Artificial Photosynthesis: Limitless Resources Now A Step Closer

Posted on 13. Mar, 2009 by Ross in Energy News

This week, research from the US Department of Energy’s Lawrence Berkeley National Laboratory moved the world a step closer to one of the true Holy Grails of modern science.

Artificial photosynthesis is a key technology required for the world to move towards a truly sustainable future; as important a development as the more famous goal of nuclear fusion reactors. Photosynthesis is the process whereby plants harness the energy of the sun to create energy-storing sugars from carbon dioxide and water, with those sugars becoming the building blocks and the fuel to create every other biochemical component of the plants’ structures. The process is far more efficient than using silicon-based photovoltaic cells to turn sunlight directly into electrical energy, and is also far more energy-efficient than other methods of splitting water and carbon dioxide to form other compounds and materials.

The ability to replicate this into man-made technologies would have world-changing ramifications for the huge numbers of industrial processes which involve chemical feedstocks such as pharmaceuticals and plastics, which are currently largely reliant on oil stocks, as well as presenting a way of removing carbon dioxide from the atmosphere and converting it to something immediately useful. It could also make the oil industry extinct, allowing the world to leave vast stores of carbon in the form of oil left safely trapped in the bowels of the earth.

The latest advance, reported in top science journal Angewandte Chemie, is the finding that nanocrystals of cobalt oxide are able to act as an efficient and fast catalyst for the solar-powered splitting of water molecules. This photochemical reaction is a key high-energy step in photosynthesis, and the group’s tests were able to use the reaction to produce oxygen gas from water at an energy density of 1,000 Watts per square metre. The aim is to use this as the first step in a process that would produce methanol (CH3OH) from water and carbon dioxide, which could be used as a carbon-neutral fuel or as a chemical feedstock. Whatever the eventual use of the products, this discovery represents a big step forward towards a long-term solution to climate change and sustainable population growth.