[Effects of three different etching methods on surface morphology and element of pure titanium]

The pure titanium disks were divided into three groups and etched for 30 minutes with HNO3, hot H2SO4/H2O2 or hot H2SO4/HCl respectively. The treated disks were studied and analyzed with scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The disks etched with HNO3 had a smooth surface, while those etched with hot H2SO4/H2O2 or hot H2SO4/HCl had rough surfaces, and the surface etched with hot H2SO4/HCl had larger micropores. The XPS analysis demonstrated that the main elements of the surface in three groups were titanium, oxygen and carbon. The carbon concentration was the lowest on the surface etched with hot H2SO4/H2O2 and the highest on that etched with hot H2SO4/HCl. The substances were TiO2, Ti2O3, TiO and metal Ti on the surface etched with HNO3 or hot H2SO4/H2O2. Only TiO2 was detected on the surface etched with hot H2SO4/HCl.