• Scientists have developed a molecule that uses light or electricity to efficiently convert the greenhouse gas carbon dioxide into a carbon-neutral fuel source.
• The molecule employs a nanographene complex to absorb light and drive the conversion of carbon dioxide to carbon monoxide.
• It is a “new milestone in the quest to recycle carbon dioxide in the Earth’s atmosphere into carbon-neutral fuels and other materials.
• “If you can create an efficient enough molecule for this reaction, it will produce energy that is free and storable in the form of fuels. 

Points to Remember:

• Burning fuel – such as carbon monoxide – produces carbon dioxide and releases energy.
• Turning carbon dioxide back into fuel requires at least the same amount of energy.
• A major goal among scientists has been decreasing the excess energy needed.
• This is exactly what Li’s molecule achieves: requiring the least amount of energy reported thus far to drive the formation of carbon monoxide.
• The molecule – a nanographene-rhenium complex connected via an organic compound known as bipyridine – triggers a highly efficient reaction that converts carbon dioxide to carbon monoxide.
• The ability to efficiently and exclusively create carbon monoxide is significant due to the molecule’s versatility.
• “Carbon monoxide is an important raw material in a lot of industrial processes.
• “It’s also a way to store energy as a carbon-neutral fuel since you’re not putting any more carbon back into the atmosphere than you already removed.
• The secret to the molecule’s efficiency is nanographene -a nanometre-scale piece of graphite, a common form of carbon -because the material’s dark colour absorbs a large amount of sunlight.
• bipyridine-metal complexes have long been studied to reduce carbon dioxide to carbon monoxide with sunlight. However, these molecules can use only a tiny sliver of the light in sunlight, primarily in the ultraviolet range, which is invisible to the naked eye.
• In contrast, the new molecule takes advantage of the light-absorbing power of nanographene to create a reaction that uses sunlight in the wavelength up to 600 nanometres – a large portion of the visible light spectrum. 

Source: Indian Express