Interfaces of graphitic carbon nitride-based composite photocatalysts

Graphitic carbon nitride (g-C3N4), a layered conjugated organic polymer with suitable bandgap values of similar to 2.7 eV, has been a welcomed nanostructure for photocatalytic applications in energy conversion and environmental purification. Some drawbacks of the pure g-C3N4 restrict the enhancement of photocatalytic performances, such as the limited solar-light harvesting ability, low surface area and rapid recombination rate of photoexcited electron-hole pairs. Interface engineering is considered as an effective strategy for addressing these issues by combining the superiorities of multi-components, as well as forming various kinds of interfaces. Broadly speaking, this enables the boosting of the light-response range, accelerate the transfer and separation of charge carriers, and inhibit the recombination of photoinduced electron-hole pairs. Unlike previous reviews, we herein summarize the interfaces-related topics of g-C3N4-based composite photocatalysts, including the methods to controllably devise and fabricate interfaces, the techniques to identify interfaces as well as the types and functions of the as-determined interface. Also, the relevant problems and ongoing challenges to design and understand interfaces of g-C3N4-based composite photocatalysts are put forward and highlighted. It is anticipated that this review could open a fresh pathway to further achievements of g-C3N4-based photocatalysts through better understanding and exploitation of interfaces.