Anchorage of anthraquinone molecules onto activated carbon fibers to enhance the reduction of 4-nitrophenol

Abstract

BACKGROUND The development of carbon materials with redox functional groups on their surface is an attractive alternative for faster treatment of contaminants with electron withdrawing groups like 4-nitrophenol (4NP). In the search for better catalytic materials, this paper reports the anchorage of two anthraquinones on the surface of polyacrilonitrile activated carbon fibers (ACFs). RESULTS 2-aminoanthraquinone (AAQ) and anthraquinone-2,6-disulfonate (AQDS) were anchored on SOCl2 treated carbon materials. The results show that fixation of AAQ and AQDS on ACFs caused changes in the surface area and the pore size distribution of ACFs, but only AQDS materials (8.3% in weight) showed an improvement in the catalytic properties of the material (49%) towards the reduction of 4NP to 4-aminophenol, providing sodium sulfide as the electron donor. HPLC and spectrometric scans at the end of the reduction experiments showed that AQDS remained anchored on ACFs. CONCLUSIONS Immobilized AQDS on ACFs was shown to be an effective solid-phase redox mediator improving the reductive transformation of 4NP. Other applications for the method of immobilization of redox mediators on the surface of ACFs were reported in other fields of study such as energy storage and microbial fuel cells. © 2014 Society of Chemical Industry