Electrochemical Remediation of Cs-contaminated Water by Adsorption under Dual Electrode Polarities: Application of Water-Dispersible Asphaltene-derived Carbon Nanoplatelet Aerogels

Summary

This paper contains the majority of the work from my PhD. In it, we synthesise the first asphaltene-derived carbon aerogel and use it to remediate cesium-contaminated water, achieving record removal capacities. This comes from two mechanisms working together: an unusual dual-polarity uptake (the material captures Cs⁺ at both positive and negative potentials) and its ability to intercalate cesium within the stable electrochemical window of water at the negative polarity.

The finding I think matters most is what it implies more broadly: that carbon materials can be engineered to intercalate alkali ions within this voltage window. If the same mechanism extends to sodium, it opens a path toward a new generation of carbon electrodes for capacitive deionization (CDI) and potentially makes CDI truly competitive with other desalination technologies, rather than a niche approach limited to lab work.

Key findings

• First asphaltene-derived carbon nanoplatelet aerogel (ASPO900), made by oxidation, freeze-drying and pyrolysis
• Cesium uptake under both cathodic and anodic polarisation
• 2.27 ± 0.25 mmol g⁻¹ Cs⁺ uptake over four polarity-switching cycles
• Evidence of Cs⁺ intercalation at the negative polarity (−0.6 V vs Ag/AgCl)