▎ 摘　　要

In this work, hierarchical zeolites constructed with Ti-containing MFI nanosheets (Ti-MFI-NSs) were synthesized via a simple hydrothermal reaction, followed by the deposition of highly dispersed Pt nanoparticles and the partially wrapping of reduced graphene oxide (RGO) nanosheets. PXRD, SEM, HRTEM, N-2 adsorption/desorption, XPS, TGA, zeta potentials, UV-vis DRS and PL analysis were employed to characterize the structural, compositional and optical properties of the RGO@Pt/Ti-MFI-NSs ternary nanocomposites. The nanocomposites showed selective adsorption and the highest photocatalytic degradation activity towards the cationic dye of methylene blue (MB). It was demonstrated that the enhanced photocatalysis was due to the synergistic effect of RGO, Pt nanoparticles and Ti-MFI-NSs. Briefly, hierarchical Ti-MFI-NSs with open ends were not only beneficial to the high dispersion of Pt nanoparticles, but also significantly shortened the diffusion pathway of MB molecules. Pt nanoparticles extended the light absorption to the visible region and synergistically excited with TiMFI-NSs to generate separated electrons and holes. And RGO could further improve the harvesting of visible light and capture electrons from the conductive band, thus remarkably enhancing the separation efficiency of photogenerated electron-hole pairs. In addition, photocatalytic degradation activity of RGO@Pt/Ti-MFI-NSs increased with increasing the Pt content in the composites. The active species trapping experiments indicated that the photogenerated holes were responsible for the degradation of MB.