It’s long been a dream of researchers to develop a way to use free and abundant resources to meet the renewable energy needs of a growing world population.
Now, in search of what might be termed a “Holy Grail” of clean energy production, scientists have – at least in theory – isolated a photocatalyst that may be able to take carbon dioxide from the air and turn it into a carbon-based fuel such as methane.
Photocatalysts absorb sunlight and use it to excite electrons to higher energy levels. These excited electrons, and the empty spaces they leave behind, then make possible the two half-reactions required to split water into oxygen and hydrogen. Currently, it’s an inefficient process because it needs a lot more energy from electricity going in than it produces in terms of usable fuel. The new material would not only make that conversion much more practical but also appears to hold great potential for meeting the world’s energy needs.
The research team, led by Dr. Ricardo Grau-Crespo, of the Chemistry Department at England’s University of Reading, studied a number of photocatalysts for possible fuel production reactions, employing supercomputer simulations. That type of analysis can be quite difficult, because the properties of the photocatalyst must be very precise in order for the desired reaction to occur.
In the report of their findings, published in the Royal Society of Chemistry’s Journal of Materials Chemistry A, they describe discovering that some metal-organic frameworks, which combine metal atoms and organic molecules, exhibit the ideal electronic structure required to catalyze these reactions.
Dr Grau-Crespo explained: “Our research is inspired by nature, as porphyrin is related to chlorophylls, the green pigments which allow plants to convert sunlight into chemical energy. The challenge now is to incorporate these wonderful natural catalysts into materials capable of doing the specific chemical job we need. If we can do this, it could lead to highly-efficient conversion of solar energy to chemical energy – providing a clean, storable and transferrable source of energy.”
And he is optimistic, saying,”While we still have a long way to go, our new findings could be a significant step forward in the search for cheaper, environmentally-friendly fuels to power the future.”