Colour attracted me towards chemistry when I was in my high school and it is only during my PhD I understood the joy of getting a colourless pure ligand purified from a myriad of colourful impurity. Thus, this journey taught me a lot through experiments: divine joy when I predicted something, and it clicked, dejection when I could not get the result even after several attempts. PhD not only helped me to earn a degree but also has built my character, the utmost target of any education. With PhD, I learnt to see life through a colourless, black and white lens rather than having a colourful biased vision. PhD taught me discipline, to be able to work in a group, ethics, responsibility and allowed me to hone my skills at the same time. I still remember the early days of my PhD when it looked to be an unsurmountable path to finish the PhD, writing papers, bear the pain of publishing it and finally writing thesis and defend it; but with time as I grew my skill everything seemed possible. PhD makes me a way more confident person than I was before. I developed some good habits during this period, meticulously maintaining my PhD lab note book was one of them. I got the inspiration from a very eminent scientist in the field whom I met in a seminar during my MSc days at IIT Kharagpur who advised to note down every minute finding and thoughts in a lab book. His logic was at our younger age we are full of ideas but lacks in experience and as we go old we are rich in experience but our brains lack.
Then we can use our experience to look back the problems noted down in your note book. I am still guided by these nice words and sketch down the innovations of my younger brain. Of course, my PhD journey would not have been accomplished without the constant motivation of my supervisor. His easy-going nature added a huge momentum to my PhD. I still remember the sleepless nights when we were to meet a project deadline and instead of pushing me alone in this difficult situation, we worked together for constant 40 hours with just few cups of coffees. As he always says, “I do not have a dream project, but I have a planned project”, “Do justice to taxpayers’ money” etc still keep me focussed. I was assigned a project in my 6th month of my PhD when a Ministry of New & Renewable Energy (MNRE) project was sanctioned to our lab. I would share the excitement and the outcome of the project which eventually led me to a PhD in a broader context as below:
Global Warming and its Impact Global warming is the term used to describe the gradual increase in temperature in the earth’s atmosphere leading to permanent climate change. However, the change is really slow and may seem a “hoax”, but the scientific consensus on climatic changes related to global warming is that the average temperature of the Earth has risen between 0.4 and 0.8 °C over the past 100 years. Greenhouse gases (carbon-di-oxide, methane, water vapour etc.) which absorb and emit the radiated heat from the sunlight in the thermal infrared region are the fundamental cause for global warming. Over the past 50 years there has been a rapid increase in the volumes of carbon dioxide in the atmosphere released by the burning of fossil fuels, land clearing and other human activities. It is alarming to note that Antarctic carbon-di-oxide level hit 400 ppm for first time in 4 million years and it is recently predicted that average global temperatures could increase between 1.4 and 5.8 °C by the year 2100.
Changes resulting from global warming may include rising sea levels due to the melting of the polar ice caps, as well as an increase in occurrence and severity of storms and other severe weather events. Thus, global warming is a global menace.
Combat with Global Warming Scientists around the world are engaged in tackling with this potential threat of mankind. There are two major ways, among many, of dealing with the problem: (i) mitigate the atmospheric carbon-di-oxide level by either capturing the carbon-di-oxide or by valorising it either to some useful commodoties or as a feedstock for fuel; (ii) switch to hydrogen based fuel economy. The latter has an added advantge that the burning of hydrogen with oxygen affords water which is environmentally benign and can be reused either to generate hydrogen again or as drinking water. The other advantegaes include its high specific heat of combustion, clean and renewable source etc. Thus, chemical storage of energy in the form of hydrogen and reduced forms of carbon-di-oxide is a logical way to address the present global warming problem and rising fossil fuel crisis.
Impact of Global Warming and Water Pollution in India (from Atmospheric science to Economy to Human race) In India, both global warming and clean water are major problems which require immediate attention. Rapid urbanisation and industrial effluents in the river aggrevates the catastrophic consequences (Scheme) and it is predicted that heavy monsoon is likely to occur in very 10 years by the end of this century, Kolkata and Mumbai are expected to experience extreme river floods, rising sea level and high temperatures. There is another outlook of this problem and that associates agriculture, economy and the human race as a whole. This erratic rainfall and overall rise in temperature would result in significant reduction of crop yeild affecting agriculture and economy. Not only that, according to a report, this would lead to a situtation where 63 million people may no longer be able to meet their calorific demand. Impact of Global Warming in Kolkata, where we do our research In metro cities like Kolkata, the air is getting polluted gradually with the increase of motor vehicles and busy life-styles and thus, the effect of global warming is more pronounced. West Bengal already loses its distinctly felt seasons and the air-quality of the Kolkata is very poor having alarmingly high level of PM10 and NOx values, (PM10, NOx are indexes to measure air pollution) (Scheme).
My research area In this scenario, my research focuses on the ways to combat this contemporary issue of global warming and clean water problem. Our group at IACS, Kolkata led by Dr. Abhishek Dey is associated with the development of the bio-inspired catalysts that are capable of producing hydrogen from water obtained from local water bodies without any pre-treatment. We have successfully developed and tested many catalysts which can perform water splitting in an energy efficient way with high turnovers (1). These catalysts are also stable for long term use and can tolerate atmospheric levels of oxygen which make them qualify for large scale industrial applications. This renewable source of energy will not only reduce the use of fossil fuel and the poisonous gases associated with its burning but also afford water as by-product which can be made drinkable.
The other part of our research is carbon-di-oxide valorisation. We use iron porphyrin complex as catalysts for this purpose and it is demonstrated that these can perform efficient carbon-di-oxide conversion to carbon monoxide (2). Now, this carbon monoxide can be used as a feedstock for fuel-forming reactions or other organometallic transformations. We are also engaged in the development of spectroscopic methods for the investigation of these catalytic transformations (3).
We hope that interception- and interrogation-based innovations will lead to viable systems for water electrolysis under ambient conditions in near future.
In my post- doctoral study in University of Wisconsin, I am currently focussing on direct application of these reactions in a practical fuel cell. I am learning a bit of engineering and assembly of the fuel cell and hope to assimilate this expertise while I come back to India. My hope is renewable energy is best perceived by developing nation like India where there is tremendous scope for the expansion of infrastructure. India, as a nation has great potential to become a world leader in the implementation of renewable energy.
Outlook beyond Science: Government’s initiative In the conclusion, it is the general concern of the public to be responsible for their own future. There are certain steps taken by the government to prevent global warming which are praiseworthy viz. banning BS-III vehicles, bringing CNG in automotive applications, National Mission for Clean Ganga etc. In fact, global warming had drawn global attention and is the centre of attention of Paris Climate meeting. However, president Donald Trump announced the withdrawal of United States from the landmark 2015 Paris climate agreement saying it favoured India and China. The move drew condemnation from allies and business leaders.
LiNO’17 and Panel Meeting on Global Warming Last year a group of delegates from India supported by DST India attended the 67th Lindau Nobel Laureate Meeting and climate change was a common lecture topic there. At the opening of the 67th Lindau Meeting, William E. Moerner presented the keynote speech prepared by Steven Chu, 1997 Nobel Laureate in physics and former U.S. Secretary of Energy where Chu described how clean energy technologies provide an insurance policy against the societal risks of climate change. During a science breakfast hosted by the Austrian Federal Ministry of Science, Research, and Economy, Bernard L. Feringa, 2016 Nobel Laureate in Chemistry, outlined three challenges for carbon capture and utilisation: separating carbon dioxide from other gases, efficiently concentrating it, and catalytically converting the inert molecule to useful fuel and chemicals. I was also an attendee in that meeting and presented my work on carbon-di-oxide reduction with molecular catalysts.
