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Scanning electron microscope or electron probe can be used to observe the surface morphology of anode coating, such as coating cracks, qualitative determination of coating components, distribution of each component element in the coating on the entire electrode surface and whether the distribution is uniform. Scanning electron microscope can generally choose Germany LEO-1530 scanning electron microscope, Philips company XL30FEG scanning electron microscope, HT-TACHI company X-650 X-ray scanning electron microscope, Netherlands Philips company XL30 ESEM environmental scanning electron microscope, Japan JEOL company JSM-6700F type Emission SEM, Japan JSM-T300 SEM, Japan Hitachi S-507 SEM, Beijing Scientific Instrument Factory KY2-1000B SEM, Japan Electronics Corporation JEOLJSM-6700 SEM and Cambridge S-360 SEM .
Electron probe can generally choose Shimadzu EPMA-8705/QH2 electron probe instrument, JXA-840A electron probe microanalyzer, Japan JCXA-733 electron probe and Japan JSM-6700F electron probe instrument.
Each component element in the active coating can be qualitatively determined by scanning electron microscope, electron probe or powder X-ray diffractometer.
Scanning electron microscope or electron probe coupled with energy dispersive spectrometer can quantitatively determine the content of component elements in active coating.
The powder X-ray diffractometer can generally use Shimadzu XRD-6000 powder X-ray diffractometer.
Profile analysis of active coating
Scanning electron microscope or electron probe can be used to observe the cross-section of the coating, measure the thickness of the coating, and observe the distribution of each component element along the cross-section.
Analysis of active coating nanocrystals
Scanning electron microscope, scanning tunneling microscope and transmission electron microscope can be used to observe the grain size of active coating oxide components. Generally, Japan JEM-1010 transmission electron microscope and JEM-200CX transmission electron microscope can be used.
X-ray diffraction structure analysis (XRD)
The X-ray diffractometer can correctly analyze the phase composition of the coating material, such as TiO2, if it is analyzed as TiO2 (R), it is rutile TiO2; if it is analyzed as TiO2 (A), it is anatase TiO2, which is an unstable phase. .
The analysis is TiO2(R) and RuO2 solid solution, that is, the TiO2 phase and RuO2 phase in the coating are integrated.
X-ray diffraction analysis shows that RuO2 and TiO2(R) exist in the ruthenium-titanium coating; for solid solution, the solid solution limit of RuO2 is about 50%, while that of TiO2 is about 20%.
According to the characteristic peaks of X-ray diffraction lines, the oxide components in the coating can be judged, and the amount of oxide components can be qualitatively judged.
X-ray diffraction analysis is carried out on the new coating of the electrode and the coating after the failure of the electrode. According to the change of the characteristic peak intensity before and after the failure of the component elements, the cause of the failure of the electrode can be judged. Generally, the MO3XHF22 X-ray diffractometer from Mac Science Company in Japan, D5005 X-ray diffractometer from BrukerAXS Company in the United States, D8-discover X-ray diffractometer from Bruker Company in Germany, XD-3A X-ray diffractometer from Shimadzu, and D8A dvance X-ray diffractometer can be used. X-ray diffractometer, Rigaku RAX-10 X-ray diffractometer, Panalytical X'Pert rotating target X-ray powder diffractometer from Philips, Shimadzu XRD-6000 powder X-ray diffractometer, Rigaku Corporation D/MAX. RC type X-ray diffractometer, Philips PW1700 X-ray diffractometer, Rigaku Corporation 4053 A3 X-ray diffractometer, etc.
Photoelectron Spectroscopy (XPS)
Photoelectron spectroscopy is a method to study the surface information of materials, which reflects the information of adsorption layers formed by 1-10 atomic layers within the surface of solid materials and other atoms, molecules and ions above it. Electrode process products can be detected by X-ray photoelectron spectroscopy, the surface state of materials can be analyzed, and the composition and element valence state of electrode surface coating can be analyzed, such as TiO2, Ti2O3, and TiO. Generally, ESCALABMKⅡ type electron spectrometer from British VG company, ESCALAB MKⅢ photoelectron spectrometer from British VG company, and XSAM800 type X-ray photoelectron spectrometer from KRATOS company can be used.
Raman scattering spectrum analysis
The crystallization state of the coating can be analyzed by Raman scattering spectroscopy. Generally, RM100 confocal Raman spectrometer from Renishaw, UK can be used.
X-ray fluorescence analysis (XRF)
X-ray fluorescence analysis can be used to determine the adhesion of various oxides in the coating. Generally, Philips PW2400 XPF spectrometer can be used.
Thermogravimetric analysis (TG)
Thermogravimetric analysis (TG) and differential thermal analysis (DTA) combined with X-ray diffraction can analyze the thermal decomposition formation process of oxides in coatings. Generally, PERKINELMER1700 differential thermal-thermogravimetric analyzer and du Pont 1090B thermal analyzer can be used.
Differential thermal analysis can determine the phase of the coating. Generally, a 1700 differential thermal analyzer from PH Company in the United States can be used.
Determination of ruthenium content in the coating
For titanium electrodes used in the chlor-alkali industry, the active coating is mainly ruthenium.
The methods for determining the ruthenium content in the coating include fluorescent X-ray analysis, electron probe method, atomic absorption spectrophotometry, 72G or 721 spectrophotometry, etc.
The characteristics of the first two methods are fast and non-destructive, but due to the non-uniformity of the electrode coating process itself and the small range of analysis points, the error of the test results is large. The latter two are destructive, and the ruthenium-containing coating is peeled off from the analytical sample by alkali fusion, and a solution is prepared for spectrophotometric analysis. Spectrophotometry has high sensitivity, accurate and reliable results, and good reproducibility, but the disadvantage is that it takes more time.
