Nanocarbon Type Xerogel Materials Designed for Water Desalination

Abstract

The relative performance of different porous solids in different applications is highly dependent on the internal pore structure of each material. Highly porous carbon materials can be prepared by evaporative drying and the pyrolysis of resorcinol-formaldehyde gels. By determining the correct synthesis parameters, the pore system of such materials can be reshaped. Depending on some important processing factors such as the dilution ratio or the initial pH of the precursor solution, various porous or non-porous carbon materials can be synthesized. This paper addresses carbon xerogels (CX) designed as a material electrode in capacitive deionization (CDI) systems for water desalination. In this work CX materials were synthesized via poly-condensation reactions of resorcinol with formaldehyde (RF) on a carbon felt sheet followed by pyrolysis. The resulting sheets were used as electrodes to develop a CDI experimental multi-cell laboratory system. The initial pH of the RF solution and the dilution ratio effect on the resulting carbon surface area and structure were analyzed. Surface area measurements using the BET method and an electrochemical capacitance evaluation of the obtained xerogels through electrochemical impedance spectroscopy were also performed. Finally, using our experimental CDI multi-cell laboratory system based on the obtained CX, we discuss the experimental data for the desalination rate as a function of the voltage and salt concentration. As a result, the developed model’s efficiency is demonstrated. The main goal of this work was to develop an efficient electrode-based novel carbon that could be commercially competitive, as well as to create guidelines for future desalination research using CX electrode materials.

Optimizing the performance of As(III) and As(V) adsorption process on magnetic carbon xerogel nanocomposites from aqueous solution and natural groundwater wells

“…Due to the properties of mesoporous gels such as texture and structure, mechanical performance, chemical stability, and possibility of control by design according to the conditions of the synthesis, they are attractive to investigate and use for speci c application (Al-Muhtaseb and Ritter 2003). A speci c application of resorcinol formaldehyde (RF) gel is found in the removal of contaminants from drinking water and wastewater (Haro et al 2011;Vivo-Vilches et al 2018;Huang et al 2018;Bono et al 2021;Hristea et al 2021). The adsorption of aqueous solution by the use of RF gels has been investigated in the removal of heavy metal ions (Ni 2+ , Cu 2+ and Zn 2+ ) using carbon aerogels and xerogels (Luzny et al 2014), Fe 3+ and Cu 2+ ions using magnetic organic xerogels (Strachowski et al 2018) and As, Fe and Mn ions using nanocarbon hybrid of carbon xerogel (Embaby et al 2021).…”