Hydrophilic bi-functional B-doped g-C3N4 hierarchical architecture for excellent photocatalytic H2O2 production and photoelectrochemical water splitting

Graphitic carbon nitride (g-C3N4) has attracted great interest in photocatalysis and photoelectrocatalysis. However, their poor hydrophilicity poses a great challenge for their applications in aqueous environment. Here, we demonstrate synthesis of a hydrophilic bi-functional hierarchical architecture by the assembly of B-doped g-C3N4 nanoplatelets. Such hierarchical B-doped g-C3N4 material enables full utilization of their highly enhanced visible light absorption and photogenerated carrier separation in aqueous medium, leading to an excellent photocatalytic H2O2 production rate of 4240.3 mu M g(-1) h(-1), 2.84, 2.64 and 2.13 times higher than that of the bulk g-C3N4, g-C3N4 nanoplatelets and bulk B doped g-C3N4, respectively. Photoanodes based on these hierarchical architectures can generate an unprecedented photocurrent density of 1.72 mA cm(-2) at 1.23 V under AM 1.5 G illumination for photoelectrochemical water splitting. This work makes a fundamental improvement towards large-scale exploitation of highly active, hydrophilic and stable metal-free g-C3N4 photocatalysts for various practical applications. (C) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. All rights reserved.

Automated summary

This study demonstrates the synthesis of a hydrophilic bi-functional hierarchical architecture of boron-doped graphitic carbon nitride (g-C3N4) material. The hierarchical structure enables highly enhanced visible light absorption and photogenerated carrier separation, leading to excellent photocatalytic performance and high photoelectric current density. This research is of great importance for the practical application of metal-free g-C3N4 photocatalysts.