Improved charge transport through 2D framework in fully condensed carbon nitride for efficient photocatalytic hydrogen production

The 1D molecular structure of traditional graphitic carbon nitride (GCN) leads to the space-confined transport of charge carriers along the chains and prohibits transport across the chains. Therefore, the for-mation of 2D network which can provide more convenient transfer paths is of great desirable. In this work, a fully condensed carbon nitride with the real 2D framework was successfully developed by post-calcining 1D GCN in a LiCl/KCl molten salt. The newly formed 2D molecular structure significantly promoted the charge transfer and separation, resulting in remarkably enhanced photocatalytic hydrogen production activity. Moreover, N-doped graphene quantum dots (NGQDs) incorporation can be simulta-neously realized via the simple one step "co-dissolution and recrystallization" method. Especially, the as -prepared 2D-CN/NGQDs sample presents a further increased photocatalytic hydrogen evolution rate up to about 30 times that of pristine GCN. The apparent quantum efficiency (AQE) for H2 evolution of 2D-CN/ NGQDs reaches 36 % at 420 nm.(c) 2022 Elsevier Inc. All rights reserved.