Synthesis And Photocatalytic Performance Of Perovskite-type ABF₃ Fluorides

Pollution abatement using semiconductor materials as photocatalysts under sunlight has been a subject of great interest. Photocatalytic degradation experiments of water-soluble dyes in the suspension system of nano-perovskite type ABO3 oxides were studied in many papers, but the photocatalytic performance of nano-perovskite type ABF₃ fluorides is lacking.The synthesis of ABF₃ samples were carried out by high temperature solid-state reaction method. Using XRD and TEM to analyse the crystal structure. All the samples have perovskite-type structure and are nano-crystals. The photocatalytic degradation experiments indicate that ABF₃ samples have high photocatalytic activities.The photocatalytic degradation experiments of supramine red 3B and Cibacron brilliant blue KGL were carried out with visible light as radiancy. Using IR, XRD and XPS to study the factors work on the photocatalytic activities.The result shows that B ion radius, eletronegativity and surface absorbed oxygen can effect on the photocatalytic activity of nano-perovskite type ABF₃ fluorides. For KBF₃ (B=Mg, Ca, Sr, Ba) samples, the photocatalytic activity enhances with the decrease of ion radius and the increase of electronegativity. For NaBF₃ (B=Cr, Fe, Co, Ni, Cu, Zn) samples, the photocatalytic activity is influenced also by the electron configuration of B ion except for the former factors. The dN number increases, the degradation is higher. Besides, NaFeF₃ has the highest photocatalytic activity because of the coexistence of Fe2+ and Fe3+.