Experimental Investigation on the Effects of Photocatalysis in Ultraviolet-Induced Nanoparticle Colloid Jet Machining

In this paper, ultraviolet (UV)-induced nanoparticle colloid jet machining is proposed to achieve ultrasmooth surface polishing by using the interaction between nanoparticles and the workpiece surface under the action of the ultraviolet field and the hydrodynamic pressure field. In the process of UV-induced nanoparticle colloid jet machining, the effects of photocatalysis on the interaction between nanoparticles and the workpiece surface need to be further studied in order to better understand the polishing process. This paper presents the interaction between TiO(2) nanoparticles and a Si workpiece surface with and without ultraviolet irradiation. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) were applied to investigate the differences in the interaction of TiO(2) nanoparticles with Si workpieces. The SEM and XPS results indicate that the photocatalysis of UV light can promote the interaction between TiO(2) nanoparticles and a Si surface by creating more interfacial reaction active centers between the TiO(2) nanoparticles and the Si workpiece. The FT-IR and XPS spectra show that TiO(2) nanoparticles are chemically bonded to the Si workpiece by oxygen-bridging atoms in Ti-O-Si bonds. Due to the effects of photocatalysis, UV-induced nanoparticle colloid jet machining has a higher polishing efficiency than nanoparticle colloid jet machining with the same polishing parameters.