Cu doped crystalline carbon nitride with increased carrier migration efficiency for uranyl photoreduction

Graphitic carbon nitride (g-C3N4) has been widely used in photocatalytic removal of uranium pollutants due to its promising metal-free visible light-responsive semiconductor material. Herein, the heteroatom introduction decorated crystal g-C3N4 (Cu-CCN) photocatalysts were successfully synthesized through element doping and molten salt method. Photocatalytic activity experimental results showed that the Cu-CCN-50 exhibits high U(VI) removal efficient (nearly 100 % after 10 mins under irradiation) and durable cycle performance. The enhanced photocatalytic activity was primarily attributed to the higher specific surface area, red-shift in the absorption band and the high separation efficiency of light-induced electron-hole (e-/h+) pairs. Finally, the possible active species and mechanism based on the photocatalytic reduction results were proposed. Thus, the synergistic strategy of element doping and molten salt crystallization inspires new insights for visible light removal of U(VI) in toxic wastewater.