Boron doped C3N4 nanodots/nonmetal element (S, P, F, Br) doped C3N4 nanosheets heterojunction with synergistic effect to boost the photocatalytic hydrogen production performance

Nonmetals doping are effective for adjusting the electronic and molecular structures of C3N4 nanosheets (CN), which could broaden the range of visible light response and improve the photo-induced electron-hole separation. Here a series of nonmetals (S, P, F and Br) doped C3N4 nanosheets (x-CN) decorated with boron doped C3N4 nanodots (BCNDs) was prepared for the first time. Compared with the pristine nonmetals doped CN, the integrating of BCNDs with x-CN can effectively facilitates the charge separation and transfer in the photocatalytic process, and endows enhanced photocatalytic activity for hydrogen production. The maximum photocatalytic hydrogen production rate of the BCNDs/S-CN, BCNDs/P-CN, BCNDs/F-CN and BCNDs/Br-CN composite can reach 3924.81 μmol·g−1·h−1, 2387.62 μmol·g−1·h−1, 2374.06 μmol·g−1·h−1 and 3471.56 μmol·g−1·h−1 respectively, which is about 3.3, 4.3, 4.0 and 3.1 times that of their counterparts, respectively. This work demonstrates that BCNDs plays an important role to improve the photocatalytic properties by forming 0D/2D isotype heterojunction with nonmetals doped C3N4 nanosheets and provides new members for heterojunction photocatalysts, which is conductive to further fundamental and applied research.