide more adsorption and been successfully synthesized in experiments and proved their stability in aqueous media with outstanding photocatalytic performance. Motivated by those interesting works on the designing of type-II heterostructures, we have selected the Cs 3 Bi 2 I 9 /C 2 N vdW heterostructure.…”

“…15–19 Owing to the resultant quantum effects from their reduced dimensions, 2D materials show many intriguing physical and chemical properties that are different from their bulk counterparts. 20,21 Meanwhile, 2D materials show great potential for photocatalytic water splitting because of the high specific surface area, which may provide more adsorption and reaction sites. 22,23 For practical applications, a promising 2D photocatalyst semiconductor must also possess a small exciton binding energy, low exciton recombination rate and high separation efficiency of photo-generated charge carriers, a band-gap value greater than 1.23 eV, good visible light response and appropriate band edge positions for overall water splitting.…”

Dual-mode surface-enhanced Raman scattering sensors assembled from graphene plasmonic nanoresonator on photoactive SOI

“…27 3D-graphene is a natural graphene plasmonic nanoresonator arranged vertically growing on a target substrate. It combines many unique characteristics of 2D-graphene (chemical inertness, specific surface area and high electrical conductivity) [28][29][30][31][32] and possesses different properties from planar graphene owing to the special 3D structure. The large specific surface area of 3D-graphene is attributed to its porous structure, providing more prominent adsorption sites for target molecules.…”