Can we achieve artificial photosynthesis?
I would like to ask a question about artificial photosynthesis, does it exist? What kind of challenges do scientists have in this field? What potential benefit to humanity can bring artificial photosynthesis?
Hannah: So, could we mimic the power of plants to meet our energy demands? With the answer is Helen Woodfield from Cambridge University's Department of Plant Sciences.
Helen: Yes, artificial photosynthesis does indeed exist. Photosynthesis is essentially the means by which energy from the sun is captured and used to split water molecules to generate fuel for the plant to use in growth. What scientists are trying to do is to use the principles from natural photosynthesis to harvest the suns energy and convert it into fuel. The main challenge being met in the field is in the splitting of water.
Hannah: And to find out what splitting of water could be used for we turn to Dirk Mersch, a chemist at Cambridge University.
Dirk: The answer's very simple - if we split water we produce hydrogen, and hydrogen's a much cleaner fuel than the fuels we are currently using, and this fuel can be used, for example, using fuel cells to power cars.
Hannah: Sounds great, so what are scientists busy working on to make this happen then? Back to Dirk.
Dirk:The challenges we are facing at the moment are coming not just from the light harvesting side where we have the same challenges as in solar cells, but also from the catalyst side because the catalysts have to be very efficient and very robust. The catalysts are essential for our devices because they speed up the reaction, (and) in general increase the efficiency of the device. At the moment, platinum catalysts fulfil these criteria. However, they're quite expensive, so what we are working on are cost effective catalysts such as copper based and nickel based ones.