Perovskite LaFeO3/montmorillonite nanocomposites: synthesis, interface characteristics and enhanced photocatalytic activity

Perovskite LaFeO3/montmorillonite nanocomposites (LaFeO3/MMT) have been successfully prepared via assembling LaFeO3 nanoparticles on the surface of montmorillonite with citric acid assisted sol-gel method. The results indicated that the uniform LaFeO3 nanoparticles were densely deposited onto the surface of montmorillonite, mainly ranging in diameter from 10 nm to 15 nm. The photocatalytic activity of LaFeO3/MMT was evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation, indicating that LaFeO3/MMT exhibited remarkable adsorption efficiency and excellent photocatalytic activity with the overall removal rate of RhB up to 99.34% after visible light irradiation lasting for 90 min. The interface characteristic and possible degradation mechanism were explored. The interface characterization of LaFeO3/MMT suggested that LaFeO3 nanoparticles could be immobilized on the surface of montmorillonite with the Si-O-Fe bonds. The abundant hydroxyl groups of montmorillonite, semiconductor photocatalysis of LaFeO3 and Fenton-like reaction could enhance the photocatalytic degradation through a synergistic effect. Therefore, the LaFeO3/MMT is a very promising photocatalyst in future industrial application to treat effectively wastewater of dyes.