In-situ grown carbon as charge transfer medium for enhanced photoinduced electrons extraction from polymer carbon nitride toward TiO2

Abstract

Interfacial charge transfer resistance is one of the main limiting factors for realizing high photocatalytic efficiency of heterostructures system. Herein, an activated carbon layer is successfully introduced between the interface of polymer carbon nitride (CN) and TiO2 heterostructure (CNP-x) as charge transfer medium by in situ pyrolysis carbonization method. Because of the lower spatial resistance of the crystalline/amorphous interface and the fast carrier transportation character of activated carbon, the efficiency of TiO2 in extracting photoinduced electrons from CN was significantly improved. That is, the separation/transport of photocarriers in CNP-x heterostructure is accelerated, and the recombination time of photogenerated electrons and holes is prolonged. The CNP-1 exhibits a H2 evolution rate of 1298.5 μmol h−1 with apparent quantum yield (AQY) of 34.5 %, 20.3 % and 12.6 % at 365 nm, 380 nm and 400 nm, respectively. This work offers a novel and unique strategy to promote interface charge separation and transport of CN-based heterostructures by accurately introduction charge transfer medium.