Engineering the Surface Chemistry of Graphite and Graphene by Covalently Anchored Triazole Derivative

Abstract

Robust engineering the surface properties of layered materials is assigned as one of essential strategies for permanently improving their overall physicochemical behaviors towards high-end technology applications. In this regard, covalent functionalization of graphitic surfaces including graphene is performed upon electrografting of 4-(1H-1,2,4-triazol-1-ylmethyl) diazonium (4-TYD). The efficiency of this approach is determined by a state-of-the-art toolbox including cyclic voltammetry (CV), atomic force microscopy (AFM), scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), Kelvin probe force microscopy (KPFM) and Raman spectroscopy. The degree of the covalent functionalization is dependent on the molecular concentration of 4-TYD, in which the full monolayer is obtained upon electrografting with a 1 mM 4-TYD containing solution. The electrografted layer could be removed by thermal annealing leaving the pristine graphitic surfaces behind. This finding provides an efficient approach for robustly anchoring bioactive compounds onto graphene and other 2D materials in a controlled manner towards high-end technology applications.