Organic covalent functionalization of graphene with long-range periodicity is highly desirable-it is anticipated to provide control over its electronic, optical, or magnetic properties-and remarkably challenging. In this work we describe a method for the covalent modification of graphene with strict spatial periodicity at the nanometer scale. The periodic landscape is provided by a single monolayer of graphene grown on Ru(0001) that presents a moiré pattern due to the mismatch between the carbon and ruthenium hexagonal lattices. The moiré contains periodically arranged areas where the graphene-ruthenium interaction is enhanced and shows higher chemical reactivity. This phenomenon is demonstrated by the attachment of cyanomethyl radicals (CH2CN(•)) produced by homolytic breaking of acetonitrile (CH3CN), which is shown to present a nearly complete selectivity (>98%) binding covalently to graphene on specific atomic sites. This method can be extended to other organic nitriles, paving the way for the attachment of functional molecules.

We describe naphthalene diimide–SWNT supramolecular hybrids in which the topology, the degree of functionalization, and the electronic interaction can be controlled.

We present an easy drop-casting based functionalization of MoS2-based photodetectors that results in an enhancement of the photoresponse of about four orders of magnitude, reaching responsivities up to 100 A·W -1 . The functionalization is technologically trivial, air-stable, fully reversible and reproducible, and opens the door to the combination of 2D-materials with molecular dyes for the development of high performance photodetectors.Among the novel two-dimensional (2D) materials, 1-8 transition metal dichalcogenides (TMDCs) [9][10][11][12] show particularly promising electronic and optoelectronic properties. 13 In particular, their intrinsic bandgap within the visible part of the spectrum, makes them highly interesting materials for optoelectronic applications.14 In fact, the presence of a bandgap has allowed for the construction of a wealth of prototype electronic devices based on TMDCs. [15][16][17][18][19][20][21][22][23][24] In the last years, there has been a significant effort to modulate the optical properties of TMDCs in order to optimize the performance of the corresponding devices. Most of the strategies investigated so far rely on physical methods, such as strain-engineering, 25,26 fieldeffect doping, 12,27 or artificial stacking of different 2D materials. 28,29 In comparison, the chemical modification of TMDCs is still rather underexplored, despite the appealing combination of low-cost and high degree of control offered by synthetic chemistry. Examples of doping of TMDCs through surface charge-transfer using metal atoms, 30 gases, 31 and a few organic molecules has already been demonstrated. 32,33 Responsivities of just a few A·W -1 have been reported for MoS2 photodetectors functionalized with a rhodamine dye, 34 a rather modest value for MoS2-based photodetectors. Among the readily available organic dyes, perylenediimides (PDIs) and porphyrins show remarkable optical properties, including large molar absorptivity -ca. 10 5 M −1 cm −1 for PDIs and 10 6 M −1 cm −1 for porphyrins-, and outstanding photostability under ambient conditions. These intrinsic properties have made them two of the most popular families of organic dyes, particularly in the frame of photovoltaics. [35][36][37][38][39][40][41][42][43][44] However, their use for the modulation of the optoelectronic properties of TMDC-based devices has not been yet described. Considering this, we decided to investigate the effects of the noncovalent functionalization of MoS2 This is the post-peer reviewed version of the following article: A.J. Molina-Mendoza et al. "Engineering the optoelectronic properties of MoS2 photodetectors through reversible noncovalent functionalization" Chem. Comm., 2016 DOI: 10.1039/C6CC07678E Which has been published in final form at: http://pubs.rsc.org/en/content/articlelanding/2016/cc/c6cc07678e#!divAbstract photodetectors with the soluble PDI and tetraphenyl porphyrin (TPP) depicted in Chart 1. Here, we describe that the supramolecular functionalization of mechanically exfoliated MoS2-based photodetector...