Artificial Photosynthesis Reaches Speed Of Real Thing

Photosynthesis uses sunlight to separate oxygen and hydrogen from water.

Artificial photosynthesis was beyond our reach because no one had been able to match the speed at which this process occurred in nature. Now, all this has changed.

This article describes how researchers from the Royal Institute of Technology (KTH) in Sweden have developed a molecular catalyzer that matches the speed of natural photosynthesis. In nature, water molecules are split into oxygen at a rate of 100 to 400 molecules per second (known as the “turnover” rate). At KTH, researchers have achieved a turnover rate of over 300 molecules per second.

What are the implications of this? An increased ability for man to produce his own renewable energy, for one. The hydrogen (which is split off from oxygen) can be used for fuel. According to Licheng Sun, a professor at KTH, “…it will be possible in ten years to produce technology based on this type of research that is sufficiently cheap to compete with carbon-based fuels.” Areas with plentiful sunlight (like the Sahara) could produce large quantities of hydrogen. Sunlight could even be used to convert carbon dioxide into methanol. This technology could be combined with solar cells to increase their efficiency in converting sunlight into electricity.

The issue with traditional solar cells is this: although researchers are working on solutions, there is a gap between the theoretical and actual limit of electricity that can be harvested from a cell. And the theoretical limit is only 33.5 percent. Obviously, more work needs to be done in order to make this technology a practical alternative to fossil fuels. Part of the solution could involve capturing and storing the solar energy in a chemical form. Licheng Sun has invested almost twenty years of research in this area and is optimistic that artificial photosynthesis could be the alternative that people are looking for.