Core-shell type Tourmaline@ZnO composites equipped with carbon dots for high efficiency photocatalyst

Abstract

Here we report that a novel type of Tourmaline@ZnO core-shell composite equipped with carbon dots (CDs) as multi-band light active sensitizer has been successfully designed and efficiently ultilized as the superior photocatalyst towards the degradation of methyl orange (MO) under Xenon lamp at room temperature. The bare ZnO, CDs/ZnO, Tourmaline@ZnO and CDs/Tourmaline@ZnO were systemically synthesized following the facile homogeneous precipitation process and characterized in detail by XRD, FTIR, FESEM, HRTEM, UV-Vis, PL, PC and EIS investigations in succession. Bare ZnO displays as 3-dimensional hierarchical nano-flowers with large specific surface area reaching up to 62.049 m2/g by BET measurement, while the other composite products confirm the core-shell structures with CDs inlaying on ZnO layer surfaces. The photocatalytic activities of the polynary hybridations obtain effective enhancements compared to pure ZnO, the ternary system (CDs/Tourmaline@ZnO) deserves more attention for achieving the maximum (91.25%). It should been the synergistic effect on the highly efficient catalysis performances exerting by the presence of CDs modifier and the Tourmaline core, which make ZnO matrix receive more photo-generated electrons and broaden the visible light response originated from CDs, and synchronously hinder the recombination of electrons-hole pairs by the spontaneous polarization and surface electric field of Tourmaline.