Page 105 - Plastics News December 2019

tEChNoLogy

Scientists convert plastics into useful chemicals using sunlight

hemists at Nanyang Technological University, Singapore and aluminum alloys for aircraft. When the vanadium-
C(NTU Singapore) have discovered a method that based catalyst was dissolved in a solution containing a
could turn plastic waste into valuable chemicals by using non-biodegradable consumer plastic like polyethylene
sunlight. In lab experiments, the research team mixed and exposed to artificial sunlight, it broke down the
carbon-carbon bonds within the plastic in six days. This
process turned the polyethylene into formic acid, a
naturally occurring preservative and antibacterial agent,
which can also be used for energy generation by power
plants and in hydrogen fuel cell vehicles. The vanadium-
based catalyst, which is supported by organic groups and
typically abbreviated as LV(O), uses light energy to drive
a chemical reaction and is known as a photocatalyst.
Photocatalysts enable chemical reactions to be powered
by sunlight, unlike most reactions performed in the
industry that require heat, usually generated through
plastics with their catalyst in a solvent, which allows the the burning of fossil fuels. Other advantages of the
solution to harness light energy and convert the dissolved new photocatalyst are that it is low cost, abundant,
plastics into formic acid—a chemical used in fuel cells and environmentally friendly, The new vanadium-based
to produce electricity. Reporting their work in Advanced photocatalyst developed by the NTU research team was
Science, the team led by NTU Assistant Professor Soo Han specially designed to break these bonds, and does so by
Sen from the School of Physical and Mathematical Sciences latching onto a nearby chemical group known as an alcohol
made their catalyst from the affordable, biocompatible group and using energy absorbed from sunlight to unravel
metal vanadium, commonly used in steel alloys for vehicles the molecule like a zipper.

105 December 2019 Plastics News