Z-scheme TiO₂@Ti₃C₂/Cd_0.5Zn_0.5S nanocomposites with efficient photocatalytic performance via one-step hydrothermal...

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/Cd_0.5Zn_0.5S (TO/CZS) multilevel structured nanocomposites via one-step hydrothermal route. The effects of hydrothermal temperature and Cd_0.5Zn_0.5S 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 Cd_0.5Zn_0.5S 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 Cd_0.5Zn_0.5S. Through anchoring Ti₃C₂ as an electron transition mediator and combination with TiO₂ and Cd_0.5Zn_0.5S, the new Z-scheme between TiO₂ oxidized by Ti₃C₂ and Cd_0.5Zn_0.5S 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.