Carbon Nanoparticle Surface Electrochemistry: High‐Density Covalent Immobilisation and Pore‐Reactivity of 9,10‐Anthraquinone

Abstract

2-Bromomethyl-9,10-anthraquinone is covalently bound to carbon nanoparticle surfaces (Emperor 2000, Cabot Corp., with sulphonamide groups, ca. 9 to 18 nm diameter) with a coverage of ca. 250 anthraquinone molecules per particle (ca. 180 2 per anthraquinone). The resulting hydrophobic carbon particles are dispersed in ethanol and coated onto glassy carbon electrodes. Electrochemical experiments are reported demonstrating the effect of surface coverage, scan rate, and pH. A linear shift in reversible potential of ca. 59 mV per pH unit from pH 2 to 12 is observed consistent with the reversible 2-electron 2-proton reduction of anthraquinone. High density of anthraquinone in carbon nanoparticle aggregates causes buffer capacity effects. Binding of hydrophobic tetraphenylborate anions into carbon nanoparticle aggregate pores is demonstrated. Applications in buffer characterisation and pH-sensing are discussed.

Surface modification of carbon black nanoparticles enhances photothermal separation and release of CO2

“…Carbon black was covalently modified by transforming the sulfonyl chloride into a series of sulfonamides. The introduction of amine groups (-NH 2 ) onto the surface of CB nanoparticles was achieved by first activating the sulfonate with thionyl chloride, then adding ethylene diamine [21]. 0.25g of CB-SO 3 Na (1) in 15 mL of dichloromethane (DCM) was sonicated for 20 mins in a round bottom flask where it was sparged with argon gas, and cooled to 0 °C.…”

“Hydrothermal wrapping” with poly(4-vinylpyridine) introduces functionality: pH-sensitive core–shell carbon nanomaterials

“…phenylsulphonate-functionalised carbon nanoparticles known as Emperor 2000, Cabot Corp.) and are attracting renewed attention for electrochemical systems [12,13]. We have recently demonstrated anthraquinonefunctionalised carbon nanoparticles [14], dopylated carbon nanoparticles for gas sensing [15], and dioctylamine functionalised carbon nanoparticles as nano-supports for lipids [16].…”

(Bio)electroanalytical Applications of Carbon Nanoparticles

“…The latter change opens the way to other modifications, not possible with original phenylsulfonated CNPs. For example, ammonium functionalities 12 were used to covalently attach the anthraquinone 16 or L‐dopa‐boronic acid 17 units (Fig. 2).…”