XPS studies on the Mo oxide-based coatings electrodeposited from highly saturated acetate bath

Abstract

The possibility to use highly saturated acetate bath to electrodeposit the mixed-phase materials containing Mo oxides has been investigated. The XRD characterization revealed that the as-deposited coatings are amorphous and consist only of MoO2 and MoO3 phases without traces of metallic Mo phase. This statement has been supported by XPS measurements, which reveal the presence of three different molybdenum oxidations states in electrodeposits: Mo4+, Mo5+ and Mo6+. It was found that the Mo6+ state prevails with 41% of total contribution, whilst Mo5+ and Mo4+ contribute to 28 and 31%, respectively. The deposits retain an amorphous structure up to 800°C; while molybdenum at this temperature is predominantly oxidized to the Mo6+ state (91%). These results, coupled to those of SEM and EDS, revealed that concentrated acetate bath could be used mainly for the formation of the mixed valence molybdenum oxide film unlike to the deposition of the metallic Mo phase.

CoMoO3 Nanoplate/Reduced Graphene Oxide Composites Decorated with Ag Nanoparticles for Electrocatalytic Water Oxidation

“…In Figure 4b, the peaks at 235.4 and 232.3 eV of the CoMoO 3 nanoplates are attributed to the Mo 4+ ions in the composite structure. 43 As for CoMoO 3 / rGO@Ag-10, a similar peak shift also occurs to the Mo 3d orbit, which shifts from 232. 44 As for the Raman spectra of CoMoO 3 / rGO@Ag-10, the characteristic peaks of the CoMoO 3 phase were inherited, and the peaks at 1353 and 1590 cm −1 are distinct D band and G band signals from the rGO component.…”

“…Due to the presence of rGO and Ag, the peak of the Co 2p 3/2 orbit shifts from 781.3 to 781.05 eV for CoMoO 3 /rGO@Ag-10, suggesting the presence of Co 2+ ions. In Figure b, the peaks at 235.4 and 232.3 eV of the CoMoO 3 nanoplates are attributed to the Mo 4+ ions in the composite structure . As for CoMoO 3 /rGO@Ag-10, a similar peak shift also occurs to the Mo 3d orbit, which shifts from 232.3 and 235.4 to 232.1 and 235.2 eV, respectively.…”

Graphene and Hexagonal Boron Nitride in Molybdenum Disulfide/Epoxy Composites for Significant X-ray Shielding Enhancement

“…Detailed narrow scans of the C 1s spectrum on the hybrid system (EP-MoS 2 -GN-hBN) evidently show that it has a chemical-rich environment with two main C peaks at ∼284.8 and ∼286.6 eV that can be deconvoluted into six components including CC (284.7 eV), C–C (285.2 V), C–N (286.0 eV), C–O (286.5 eV), CO (287 eV), and OCO (288 eV). The high-resolution spectral region with two main sets of signals that give rise to Mo 3d (∼229.8 and ∼232.9 eV) and S 2s (∼227.0 eV) peaks, with no peak at 228 eV detected for metallic phase (Mo 0 ), confirm the presence of Mo in the semiconducting phase of MoS 2 . , Fitting of the Mo 3d peaks led to three doublets, with the first pair located at 229.8 and 232.9 eV, corresponding to the characteristic binding energies of Mo 4+ (charged state of Mo in MoS 2 ) for Mo 3d 5/2 and Mo 3d 3/2 spin–orbit states, respectively. − The second doublets due to the presence of Mo 6+ of MoO 3 or MoO x for Mo 3d 5/2 and Mo 3d 3/2 were visible at 232.6 and 235.7 eV, respectively. , Small satellite peaks corresponding to its oxide were also found at 234.0 and 237.0 eV, indicating a slight oxidation of MoS 2 resulting from the surface oxidation of MoS 2 in air. , The existence of hBN as an additive in the hybrid system was validated, with the appearance of peaks arising from ∼187.8, ∼188.9, 191.1, and 191.9 eV attributed to B–B, B–C, B–N, and B–O species, respectively. , …”

“…The high-resolution spectral region with two main sets of signals that give rise to Mo 3d (∼229.8 and ∼232.9 eV) and S 2s (∼227.0 eV) peaks, with no peak at 228 eV detected for metallic phase (Mo 0 ), confirm the presence of Mo in the semiconducting phase of MoS 2 . 53,54 Fitting of the Mo 3d peaks led to three doublets, with the first pair located at 229.8 and 232.9 eV, corresponding to the characteristic binding energies of Mo 4+ (charged state of Mo in MoS 2 ) for Mo 3d 5/2 and Mo 3d 3/2 spin−orbit states, respectively. 55−57 The second doublets due to the presence of Mo 6+ of MoO 3 or MoO x for Mo 3d 5/2 and Mo 3d 3/2 were visible at 232.6 and 235.7 eV, respectively.…”

Mo-Doped CuO Nanomaterial for Photocatalytic Degradation of Water Pollutants under Visible Light

“…In Figure 4b, the peaks shown at 933.4 eV and 952.6 eV are related to Cu 2p3/2 and Cu 2p1/2, which are the features of the Cu 2+ ions [24]. Furthermore, the presence of CuO was also confirmed by the appearance of peaks with binding energies of 942.11 eV and 962 eV [25]. Figure 4c shows two peaks at binding energies of 231.49 eV and 234.79 eV, which can be indexed to Mo 3d3/2 and Mo 3d5/2, thus demonstrating the successful doping of the CuO crystalline lattice [26].…”