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

Graphitic carbon nitride (g-C 3 N 4 ) 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-C 3 N 4 nanoplatelets . Such hierarchical B-doped g-C 3 N 4 material enables full utilization of their highly enhanced visible light absorption and photogenerated carrier separation in aqueous medium , leading to an excellent photocatalytic H 2 O 2 production rate of 4240.3 μM g −1  h −1 , 2.84, 2.64 and 2.13 times higher than that of the bulk g-C 3 N 4 , g-C 3 N 4 nanoplatelets and bulk B doped g-C 3 N 4 , 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-C 3 N 4 photocatalysts for various practical applications.