Mechanism Insight into Enhanced Photocatalytic Hydrogen Production by Nitrogen Vacancy-Induced Creating Built-In Electric Field in Porous Graphitic Carbon Nitride Nanosheets

Abstract

An appealing and efficient route to modify the catalytic behavior of g-C3N4 (gCN) is to control textures and defects at the molecular scale, which is beneficial to enhancing its built-in electric field (BIEF) and accelerating the photogenerated charge carrier separation. Herein, we deliberately design a precursors-reforming strategy for enhancing the BIEF of gCN porous microstructures through constructing N vacancies to accelerate charge separation. The N vacancies can not only enhance the BIEF, thus accelerating photocharge delocalization, but also promote reaction kinetics. Also, the porous structures offer a large number of active sites to expedite the reaction and shorten the migration distance of photogenerated carriers to the surface. As anticipated, the modified gCN exhibits a much higher photocatalytic performance, around 7.1 times that of the bulk gCN. This work will provide a fascinating method to combine textures and electronic structure regulation for gCN-based photocatalysts.

Keywords: Graphitic carbon nitride, porous structure, Nitrogen vacancy, Built-in electric field, Photocatalytic hydrogen evolution