New Delhi: Have you envisioned a future where you can charge your phone through photosynthesis?
Well, that future is not too far away, thanks to scientists at the Indian Institute of Science Education and Research (IISER), Thiruvananthapuram and the Indian Institute of Technology (IIT), Indore, who have successfully developed a method to artificially mimic photosynthesis.
These researchers have an exciting first that could potentially change the way solar energy is collected advanced A new system to artificially capture light and convert it into power, thus recreating photosynthesis, the process through which plants absorb sunlight and produce sugar.
Scientists around the world have attempted to create more efficient solar cells by mimicking the molecular and atomic structure of chromophores – the light-absorbing molecules that plants use in photosynthesis – in their engineered systems in the laboratories.
Chromophores absorb visible light and transmit it to other components that use the energy for various chemical reactions. Exposed chromophores on leaves absorb solar energy and transmit it to nearby chromophores until the energy reaches its destination.
However, these attempts using polymeric structures, detergent-type molecules and other similar structures have encountered a common problem, in which the clumping or aggregation of the molecules leads to loss of light and degradation of the conversion efficiency.
Aggregation of molecules reduces their activity and reduces their ability to receive light because it reduces the active sites on these molecules. Therefore, this aggregation leads to less efficient absorption of light.
“Understanding the structure of these nanoclusters is essential to find ways to improve the efficiency of these nanoclusters. Previously, silver nanoclusters were showing very weak emission properties at room temperature. By strategically synthesizing them, we can improve its emission Were able to enhance the properties, improving the way it captures, absorbs and transfers light between molecules, Dr Sukhendu Mandal, Associate Professor, Department of Chemistry, IISER, TVM told ThePrint.
Through the results of this study, researchers have found a way to create a highly efficient photosynthetic system using silver nanoclusters, which are a million times smaller than the width of a human hair.
To stabilize and prevent these nanoclusters from reacting with each other as well as other substances, the scientists used organic adamantanethiol ligands that react with and surround inorganic silver molecules, thus protect it from the environment.
Ligands are ions or neutral molecules that bind to a central metal atom or ion.
This ligand-protected molecule is then trapped inside another larger molecule called cyclodextrin, which protects the silver nanoclusters, increasing its longevity and enhancing its emission properties.
Using this method, the scientists achieved 93% energy transfer efficiency, showing that this harvested energy can generate current with much higher yields than the individual components.
“We used silver clusters because they are much cheaper than other metal clusters like gold and platinum. However, using silver also presented some challenges as the material is prone to oxidation and sensitive to light,” said Dr. Mandal, IISER, TVM.
The lead researcher of the project further added, “To overcome these challenges with silver, we used organic ligands to protect the silver clusters from oxidation and left it on overnight to avoid any reaction with light.” Trapping the clusters in the cyclodextrin molecule helped protect the cluster as well as increase its longevity and improve its emission properties.
The scientists hope that such research into highly efficient energy transfer systems will provide a foundation for designing new light-harvesting materials that can increase the efficiency of solar cells and reduce energy loss.
“We are also working with copper clusters in this project as it is the cheapest material and we aim to make this technology as cost-effective as possible. However, since copper oxidizes faster, it presents a bigger challenge than silver.
The paper has been co-authored by Dr. Sukhendu Mandal, Dr. Sourav Biswas and Anish Kumar Das from IISER, TVM, and Professors Biswaroop Pathak and Surya Shekhar Manna from IIT Indore.
These researches are expected to help India achieve net-zero carbon emissions by 2070 and meet 50% of its electricity needs from renewable sources such as solar energy by 2030.
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