Cobalt porphyrin (CoTCPP) advanced visible light response of g-C3N4 nanosheets

Graphitic carbon nitride (g-C3N4) sheets have been assembled firstly with cobalt-meso-tetra-(4-carboxyphenyl)porphyrin (CoTCPP) (CoTCPP/g-C3N4) through noncovalent interaction (hydrogen bonding, electrostatic interaction and π-π stacking) and covalent interaction. The CoTCPP/g-C3N4 composites show high sensitivity to visible light irradiation and excellent photodegradation performance of methylene blue (MB). g-C3N4 sheets supply photocatalytic active sites, while CoTCPP responds to the light-harvesting and promotes the separation of the photogenerated electrons and holes by transferring photogenerated electrons from the conduction band to the conduction band of g-C3N4 and receiving photogenerated holes from the valence band of g-C3N4. This work provides a new insight to enhance the efficient absorption of visible-light and facilitate the separation of photogenerated electrons and holes through the visible light sensitive organic components rather than the bandgap modulation of the catalysts.