Sustainability : Artificial Leaf Makes Petrol Alternative

University of Cambridge researchers have developed an ‘artificial leaf’ that uses sunlight to convert water and carbon dioxide into ethanol and propanol that could be used as a low-emissions petrol alternative to power car engines. 

Inspired By Photosynthesis 

The ‘leaf,’ made from thin-film metal oxides and materials known as perovskites and including multiple layers including copper, glass, silver, and graphite, was made as part of University of Cambridge researchers’ experiments designed to produce ultra-thin, flexible devices, which take their inspiration from photosynthesis.  

Why? 

Although renewable technologies (e.g. wind and solar) have become cheaper and more available in recent years, other industries such as global shipping using fossil fuel powered vessels have not made much progress in decarbonisation. For, example, global shipping produces three per cent of the world’s CO2 emissions. The Cambridge researcher group, led by Professor Erwin Reisner has therefore been working to tackle this challenge by developing sustainable solutions to petrol which are based on the principles of photosynthesis. 

Floating Artificial Leaves 

The idea with the leaf design was to create a low-cost, autonomous device that’s light enough to float on water and which could be used to generate a sustainable alternative to petrol without taking up space on land.  

The thin leaf is coated onto flexible plastic and metal foils and covered with micrometre thin, water-repellent carbon-based layers that prevent moisture degradation.  

Tests 

Tests of the artificial leaves have taken place in Cambridge on the River Cam, near the iconic the Bridge of Sighs, the Wren Library and King’s College Chapel. The latest leaf design, which can split water into hydrogen and oxygen (or reduce CO2 to syngas) has been shown to convert sunlight into fuels as efficiently as plant leaves. 

Like Solar Farms But For Fuel Synthesis 

Cambridge researchers Dr Virgil Andrei says: “Solar farms have become popular for electricity production; we envision similar farms for fuel synthesis,” and “these could supply coastal settlements, remote islands, cover industrial ponds, or avoid water evaporation from irrigation canals.” 

Professor Reisner also highlighted another beneficial aspect of the leaf design saying, “In theory, you could roll up these devices and put them almost anywhere, in almost any country, which would also help with energy security.” 

What Does This Mean For Your Organisation? 

The floating fuel synthesis leaf design is an early step towards the automation and up-scaling of solar fuel production and could help industries that have struggled to decarbonise (such as global shipping) to find a simple way to do so. The fact that the ‘leaves’ can simply be rolled-up to be moved to where they’re needed and floated on water (i.e. not taking up space on land) give the design real flexibility in where and how they could be used. For example, as highlighted by the researchers, the leaves could be used to supply coastal settlements, remote islands, cover industrial ponds, or even be used to avoid water evaporation from irrigation canals. The leaves could, therefore, benefit whole industries, businesses, and individuals wherever there’s an expanse of water (which accounts for most of the earth’s surface) and, if scaled up, offer a real a sustainable and low-carbon alternative to petrol.