Have you ever watched a thriller movie and were surprised that the mystery or the climax was already hinted at the start of the story itself? Likewise, ever felt lost seeking a solution only to know that you already had it all along? Humans starting to use solar energy is the same as plants that have been using it since the dawn of time. It’s the most abundant, cheap, and clean source of energy being converted into photosynthesis. Besides, it’s an effective method to deal with carbon dioxide. If it’s hard to get rid of them, recycling them into a food source for the plant's growth, and in turn, those plants become a valuable food source for living beings. Not only does it follow the rules of the food chain, but it is an effective remedy against carbon dioxide. The same gas is emitted from the internal combustion vehicles fed with liquid fuel. Yet, electric vehicles (EVs) are now being sought as one of the options to promote a healthy and breathable environment. However, photosynthesis is now being looked at as a method to cultivate plants using energy efficiently.
Today, that process of making photosynthesis is being mimicked into a method called artificial photosynthesis. Otherwise termed as photoelectrochemical cells, artificial photosynthesis can produce an endless supply of inexpensive, clean gas and electricity to run a livelihood.
The method has existed for years and probably grows plants after sundown or in complete darkness is seeing the light. A photoelectrochemical reaction can remove large amounts of CO2 from the atmosphere as it produces fuel. Scientists at UC Riverside and the University of Delaware have used this method to grow food plants.
In Darkness, they Rise
By replacing naturally produced photosynthesis, scientists cultivated these plants in complete darkness in a medium called acetate. They deployed a two-step electrocatalytic process to form acetate by converting carbon dioxide, water, and electricity. The food-producing plants devoured acetate as they grew.
The scientists used an electrolyzer to convert raw materials such as carbon dioxide into acetate. The results were a boost to help power these plants by increasing the amount of acetate produced and decreasing the amount of salt produced as a byproduct.
To date, the researchers recalled that this method produced the highest amounts of acetate from an electrolyzer.
“Using a state-of-the-art two-step tandem CO2 electrolysis setup developed in our laboratory, we were able to achieve a high selectivity towards acetate that cannot be accessed through conventional CO2 electrolysis routes,” said corresponding author Feng Jiao of the University of Delaware.
“We were able to grow food-producing organisms without any contributions from biological photosynthesis. Typically, these organisms are cultivated on sugars derived from plants or inputs derived from petroleum—which is a product of biological photosynthesis that took place millions of years ago. This technology is a more efficient method of turning solar energy into food, as compared to food production that relies on biological photosynthesis,” said Elizabeth Hann, a doctoral candidate in the Jinkerson Lab and co-lead author of the study.
The scientists also discovered that other plants could be grown using this technology.
Artificial Photosynthesis Vs. Natural Photosynthesis
The scientists revealed that this technology could help grow a wide range of food-producing organisms such as green algae, yeast, and fungal mycelium that produce mushrooms, all while cloaked in the shadows.
They also realized that producing algae through this technology is four times more energy efficient than what photosynthesis has been producing. Also, yeast production is 18 times more energy efficient compared to how it is cultivated using sugar extracted from corn.
Then their research found that Cowpea, tomato, tobacco, rice, canola, and green peas can also be grown using this technology. Every plant that participated in the research raised its leaves, saying they were able to feed on the carbon emitted from the acetate medium in the dark.
Artificial photosynthesis could also be a way to deal with future climatic changes if growing food could become hard. Other natural disasters such as droughts, floods, and reduced land availability will probably have to back down if they reign havoc on global food security. Food grown in such a controlled and efficient environment could care less about dealing with such disasters.
Moreover, combining solar power panels in this system meant an increase in the conversion efficiency of sunlight, up to 18 times more than what is produced by natural photosynthesis.
However, since plus and minus are natural in most phenomena, is the food produced through this method safe for consumption?
The Darkside of Growing Food in the Dark
Even though plants grown using artificial photosynthesis function in a lab setting, it is not yet suitable for widespread use. It is difficult to duplicate what occurs spontaneously in green plants.
Since manganese is rather unstable, it doesn't function as well as a catalyst in a man-made system as it does in plants. A manganese-based method is somewhat inefficient and unworkable since it doesn't last very long and won't dissolve in water. The fact that the molecular geometry in plants is so precise and intricate makes it difficult for most artificial settings to match it as a challenge.
In many possible photosynthetic systems, stability is a problem. Organic catalysts frequently decay or may start new processes that can harm a cell's ability to function. It is possible to use inorganic metal-oxide catalysts, but they must operate quickly enough to utilize the incoming photons effectively. It's challenging to find the catalytic speed of that caliber. Additionally, some metal oxides with high speed also lack abundance.
The issue with today's cutting-edge dye-sensitized cells is the electrolyte solution, which absorbs the protons from the split water molecules rather than the catalyst. Although it is a crucial component of the cell, the volatile solvents used to make it can corrode other parts of the system.
Recent developments have begun to resolve these problems. A stable, quick, and plentiful metal oxide is cobalt oxide. The corrosive material has been replaced by a non-solvent-based alternative developed by researchers in dye-sensitized cells.
Though artificial photosynthesis research is gaining momentum, it won't be leaving the lab anytime soon. Before this kind of system becomes commonplace, at least ten years will pass [source: Boyd]. And even that is a somewhat optimistic estimate. Some people doubt that it will ever occur. Who can, however, help but wish for synthetic plants to act just like real ones?