A novel metal-free photocatalyst with post-illumination catalytic memory was fabricated by the graphitic carbon nitride (g-CN), carbon nanotubes (CNTs), and graphene (Gr), in which g-CN acts as an efficient photocatalyst and the CNTs and Gr act as supercapacitors. The removal of phenol was achieved in the dark by post-illumination catalytic memory because the photocatalyst could store a portion of its photoactivity via photogenerated electrons in the CNTs and Gr under visible-light illumination and then release the electrons again in the dark. Therefore, this metal-free photocatalyst is capable of operation in the dark for a broad range of applications.
