Fabrication and characterization of Ca2Fe2O5 nanofibers photocatalyst by sol-gel assisted electrospinning at low-temperature

• Continuous Ca2Fe2O5 nanofibers have been successfully synthesized at a relatively low temperature (500 °C) by a sol-gel assisted electrospinning method for the first time.
• The obtained Ca2Fe2O5 nanofibers are 200 nm in diameter. Investigated the relationship between photocatalytic activity and morphology of Ca2Fe2O5 nanofibers.
• The result shows that Ca2Fe2O5 nanofibers exhibit excellent photocatalytic activity compared with Ca2Fe2O5 nanoparticles synthesized at the identical conditions by a sol-gel route.

Brownmillerite Ca2Fe2O5 nanocrystals were traditionally synthesized at temperatures higher than 800 °C. In this study, continuous Ca2Fe2O5 nanofibers have been successfully synthesized by a sol-gel assisted electrospinning method for the first time, followed by heat treatment at a relatively low temperature (500 °C) for 2 h in air. This synthetic method may be extended to prepare other ternary metal oxides at relatively low temperatures. The crystal structure, surface morphology and microstructure are investigated by thermogravimetry (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The TG curve indicates that 500 °C is the lowest calcination temperature for obtaining pure Ca2Fe2O5 nanofibers. The XRD analysis shows that the nanofibers possess highly crystalline structure without any impurity phase. The SEM results reveal that the obtained Ca2Fe2O5 nanofibers are 200 nm in diameter. The photocatalytic activity of Ca2Fe2O5 nanofibers is investigated for the photo-degradation of Rhodamine B (Rh B) aqueous solution under visible light. The result shows that Ca2Fe2O5 nanofibers exhibit excellent photocatalytic activity compared with Ca2Fe2O5 nanoparticles synthesized at the identical conditions by a sol-gel route.