SCIENCE &TECH

Researchers at IISER used human hair to produce cathodes for solar cells Researchers at the Indian Institute of Science Education and Research (IISER) in Kolkata have found a new way to produce cathodes for solar cell. The IISER researchers have used human hair to produce cost-effective, metal-free cathodes for use in solar cells. The results have been published in the journal Carbon. This is the first time where a bio-waste-derived electrode has been used as cathode in a quantum dot sensitised solar cell device. Key highlights • The graphitic porous carbon cathode shows an impressive performance to help converting visible sunlight to electricity, which is much higher than commercially available activated carbon cathodes. • It offers higher efficiency to convert visible sunlight to electricity. • The cathode was found to generate high open-circuit voltage, which is at par with conventional platinum and activated carbon cathodes. • Producing graphitic porous carbon cathode using human hair is also simple, quick and inexpensive. • Unlike in the case of other synthetic porous carbons, no physical or chemical activation process or templates were required to produce the pores of 2-50 nanometres diameter. • The porosity, along with high surface area to volume ratio, plays an important role in adsorption-desorption of electrolyte. • The cleaned and dry human hair was first treated with sulphuric acid at 165 degrees C for 25 minutes to achieve precarbonisation. • It was then heated to different temperatures in the presence of an inert gas for six hours to carbonise and bring better electrical conductivity for efficient charge transfer.