Improved H2O2 photogeneration on Rb-doped-polymeric carbon nitride via enhanced O2 adsorption

The H2O2 yield is substantially hindered by the four-electron competitive reaction and limited oxygen-capture ability of PCN. We herein demonstrated a Rb+-modified PCN photocatalyst (CNR-0.5) for highly efficient H2O2 production, in which the introduction of Rb+ ions creates abundant edge active sites within the-C equivalent to N/-OH groups of the triazine ring. The hydrophilicity and O-2 adsorption capacity of the PCN catalyst were significantly improved. As a result, CNR-0.5 achieved a relatively high H2O2 yield (2225.05 mmol g(-1) h(-1)), which is 37.58 times higher than that of pristine PCN under white light-emitting diode (LED) light. Experimental and theoretical results demonstrated that CNR-0.5 followed a two-step single-electron O2 reduction reaction pathway in the H2O2 photogeneration reaction. Additionally, the AQE of CNR-0.5 was 24.52% at 385 nm in an ethanol system with O-2 injection. The excellent photocatalytic H2O2 production performance of CNR-0.5 in a real water body broadens the path for practical applications of PCN materials in photocatalytic H2O2 production.