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Scalable Production of Nanographene and Doping via Nondestructive Covalent Functionalization
Author(s) -
Guday Guy,
Donskyi Ievgen S.,
Gholami Mohammad Fardin,
AlgaraSiller Gerardo,
Witte Felix,
Lippitz Andreas,
Unger Wolfgang E. S.,
Paulus Beate,
Rabe Jürgen P.,
Adeli Mohsen,
Haag Rainer
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201805430
Subject(s) - surface modification , materials science , covalent bond , raman spectroscopy , cycloaddition , x ray photoelectron spectroscopy , conjugated system , chemical engineering , conductivity , oxide , nanotechnology , polymer , organic chemistry , chemistry , catalysis , physics , optics , engineering , metallurgy , composite material
A new method for top‐down, one‐pot, gram‐scale production of high quality nanographene by incubating graphite in a dilute sodium hypochlorite solution at only 40 °C is reported here. The produced sheets have only 4 at% oxygen content, comparable with nanographene grown by chemical vapor deposition. The nanographene sheets are covalently functionalized using a nondestructive nitrene [2+1] cycloaddition reaction that preserves their π‐conjugated system. Statistical analyses of Raman spectroscopy and X‐ray photoelectron spectroscopy indicate a low number of sp 3 carbon atoms on the order of 2% before and 4% after covalent functionalization. The nanographene sheets are significantly more conductive than conventionally prepared nanographene oxide, and conductivity further increases after covalent functionalization. The observed doping effects and theoretical studies suggest sp 2 hybridization for the carbon atoms involved in the [2+1] cycloaddition reaction leading to preservation of the π‐conjugated system and enhancing conductivity via n‐type doping through the bridging N‐atom. These methods are easily scalable, which opens the door to a mild and efficient process to produce high quality nanographenes and covalently functionalize them while retaining or improving their physicochemical properties.