Fabricating Z-scheme C-doped TiO2/rGO nanocomposites for enhanced photocatalytic NO removal

It is attractive to explore practical approaches to optimize the photodegraded NO property of TiO2. Herein, a typical Z-shaped heterojunction C-TiO2/rGO composed of carbon-doped TiO2 and reductive graphene oxide (rGO) was constructed to optimize the NO removal efficiency through an in situ one-pot hydrothermal process with glucose as reductant and dopant. The C-TiO2/rGO (0.11%) composite displays a remarkable NO removal performance of 40.6% under visible light illumination. It was found that the C-TiO2 nanoparticles were tightly attached to the rGO sheets and had strong interactions with rGO, which induced a positive impact on not only the light absorption and photo-generated charge separation but also the NO adsorption and reactive oxygen species formation, resulting in boosted photodegrade NO activity. As to the photodegrade NO process over the C-TiO2/rGO, the HO center dot and O-2 (center dot-) were the dominant radicals, of which the O-2 (center dot-) radical originated from the interactions between C-TiO2 and rGO. We proposed a Z-scheme mechanism to illuminate the advanced photocatalytic activity of C-TiO2/rGO. This work affords an approach to developing effective photocatalysts in the NO purification field.