Phase reduction of coated maghemite (γ-Fe₂O₃) nanoparticles under microwave-induced plasma heating for rapid heat treatment

Assessing the environmental performance of NADH regeneration methods: A cleaner process using recyclable Pt/Fe3O4 and hydrogen

“…It is to take care on the fact that the crystal structure of γ-Fe2O3 is similar to that of Fe3O4 and the diffraction peaks from Fe3O4 nearly overlap with those from γ-Fe2O3 [69]. The disappearance of peaks at 23.8° and 26.1° and the increase in the intensity of the peak at 18.3°, however, prove the formation of the Fe3O4 phase in the reduced catalyst, in agreement with both the TPR results and the literature [68]. This reduction is also evident by the colour change of the catalyst from brownish-red to black and the very small shift in the diffraction peaks to a lower angle side [70].…”

“…The XRD patterns of Fe2O3 support, (as prepared) Pt/Fe2O3 and (reduced) Pt/Fe3O4 are shown in Figure 4. [68], are associated with the γ-Fe2O3 phase which is present in both the support and the as prepared catalyst. It is to take care on the fact that the crystal structure of γ-Fe2O3 is similar to that of Fe3O4 and the diffraction peaks from Fe3O4 nearly overlap with those from γ-Fe2O3 [69].…”

Morphology and properties of silica-based coatings with different functionalities for Fe3O4, ZnO and Al2O3 nanoparticles

“…This can be compared with the three narrow Si-O-Si peaks associated with the network in the TEOS-coated nanoparticles (spectrum 1), which originated from small nonrepulsing silanol groups that could readily condense into a thick densely cross-linked silicon oxide network. 32 The amounts of water released at 200 °C were 0.8 % (uncoated), 0.6 % (APTES), 0.6 % (MTMS), 0.9 % (OTES) and 0.4 % (TEOS). The dominant carbon functionality in the OTES coating was also confirmed by EDS (TEM), showing a relatively weak Si signal (diluted) as compared to iron content, Fig.…”

“…The APTES coating constituted 16.9 wt.%, the MTMS: 36.3 wt.%, and the OTES 9.7 wt.% of the core-shell particles. 32 In order to obtain a more reliable estimate of the coating fraction, the coatings were removed by NaOH-etching, and the mass loss associated with this procedure was taken as an absolute value for the coating mass. 15,33 The greater mass loss above 200 Ԩ for the TEOS-coated particles supported this hypothesis (Fig.…”

Dielectric properties in microwave remote plasma sustained in argon: Expanding plasma conditions

“…Microwave plasma, working at 2.45 GHz is used for various industrial applications like surface treatments, 1,2 microcircuit fabrications for electronic devices, 3 or chemical transformations. [4][5][6] These plasma discharges are sustained in electrode-less reactor. However, in an unmagnetized plasma, the electromagnetic wave can propagate only at low electron density and it is reflected as soon as the wave frequency becomes lower than the plasma frequency.…”