Three-dimensional crosslinked structure assembled by novel elemental iodine doped Nb₂O₅ ultrathin nanosheets for exceptional visible-light photocatalytic performance

The application of Nb₂O₅ in photocatalysis has sparked interest due to its potent oxidation capabilities and eco-friendly properties. However, challenges such as poor visible light response, limited reactive active sites and rapid charge recombination still hinder its practical use. Herein, a novel approach introduces elemental I-doped Nb₂O₅ (INO) catalyst with a three-dimensional crosslinked structure formed by ultrathin nanosheets, for the first time. This pioneering approach results in the INO catalyst with a high specific surface area (98.51 m² g⁻¹), abundant active sites, and enhanced visible light absorption. The dispersion of elemental I within the Nb₂O₅ lattice promotes the presence of delocalized electrons and improves charge carrier mobility, leading to superior catalytic performance for the degradation of diclofenac (DCF). During a 75-min period, the degradation efficiency of INO catalyst to diclofenac was found to reach 91.5 %, with a corresponding rate constant of 35.0 × 10⁻³ min⁻¹. Furthermore, the study investigates the DCF degradation pathway and the toxicity changes in its byproducts. This innovative research opens new avenues for enhancing the visible light catalytic activity of Nb₂O₅ catalysts.