Since the discovery of graphene by Geim and Novoselov in 2004, it has attracted significant attention in various fields due to its unique physical and chemical properties.1 The inspiration behind this unprecedented attention is due to its exceptional structure and extraordinary electronic, mechanical, and thermal properties. Few promising applications include memory devices, sensors, hydrogen storage, solar cells, and super-capacitors, transparent electrodes, environmental clean-up, and polymer composites. Molecular adsorption on graphene/graphene based composites and their applications in water purification have recently gained momentum. Special properties like large surface area, antibacterial nature, reduced cytotoxicity, and tuneable chemical properties make these materials attractive choices for these applications.2 Nowadays, there is an alarming need for quality drinking water due to growing population, climatic changes, and contamination of various water resources.3 To address this issue, different technologies (reverse osmosis (RO), capacitive deionization (CDI), ultrafiltration (UF), adsorption, photocatalytic degradation, and distillation, etc.) are being used. Some of these techniques are expensive, and they consume high energy.4 I have synthesized graphene-grafted super absorbing polymer composite, which was thoroughly characterized by various spectroscopic and microscopic techniques. This material was used for organic dye removal and oil-water separation. I have also prepared graphene oxide-aminoclay composite and used it as RO membrane. Moreover, electro-adsorbent ion-exchange resins (EAIERs) and micro-crystalline cellulose-derived graphenic materials were prepared and used for the application in water desalination using CDI. EAIERs electrode material shows excellent electro-adsorption capacity of 15.93 mg/g and was used for multiple adsorption-desorption cycles.5 In addition, fluoride and other toxic metals (As and Pb), and different mining contaminants were removed and desalination was performed using CDI technology. Furthermore, the micro-crystalline cellulose-derived graphenic material was prepared in large scale and CDI prototype was made for real-time application (lab scale to industrial scale).

References
1. K. S. Novoselov, A. K. Geim, S. V Morozov, D. Jiang, Y. Zhang, S. V Dubonos, I. V Grigorieva, A.
A. Firsov, Science 2004, 306, 666.
2. A. Aghigh, V. Alizadeh, H. Y. Wong, M. S. Islam, N. Amin, M. Zaman, Desalination 2015, 365, 389.
3. S. Porada, L. Weinstein, R. Dash, A. Van Der Wal, M. Bryjak, Y. Gogotsi, P. M. Biesheuvel, ACS
Appl. Mater. Interfaces 2012, 4, 1194.
4. S. Sen Gupta, M. R. Islam, T. Pradeep, In Advances in Water Purification Techniques (Ed.: Ahuja, S.),
Elsevier 2019,165–202.
5. M. R. Islam, S. Sen Gupta, S. K. Jana, P. Srikrishnarka, B. Mondal, S. Chennu, T. Ahuja, A.
Chakraborty, T. Pradeep, Adv. Mater. Interfaces 2021, 8, 1.