Using bacteria that convert light into energy can make solar energy more widely available in cloudy places. Source: ©FotoAndalucia / Fotolia
Researchers at the University of British Columbia have discovered an inexpensive, sustainable way to build solar cells from bacteria that convert light into energy.
Their batteries produce more current than previous devices, and are as effective in dim light and under strong light.
This innovation may be a step in the widespread adoption of solar energy in British Columbia and parts of northern Europe, where cloudy days are common. With further development, these solar cells - called bio-sources because they are composed of organisms - Can become as efficient as synthetic batteries used in traditional solar panels.
Vikramaditya Yadav, professor of the Department of Chemical and Biological Engineering at UBCs who led the project, said: 'We have solved an ancient problem and made solar energy an important step in a more economical direction.'
Solar cells are the cornerstone of solar panels. They are responsible for converting light into electricity. Previous efforts to build bio-solar cells focused on extracting natural pigments used by bacteria for photosynthesis. This is an expensive and complicated process involving toxic solvents and May cause dye degradation.
UBC's researchers' solution is to leave dyes in bacteria. They genetically engineered E. coli to produce large amounts of lycopene, a pigment that makes tomatoes red-orange, especially when harvesting light energy into energy. Effective. The researchers coated the bacteria with minerals that could be used as semiconductors and applied the mixture to the glass surface.
The conceptual diagram shows that the anode of a solar cell is made of biological material, which is produced by orange globular bacteria coated with titanium dioxide nanoparticles on the surface that produces lycopene. (Photo / Vikramaditya Yadav) Coated glass acts as the anode at one end of the cell, and they produce a current density of 0.686 mA per square centimeter, which is an improvement over the 0.362 mA created by others in the field.
Yadav said: 'We recorded the highest current density of bio-solar cells. The hybrid materials we are developing can be manufactured economically and sustainably. And after being fully optimized, they can operate at the equivalent efficiency of traditional solar cells.'
The cost savings are hard to estimate, but Yadav believes that the process can reduce the cost of pigment production to one-tenth. Yadav says that the 'Holy Grail' will find a way to kill bacteria, so bacteria can Produce pigments indefinitely.
He added that these biomaterials have other potential applications in mining, deep sea exploration and other low-light environments.
Accidental income
Like many previous scientific discoveries, this research is also accidental. 'Our initial motivation was to develop bacteria 'small factories' to produce large amounts of lycopene and other carotenoid molecules to make health supplements,' Yadav said. Our team has encountered challenges in storing the newly produced lycopene.'
When lycopene is stored in transparent glass bottles, they degrade rapidly, so the researchers switch to opaque bottles. The problem is solved, but this discovery has caused more scientific problems, and the researchers opened up. A new way of exploring. 'In chemistry, degradation usually means releasing electrons. We think: If the rate of electron release is high enough, can it produce a measurable current?' Yadav said.
'A student in the research team, after seeing the change in lycopene in a transparent bottle, said out loud: 'Is lycopene so easy to degrade in the sun? What if we put it in a solar cell? 'This problem has aroused our interest in developing dye-sensitized solar cells,' recalled Yadav. 'The decision to use mineral coating directly on bacteria is a gamble, and this gamble is finally rewarded. It is a great ally of scientists. We are very grateful for this unexpected discovery and the curious student, because he asked, 'Why can't I try?'
