CaTiO3 nanoparticles (NPs) with diverse morphologies have been successfully synthesized by the precursor morphology-controlled formation based on a facile hydrothermal approach. The fabricated CaTiO3 NPs were characterized by X-ray diffraction, field emission scanning electron microscope, high-resolution transmission electron microscopy, electron spin resonance, X-ray photoelectron spectra, and electro-chemistry technology. It is found that the morphologies of as-synthesized CaTiO3 NPs are strongly dependent on the aggregate status of the titania hydrogel precursors. Especially, the as-prepared CaTiO3 NPs was, for the first time, used as the highly efficient photocatalysts to remove arsenite from aqueous solution. Due to their unique morphologies, the fern-like CaTiO3 NPs exhibit a high photocatalytic activity toward the oxidation of As(III) (up to 98.4%) under irradiation. The photogenerated holes (h(+)) are recognized as the primary active species responsible for As(III) oxidation. Meanwhile, a possible mechanism for the photo-oxidation of As(III) over CaTiO3 has also been proposed. (C) 2014 Elsevier B.V. All rights reserved.