X-ray Photoelectron Spectroscopy (XPS) is an advanced surface analysis technique used to determine the elemental composition, chemical states, and electronic structure of materials. XPS operates by irradiating a sample with X-rays, which causes the emission of core-level photoelectrons. The kinetic energy of these emitted electrons is measured, and their binding energy is calculated to identify the elements present and their oxidation states. XPS is widely utilized in fields such as materials science, nanotechnology, and surface chemistry, particularly for analyzing thin films, catalysts, and coatings.