Critical roles of H 2 O and O 2 in H 2 O 2 photoproduction over biomass derived metal-free catalyst

In this paper, in-situ transient photoinduced-voltage combined with the continuous wavelet transform was used for the first time to study the critical roles of H 2 O and O 2 in the H 2 O 2 photoproduction. A metal-free photocatalyst containing carbon dots was synthesized by a one-step hydrothermal method using hesperidin as raw material. The photocatalytic H 2 O 2 yield of the catalyst can reach 4480 μmol·L −1 under visible light without sacrificial agent. In addition to being raw materials, we have proved that H 2 O and O 2 can regulate the photogenerated electron transport kinetics, namely, O 2 can decelerate low-frequency electron transport, while H 2 O can accelerate the low-frequency electron transport. This work provides an in-depth understanding on photocatalytic production of H 2 O 2 over composite metal-free photocatalysts and new insight for their design.