Clay minerals are inexpensive and available materials with many applications in a wide range of fields such as adsorbents, ion exchangers, supports, catalysts, paper coatings, ceramics, and pharmaceuticals. Moreover, clay minerals can be easily modified by acid/base treatment, by the insertion of bulky ions or pillars in the interlayer spacing, modifying their physicochemical properties to be used for other applications. Knowledge of the composition and properties of clay minerals or the materials synthesized from clay minerals is a key factor in the use of these materials for different applications.

This special issue is focused on the use of different spectroscopic techniques in clay minerals or materials obtained from clay minerals with applications relating the characterization and composition of the clay mineral with its potential application.

Spectroscopic techniques in this special issue include atomic spectroscopy, molecular spectroscopy, luminescence, laser spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry, X-ray photoelectron spectroscopy, and synchrotron radiation.

Potential topics include but are not limited to the following:

• Spectroscopic studies in clay minerals and hydrotalcites
• Modification of clay minerals/hydrotalcites and characterization by spectroscopic techniques
• Functionalization of clay minerals/hydrotalcites (spectroscopic studies)
• Intercalation of clay minerals/hydrotalcites (spectroscopic studies)
• Delamination of clay minerals/hydrotalcites (spectroscopic studies)
• Synthesis of nanocomposites (spectroscopic studies)
• Rheological studies (spectroscopic studies)
• Application of clay minerals/hydrotalcites as adsorbents (spectroscopic studies)
• Application of clay minerals/hydrotalcites as catalysts/catalytic supports (spectroscopic studies)
• Other applications of clay minerals/hydrotalcites (spectroscopic studies)