Multiple heteroatom-doped urea and thiourea-derived polymeric carbon nitride for high-performance visible light-driven photocatalytic O2 reduction to H2O2.

To photocatalytically reduce O 2 to H 2 O 2 over polymeric carbon nitride (PCN) in high efficiency is essential for practical application but remains a considerable challenge. Herein, we synthesized a K, S, and O co-doped PCN (akut -CN) via one-pot polymerization of urea and thiourea in the presence of KCl and NaOH, which afforded an unprecedentedly high H 2 O 2 production rate of 4.46 mM h–1 under visible light irradiation, about 210 times that over the un-doped PCN. The heteroatom doping and the incorporation of the cyano and hydroxyl groups into akut -CN are identified to enhance light absorption, accelerate the separation and transfer of the photogenerated charges, and improve the surface electronegativity and the O 2 adsorption capacity and strength, which collaboratively boosted the reaction kinetics. This work highlights the great potential of the elaborately decorated PCN in photocatalytic O 2 reduction to H 2 O 2 and paves the way to the decentralized production and application of H 2 O 2. [Display omitted] ● One-pot polymerization of urea and thiourea to akut -CN with KCl and NaOH co-existing. ● Its H 2 O 2 production rate under visible light is 210 times that on the un-doped PCN. ● Heteroatoms are incorporated and cyano and hydroxyl groups are grafted on akut -CN. ● These modifications accelerate the separation and transfer of the charge carriers. ● Surface electronegativity and O 2 adsorption capacity and strength are also enhanced. [ABSTRACT FROM AUTHOR]