Tetragonal BaTiO3 nanoparticles have been hydrothermally synthesized using the electrospun TiO2 nanofibers as the Ti-source. Microstructural and compositional analyses have been carried out using XRD, SEM, TEM, XPS, and Raman spectroscopy. Characterization studies confirmed that the BaTiO3 nanoparticles had a tetragonal structure with an average particle size of 100 nm. Photocatalytic activities of the nanoparticles were investigated via the decolorization of methylene blue dye aqueous solutions under visible light and UV-A irradiations. The degradation efficiency reached to 13 and 35% after exposing to light for 60 min with visible and UV-sources, respectively. Effect of sintering temperatures on the dielectric properties was also investigated. Among all the sintering temperatures employed, 1473 K was the optimum sintering temperature for these ceramics in terms of high relative density (95.3%), high dielectric constant (3162 at 1 MHz), and low loss tangent (15 x 10(-3) at 1 MHz). Experimental results showed that electrospun TiO2 fibers can be used as a precursor template to produce nano-scale BaTiO3 particles which are suitable for various applications such as photocatalysis and capacitors. (C) 2018 Elsevier B.V. All rights reserved.