A novel method was used to synthesize orthorhombic FeNbO4 nanoparticles by a hydrothermal process followed by calcination at 600°C, and their optical, photoelectrochemical, and photocatalytic properties were investigated. The microstructural and local structural properties were characterized using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM), and Raman spectroscopy. The FeNbO4 particles obtained were composed of much smaller nanocrystallines, with an average size of 10-20 nm, compared to particles prepared at 1000°C through a conventional solid-state reaction method. Moreover, the optical band gap energy of the nanoparticles was estimated to be 1.93 eV from the UV-vis diffuse reflectance, and their flat-band potential in 1 M NaOH was -0.4 V (SCE). The X-ray photoelectron spectroscopy analysis revealed that the nanoparticles had fewer surface defects, such as oxygen vacancies, than the particles prepared by the solid-state reaction method. The FeNbO 4 nanoparticles also exhibited a much higher photocatalytic activity for the degradation of rhodamine B dye solution under visible light irradiation (>420 nm). This higher photocatalytic activity of the FeNbO4 nanoparticles was attributed to their higher optical absorption ability and smaller particle size, as well as fewer surface defects.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films