Table 1.
Summary of characterization techniques used for materials evaluation.
| Information | Type | Techniques | Comments |
|---|---|---|---|
| Composition | Qualitative | EA | C, O, N, S, X analysis, combustion techniques; determining the ratio of elements from within the sample |
| MS | Ionization techniques for organic species; give information for molecular weight, and mass per charge (m/z); Can be extended for particle distribution into a material via imaging technique | ||
| Quantitative | AAF | Measure element in solution as ppm; require digestion with an acid such as nitric acid | |
| ICP-MS | Sensitive; for liquids; sample pretreatment via acidic dissolution is required | ||
| ICP-OES/AES | |||
| XRF | Use X-ray for element excitation; can detect ppb | ||
| XPS | For surface analysis with a penetration depth of 10–100 Å | ||
| EDX | Surface analysis technique; Penetration depth of <1000 Å, not suitable for light elements | ||
| TGA | Determine the ratio between components; distinguish among components based on temperature | ||
| Structure | Crystal | XRD | SXRD for big crystal; PXRD for powder or small crystal; Avergae of the structure |
| SAED | Use for cell parameters determination; 3D diffraction can be achieved using different shots | ||
| Local | EXAFS | Can be used for specific elements in a nanomaterial; require synchrotron facilities | |
| EELS | TEM-based analysis using electron beam; complementary to EDX | ||
| XPS | Available; local structure of each element in the sample can be obtained via peak deconvolution | ||
| Connectivity | FT-IR | Useful for bond changes or formation | |
| NMR | Can be used for liquid and solid state | ||
| Inner electronic | EXAFS, EELS, XPS | Determine oxidation state and element valences | |
| Morphology | Light | OM | Maximum magnification 1000x; |
| Electron | TEM | Offer 3D model via tomography; can be used for <1 nm; | |
| SEM | Surface imaging, perfect for morphology, particle size >25 nm | ||
| Probe | SPM | e.g., AFM, STM, and SPE | |
| Size | Solid | TEM | Can be used for particles less than 1 nm; High-resolution TEM can be used for lattice fringes determination |
| SEM | Particle size >25 nm; can be used for the determination of 2D thickness | ||
| AFM | Use for the thickness determination of 2D nanomaterials | ||
| liquid | DLS | Measure the light scatters in all directions; Rayleigh scattering; is used only for the particles smaller than the light wavelength (<250 nm). | |
| LDS | Record the diffraction of a laser beam due to a the interaction with ny particles. | ||
| NTA | Laser techniques; 10–1000 nm; Brownian motion | ||
| Optical Properties | Absorption | UV–Vis | Liquid phase; characterize electronic transition within nanomaterials |
| DRS | Determine the optical band gap for solid-state nanoparticles | ||
| Emission | FL | Characterize the excitation-emission transition; a useful technique for charge transfer characterization | |
| PL | Similar to FL; used for particles with long-lifetime emission |
Notes: Atomic force microscopy, AFM; atomic absorption/emission spectroscopy, AAS/AES; nanoparticle tracking analysis, NTA; STM, scanning tunneling microscopy, STM; Scanning Probe Electrochemistry, SPE; inductively coupled plasma mass spectrometry, ICP-MS; ICP-optical/atomic emission spectrometry (ICP-OES/AES); scanning probe microscopy, SPM.