Semi-artificial photosynthesis: Scientists find a new way to draw fuel from the Sun

The natural process of photosynthesis in plants has been reinvented in a new study by Cambridge University researchers with a semi-artificial process of photosynthesis as a new way to produce and store solar energy. The new semi-artificial process of photosynthesis absorbs and converts a lot more energy than natural photosynthesis does. It is described in a new study  published on 3 September in Nature Energy. The process uses a mixture of biological and artificial technology to carry out the same conversion of water to oxygen and hydrogen with natural sunlight. One of the most important chemical reactions in the world is photosynthesis — the conversion of water into energy using sunlight. It uses up water molecules in the process, splitting them into oxygen and hydrogen. The oxygen from photosynthesis alone accounts for nearly all of the world’s oxygen, and hydrogen is the future resource of unlimited, green energy worldwide. [caption id=“attachment_5114251” align=“alignnone” width=“1280”] Representational image. Image courtesy: Wikimedia Commons[/caption] “Natural photosynthesis is not efficient because it has evolved merely to survive so it makes the bare minimum amount of energy needed — around 1-2 percent of what it could potentially convert and store,” Katarzyna Sokól, first author of the study, said. The reason for this ‘inefficiency’ is that it is a difficult process to scale up to an industrial level — the many catalysts involved are expensive and toxic. These catalysts were replaced by enzymes in the reinvented process, which are more cost-efficient than catalysts to produce and purify. The team of researchers not only increased the energy produced and stored, but managed to bypass a process in the algae that grew dormant over the course of evolution. The enhanced reaction bypassed the activity of an enzyme called hydrogenase, an enzyme that converts protons (H+) to molecular hydrogen (H2), thought to be indispensable to photosynthesis. The researchers see potential for the technology to find use in building synthetic, robust pieces of semi-artificial solar technology. Dr Erwin Reisner, a senior author of the paper described the research as a ‘milestone’. “This work overcomes many challenges associated with the integration of biological and organic components into inorganic materials for the assembly of semi-artificial devices.”