Chemists at Nanyang Technological University, Singapore, have found a method that would transform plastic waste into valuable chemical compounds by using sunlight.
In lab experiments, the research group combined plastics with their catalyst in a solvent, which allows the solution to control light energy and transform the dissolved plastics into formic acid—a chemical utilized in fuel cells to produce electricity.
Reporting their work in Advanced Science, the group led by NTU Assistant Professor Soo Han Sen from the School of Physical and Mathematical Sciences made their catalyst from the affordable, biocompatible metal vanadium, often used in metal alloys for automobiles and aluminum alloys for planes.
When the vanadium-based catalyst was dissolved in a solution having a non-biodegradable consumer plastic like polyethylene and exposed to artificial sunlight, it broke down the carbon-carbon bonds inside the plastic in six days.
This process transformed the polyethylene into formic acid, a naturally occurring preservative and antibacterial agent, which may also be used for power generation by facilities and in hydrogen fuel cell vehicles.
In Singapore, most plastic waste is burned, emitting greenhouse gases, including carbon dioxide, and the remaining mass-burn ash—is brought to the Semakau landfill, which is predicted to run out of space by 2035.
Creating innovative zero-waste solutions, such as this eco-friendly catalyst to convert waste into resources, is a part of the NTU Smart Campus vision to pave the way for a sustainable future.
The vanadium-based catalyst, which is supported by organic teams, utilizes light energy to drive a chemical reaction and is called a photocatalyst.
Photocatalysts allow chemical reactions to be powered by sunlight, unlike most reactions carried out in the industry that require heat, often generated by the burning of fossil fuels.