Emerging two-dimensional materials: Synthesis, physical properties, and application for catalysis in energy conversion and storage

Abstract

<p>Inorganic, organic, and hybrid two-dimensional (2D) materials are being developed for ever-expanding numbers of applications, though energy and catalysis remain the main drivers of their development. We present overviews of bottom-up and top-down synthetic strategies of such materials and examine manufacturing scalability issues. Mechanical, electrical, and thermal properties and their modulation are highlighted because they are fundamental to the above-mentioned drivers. The burgeoning importance of heterostructures in such materials, particularly for catalysis and electrode design and function is stressed. Detailed attention is given to applications of 2D materials to the electrocatalysis reactions: oxygen reduction, oxygen evolution, hydrogen evolution, carbon dioxide reduction, and nitrogen reduction. Water splitting, carbon dioxide reduction, and nitrogen reduction by photocatalysis are also examined. A perspective of expected advances in the expansion of applications and types of 2D materials, with a focus on heterostructure development, is presented in the conclusion.</p>

Photochemically Patterning Graphene in a Highly Efficient, Anisotropic, and Clean Way

“…When the OH­( X 2 Π) and H­(1 2 S ) radicals combine with graphite at the atomic scale, three stable configurations are obtained according to the first-principles calculation, consistent with the experimental results. This study provides a comprehensive perspective on the highly efficient, anisotropic, and nonbombing photochemical oxidation, and it opens up an avenue of material functionalization, etching, and clean patterning by radicals. − …”

Leaflet-heterostructures by MWCNT self-assembly following electrospinning

“…Two-dimensional (2D) materials and networks are becoming increasingly important in designing advanced catalytic electrodes and membranes for energy storage and conversion, 1 , 2 , 3 and they offer novel and diverse design opportunities for multifunctional catalytic systems. Heterostructures derived from 2D materials provide independent approaches to tuning electronic structure, an important feature in modifying catalytic activity 4 , 5 and an important new tool for interfacial engineering. 2 Such heterostructures include sandwich core-shell structures of one type of nanosheet (MoS 2 ) encapsulated in another (heavily pyrrolic N doped graphene), 6 Ni/Fe layered double hydroxides (LDH) sheets interspersed with MoS 2 nanosheets, 7 phosphorene/graphene bilayers, 8 reduced graphene oxide (rGO) – graphitic carbon nitride nanostructures, 9 alternating graphitic boron-nitride and MoS 2 nanosheets, 10 and electrically conducting 1T-MoS 2 domains within 1H-MoS 2 nanosheets, 11 among numerous other examples.…”