. Author manuscript; available in PMC: 2020 Nov 7.

Published in final edited form as: J Mater Chem B. 2019 Jul 10;7(41):6293–6309. doi: 10.1039/c9tb01006h

Table 1.

Comparison of chemical structure, class, lattice structure, notable physical properties, and applications of various 2D materials.

Chemical structure	2D Class	Lattice Structure	Comments	Applications
Graphene	Graphene	Hexagonally arranged sp² bonded carbons.	High electric and thermal conductivity with a Young’s modulus of 1 TPa.	Electronics, chemical barriers, fuel cells, catalysts, and sensors.
Graphene Oxide	Graphene	Hexagonally arranged sp² bonded carbons with regions of sp³ carbons where the basal (epoxides) and edge (carboxyl and hydroxyl) oxygen functional groups are attached.	Hydrophilic, synthesized through the chemical oxidation and mechanical exfoliation of graphite.	Wearable electronics, chemical barriers, catalysts, sensors, and biomedical devices.
Phosphorene	Xene Groups IIIA - VA	Hexagonally arranged lattice (silicene, germanene, phosphorene, borophene, stanene, and antimone).²² Orthogonal with zigzag conformation out-of-plane.	A semiconductor with anisotropic properties (electric, thermal, mechanical) due to the zigzag conformation. While most of these materials are synthetically grown, phosphorene is prepared from black phosphorus through mechanical or liquid exfoliation, similar to graphene.	Batteries, transistors, optoelectronics, and sensors. Exceptional near-infrared adsorption.^23,24
Molybdenum disulfide (MoS₂)	Transition Metal Dichalcogenides (TMDs) MX₂; M = transition metal, X = chalogen (S,Se, or Te)	Transition metal coordination of the chalcogen atoms by either octahedral or trigonal prismatic geometry, after exfoliation.	Tunable electronic properties and semiconducting states through mechanical strain. MoS₂ exhibits similar functional properties as GO, including large surface areas, strong near-infrared adsorption, as well as ease of chemical functionality, but can be degraded or cleared more rapidly in living systems.²⁵	Energy storage, biomaterials, optoelectronics, electrochemical catalysis, and piezoelectrics.
Titanium carbide (Ti₃C₂T_x)	MXene M_n+1X_nT_x; M = transition metal, X = carbide or nitride, T_x = termination functional group (-F, -O, and -OH)	AB or ABC ordering of titanium atoms with carbon atoms in layers with terminal functional group either -F, -O, or -OH.	High electric conductivity, metallic and hydrophilic. MXenes are synthesized by selective etching of A elements from the MAX phase using strong acids (normally contain HF) and exfoliation.	Energy storage, hydrogen storage, and catalysis.
Hexagonal Boron Nitride	Boron Nitride	Hexagonally arranged alternating boron and nitrogen atoms.	2D h-BN flakes can be controllably synthesized by mechanical/chemical exfoliation and chemical vapor deposition methods.²⁶ Chemically inert, good thermal stability,²⁷ mechanical property, outstanding thermal conductivity²⁸ and biocompatibility,²⁹ Nevertheless, it should be noted that h-BN may be more challenging to chemically functionalize, due to the inorganic boron and nitrogen surface groups.³⁰	Insulating charge leak barrier in electronics and biomedical devices.