Efficient degradation of organic pollutants by enhanced interfacial internal electric field induced via various crystallinity carbon nitride homojunction

Herein, a homojunction carbon nitride photocatalyst integrated with three crystallization levels (Tri-crystallinity) is developed to enhance the degradation activity of organic pollutants . The increase in crystallinity induces the Fermi level and band position to decrease. This difference constructs an internal electric field (IEF) at the interface with a lower to higher crystallinity direction. The multiple contact interfaces in Tri-crystallinity reinforce the interfacial IEF twice compared to a conventional single-interface. The interfacial IEF improves charge separation and transfer, and the degradation of antibiotics by Tri-crystallinity carbon nitride is at least 20 times greater than primary carbon nitride. Further, the Tri-crystallinity carbon nitride loading on a nonwoven fabric in a continuous-flow reactor achieves 91.0% purification of the organic wastewater at a flow rate of 14.2 L h −1 m −2 from 11:00 a.m. to 3:00 p.m. This work provides a strategy for engineering interfacial IEF of future efficient photocatalysts.