Study On Covalent Functionalization Of Graphene With9-(4-Aminophenyl) Acridine And Its Derivatives

Graphene, a novel two-dimensional honeycomb sp~2-hybridized monolayer carbon atomspacked into hexagonal structure of atomic crystal, which owns several unique properties,such as remarkable electronic, good thermal conductivity, mechanical properties and hugespecific surface area. So far, graphene intrigues world-wide research interest, includingmaterial science, condensed matter physics, chemistry and microelectronics.Graphene-based materials have been continuous prepared, such as electron devices,composite materials and photoelectric materials. Graphene-based function materialsgradually arouse the interest of many researchers. Functionalization of graphene can notonly change its solubility and dispersion, but also enhance its workability andcompatibility.This article is a study on covalent functionalization of graphene with9-(4-aminophenyl)acridine and its derivatives (APA), mainly includes two aspects of content:(1) Synthesisand characterization of covalent functionalization of graphene (Acr-G) with APA;(2)Functionalization of graphene device with diazonium salt of9-(4-aminophenyl) acridine.Firstly, the research project mainly utilized modified Hummers methods to obtaingraphite oxide with cheap graphite powder as raw materials. Then, graphene oxide (GO)was obtained after ultrasonic treatment, which contains abundant and active oxygenfunctional groups such as carbonyl, carboxyl, hydroxyl and epoxy groups. In addition, theAcr-G can be obtained by grafting synthetic four APA compounds on the surface of GO.The Acr-G was characterized by Raman spectroscopy (Raman), ultraviolet visiblespectrophotometry (UV-Vis), and Fourier transform infrared spectroscopy (FT-IR). It wasdemonstrated that the above organic molecules have been attached successfully on thesurface of GO. Particularly, X-ray photoelectron spectroscopy (XPS) analysis revealed thatthe binding energies of spectra of N1s for acridine derivatives and Acr-G were shifted tohigher values, suggesting that excess delocalized electrons are accumulated in the graphenelayer, therefore inducing downward band bending at the graphene surface region andenhanced n-type conduction in graphene. This finding is significant because it will becentral to the development of high-performance graphene-based optoelectronic devices inmolecular electronics.Secondly, graphene device also was prepared by CVD method and semiconductortechnology. The9-(4-aminophenyl) acridine was directly grafted onto the surface of the graphene device by diazotization, after light response test, the functionalized graphenedevice has optical response as the introduction of9-(4-aminophenyl) acridine. The findingis novel and groundbreaking, avoiding traditional synthetic organic chemistry of thereaction between the pure substrate and substrate. This study may enhance the graphene inthe optoelectronic materials field, especially in the solar cells field.