BiFeO3 nanomaterials have recently generated much interest due to their relatively narrow band gap energies (∼2.0–2.8 eV), their stability and low cost which leads to effective visible-light photocatalysts for water splitting and for the degradation of organic pollutants. Here, we show that very high removal efficiency of a variety of organic pollutants can be achieved using GdxBi1-xFeO3@SBA-15 nanocomposites (x = 0, 0.05. 0.10, 0.15) under visible light irradiation. Specifically, we study the photocatalytic degradation of dyes using the above nanocomposite materials, with pore volume loadings of 5-25%, prepared by a wet-impregnation nanocasting technique with pre-fabricated metal tartarates, as metal precursors, and mesoporous silica SBA-15, as a host matrix. We compare the obtained catalytic results for the nanocomposite materials to monodisperse BiFeO3 nanoparticles with a particle diameter of 5.5 nm. The latter catalysts were synthesized also by a nanocasting technique using SBA-15 and subsequently leached out of the host silica matrix resulting in the smallest BiFeO3 particles ever prepared by any method. We find that the best removal performance is achieved by a 10 vol% Gd0.05Bi0.95FeO3@SBA-15 sample, shown by a complete dye degradation in approximately 3h using extremely low concentrations of the actural active photocatalyst. The superior efficiencies of the nanocomposites, which outperformed their parent compounds, i.e. GdxBi1-xFeO3 nanoparticles as well as unfilled SBA-15, are attributable to a synergistic adsorption enhanced photocatalytic degradation process. The possible mechanism in the photodegradation process was investigated and discussed on the basis of trapping experiments.

Synergistic adsorption enhanced photocatalytic degradation of organic pollutants using BiFeO3 nanocomposite materials

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.