Phosphorus-doped porous carbon nitride for efficient sole production of hydrogen peroxide via photocatalytic water splitting with a two-channel pathway
The production of hydrogen peroxide (H2O2) by photocatalytic water splitting has attracted much attention due to the wide application of H2O2 as multi-functional chemicals. Most of present photocatalysts require sacrificial agents and/or noble metal cocatalysts. Here, we report that the phosphorus-doped porous carbon nitride (CPN), as metal-free photocatalyst, achieves the photocatalytic water splitting via two-channel pathway (water oxidation reaction and oxygen reduction reaction) with high H2O2 yield of 1968 μmoL/g/h (highest yield in current records without sacrificial agent) under room temperature and normal pressure without sacrificial agent and cocatalyst. The quantum efficiency of sole production of H2O2 was measured to 1.57 % under wavelength λ = 420 nm and determined solar energy conversion efficiency of 0.43 %. In present reaction system, the concentration of H2O2 can up to 0.171 % (wt %) in one-batch reaction with 80 mg CPN catalyst (in 15 mL oxygen saturated H2O) after 36 h under visible light illumination. H2O2 obtained by this metal-free catalyst without adding sacrificial agent is more conducive to subsequent purification in industrial production.