Preparation, characterization and CDI application of KOH-activated porous waste-corn-stalk-based carbon aerogel

Capacitive deionization (CDI) is an electrochemical desalination process that is not only efficient but also cost effective and environmentally friendly. In terms of electrode materials, nanoporous carbon aerogel (CA) has been regarded as a perfect material. Corn stalk, with its natural sponge-like porous channel structure that can provide a mesoporous structure after carbonization, is a common agricultural waste, which is plentiful, cost effective, renewable, and has a low resource utilization rate. Carbon aerogels synthesized from waste corn stalks possessed high surface area of 370.37 m(2) g(-1), which can be further enhanced to 721.42 m(2) g(-1) via KOH activation. High NaCl removal capacity was achieved, with SAC value of 19.47 mg g(-1) after 1100 s, which was higher than the activated carbon from the same ingredient. This method was proved to be a promising green process to make use of the waste biomass for the fabrication of CDI-utilized carbon aerogel electrodes.

Automated summary

Capacitive deionization (CDI) is an efficient, cost-effective, and environmentally friendly electrochemical desalination process. Nanoporous carbon aerogel (CA) has been considered the ideal electrode material. Waste corn stalks, a common agricultural waste, can be carbonized to provide a mesoporous structure due to its natural sponge-like porous channel structure. Carbon aerogels synthesized from waste corn stalks exhibited a high surface area of 370.37 m(2) g(-1), which can be further increased to 721.42 m(2) g(-1) through KOH activation. The CDI-utilized carbon aerogel electrodes made from waste biomass showed a promising green process with a higher NaCl removal capacity compared to activated carbon from the same source.