X-Ray Photoemission Spectroscopy (XPS) is a surface-sensitive analytical technique used to determine the elemental composition and chemical state of materials. It works by irradiating a sample with X-rays, which causes the emission of photoelectrons. By measuring the kinetic energy of these electrons, researchers can identify the elements present and their oxidation states. XPS is particularly valuable in fields like materials science, chemistry, and nanotechnology. It provides insights into surface properties, such as thickness and composition, making it essential for studying thin films, coatings, and catalysts. The technique is non-destructive, allowing for the analysis of delicate samples.