Composite graphene-containing porous materials used for electrosorption and capacitive deionisation
Abstract
Highly porous aerogels based on carbon nanomaterials are promising materials that can be used in new electrochemical technologies. Capacitive deionisation is a technology for removing ion species from aqueous solutions. The removal is performed by applying low external voltage to the electrodes with the high specific surface area. This is one of the most advanced methods for the desalination of low-mineralised solutions. The main problem pertaining to capacitive deionisation is the need to obtain affordable electrode materials with high porosity, high electrical conductivity, high hydrophilicity, and good mechanical properties, which can be used in a large number of adsorption-desorption cycles. Among the most promising materials are carbon aerogels. The article describes the process of synthesising new materials, highly porous monolithic composite aerogels with 3D structure formed by reduced graphene oxide and nanotubes. The electrosorption properties of the materials were studied in a series of experiments, where the said monoliths were used as electrodes for membrane capacitive deionisation. The article suggests new methods of synthesising highly porous composite carbon aerogels with 3D network structure formed by reduced graphene oxide and carbon nanotubes. Simple techniques for the hydrophilisation of the synthesised samples were developed. New electrode materials for electrosorption were created, studied, and tested in electrochemical cells for membrane capacitive deionisation. Super-porous (over 99%) composite carbon aerogels with a density under 0.02 g/cm3, rigid structure, and fragile monoliths are not effective during membrane capacitive deionisation. More dense elastic aerogels with 95% porosity and a density of at least 12 g/cm3, synthesised in the presence of polyvinyl alcohol, have relatively high electrosorption capacity with respect to sodium chloride. For instance, when the concentration of the solution is 1 g/dm3, the capacity of the material is 25 mg/g (3 mg/cm3). The synthesised aerogels are also quite stable, which makes them a promising material for capacitive deionisation.
Downloads
References
Oren Y., Desalination, 2008, Vol. 228, pp. 10-29, DOI: 10.1016/j.desal.2007.08. 005, available at: https://doi.org/10.1016/ j.desal.2007.08.005 (accessed 15.08.2008). 2. Porada S., Zhao R., Van der Wal A., Presser V. et al., Progress in Material Science, 2013, Vol. 58, pp. 1388-1422, DOI: 10.1016/j.pmatsci.2013.03.005, available at: https://doi.org/10.1016/j.pmatsci.2013.03.00 5 (accessed 10.2013).
Andelman M.D., Walker G.S. Charge barrier flow-through capacitor. Patent US, No 6709560B2, 2004. 4. Suss M.E., Porada S., Sun X., Biesheuvel P.M., et al., Energy & Environmental Science, 2015, Vol. 8, pp. 2296-2319, DOI: 10.1039/C5EE00519A, available at: https://doi.org/10.1039/C5EE00519A (accessed 05.05.2015). 5. Wenchao W., Ruiyang Z., Wei Li, Hao L. et al., Environmental Science: Nano, 2016, Vol. 3, pp. 107-113, DOI: 10.1039/C5EN00125K, available at: https://doi.org/10.1039/C5EN00125K (accessed 2016). 6. Bakhia T., Khamizov R.Kh., Konov M.A., Bavizhev M.D. Patent RF, no. 2 662 484, 2018. 7. Akhavan O., Ghaderi E., Aghayee S., Fereydooni Y. et al., J. Mater. Chem., 2012, Vol. 22, pp. 13773-13781, DOI: 10.1039/C2JM31396K, available at: https://doi.org/10.1039/C2JM31396K (accessed 20.07.2012). 8. Huang J., Li Zh., Wu X., Wang J., Yang Sh., J. Phys. Chem. C, 2019, Vol. 123, pp. 3781-3789. 9. Haiyan S., Zhen X., Chao G., Advanced materials, 2013, Vol. 25, pp. 2554-2560, DOI: 10.1002/adma.201204576, available at: https://doi.org/10.1002 /adma.201204576 (accessed 2013). 10. Tokmachev M.G., Tikhonov N.A., J. of Mathematical Chemistry, 2019, Vol. 57, No.
, pp. 2169-2181, DOI: 10.1007/s10910-01901064-7, available at: https://doi.org/10.1007/s10910-019-01064-7 (accessed 12.09.2019). 11. Marmanis D., Christoforidis A., Ouzounis K., Dermentzis K., Global NEST Journal, 2014, Vol. 16, No4, pp. 609-615, DOI: 10.30955/gnj.001253, available at: https://doi.org/10.30955/gnj.001253 (accessed 23.05.2014). 12. Zhuyin S., Qinghan M., Xuetong Z., Rui M. et al., J. of Mater. Chem., 2012, Vol. 22, pp. 8767-8771, DOI: 10.1039/C2JM00055E available at: https://doi.org/10.1039/C2JM00055E (accessed 15.03.2012). 13. Zhu G., Wang W.Q., Li X., Zhu J. et al., RSC Advances, 2016, Vol. 6, pp. 5817-5823. 14. Fan W., Zhang L., Liu T., Graphenecarbon nanotube hybrids for energy and environmental applications Springer, 2017, pp. 1104. available at:https://doi.org/10.1007/978981-10-2803-8(accessed 2017).
