Enhanced photocatalytic hydrogen production of restructured B/F codoped g-C3N4 via post-thermal treatment

Restructured B/F codoped carbon nitride (r-CN-B/F) with enhanced photocatalytic H2 evolution was prepared by post-thermal treatment of B/F codoped carbon nitride (CN-B/F), which is obtained from direct condensation doping using ionic liquid as doping dopant. Characterization results show that B and F doped in the skeleton and surface layer of CN material respectively. It is found that the post-annealing strategy makes for compact interlayer accumulation and large surface area for doped CN. In particular, decreased surface graphitic carbon, increased B doping content and optimized conjugate aromatic ring structure of catalyst after post-sintering treatment are favorable for the photo-generated charge transfer and separation, thereby, the photocatalytic H2 production of r-CN-B/F was much enhanced. This study demonstrates a facile way for optimizing the polymeric structure of heteroatom doped semiconductor materials.