Etching Behavior of Pb Ion from PbO-B2O3-SiO2 Glasses in HNO3 Solution

Quantitative studies on the dissolution of Pb in an acid solution were conducted to understand the etching mechanism in PbO-SiO2-B2O3 glasses. In this study, the etching was done on bulk glasses of a PbO-SiO2-B2O3 system with a HNO3 solution at 40 degrees C, and the surface structure of the glasses and ion dissolution behavior were analyzed using X-ray photoelectron spectroscopy (XPS), Raman spectrophotometer, and inductive coupled plasma spectrometry, respectively. The results showed that Pb (1.5-5.5%) and B (0.8-3%) ions are the major components etched. Small amounts of Si, Al, Ti, and Zr were detected in the etching solution. The analysis of O-1s in the XPS peaks showed that the ratio of non-bridging oxygen (NBO) to bridging oxygen (BO) changed from 1:2.7 to 1:0.6 after leaching with the HNO3 solution. The Si-O-Pb and Si-O-Si bindings on the glass surface appeared to be a silicon-rich region where Si-O binding occurs after etching.