Characterization techniques for graphene-based materials in catalysis

Graphene-based materials have been studied in a wide range of applications including catalysis due to the outstanding electronic, thermal, and mechanical properties. The unprecedented features of graphene-based catalysts, which are believed to be responsible for their superior performance, have been characterized by many techniques. In this article, we comprehensively summarized the characterization methods covering bulk and surface structure analysis, chemisorption ability determination, and reaction mechanism investigation. We reviewed the advantages/disadvantages of different techniques including Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS), X-Ray diffraction (XRD), X-ray absorption near edge structure (XANES) and X-ray absorption fine structure (XAFS), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible spectroscopy (UV-vis), X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), and scanning tunneling microscopy (STM). The application of temperature-programmed reduction (TPR), CO chemisorption, and NH₃/CO₂-temperature-programmed desorption (TPD) was also briefly introduced. Finally, we discussed the challenges and provided possible suggestions on choosing characterization techniques. This review provides key information to catalysis community to adopt suitable characterization techniques for their research.