Effect of SiO2 incorporation on stability and work function of conducting MoO2

Liang, Yong; Tracy, Clarence; Weisbrod, Eric; Fejes, Peter; Theodore, N. D.

doi:10.1063/1.2176859

Cited by 24 publications

(21 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the existence of Al, Ce(III,IV) oxides and hydroxides and Mo oxides apparently influences the electronic properties of the protecting oxide film. A similar case has been reported by Liang et al 56 Accordingly, a mixed oxide system containing MoO 2 and SiO 2 oxides has been prepared by coevaporation in order to tune electronic properties of MoO 2 oxide. The addition of SiO 2 has resulted in gradual decrease of the work function of a mixed system from 6.5 eV to about 5.5 eV where maximal content of SiO 2 was 33%.…”

Section: ■ Discussionsupporting

confidence: 57%

Mechanisms of Localized Corrosion Inhibition of AA2024 by Cerium Molybdate Nanowires

Yasakau

Tedim

Montemor³

et al. 2013

J. Phys. Chem. C

View full text Add to dashboard Cite

The cerium molybdate nanowires were recently reported as an efficient inhibiting pigment for aluminum alloys. In the present work, the inhibition mechanism of localized corrosion of S-phase intermetallics in AA2024 was studied in detail using a complementary combination of localized and analytical techniques. A significant suppression of dealloying of S-phase was demonstrated in the presence of cerium molybdate nanowires. Microscopic observations clearly show the formation of a conversion layer on the entire alloy surface after immersion in nanowire-containing solutions. A noticeable Volta potential difference (VPD) increase up to around −0.25 V vs Ni reference was measured on alloy after immersion in inhibited solutions. Such VPD changes have been related to the presence of Mo oxides on the alloy surface. Analysis performed by energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) showed that the surface oxide film is mainly composed by Mo(VI) and/or Mo(IV) oxides, and cerium(III) and cerium(IV), and aluminum oxides/hydroxides. A model galvanic couple made of aluminum and copper wires was used to simulate corrosion inhibition processes on S-phase intermetallics and alloy matrix. An enhanced inhibition efficiency of cerium molybdate was observed in electrolytes with higher concentration of sodium chloride. This was associated with the structural transformation of amorphous cerium molybdate nanowires into crystalline (NaCe) 0.5 MoO 4 in concentrated NaCl solution, thereby triggering the release of cerium(III). This active feedback release can be used for development of "smart" self-healing coatings with inhibition triggered by the presence of corrosive salts in environment.

show abstract

Section: ■ Discussionsupporting

confidence: 57%

Mechanisms of Localized Corrosion Inhibition of AA2024 by Cerium Molybdate Nanowires

Yasakau

Tedim

Montemor³

et al. 2013

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…From the equation above, the work‐functions were estimated to be ≈5.3, 5.7, and 5.6 eV, respectively, for monolayer MoS 2 , MoS 2 –MoO 2 heterostructure on SiO 2 /Si, and MoS 2 –MoO 2 heterostructure on fused silica. In addition, the work‐function of metallic MoO 2 was known to be ≈6.5 eV, much higher than that of MoS 2 . Based on this analysis, we can deduce that for the MoS 2 –MoO 2 heterostructure on SiO 2 /Si, which has a larger work‐function, its metallic behavior is attributed to a lower coverage of MoS 2 (or insufficient sulfurization) on MoO 2 , while sufficient sulfurization in the MoS 2 –MoO 2 heterostructure on fused silica with a lower work‐function enables its semiconducting behavior.…”

mentioning

confidence: 99%

Large‐Area 2D/3D MoS₂–MoO₂ Heterostructures with Thermally Stable Exciton and Intriguing Electrical Transport Behaviors

Xiao

Golgir

et al. 2017

Adv Elect Materials

View full text Add to dashboard Cite

increasing attention as an emerging class of new materials due to their unique aspects and new functionalities in optical, electrical, and chemical properties. [1] The design and fabrication of 2D semiconductor heterostructures stand as a major strategy for the development of various kinds of devices that range from electronics, [2] photovoltaics, [3] sensors, [4,5] spintronics, [6,7] and memories [8] with the intriguing possibility of enhanced performance. For example, TMD (MoS 2 /WS 2 ) heterostructures exhibit ultrafast charge transfer due to the close proximity of the two heterolayers and the collective motion of excitons at the interface, which enables novel 2D devices for optoelectronics and light harvesting. [9] In the TMD/graphene heterostructures, such hybrid systems exhibit obvious rectification and ambipolar properties with a high field-effect on-off ratio of >10 6 due to the strong interlayer coupling and large band offset between two layers, suggesting their great potentials for future novel optoelectronic devices. [10] Additionally, TMD/graphene heterostructures also demonstrate excellent chemical sensing capability and stability, which provide an essential sensing platform for wearable electronics. [5] To date, scale-up fabrication of transition metal dichalcogenide (TMD-) based 2D/2D or 2D/3D heterostructures with specific functionalities is still a great challenge. This study, for the first time, reports on the controllable synthesis of large-area and continuous 2D/3D semiconductor/metal heterostructures consisting of monolayer MoS 2 and bulk MoO 2 with unique electrical and optical properties via one-step, vapor-transport-assisted rapid thermal processing. The temperature-dependent electrical transport measurements reveal that the 2D/3D MoS 2 -MoO 2 heterostructure grown on SiO 2 /Si substrates exhibits metallic phase, while this heterostructure becomes a lowresistance semiconductor when it is grown on fused silica, which is attributed to the different degrees of sulfurization on different substrates, as being confirmed by surface potential analyses. Photoluminescence measurements taken on the MoS 2 -MoO 2 heterostructures reveal the simultaneous presence of both negative trions and neutral excitons, while only neutral excitons are observed in the monolayer MoS 2 . The trion-binding energy is determined to be ≈27 meV, and the trion signal persists up to 330 K, indicating significant stability at room temperature. This work not only provides a new platform for understanding the intriguing physics in TMD-based heterostructures but also enables the design of more complicated devices with potential applications in nanoelectronics and nanophotonics.To date, 2D semiconducting transition metal dichalcogenides (TMDs) and TMD-based heterostructures have gained

show abstract

“…For example, the metal-oxygen bond of MoO 2 is primarily "ionic" while that of SiO 2 is "covalent." Consequently, the lattice oxygen mobility of MoO 2 decreases by doping it with a small amount of SiO 2 [106]. The metallic property of MO 2 actively breaks various chemical bonds in bio-fuels leading to their high oxidation activity, while their ability to selectively transfer lattice oxygen to the carbon fragments minimizes coke formation during fuel oxidation [90,[107][108][109][110][111].…”

Section: Alternative Mo 2 Catalytic Materials In Direct Sofcsmentioning

confidence: 99%

Catalysis Using Metal Oxides with Mixed Ionic -Electronic Conductivity for Clean Energy Electrochemical Systems

Ha¹

2018

PPS

View full text Add to dashboard Cite

Effect of SiO2 incorporation on stability and work function of conducting MoO2

Cited by 24 publications

References 7 publications

Mechanisms of Localized Corrosion Inhibition of AA2024 by Cerium Molybdate Nanowires

Mechanisms of Localized Corrosion Inhibition of AA2024 by Cerium Molybdate Nanowires

Large‐Area 2D/3D MoS₂–MoO₂ Heterostructures with Thermally Stable Exciton and Intriguing Electrical Transport Behaviors

Catalysis Using Metal Oxides with Mixed Ionic -Electronic Conductivity for Clean Energy Electrochemical Systems

Contact Info

Product

Resources

About

Effect of SiO2 incorporation on stability and work function of conducting MoO2

Cited by 24 publications

References 7 publications

Mechanisms of Localized Corrosion Inhibition of AA2024 by Cerium Molybdate Nanowires

Mechanisms of Localized Corrosion Inhibition of AA2024 by Cerium Molybdate Nanowires

Large‐Area 2D/3D MoS2–MoO2 Heterostructures with Thermally Stable Exciton and Intriguing Electrical Transport Behaviors

Catalysis Using Metal Oxides with Mixed Ionic -Electronic Conductivity for Clean Energy Electrochemical Systems

Contact Info

Product

Resources

About

Large‐Area 2D/3D MoS₂–MoO₂ Heterostructures with Thermally Stable Exciton and Intriguing Electrical Transport Behaviors