Identification of the reconstruction and bonding structure of SiC nanocrystal surface by infrared spectroscopy

Electrochemical Synthesis of Carbon Fluorooxide Nanoparticles from 3C-SiC Substrates

“…SiC + H 2 O + 6F − − 4e − = SiF 6 2− + CO + H 2 (3) Of course, the formation of hexafluorosilicate during the SiC etching seems doubtless, furthermore its intense bands at 738 at 482 cm −1 can be seen in the FTIR spectra of insufficiently washed samples of SiC nanomaterials, being often misinterpreted as bands of some surface species 18,19 . However, chemical compounds containing carbon atoms from the etched SiC materials should be in reality much more complicated than those described by the reactions (1-3) mentioned above.…”

“…(i) relatively small (few rings) aromatic domains causing the UV-vis absorbance and the PL spectra reported above; (ii) labile to hydrolysis fluorine atoms giving a signal at -150 ppm in the19 F NMR(Fig. 10); (iii) hydrolytically-stable -CF 3 , -CF 2 -and ≡C-F groups; (iv) some carbon atoms bound to oxygen, probably, in the form of -OH, -OC 2 H 5 (in this case the signals at 14.2 and 15.3 ppm in the 13 C NMR(Fig.…”

“…13 C NMR spectrum (proton-decoupled) of CFO dissolved in CD 3 OD 19. F MAS NMR spectra of the initial CFO and the CFO_hydr samples are shown inFig.…”

“…19 F MAS NMR spectra (13 kHz, proton-decoupled) of CFO and CFO_hydr.3.3.3. XPS analysisXPS analysis (standard RSF were used) gives the following elemental composition (in % wt.…”

Size and Surface Chemistry Tuning of Silicon Carbide Nanoparticles

“…Widely used chemical oxidation of SiC micropowders requires rather harsh fabrication conditions (HNO 3 :HF (1:3, v/v) at 100 °C), 33−37 while an electrochemical etching of SiC wafers can be carried out in a more controllable way. 23,24,38,39 Recently, the electrochemical procedure was successfully applied to obtain small (<10 nm) SiC NPs from the slurry of relatively large SiC nanopowder (>50 nm). 40 According to different groups of authors, [34][35][36]38,39 the surface of as-prepared "top-down" SiC NPs can be terminated with a wide variety of functionalities, such as hydroxyls, Si−O− Si, Si−O−C and C−O−C bridges, CH x groups, "sp 2 -carbon", silane (Si−H) groups, Si−Si bonds, and some fluorinecontaining species.…”