From waste to resource: Transforming waste carbon felt into efficient cathodes for circular economy practices

Abstract

This study investigates the enhanced electrical conductivity of waste carbon felt (CF) which is coated with Polyaniline (PANi) through chemical oxidative polymerization, for its potential use as a cathode in electrooxidation (EO) processes. Optimum polymerization conditions were determined to be 1 M HCl dopant, a monomer-oxidant ratio of 1:1.5, and a temperature of 5 °C. Under these conditions, the CF/PANi electrode exhibited a 55 % mass gain and a 79 % resistance reduction compared to the CF. A Ti/TiO2-RuO2-IrO2 electrode was prepared by spray coating as an anode in the EO. In EO experiments with real textile wastewater samples containing different initial COD values, the COD removal efficiency of the cathode coated with PANi under optimal conditions increased by an average of 64 % compared to raw carbon felt, with an average removal efficiency of 96 %. Moreover, after 12 cycles, efficiency dropped by only 2 %, proving its high reusability and industrial potential.