Mandi, March 28
The researchers of the Indian Institute of Technology, Mandi, have produced new photocatalyst that converts plastic to hydrogen and other useful products.
The researchers have developed a method that can transform plastic into hydrogen when exposed to light. The researchers said that the generation of hydrogen from plastics is particularly useful because the gas is considered the most practical non-polluting fuel of the future.
Dr Prem Fexil Siril, Professor, School of Basic Sciences, IIT Mandi, said that “Plastics, most of which are derived from petroleum, are not bio-degradable, which cannot be easily broken down into harmless products. It is said that most of the 4.9 billion tonnes of plastics ever produced would end up in landfills, threatening human health and the environment.”
The research was led by Dr Prem Fexil Siril, and Dr Aditi Halder, Associate Professor, School of Basic Sciences, IIT Mandi, and co-authored by their Ph.D. scholars, Rituporn Gogoi, Astha Singh, Vedasree Moutam, Lalita Sharma and Kajal Sharma.
“We first ascertained the photocatalytic activity of our catalyst by seeing its action on methyl orange, whose colour change from orange to colourless showed the extent to which our catalyst was able to degrade it,” said Dr Fexil Siril.
“The researchers found there was 100 per cent degradation within four hours when they used a catalyst in which about 4 per cent weight iron oxide was present in the polypyrrole matrix. The researchers then tested this catalyst on polylactic acid (PLA), a plastic that is extensively used in food packaging, textiles, medical articles and cosmetics. The team found that hydrogen was evolved during the breakdown of PLA when the catalyst was exposed to visible light,” he added.
“While the generation of hydrogen is good in itself, we are even more excited about the absence of carbon dioxide,” he said. “While most other photocatalysts that have been developed for hydrogen generation from plastics release greenhouse gas as a by-product, the IIT Mandi catalyst did not but instead co-produced useful chemicals such as lactic acid, formic acid and acetic acid,” he said.
“The use of the photocatalyst does not stop with plastic treatment. It can also be used for photoreforming of food waste and other biomass and also for breaking down pollutants in water. The interesting heterojunction properties of nano iron oxide and polypyrrole offer scope for the development of new catalysts for energy production and environmental applications” he remarked.
Need of the hour
Plastics are not bio-degradable. Fuelled by the need to prevent runaway plastic pollution, IIT Mandi researchers are developing methods that can transform plastic into useful chemicals. — Dr Prem Fexil Siril, professor, IIT