A facile method of modifying graphite powder with aminophenyl groups in bulk quantities

Abstract

A facile and rapid method of covalently modifying the surface of graphite powders with aminophenyl groups is described. This chem. modification strategy gave bulk quantities of amino-modified C powder. 4-Nitrophenyl groups are covalently attached to graphite powder via the chem. redn. of the corresponding 4-nitrobenzenediazonium tetrafluoroborate salt using aq. hypophosphorous acid. The 4-nitrophenyl groups on the C surface are then reduced to the corresponding 4-aminophenyl groups using alk. Fe(II) ammonium sulfate solns. Electrochem. and x-ray photoelectron spectroscopic characterization is carried out at each stage of the synthesis. [on SciFinder(R)

Quantitative Studies of Metal Ion Adsorption on a Chemically Modified Carbon Surface: Adsorption of Cd(II) and Hg(II) on Glutathione Modified Carbon

“…To this end we oxidized the carbon surface and oxygen-containing surface groups (e.g. hydroxyl and quinonyl groups) which are known to decorate the edge plane defect sites on the graphite surface [27], by stirring the graphite powder in concentrated nitric acid and sulfuric acid [27] [HNO 3 (15 M): H 2 SO 4 (18 M) in 3 : 1 ratio] for 12 h. The oxidized graphite powder was then washed well with a sufficient quantity of pure water until the washings ran neutral. The modification of graphite powder was then performed as follows: oxidized graphite powder was first treated with thionyl chloride by suspending 2 g of the powder in 15 cm 3 of thionyl chloride with gentle stirring for 90 minutes [28].…”

Electrografting of Diazonium‐Functionalized Polyoxometalates: Synthesis, Immobilisation and Electron‐Transfer Characterisation from Glassy Carbon

“…In the herein contribution, we describe 1) the efficient synthetic procedure of the new functionalized Keggin‐type POM [PW 11 O 39 {Ge( p ‐C 6 H 4 ‐CC‐C 6 H 4 ‐N 2 + )}] 3− (K Ge [N 2 + ]),11 bearing a much simpler organic tether than the one of the previously described hybrid,10a 2) its covalent immobilisation onto a glassy carbon electrode and 3) its thorough electrochemical characterisation once confined at the surface. The diazonium function was chosen because of its ability to graft to various substrates:12 1) by electrochemical13 or chemical reduction of the diazonium salt,14 2) spontaneously on some reducing or non‐reducing materials, 3) photochemically in the presence of a photosensitiser15 or 4) by irradiation of a charge‐transfer complex 16. Although the reaction generally leads to disordered multilayers, it is possible to obtain bonded monolayers, for example by 1) control of the grafting conditions,17 2) cleavage of multilayers18 or 3) steric effects 19.…”

Covalent Modification of Glassy Carbon Surfaces by Using Electrochemical and Solid‐Phase Synthetic Methodologies: Application to Bi‐ and Trifunctionalisation with Different Redox Centres

“…[27,[35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] The main strategy consists of immobilising a 4-nitrophenyl group at the carbon surface by reducing the corresponding diazonium salt, reducing the nitro group to an amine group, then allowing subsequent chemical modifications. [27,35,36,41,43,48,50] Other examples include the immobilisation of a 4-carboxyphenyl group, [39,42,46,47] 4-(chloromethyl)phenyl group, [37,38] 4-(aminoethyl)phenyl group, [40] and more recently phenylmaleimide group, [44] phenylazide or phenylacetylene groups, [45] and boronic acid group, [49] followed by further chemical modification at the reactive groups for the preparation of single modified carbon A C H T U N G T R E N N U N G electrodes.…”