Most common characterization techniques for chemically functionalized 2D materials and summary of the information provided by each of them.

Characterization techniques
Nanostructure information
Scanning electron microscopy	SEM	Based on backscattered and/or secondary electrons from the sample
		Morphology of the material with nm resolution
Transmission electron microscopy	TEM	Based on electrons transmitted through the sample
		Morphology of the material with resolution down to the atomic level
Atomic force microscopy	AFM	Based on the repulsive electronic forces between a tip and the sample
		Topographic images of the surface
Scanning tunnelling microscopy	STM	Based on the quantum tunnelling effect
		Imaging of the density of states of the material with (sub)atomic resolution
Brunauer–Emmett–Teller analysis	BET	Based on gas (typically N2) adsorption experiments
		Surface area and pore size information
X-ray diffraction	XRD	Based on the scattering of X-rays by the atoms of the sample
		Information on the crystalline structure, including interplanar distance
Raman spectroscopy	Raman	Based on the inelastic scattering of photons due to vibrational states
		Number of layers, presence of defects, etc.
Chemical composition
Thermogravimetric analysis	TGA	Measures changes in weight as a function of temperature
		Quantitative information about the presence of components with different decomposition/desorption temperatures
Inductively coupled plasma mass spectrometry	ICP-MS	Based on the ionizing the samples into elemental species
		Quantitative information on the elemental composition of the materials
Energy-dispersive X-ray spectroscopy	EDS	Based on the interaction of X-rays with the sample
		Elemental composition of the materials
X-ray photoelectron spectroscopy	XPS	Based on the interaction of X-rays with the sample
		Binding energy of different elements, their electronic state and hybridization
Electron energy loss spectroscopy	EELS	Based on the inelastic scattering of electrons by the sample
		Information about types of bonds in the material
Infrared spectroscopy	IR	Based on the activation of different vibrational modes under infrared radiation
		Information about bonds present in the material
Nuclear magnetic resonance spectroscopy	NMR	Based on the magnetic interactions with the spins of the atomic nuclei
		Information on the bonding environment of the nuclei under observation
Electronic structure
Ultraviolet-visible-near infrared	UV-Vis/NIR	Based on the absorption, reflection and scattering of light
		Information on electronic transitions of the material
Photoluminescence spectroscopy	PL	Based on the emission of light by excited states to return to ground state
		Information on electronic transitions of the material
Ultraviolet photoelectron spectroscopy	UPS	Based on the interaction of the sample with UV photons
		Information about the band structure of the material in the valence region