Novel electron donor boosting the electron supply capacity of hierarchical structure carbon nitride for efficient photocatalytic hydrogen peroxide production

A large number of residual amino groups may be formed in graphitic carbon nitride (g-C 3 N 4 ), leading to the destruction of active sites and increased carrier recombination centers. Herein, we develop a meaningful material (benzo[b]thiophene-3-carboxaldehyde post-grafting three-dimensional agaric-shaped g-C 3 N 4 (3DA-CN): CNBT) that solves the problems above by prolonging the delocalization of π electrons and changing the intrinsic semiconductor properties. CNBT has a special hierarchical structure, excellent visible light absorption capacity and high carrier separation efficiency. The introduction of BTC promotes the activation of O 2 and spontaneously produces more H 2 O 2 . The H 2 O 2 production rate of CNBT-7 is 2249 μM in 2 h, which is 5.95 times higher than that of 3DA-CN (378 μM). The formation rate constant value of CNBT-7 (31.45 μM·min −1 ) increased to 8.71 times higher than that of 3DA-CN (3.61 μM·min −1 ). The H 2 O 2 production mechanism follows two-step single electron reaction path and has been deeply studied by experiments and density functional theory (DFT) calculations. This work provides a meritorious activity strategy to enhance photocatalytic H 2 O 2 production.