The poster, which reads 'we can live zero carbon', is treated with a photocatalyst that reacts with natural UV light to remove pollution.
The treatment, from brand PURETi, enables the poster to clean the air around it and is also self-cleaning - reducing the need for maintenance.
'Nature's strongest reducing agents'
"We're removing pollution in Shoreditch every single minute with our latest poster," OVO Energy tweeted.
"The poster is treated with PURET which is activated by light energy. PURETi then transforms the humidity in the air into Super Oxide Anions which is one of nature's strongest reducing agents."
'The impact is powerful'
PURETi can also be applied to infrastructures such as roads, bridges, and buildings.
"Concrete, asphalt, and other building materials – treated with PURETi and exposed to light - actively and continuously reduce the indirect greenhouse gases (NOx and SOx) and particulates (PM 2.5 and PM 10) that cause smog," PURETi's website states.
"The impact is powerful. One lane mile (or 6000m2) will remove one ton of NOx per year – year after year. This is equivalent to reversing the polluting effect of cars driving 650,000 miles."