Iodide-Induced Fragmentation of Polymerized Hydrophilic Carbon Nitride for High Performance Quasi-Homogeneous Photocatalytic H2O2 Production.

Polymeric carbon nitride (PCN) as a class of two-electron oxygen reduction reaction (2e - ORR) photocatalyst has attracted much attention for H 2 O 2 production. However, the low activity and inferior selectivity of 2e - ORR greatly restrict the H 2 O 2 production efficiency. Herein, we develop a new strategy to synthesize hydrophilic, fragmented PCN photocatalyst by the terminating polymerization (TP-PCN) effect of iodide ions . The obtained TP-PCN with abundant edge active sites (AEASs), which can form quasi-homogeneous photocatalytic system, exhibits superior H 2 O 2 generation rate (3265.4 µM h -1 ), far surpassing PCN and other PCN-based photocatalysts. DFT calculations further indicate that TP-PCN is more favorable for electron transiting from β spin-orbital to the π* orbitals of O 2 , which optimizes O 2 activation and reduces the energy barrier of H 2 O 2 formation. This work provides a new concept for designing functional photocatalysts and understanding the mechanism of O 2 activation in ORR for H 2 O 2 production.