Photo- and electrochemical processes to convert plastic waste into fuels and high-value chemicals

The massive waste of plastics is resulting in serious environmental issues, yet plastics can be regarded as raw carbon materials to produce value-added chemicals by catalytic methods. In particular, recently-developed photocatalytic and electrocatalytic processes are promising for plastic conversion. Recent reviews about plastic recycling focus on traditional thermochemical methods, however, there have been few reported reviews on advanced photo- and electrochemical processes. Therefore, here we review clean catalytic technologies to convert plastics into fuels, materials and fine chemicals, with focus on photo-, electro-, photoelectrochemical catalysis and solar thermal electrochemical processes. The catalytic mechanisms, processes, conditions as well as pretreatment methods for various plastics upcylcing are discussed and summarized, challenges are explained, and directions for upgrading and transforming plastics in the future are proposed.