Construction of BiOI-FTO devices with outstanding photocatalytic nitrogen fixation performance

BiOI is a promising photocatalytic nitrogen fixing material, with a significant photoresponse in the visible light spectrum. Future development of BiOI catalysts will depend on extending the lifespan of photogenerated carriers, modifying the proper valence band location, and enhancing sample stability. Here, a BiOI-FTO photocatalytic nitrogen fixation device is initially built after the BiOI nanosheets array is vertically grown on the surface of FTO conductive glass by CVD. Schottky junction is formed owing to the compact growth of BiOI on FTO and the difference in work functions between them. Consequently, photogenerated holes and electrons of BiOI are separated under the simulated visible light irradiation. Photogenerated electrons of BiOI are moved to the surface of FTO to take part in the nitrogen fixation reaction. Compared with BiOI nanosheets, the light absorption range in visible light is expanded and the carrier separation efficiency of BiOI-FTO is boosted. The photocatalytic nitrogen fixation performance of BiOI-FTO reaches 103.2 μmol g−1 h−1, which is about 9 times greater than that of pure BiOI nanosheets, and it still displays good stability after 100 h of catalysis. This work provides a fresh strategy for creating efficient and stable photocatalytic nitrogen fixation devices based on BiOI.