XPS: The Technique That Reveals the Chemistry of a Surface

This infographic provides an educational overview of X-ray Photoelectron Spectroscopy (XPS), a surface-sensitive analytical technique widely used for chemical characterization of materials. The material summarizes the basic physical principle of XPS, including the photoelectric effect, Einstein’s photoemission equation, binding energy determination, chemical shifts, and final-state effects. The infographic is designed as a scientific communication and educational resource for students, researchers, and professionals working in surface analysis, materials science, nanotechnology, catalysis, corrosion science, semiconductors, and related fields. It emphasizes how XPS can identify elemental composition and chemical states within the near-surface region of a material, typically within an information depth of approximately 1–10 nm. Special attention is given to the interpretation of binding energy shifts, including the influence of oxidation state, electronegativity, electronic screening, and relaxation processes. The infographic also highlights representative applications of XPS in materials science, polymers, catalysis, metallurgy, corrosion, semiconductors, nanotechnology, nanoparticles, coatings, biology, and medicine. This work is intended for scientific outreach, teaching, and introductory training in surface characterization techniques.