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Photocatalytic degradation of pollutants has been proved to be an effective strategy for wastewater treatment. Herein, TiO2 nanoparticles were synthesized on a Ti3C2 matrix by in situ growth, forming Z-scheme TiO2@Ti3C2/Cd0.5Zn0.5S (TO/CZS) multilevel structured nanocomposites via one-step hydrothermal route. The effects of hydrothermal temperature and Cd0.5Zn0.5S content on microstructure and properties of composites were assessed. TO/CZS nanocomposites were probed into phase composition, morphological and optical properties with x-ray diffractometer, infrared radiation, scanning electron microscope and UV–vis reflective spectra. Following the hydrothermal reaction at 160 °C for 12 h, TiO2 nanoparticles of 30 nm in diameter were generated in situ on Ti3C2 lamina and Cd0.5Zn0.5S particles were evenly distributed on the Ti3C2 matrix. The photocatalytic activity of TO/CZS composites were evaluated, which found that degradation rate constant (k = 0.028 min−1) of TO/CZS-40 on Rhodamine B was 5.19 times that of pure TiO2 and 4.48 times that of Cd0.5Zn0.5S. Through anchoring Ti3C2 as an electron transition mediator and combination with TiO2 and Cd0.5Zn0.5S, the new Z-scheme between TiO2 oxidized by Ti3C2 and Cd0.5Zn0.5S establishes a multilevel structure of separating electron-hole pairs. This work demonstrates a valid way to control electrons and hole transfer directions efficiently through designing multilevel semiconductor structural designs.

Nanofabrication on insulating and flexible films of polydimethylsiloxane (PDMS) using a focused ion beam (FIB) has been illustrated in this study. The charge accumulation effect, which is inevitable in polymeric fabrication, was shown to be relieved by simultaneously introducing electron beam flooding in the area exposed to FIB. The topography of the fabricated pattern is subsequently characterized by using an atomic force microscope (AFM), by which the dependence of height/depth of the fabricated arrays on ion beam dose could be obtained. In addition, the swelling effect and milling effect relating to focused ion beam dose could be identified in this study.