Green leaves floating on rivers are not necessarily true leaves. Recently, British scientists have developed "artificial leaves" that convert sunlight and water into fuels inspired by green leaves.
Leaves can convert sunlight, carbon dioxide, and water into their own energy which can be said to be small machines in nature. Based on past research, scientists at the University of Cambridge in the United Kingdom combined perovskite light absorbers and cobalt catalysts to absorb water, carbon dioxide to make oxygen, hydrogen, and carbon monoxide, which the team can then combine to create syngas, a key fuel for industries such as plastics, fertilizers, and diesel.
The equipment developed by Cambridge University in the past may not be considered a "leaf." After all, it has thick glass and complicated materials and it is neither light nor floats on the water. The team first deposited a perovskite light-absorbing layer on a thin polyester layer coated with indium tin oxide, then added a platinum catalyst, and finally coated it with a hydrophobic ultra-thin carbon-based material to avoid wetting the inside of the leaf.
The team also conducted real-world tests in outdoor water and found that the yield per gram is equivalent to that of leaves in nature. Hydrogen is 0.58% and carbon monoxide is 0.053%. Although not much, it has made great progress compared with the past and the team believes that they can also increase yields by enlarging the leaves. If you expand the size from 1.7 cm2 to 100 cm2, it becomes a huge leaf, and the amount of fuel produced will be different.
The team said that artificial leaves can be used in a wide range of applications, whether in clean waters or polluted waters, or even at sea, where artificial leaves can float and produce clean fuel.