Keerthi Manikandan

PhD. Researcher at IT Sligo

Nanomaterials synthesis and its environmental and energy applications

 

Research Topic

‘Design and fabrication of novel electrode materials for electro Fenton degradation of Contaminants of emerging concerns (CECs)’

Keerthi joined IT Sligo under the supervision of Prof. Suresh C. Pillai, as a part of ‘PANIWATER’ project which has received funding from the European Union’s Horizon 2020 Research and Innovation Program and is jointly funded by the European Commission and the Department of Science Technology of India (DST). The PANI-water project is a multinational project encompassing 18 universities and colleges in both Europe and India to develop treatment methods for the removal of contaminants of emerging concern. As a PhD researcher in the PEM centre, Keerthi is working on the development of novel electrode materials for electro Fenton reactions and electrochemical oxidation mechanisms in wastewater. The project also focuses on improving photo and electrochemical processes for wastewater treatment and the development of novel routes for the photo-and electro-generation of oxidising species. The effect of the electrolyte on the generation rate and type of ROS formed will also be evaluated.

Electro-Fenton (EF) technique has gained significant attention in recent years owing to its high efficiency and environmental compatibility for the degradation of organic pollutants and contaminants of emerging concern (CECs) (Figure 1). The efficiency of an EF reaction relies primarily on the formation of hydrogen peroxide (H2O2) via 2e─ oxygen reduction reaction (ORR) and the generation of hydroxyl radicals (●OH). This could be achieved through an efficient cathode material that operates over a wide pH range (pH 3–9). An effective cathode material should possess a high overvoltage for hydrogen evolution reaction (HER), low catalytic activity for H2O2 decomposition, high stability, and conductivity. Apart from the cathodic influence, stable anodes with high overpotential for oxygen evolution reaction (OER), which allows the supplementary ●OH generation, is also significant for the enhancement of EF process.

                Figure 1: Schematic illustration of electro Fenton degradation of CECs

Carbonaceous cathode materials that are non-toxic, inexpensive and with lower H2O2 degradation rate are the most explored cathode material for the EF process. Several structural and chemical modifications were introduced to improve the surface area, conductivity, catalytic sites, and stability. As a result, three-dimensional electrodes with high surface area to volume ratio such as activated carbon fibres (ACFs), carbon felt (CF), carbon sponge (CS), reticulated vitreous carbon (RVC), etc., and porous GDE have been widely explored. In recent decades, various forms of carbon materials such as carbon nanotubes (CNTs), graphene oxide (GO), reduced graphene oxide (rGO), ordered mesoporous carbon (OMC), etc. have been applied as cathode materials in the EF process. Besides, surface features such as heteroatom doping, metal/metal oxide incorporation, polymer-based composite formation, etc. have also been implemented to improve the surface area, conductivity, and pore size of the electrode. An increased surface area and porosity have shown direct effect on oxygen diffusion and mass transfer, improving the overall efficiency of EF process.

Keerthi’s aim in her research work includes:

  • Synthesis of several coordination polymers including Prussian blue analogues (PBAs), Metal organic frameworks (MOFs) and their corresponding carbon-based composites

  •  Advanced Characterisation techniques such as Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), Raman and FTIR Spectroscopy, Differential Scanning Calorimetry, Thermogravimetric Analysis, BET analysis, and water contact angle measurements are performed.

  • Testing the synthesized materials as cathodes for electro Fenton reaction for the degradation of organic pollutants and CECs

  • Extending the use of developed electrodes in other energy applications (battery, supercapacitors, etc.)

  • Cytotoxic analysis of these synthesised materials.

Keerthi graduated with a dual degree of Bachelor of Science and Master of science in Chemistry from Indian Institute of Science Education and Research, Thiruvananthapuram (IISER Tvm), Kerala, India in 2019.

Her field of expertise falls under the field of electrochemistry, mainly electrocatalysis and Li-ion batteries.

 

For her Master thesis, Keerthi undertook a project on ‘Vanadium Oxide-based clusters for Electrochemical Energy Storage Applications’ at IISER Tvm. She had also undertaken various projects on Electrocatalysis, Nano-material synthesis, characterizations, and its various environmental and biological applications, during her five years of Integrated BS-MS course. Keerthi has hands-on experience on three electrode electrochemical systems, and a variety of synthesis procedures (electrochemical and hydrothermal), characterization techniques (XRD, Raman, FTIR, etc.) and the BioLogic EC-Lab for electrochemical applications, including electrode fabrication and CR2032 coin cell assembly during this period. Keerthi had several opportunities to work under several research groups during her internship period, which ensued the following publications:

Published papers:

[1] K.M. Nair, V. Kumaravel, S.C. Pillai, Carbonaceous cathode materials for electro-Fenton technology: Mechanism, kinetics, recent advances, opportunities and challenges, Chemosphere, 269 (2021) 129325. (https://doi.org/10.1016/j.chemosphere.2020.129325)

[2] K. M. Nair, P. Ganguly, S. Mathew, V. Kumaravel, S. C. Pillai (2020);       based Z-scheme photocatalysts for energy and environmental applications’; in S. Ghosh; Heterostructured Photocatalysts for Solar Energy Conversion, Elsevier, 257-277 (https://doi.org/10.1016/B978-0-12-820072-8.00007-X)

[3] K. O’Dowd, K.M. Nair, P. Forouzandeh, S. Mathew, J. Grant, R. Moran, J. Bartlett, J. Bird, S.C. Pillai, Face Masks and Respirators in the Fight Against the COVID-19 Pandemic: A Review of Current Materials, Advances and Future Perspectives, Materials, 13 (2020) (https://doi.org/10.3390/ma13153363)

[4] K. O’Dowd, K. M. Nair, S. C. Pillai, Photocatalytic degradation of antibiotic-resistant genes and bacteria using 2D nanomaterials: What is known and what are the challenges? , Current Opinion in Green and Sustainable Chemistry, (2021) In Press

https://doi.org/10.1016/j.cej.2021.129071

[5] V. Kumaravel, K.M. Nair, S. Mathew, J. Bartlett, J. Kennedy, H. Manning, B J. Whelan, N. S. Leyland, S. C. Pillai, 'Antimicrobial  nanocomposite coatings for surfaces, dental and orthopaedic implants', Chemical Engineering Journal, (2021), (In Press) https://doi.org/10.1016/j.cej.2021.129071