Coupling polymorphic nanostructured carbon nitrides into an isotype heterojunction with boosted photocatalytic H2 evolution.

A heterojunction photocatalyst made up of a single substrate is reported. The heterointerfaces of carbon nitride (CN) are natively compatible due to their very similar chemical and crystalline structures. Moreover, the varieties in the nanostructures of CN led to different energy levels that not only matched well with each other but also enabled a sufficient internal electric field at their interfaces to suppress unwanted recombination of charge carriers in photocatalysis.