Lewis acid-base surface interaction of some boron compounds with N-doped graphene; first principles study Ali Shokuhi Rad * , Arvin Shadravan, Amir Abbas Soleymani, Nazanin Motaghedi Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran article info Article history: Received 9 May 2015 Received in revised form 16 July 2015 Accepted 17 July 2015 Available online 20 July 2015 Keywords: DFT N-doped graphene BF 3 BC1 3 B(OCH 3 ) 3 WB97XD abstract We studied density functional theory (DFT) calculations in terms of energetic and electronic properties toward adsorption of some boron compounds (B(OCH 3 ) 3 , BF 3 and BC1 3 ) on the surface of pristine as well as N-doped graphene using WB97XD/6-31 þ G(d,p) level of theory. The net charge transfer of mentioned molecules on the surface of pristine and N-doped graphene was calculated with above-mentioned basis set using natural bond orbital and Mulliken charge analysis during complex formation. The computed dipole moment shows when above-mentioned molecules approach to the surface of N-doped graphene, the amount of the dielectric (mD) will change depending on the kind of molecule. Our calculations reveal that N-doped graphene system has much higher adsorption energy, higher net charge transfer value than pristine graphene due to Lewis acid-base interaction. Comparing B(OCH 3 ) 3 as an organic boron derivative with boron trihalides (BF 3 and BCl 3 ), the Lewis acidity increases in the order of BF 3 < BC1 3 < B(OCH 3 ) 3 with adsorption energies (E ads ) of À8.7, À18.3 and À26.5 kJ/mol (BSSE) respectively, while low adsorption energies were calculated on pristine graphene for mentioned molecules. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Boron trifluoride (BF 3 ) and Boron trichloride (BCl 3 ) are the inorganic compounds (See Fig. 1) and colorless gases which known as significant reagents in organic synthesis [1]. They are important Lewis acids and widespread building blocks for other boron com- pounds. They are commonly known as electron deficient which result their exothermic reactivity with Lewis bases. Due to mentioned properties, boron trihalides involved many consider- ations [1e4]. In other hand trimethyl borate (B(OCH 3 ) 3 ) is one of the simplest organic metals (See Fig. 1) having rich density of electron. It is recognized that in the gas phase the molecule is planar with a sp 2 hybridized boron atom [5]. Due to the unfilled 2pz orbital on a trigonal coordinated boron atom is able of accepting electron from p-donor ligands complexed to it. The study of such mesomeric interaction is interesting from a theoretical or experi- mental point of views. Accordingly alongside boron trihalides as inorganic boron compounds we selected B(OCH 3 ) 3 as a sample of organic boron compounds to be compared and studied in terms of energetic and electronic properties during complex formation. Nano-structured carbon materials have great attentions towards improved binding [6,7]. Graphene is nano-structure of carbon having single-layer two-dimensional material with huge surface area (2630 m 2 /g) with atoms assembled in a honey-comb model with ultra-high surface area arranged of layers of carbon atoms shape six member rings and reactive ends perhaps has even advanced competent for application [8e10]. Graphene is chiefly more available to doping and chemical modification but in addition more vulnerable to structural defects and impurities. According to outcomes of some published papers, the most effective process for increasing the adsorption potential of carbon nano-material were obtained using chemical modification by means of atom doping [11e 16]. Doping is an ordinary method to adapting the electronic traits of the semi-conductor materials. For example, behind doping with B or N atoms, carbon nanotubes (CNTs) expanded into p-type or n- type correspondingly [17]. Theoretic studies show that the replacement of atom by doping can alter the band structure of graphene [18e20]. The applications of graphene can be mainly enhanced and expanded. The doped graphene guarantees a lot of gorgeous prop- erties and widespread potential purposes such as superconductor [21] ferro-magnetism [22] etc. Wei et al. [23] show the synthesis of the N-doped graphene by the CVD method. Furthermore, they * Corresponding author. E-mail addresses: a.shokuhi@gmail.com, a.shokuhi@qaemshahriau.ac.ir (A.S. Rad). Contents lists available at ScienceDirect Current Applied Physics journal homepage: www.elsevier.com/locate/cap http://dx.doi.org/10.1016/j.cap.2015.07.018 1567-1739/© 2015 Elsevier B.V. All rights reserved. Current Applied Physics 15 (2015) 1271e1277