Construction of mesoporous CeO2/ZnO composite abrasives with heterogeneous structure and application to photochemical mechanical polishing (PCMP) of quartz glass

In this work, mesoporous CeO 2 /ZnO composite abrasives with a heterogeneous structure were constructed by a two-step hydrothermal method and applied to a photochemical mechanical polishing (PCMP) system. Characterization of morphology, structure, and properties of mesoporous CeO 2 /ZnO composite abrasives by XRD, SEM, TEM, Raman, BET, XPS, and PL spectroscopy. To discuss the removal mechanism of materials by the synergistic effect between the chemical-mechanical behavior of mesoporous CeO 2 /ZnO composite abrasives and photocatalytic oxidation. The elastic deformation ability of the mesoporous CeO 2 matrix can reduce the generation of mechanical scratches. The loading of ZnO leads to the enhancement of Ce 3+ and oxygen vacancies in the CeO 2 lattice, which increases the active sites during polishing and promotes the generation of chemical bonding of Ce-O-Si. The type-II heterostructure formed by CeO 2 /ZnO enhances the photogenerated carrier separation efficiency and accelerates the generation of oxidatively active groups and the formation of hydrated layers on the surface of silicon-based materials. The combined effect of all three makes it possible to achieve efficient material removal and a high-quality surface for quartz glass in the PCMP process. The experimental results showed that the mesoporous CeO 2 /ZnO composite abrasives polished the silica-based material with a smooth and flat surface (Ra = 0.17 nm), and the MRR was increased by 41 % relative to mesoporous CeO 2 . Schematic of the PCMP mechanism of CeO 2 /ZnO composites on quartz glass. • Mesoporous CeO 2 /ZnO composite abrasives with type-II heterostructure constructed via a two-step hydrothermal method. • Type-II heterostructures can reduce the electron and hole complexation efficiency and improve photocatalytic performance. • Loading of ZnO leads to the enhancement of Ce 3+ and oxygen vacancies in CeO 2 lattice. • In PCMP, the polishing performance of abrasive grains is influenced by morphology, defects, and photocatalytic capacity.