環境（1）

[PY-33] Enhanced photocatalytic reduction of hexavalent chromium by using ZnTi layered double hydroxide/montmorillonite composite

○Chitiphon Chuaicham¹, Keiko Sasaki¹ (1. Kyushu University )

Keywords:ZnTi layered double hydroxide, montmorillonite, hexavalent chromium reduction, photocatalyst

Nowadays, two-dimensional/two-dimensional (2D/2D) composites have been received considerable attention for photocatalytic application because it has high electron-hole mobility across the heterojunction interface, which can impede the electron-hole recombination rate. In this work, ZnTi layered double hydroxide/montmorillonite composite (ZTL@MT) were prepared via a hydrothermal method by varying the weigh percent of MT (10 %, 20 % and 30 %). The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy energy-dispersive X-ray spectroscopy (TEM-EDS), thermogravimetric analysis (TGA), UV-Vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The photocatalytic activity of the obtained samples was investigated by reduction of Cr(VI) under UV light irradiation. In comparison, the photocatalytic performance of ZTL@MT composites displayed higher than pristine samples of ZnTi layered double hydroxide (ZTL) and montmorillonite (MT), and ZTL@MT20 % exhibited the highest photocatalytic efficiency. The improved photocatalytic activity of the ZTL@MT composites could be attributed to improve light absorption ability and reduced the energy gap of the composites. In addition, the composite had shown a synergistic effect of ZTL and MT, which leads to suppressing the recombination of photogenerated electron-hole pairs. The catalytic mechanism, stability and reusability of the composite were investigated in detail. The ZTL@MT composites can be potential catalysts for removal of heavy metal pollutants in wastewater.