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, TiO 2 -Au, TiO 2 -BiOI, TiO 2 -BiOI-Au and TiO 2 -Au-BiOI were synthesized by using n-type TiO 2 , p-type BiOI and plasmon metal Au as components for photocatalytic nitrogen fixation. The as-prepared “Z-scheme” TiO 2 -Au-BiOI photocatalyst showed the highest photocatalytic performance for N 2 photofixation with 543.53 μmol L −1 h −1 g −1 in the pure water system, which is 1.68 times higher than that of TiO 2 -BiOI-Au nanocomposite, 1.85 times higher than that of TiO 2 -BiOI and 6.69 times higher than that of TiO 2 -Au, revealing superiority of the heterojunctions of TiO 2 -Au-BiOI in kinetics among these different heterostructured photocatalysts during the photocatalytic N 2 reduction process. Moreover, the as-prepared TiO 2 -Au-BiOI exhibited considerable performance under real natural environment, showing a promising potential in future application.