BaTiO3@ZnO core-shell nanoparticles were synthesized by sal-gel method using polyethylene glycol (PEG) 4000 (4k) and 20,000 (20k). The powder X-ray diffractograms and energy dispersive X-ray spectra confirm the core-shell nature of the prepared nanoparticles. While the use of PEG 20k instead of PEG 4k increased the interplanner distances in ZnO of BaTiO3@ZnO core-shell nanoparticles it decreased the d-spacing in sol-gel synthesized pristine ZnO nanoparticles. The diffuse reflectance spectra of BaTiO3@ZnO core-shell nanoparticles are similar to those of ZnO nanoparticles. So are the photoluminescence (PL) spectra. The charge transfer resistances of BaTiO3@ZnO core-shell nanoparticles are larger than those of pristine ZnO nanoparticles. The PEG-assisted sol-gel prepared BaTiO3@ZnO core-shell nanoparticles are better photocatalysts than the PEG-assisted sol-gel synthesized pristine ZnO nanoparticles. (C) 2014 Elsevier B.V. All rights reserved.