IISER Bhopal Scientists Produce Magnetic Porous Carbon Nanoparticles for Sustainable Water Desalination and Purification

Indian Institute of Science Education and Research Bhopal (IISER) Researchers have successfully produced magnetic nanoparticles, which are minuscule particles approximately one hundred thousand times smaller than the width of a human hair.

These nanoparticles have been engineered for multiple applications such as heat and light-induced removal of salt from seawater, the extraction of potable water from wastewater contaminated with dyes and deicing and anti-icing processes.

One of the primary global challenges in the world is obtaining clean and usable freshwater from sources like wastewater and seawater. It is estimated that around two-thirds of the world’s population will soon live in regions with water scarcity issues. To address this, desalination, a process that can provide local water sources for about 40% of coastal communities, is crucial.

Desalination methods that produce usable water from seawater typically involve processes that need a lot of heat, like distillation or membrane-based techniques like reverse osmosis. However, these methods often require expensive equipment, large setups, and substantial energy consumption. A more sustainable alternative is photothermal (light+heat) --assisted desalination, which harnesses renewable solar energy.

The creation of magnetic nanoparticles with diverse applications, from efficient desalination processes to dye removal and de-icing represents a significant step towards sustainable and accessible water resources. Such advancements in science offer hope for a future where clean and safe water is more readily available to communities worldwide.

The Research was led by Dr. Sankar Chakma, Assistant Professor, Department of Chemical Engineering, IISER Bhopal. The findings of this research group have been published in the reputed peer-reviewed journal American Chemical Society – EST Engineering. The paper was co-authored by Vishrant Kumar, Abhinav Chandel, Prachi Upadhyay, and Dr Sankar Chakma. The paper may be accessed at https://doi.org/10.1021/acsestengg.3c00297

Explaining the significance of this research, Dr. Sankar Chakma, Assistant Professor, Department of Chemical Engineering, IISER Bhopal, said, “The photothermal desalination using our magnetic nanoparticles was effective with excellent water evaporation rate. This is because of improved mass transfer through a porous medium, like transpiration and capillary action, aiding faster upward movement of water molecules.”

Discussing the technical aspects of their experiments, Dr. Sankar Chakma, the lead researcher, said, “Porous magnetic carbon materials are excellent for photothermal applications because they interact with light waves in unique ways. The interaction is more effective with highly porous materials, as they offer additional pathways for waves to bounce around and be absorbed.”

The researchers used a simple method inspired by Indian earthen lamps to produce the magnetic Porous Carbon Nanoparticles. The process involved saturating cotton with nickel salt and mustard oil, and igniting it using a lighter, resulting in the formation of these specialized MNPs. The synthesized MNP was assessed for its photothermal activities for three purposes - Photothermal Desalination of Simulated Seawater, Photothermal Separation of Dye Molecules from Effluent and De-icing applications.

The study further showed that the nanoparticles could completely remove dye molecules from water when exposed to light and heat. Furthermore, these nanoparticles absorb Near-Infrared radiation from their environment, leading to effective de-icing properties as they heat up.