Women in Science: Superconducting seaweed: adventures in green nanotechnology
Zoe Schnepp is a Lecturer in the School of Chemistry at the University of Birmingham. She is from the UK but has worked in the US, Germany and Japan. She is passionate about Green Chemistry and designs new materials for water treatment and solar energy capture using simple resources such as seaweed or sawdust. Zoe took part in Soapbox Science 2013, on 5th July where she stood on a soapbox on London’s Southbank and spoke to the public about her work and to help promote the role of women in science. www.soapboxscience.org
Enough energy from sunlight strikes our planet in one hour to provide all the energy needed for human activity in one year. Given this astonishing fact, it is not surprising that governments and industries all over the world now consider solar research and development to be a priority.
Several approaches exist, the most well known being the direct conversion of sunlight into electricity (so-called ‘solar cells’). However, sunlight is not constant and so to ensure a reliable national power supply an energy storage system is required. The storage solution cannot just be a daily charge-recharge cycle. For energy security most countries require a buffer and store enough energy to last several months. Batteries can provide part of the solution, but current technology does not have the energy capacity or stability for large-scale long-term storage. It’s not surprising then, that many scientists have turned to the well-established solar capture system of green plants.
Green plants use sunlight to generate chemicals. They convert carbon dioxide and water into energy-rich carbohydrates for storage, or for building cell-walls. The chemical bonds in carbohydrates contain a lot of energy and mankind has been releasing this energy for thousands of years in the simple act of burning wood. But plant matter is not the ideal energy source. Our cars rely on pure liquid fuels and many of us cook or heat our homes with natural gas. The question is: can we design a system that uses sunlight to produce a simple fuel? Can we develop ‘artificial photosynthesis’?
Generating fuels with sunlight is one of the biggest challenges in science at the moment. Chemical fuels store much more energy than batteries and can be stored for use either in stationary power plants or in vehicles. The main problem is that ‘copying nature’ is not straightforward. Photosynthesis in plants is actually quite inefficient and so to make artificial photosynthesis a viable industry we can’t just settle with copying nature. We need to go one better.
Making artificial photosynthesis work is going to rely on contributions from many different scientists. One of the challenges that I am focussing on is the materials. As a chemist, I’m interested in designing new routes for making materials. I’m particularly keen on applying the principles of Green Chemistry to materials synthesis. This involves using simple and safe procedures based on readily-available starting materials and generating minimum waste. For example, my group is working on transforming things like sawdust and seaweed into materials that perform one of the key chemical reactions in artificial photosynthesis.
The advantage of using natural materials is that they encompass exquisite complexity, such as helices and networks. We can harness this to generate complexity and detail in our artificial systems. This structural detail is important for material performance. Since we use simple chemistry and cheap precursors, the materials can be made extremely cheaply and on a large scale. These factors are critical if artificial photosynthesis is going to become a global reality, particularly in the developing world.Tagged in: women in science
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