Facile route for C-N/NbO nanonet synthesis based on 2-methylimidazole for visible-light driven photocatalytic degradation of Rhodamine B.

Herein, we fabricated a C and N co-modified NbO nanonet structure (C-N/NbONNs) from niobium oxalate using 2-methylimidazole (Hmim) as a source for C and N a simple hydrothermal route. The obtained nanonets are robust and cost-effective with excellent recycling stability. Compared with N-doped TiO (N-TiO) and a NbO control sample (NbO-CS), the resulting nanonets exhibited the highest performance toward the photocatalytic degradation of Rhodamine B (RhB) upon visible light irradiation ( > 420 nm). Through this study, we revealed that the synergetic effects of C and N on the nanonet surface, which were effectively incorporated into the surface of the NbO nanonet structure, not only remarkably enhanced the visible light response by decreasing the bandgap to 2.9 eV but also improved the light utilization efficiency and photo-induced electron-hole pair separation efficiency of our nanonet structure. We also proposed that the presence of carbonate species (CO ) and nitrogen species (NO ) increased the population of generated holes (h) that had the key role in the photodegradation mechanism of RhB, suggesting reasonable importance for the modification of NbO with C and N. This synergism offers a new view to reveal the origin of photodegradation processes, introducing h as a key intermediate. Our approach provides a new insight to design 2D nanostructures with potential applications in catalysis, solar energy conversion, and environmental protection.