Ce 2 S 3 decorated ZnO-ZnS core-shell nanorod arrays: Efficient solar-driven photocatalytic properties

We demonstrate a facile synthesis of vertically aligned Ce2S3 decorated ZnO-ZnS and ZnO-ZnS-Ce2S3 core-shell nanorod (NR) arrays via simple two-step process: aqueous solution growth and sulfidation. By controlling the sulfidation time, ZnS nuclei were formed at the initial stage of sulfidation. Upon increasing the sulfidation time, Ce2S3 nanoparticles with an average size of ∼5 nm are decorated over the ZnO-ZnS core shell NR arrays, followed by, ZnO-ZnS-Ce2S3 core-shell ternary heterostructures. FESEM, HRTEM, EDX, XRD and XPS analyses revealed that the interior cores and exterior shells of the as-prepared hetero-nanorods comprised of single-crystal wurtzite-type ZnO and polycrystalline wurtzite ZnS, respectively, with a large quantity of Ce2S3 NPs inlaid over the ZnS shell. Photocatalytic behavior of the Ce2S3 decorated ZnO-ZnS hybrid photocatalyst was studied by means of photodegradation of methylene blue (MB) under visible irradiation. Ce2S3 decorated ZnO-ZnS hybrid structures show an enhanced photodegradation rate of nearly 2.8, 1.3 and 2.5 times higher than that of the bare ZnO, ZnO-ZnS and ZnO-ZnS-Ce2S3, which is attributed to the increase in the light absorption in visible region, electron-hole separation at the ZnO-ZnS and ZnS-Ce2S3 interfaces.