One-step synthesis of iodine-doped g-C3N4 with enhanced photocatalytic nitrogen fixation performance

Photocatalytic nitrogen fixation has attracted great attention recently due to the mild condition with solar energy as the only energy input. In this work, the iodine-doped g-C3N4 with carbon vacancies has been successfully synthesized via a one-step thermal-decomposition method. The results showed that the band gap of g-C(3)N(4 )decreased and the average PL lifetime of g-C3N4 increased after iodine doping. This demonstrated the expansion of light responsive range and the high separation efficiency of the photo-generated charge carriers in iodine-doped g-C3N4. The g-C3N4 with 10 wt% iodine doping exhibited excellent performance and well stability for the photocatalytic nitrogen fixation under simulated sunlight irradiation within 3 h (200.8 mg/L/g cat ), which is 2.8 times as high as that of bulk g-C3N4, owing to the reduced band gap, existence of carbon vacancies and enhanced separation efficiency of the photo-generated charge carriers. A feasible mechanism was proposed for photoinduced charge separation and nitrogen photofixation over iodine-doped g-C3N4.