The response to the need to protect the solar cells in a sustainable way could come … from the kitchen. A group of Finnish and Dutch researchers has created an innovative UV filter e biodegradablemade with Nanocellulosa treated with red onion peel extractcapable of offering performance higher than conventional plastic materials.
The study was conducted byTurku University In collaboration with theAalto University (always in Finland) and the Wageningen University in the Netherlands. The results were published in the scientific journal ACS Applied Optical Materialsand are part of the project Bioestfinanced by Council of research of Finland.
The red onion filter blocks almost 100% of UV rays
Today the solar cells are protected by plastic films such as the Pet (polyethylene tereftolato) or the PVF (Polivinile fluoride)materials derived from oil that contribute to environmental pollution. But the urgency to develop alternatives with low impact has pushed science to explore materials Bio-Based. This is where the nanocellulosea material derived from vegetable cellulose reduced to a nanometric, light, resistant and versatile scale.
In the study, the researchers compared four types of nanocellulose films treated with different natural compounds: red onion extract, lignina And iron ions. The result? The film enriched with red onion peel showed a surprising capacity of block up to 99.9% of UV radiation Up to 400 nanometers. No other tested material, including the reference pet, has reached such a level of protection, as explained by Rustm NizamovPhD student and author of the study at the University of Turku:
These films offer an ecological and extremely efficient UV barrier, and could replace plastic materials in systems that require transparency and durability.
High transparency and zero degradation
The great advantage of the new material is not just UV protection. To make it very special is his transparencya fundamental feature for solar cells, which need to absorb light visible to generate energy.
Many effective natural materials against UV rays, such as Lignina, present a dark color that hinders the passage of lightreducing the efficiency of the cells. The red onion film, on the other hand, has maintained Over 80% of transparency in the region of the nearby infrared (650–1100 Nm). And above all, he resisted at 1,000 hours of artificial light exhibitionequal to about A year of sun in central Europewithout losing its properties.
During the test, the researchers monitored any variations in films with high resolution digital photographs. Only one with the red onion did not show signs of degradationwhile the others – in particular the one with iron ions – have undergone one remarkable loss of transparency and filter ability.
The red onion film has been tested on solar cells sensitized with dyea technology particularly exposed to the damage from UV. However, its potential also extends to other types of photovoltaic panels, such as Celle Perovskite and those organicas well as in applications such as biodegradable sensors, portable devices And Smart packagingas pointed out by Kati myttunenProfessor of Materials Engineering and Head of the Sems Research Group at the University of Turku:
Our goal is to develop biodegradable electronic and organic electronic materials, to be used also in completely new contexts, such as food packaging with integrated sensors. The Finnish forest industry looks with great interest to these solutions, which add value to natural by -products.
A virtuous example of circular economywhere even the peel of an onion can become a high -tech componenthelping to make solar energy cleaner and respectful of the environment.
