A comprehensive guide for characterization of adsorbent materials

[Display omitted] •The most relevant adsorbent characterization techniques presented and discussed.•Support to choose the most suitable characterization for each type of adsorbent.•Chemical, physical and thermal characterizations.•Discussion and examples of expected results.•High quality schematic representations illustrating the techniques. Given the great relevance that adsorption processes have for many applications, especially for the water and wastewater treatment, the development and improvement adsorbent materials is a key research topic. When a new adsorbent is proposed, a good characterization of the material is fundamental to in order to know its properties, support its application and understand its performance in the desired process. There is a variety of physical and chemical information that can obtained by different techniques, whose choice depends on the type of material to be studied and on the available instrumentation. The available techniques include UV–vis, FTIR, Raman, XPS, EDX, zeta potential, XRD, SEM/FESEM, TEM, AFM, surface area and porosimetry, VSM, DLS, thermoanalytical analysis (TG, DTA, DSC and DTG), among several others. These techniques enable the identification, location and quantification of chemical constituents, like elements, functional groups and molecules, as well as the study of the structure, topography, morphology, magnetic properties, and size, among other physical properties of materials. This information can provide great support for the assessment of the synthesis/functionalization of adsorbent materials as well as in the study of the adsorption process by the interactions between adsorbent and adsorbate. In the face of that, this review intends to be a comprehensive and concise guide for researchers that study adsorbent materials to consult the available characterization techniques and choose the most suitable ones for their specific needs.