Analysis of epoxy functionalization of graphene

Epoxy group functionalization

Graphene oxide epoxy group on the function of the most common organic molecules has amino or thiol and nucleophilic ring-opening reaction. Shi and other highly reversible REDOX, stable organic small molecules - 2 - amino anthraquinone (AAQ), by the ring opening reaction of epoxy functional groups on the graphene oxide will AAQ amino covalent grafting to the oxidation of graphene sheet, get anthraquinone of graphene oxide (hereinafter referred to as AQGO) will get the AAQ AQGO reduction, the assembly after the modified chemical conversion graphene (CCG)/undecorated CCG complex porous hydrogels (hereinafter referred to as AQSGH) capacitors.

Element analysis results show that AQGO nitrogen content is 1.1 wt %, C/N atomic number ratio of about 55:1. Due to the C/N ratio AAQ for 14:1, so the average 41 graphene oxide grafted carbon atoms a AAQ molecules, grafting rate is quite high, AAQ residues in AQGO content is 17.5%. The XRD results showed that AQGO layer spacing is bigger than the (0.907 nm) graphene oxide (0.798 nm), and half peak width increase, show that the arrangement between lamella because AAQ covalent graft becomes more loose. The AFM characterization, AQGO thickness of about 1.2 nm, slightly greater than the undecorated monolayer graphene oxide, is still the single layer. Graphene and its self-assembly of hydrogel layer structure as the AAQ matrix, provides a high grafting rate, good electrical conductivity and solid mechanics.

Mao, such as using epoxy groups on the surface of the ring opening reaction with cysteamine, first of all get the thiol functionalization of graphene, and then through the thiol sulfur and gold electrode surface to form gold - key, so as to realize the detection of mercury ion, as shown in figure 15. Swager etc with malononitrile anion and graphene oxide, under the attack of malononitrile anion, epoxy group open loop, one end connected to the hydroxyl, the other end connected to malononitrile. When using malononitrile sulphonate reagent and graphene oxide reaction, due to the strong hydrophilic sulfonate, get the functionalization of graphene dispersion in water is very good. Based on the nucleophilic reaction of epoxy group provides a simple method of the preparation of modified graphene material, has a potential application prospect.

Element doping modification

Through covalent and non-covalent bond connection can introduce new groups give graphene some excellent performance. The other is a kind of functional modification methods of graphene element doping modification. Usually the annealing heat treatment, ion bombardment, arc discharge method is adopted in graphene methods such as mixed with different elements, so as to replace the defects in the graphene, vacancy defects, the eigen two-dimensional graphene structure unchanged at the same time, the surface characteristics of change and give new performance. Duan adopts thermal annealing treatment such as graphene and preparation method of ammonium nitrate at 6.54. % of nitrogen doped graphene, the catalytic oxidation of phenol degradation efficiency is 5.4 times of doping, also studied the B, P or N doped graphene synergies. Dai, etc will be oxidized graphene in NH3 atmosphere temperature heat treatment, get different nitrogen content of N type nitrogen doped graphene. Temperature between 300 ℃ and 1100 ℃, the nitrogen doping content is about 3% ~ 5%, of which 500 ℃, the nitrogen content doping reached a maximum of 5% Jafari etc. HotFilament chemical vapor deposition method with ethanol steam by boron oxide powder mixed with B in the surface of graphene, boron doped graphene devices can be used in the detection of the toxic gas such as NO and NO2. Element doped graphene can effectively change the band structure of graphene, facilitate the development of novel functional graphene electronics.

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