Shape evolution of perovskite LaFeO3 nanostructures: a systematic investigation of growth mechanism, properties and morphology dependent photocatalytic activities

Shape evolution of nanostructured LaFeO3 with fascinating morphologies like cubes, rods and spheres was successfully synthesized by a facile and environmentally friendly hydrothermal process. Tuning the morphologies was achieved using different surfactants. The prepared samples were systematically characterized using X-ray diffraction, micro-Raman spectroscopy, scanning electron microscopy and high-resolution transmission electron microscopy for structural, morphological and chemical composition analysis by X-ray photoelectron spectroscopy. The optical properties of prepared samples were studied employing UV-Vis diffusion reflectance analysis. Brunauer-Emmett-Teller measurement reveals a large surface area for all the prepared nanostructures. Most importantly, the visible-light photocatalytic activities of the three LaFeO3 nanostructures were evaluated by photocatalytic decolorization of Rhodamine B in aqueous solution. The enhanced photocatalytic activity of LaFeO3 nanospheres compared to other nanostructures and commercial Degussa P25 TiO2 can be ascribed to high specific surface area, pore size distribution and the smaller particle size. The underlying growth mechanism responsible for the formation of LaFeO3 nanostructures is also discussed. The results from this study illustrate the morphology-dependent photocatalytic performance of LaFeO3.