New artificial leaves – new fuel source

The artificial leaf was created by a research team at USTH.

These artificial leaves very thin, light and has the ability to help break down water into hydrogen gas and oxygen to create new fuel sources.

Generate energy from the photosynthesis mechanism of the leaves

Sunlight is considered clean energy source and extremely abundant from nature. “Imitating” the photosynthesis mechanism of natural leaves, a group of researchers from the University of Science and Technology – USTH (Vietnam Academy of Science and Technology), Laboratory of Metallurgy and Chemistry (Center and Center for Atomic and Alternative Energy CEA – Grenoble, France) has collaborated to research and manufacture an artificial leaf – a device capable of converting solar energy into stored chemical energy. stored in hydrogen fuel (H2) through photolysis of water.

The H2 fuel can then be stored, transported and used in fuel cells. The product of the process of using this fuel is only water, so it does not pollute the environment. This research has been started by the team at USTH since 2015.

The first version of the artificial leaf was a device capable of converting solar energy into chemical energy stored in fuel H2 (273 KJ/mol H2) through the photolysis of seawater. The H2 fuel is then stored, transported and used in the fuel cell.

The product of the process using this fuel is only H20. An artificial leaf consists of two main parts, which absorb sunlight and catalyze the dissociation of water to produce hydrogen and oxygen.

This first artificial leaf is capable of working at least 10 hours. Leaves are easily fabricated with large amounts of readily available materials in nature such as silicon, cobalt, tungsten, and molybdenum.

After the first version of the artificial leaf, the team has just published the results of research on creating an “artificial leaf” that allows the preparation of hydrogen fuel from water and sunlight with an efficiency of 1.9% in the journal. of the Journal of the American Chemical Society.

This is one of the leading prestigious scientific journals in the field of chemistry, founded in 1879 by the American Chemical Society with an Impact Factor: 15.42.

To be able to apply in industrial production, improving the efficiency of H2 generation as well as extending the “lifetime” of artificial leaves is a difficult problem for research teams not only at USTH, but also at many other countries. nation.

“Getting sick” for artificial leaves

In research published in the Journal of the American Chemical Society on May 27, 2022, “artificial leaves” are formed when a solar panel is dipped in solution and illuminated by sunlight.

Solar cells absorb light, generate the necessary energy to decompose and create 2 layers of CoWO and CoWS catalysts that are deposited on the front and back of the solar cell, completing the desired artificial leaf structure. In the pH7 solution, this artificial leaf gave H2 generation efficiency of 1.9%.

Also in this study, the research team has successfully developed a technique to identify the error of “artificial leaves” so as to “catch the disease” to find out the cause of the failure and offer a protective method, prolonging the “age of the leaves”. life” of this device.

According to Assoc. Prof. Dr. Tran Dinh Phong, after being fully assembled, it is very difficult to determine the operating mechanism, find the bottlenecks, or the cause of the failure of the “artificial leaf”.

The new method, which the development team uses simultaneously with 2 or 3 electrochemical gauges, is groundbreaking in its contribution to solving a problem facing research groups around the world on artificial leaves. From understanding the errors arising in artificial leaves, scientists can come up with treatment methods, to protect and prolong its life.

Dr. Tran Dinh Phong said that there are currently many major centers around the world conducting research in this field. Quite a bit of progress has been made in the past few years but the road to technology that uses H2 fuel to replace gasoline is still a long way off.

“There are times when, on the sidelines of international conferences, researchers wonder if we are ‘dreaming’ a dream too big? Maybe, in the future, when the artificial leaf meets the eye. If all the requirements for industrial production are successfully manufactured, a more superior technology is developed and applied. But at present, we are still doing our best to realize the dream.” Dr. Phong shared.