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An innovative device produces fuel out of carbon dioxide with no other energy than sunlight
While were recently talked about a technology project that leverages spinach enzymes to convert carbon dioxide into fertilizer, this time it is an even simpler system. Essentially, it is a technology that generates oxygen and formic acid with no other resources than sunlight and water. This high-density liquid fuel can be stored or converted into hydrogen. However, deep down, it is not a very new technique: plants have been doing it for millions of years. In fact, the best description of this process is "artificial photosynthesis." And it's a bit of a holy grail of science since it would succeed in replicating one of nature's basic mechanisms for generating energy. The techniques used so far had not achieved efficient conversion without causing waste.
Fortunately, the University of Cambridge recently announced that it has developed a wireless device that transforms carbon dioxide into usable fuel. The results, published in the journal Nature Energy, indicate that the new process can efficiently generate clean fuel. The device is a photocatalytic film made from semiconductor powders at a low manufacturing cost. A cobalt-based catalyst is then added, although researchers are already exploring other materials that can produce different types of fuel. The film is then submerged in water with carbon dioxide. When exposed to sunlight, it releases electrons that combine with the carbon dioxide and protons in the water to generate formic acid.
The initial prototype is a twenty square centimeter unit, although its simplicity gives it great scalability. Technically, it would not be challenging to manufacture devices of several square meters that would become the solar farms of the 21st century. For now, the developers are working on improving the energy efficiency of the system. However, they point out that the initial results are much better than expected and that the waste produced is practically zero.
This is not the first experience of the research team of the University of Cambridge with artificial photosynthesis. As is often the case in science, the new achievement results from an iteration over previous technology. In 2019, the same team announced a leaf capable of generating syngas, a synthetic gas. This prototype required various components, which made production difficult, although it demonstrated the basic principle's viability.
Of course, other researchers are studying the possibilities of artificial photosynthesis. One of them, belonging to the University of Singapore, announced a few years ago a prototype capable of producing chemical compounds for industrial use at room temperature. Also based on sunlight and water, the difference is that it required the use of pressure. Besides, the gas generated was ethylene, a hydrocarbon used mainly in polyethylene production and a large number of plastics.
Initiatives at the universities of Cambridge and Singapore, along with other teams worldwide, demonstrate that this is a promising technology. The plant kingdom may ultimately hold the key to a new generation of renewable energy. As Cambridge researchers say, plants have been learning to process and store energy for millions of years.
Source: University of Cambridge