Constructing the Z-scheme TiO2/Au/BiOI nanocomposite for enhanced photocatalytic nitrogen fixation

Aiming at comparing the charge separation efficiencies of various heterojunctions, such as p-n junction, metal–semiconductor junction, Z-scheme junction, TiO2-Au, TiO2-BiOI, TiO2-BiOI-Au and TiO2-Au-BiOI were synthesized by using n-type TiO2, p-type BiOI and plasmon metal Au as components for photocatalytic nitrogen fixation. The as-prepared “Z-scheme” TiO2-Au-BiOI photocatalyst showed the highest photocatalytic performance for N2 photofixation with 543.53 μmol L−1h−1 g−1 in the pure water system, which is 1.68 times higher than that of TiO2-BiOI-Au nanocomposite, 1.85 times higher than that of TiO2-BiOI and 6.69 times higher than that of TiO2-Au, revealing superiority of the heterojunctions of TiO2-Au-BiOI in kinetics among these different heterostructured photocatalysts during the photocatalytic N2 reduction process. Moreover, the as-prepared TiO2-Au-BiOI exhibited considerable performance under real natural environment, showing a promising potential in future application.