Graphene Derivative As a Highly Efficient Nitrosonium Source: A Reusable Catalyst for Diazotization and Coupling Reaction

Abstract

An efficient and a simple approach for the synthesis of azo dyes have been developed by the diazo coupling reactions of active aromatic compounds in the presence of in‐situ nitrite functionalized graphene oxide polyvinyl alcohol GO‐PVA composite as a highly efficient nitrosonium ion source. This methodology was objected to defeat the limitations of the earlier reported method such as use of acids, alkalis and toxic solvents, to reduce the stability of diazonium salts at room temperature, modest yields and long reaction time. Additionally, the attractive advantages of the process are that it incorporated mild conditions with excellent yield, simple product isolation process, fastest reaction time and recyclability of catalyst. The isolated products were characterized by FT‐IR spectrum, UV‐spectroscopy and 1H‐NMR. The as‐prepared composites were confirmed by UV‐Visible, XRD, XPS, FT‐IR spectrum, SEM and TGA analysis.

One‐Pot Synthesis of Sulfur and Nitrogen Co‐Functionalized Graphene Material using Deep Eutectic Solvents for Supercapacitors

“…[54] TheS N-rGO has an I D /I G ratio of 1.06, signifying that the doping of Sa nd N produces defects in the carbon framework. [9] The SN-rGO O1sX PS spectrum (Figure 5c)r eveals the remaining oxygen bindings in the material. The XPS survey scans of GO andS N-rGO werec ompared;t he GO sheets show the presenceo fo nly Ca nd O atoms (Figure 5a).…”

“…The CÀOp eak intensity is significant because of the oxidation of the natural graphite powdert oG O. [9] The SN-rGO O1sX PS spectrum (Figure 5c)r eveals the remaining oxygen bindings in the material. The three peaks appeareda t5 31.1, 532.2, and5 34.2 eV for C=O, OÀC=O, and CÀO, respectively.…”

“…[1][2][3] The high surfacea rea,e xcellent chemical, thermal, electrical, and mechanicalp roperties,a nd electricalc onductivityo fg raphene make it af avorable electrode materialf or supercapacitors. [4][5][6][7] To obtain graphene in good quantities, researchers developed ap rocessi nw hich graphene oxide is synthesized from graphite, then reduced to give graphene;t his has opened up many different applications of graphene [8] in fields such as catalysis, [9] oil absorption, [10] flame retardants, [11] sensors, [12] photocatalytic water splitting, [13] Li-ion batteries, [14] supercapacitors, [15] and so on.…”

Synthesis of Aqueous Dispersible Reduced Graphene Oxide by the Reduction of Graphene Oxide in Presence of Carbonic Acid

“…The TGA curve of GO showed that it is thermally unstable and weight loss occurred at three stages. The higher weight loss is observed at about 58% near about 100 °C to 200 °C, which is due to the decomposition of trapped water molecule, while second stage observed about 68% mass loss near 250 °C, which is due to other functionalized group . Third stage showed about 90% weight loss at 650 °C because of the pyrolysis of the remaining oxygen functionalized groups as well as burning of aromatic ring carbon .…”

Remediation of Toxic Dye Pollutants by Using Graphene‐Based Adsorbents

“…GO and G@SiO 2 -AR (Table S1) shows low C/O ratio 2.07 and 1.1, respectively, which is quite less as compared to GO. The high resolution C1s spectrum of GO ( Figure S3) showed carbon atom in various functionalities such as CÀ C (283.5 eV), C=C/ CÀ O bond (286.7 eV) and carboxylate carbon C=O (OH) (288 eV) [48] ( Figure S3). The high-resolution C 1s spectra of both adsorbents show the presence of 284.4 eV due to the CÀ C/À CÀ SiÀ bonds, 286.3 eV due to C=C/CÀ O bonds while 288.8 eV is for C=O bond (Figure 3b).…”