Mesoporous carbon black-aerogel composites with optimized properties for the electro-assisted removal of sodium chloride from brackish water

Abstract

A simple modification of the sol–gel polymerization of resorcinol–formaldehyde mixtures allowed the preparation route of homogeneously dispersed carbon black-activated carbon aerogel composites with high pore volumes and improved electrical conductivity. These materials showed good performance as electrodes for the electro-assisted removal of sodium chloride from saline water using high voltages. Besides the effect of the carbon black additive, we have investigated the influence of resorcinol–water ratio on the textural and electrochemical properties of the resulting materials.

Data has shown a slight dependence on the structural order of the aerogels with the R/W ratio, regardless the incorporation of the conductive additive. The effect of the carbon black on the textural features was also negligible, due to the low amount incorporated. Nonetheless, the samples showed higher capacitance values for the removal of ions from solution, due to the enhanced conductivity provided by the carbon black, being the effect more evident for the materials prepared using a low R/W ratio.