Field-induced cation migration in Cu oxide films by <i>in situ</i> scanning tunneling microscopy

Singh, J. P.; Lu, T.‐M.; Wang, G.-C.

doi:10.1063/1.1586461

Cited by 13 publications

(4 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This stabilization is perhaps correlated to the dissolution of V (for OER, will be discussed in the following section) and a rearrangement (e.g., redox reaction, dissolution, electromigration) of the catalyst surface. [ 21 ] They are maintaining stable within 2 h.…”

Section: Resultsmentioning

confidence: 99%

Bifunctional CoFeVO_x Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Lee

Ding

Banerjee

et al. 2020

Adv Materials Technologies

View full text Add to dashboard Cite

ferent solar driven hydrogen production approaches (i.e., photocatalyst, [4] photoelectrochemical, [5] PV [6]), where the PV part as power supply can be directly connected to the electrochemical (EC) part. [7] Although water electrolysis can be operated in any pH condition, efficient and stable catalysts made of earth-abundant materials are mostly found for strong alkaline electrolytes. [8] Among the promising candidates in alkaline electrolysis, inorganic Co-based compounds have been intensively investigated due to their reasonable performance. [9,10] Iron is relatively well known as a dopant in the Co-based catalysts, and the activity of Fe-doped Co catalysts is significantly enhanced by synergistic effects between Co and Fe. [11] Recently, it was found that the incorporation of high-valence vanadium (V) in Co-based catalysts is beneficial for the oxygen evolution reaction (OER) performance. [12] It is suggested that V doping may play a role in adjusting the electronic structure in the Co-based catalysts. In order to increase the activity of the OER catalysts also ternary CoVFe compounds have been prepared and investigated. [13] We have investigated the use of different Co-based catalysts in bifunctional configuration. A bifunctional configuration (one type of the catalyst for both, anode and cathode at the same time) offers a great potential for reducing the cost of catalyst production and thus of the entire system. [14] The composition of the binary and ternary catalysts was adjusted according to the metalhydroxide (MOH) bond strength theory. [12a,15] Each type of mixed compound was explored in both OER and hydrogen evolution reaction (HER) in the same alkaline electrolyte. We found that the sample consisting of Co 0.6 Fe 0.3 V 0.1 O x shows the best performance (at 10 mA cm −2) with an overpotential of 269 mV for HER and 266 mV for OER, respectively. An X-ray photoelectron spectroscopy (XPS) analysis has revealed that vanadium is almost completely depleted in the OER catalyst after the reaction. In combination with the Pourbaix diagram of V species, we assume that for OER vanadium does not modify the electrical property, [13b] the MOH binding energy, [12a] or the coordination environment in the mixed film [12b,16] as previously suggested. Probably the dissolution of the vanadium results in the creation of pores in the mixed catalyst that might be related to the positive Photovoltaic driven electrochemical (PV-EC) water splitting technology is considered as one of the solutions for an environmental-friendly hydrogen supply. In a PV-EC system, efficient catalysts are required to increase the rate of both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Here, the development of a CoFeVO x bifunctional catalyst produced by a simple electrodeposition method is presented. It is found that after the water splitting reaction, vanadium is almost completely depleted in the mixture of elements for OER, while its concentration at the HER catalyst is similar or even higher after the reaction. Fo...

show abstract

Section: Resultsmentioning

confidence: 99%

Bifunctional CoFeVO_x Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Lee

Ding

Banerjee

et al. 2020

Adv Materials Technologies

View full text Add to dashboard Cite

show abstract

“…In addition to nanowires of oxides, electric field-assisted growth of metal and semiconductor nanostructures have been reported for other materials, e.g., copper, [48] silicon, [49] or zinc. [50]…”

Section: Effect Of An External Electric Field On Oxide Nanowire Growth During Thermal Oxidationmentioning

confidence: 99%

Growth of Metal Oxide Nanostructures by Thermal Oxidation of Metals Under Influence of External Electric Fields and Electric Current Flow

Piqueras

Hidalgo

2021

Physica Status Solidi (a)

View full text Add to dashboard Cite

Thermal oxidation of metals in a furnace or a hot plate is a simple and low‐cost method to grow nanowires and other nanostructures of oxides of technological interest. In comparison with evaporation–deposition techniques based on vapor–solid (VS) or vapor–liquid–solid (VLS) mechanisms, thermal oxidation is a more direct and easy technique but does not normally lead to the formation of complex heterostructures or ternary oxides. Application of an external electric field at the sample during thermal oxidation has been used to improve the control of the nanowire dimensions, or final concentration on the starting metal surface. Other approach to grow oxide nanowires during the oxidation process is to heat the sample by Joule effect by the flow of a high‐density electric current in a metal wire. Joule heating has been found to reduce the growth time, typically some hours in thermal oxidation or evaporation–deposition methods, to few seconds or minutes. Herein, the results of representative articles on nanowire growth during thermal oxidation under the presence of an electric field and on the growth during Joule heating are summarized in the frame of mechanisms of stress relaxation‐driven ion diffusion and of thermally assisted electromigration.

show abstract

“…19 Electromigration, which takes place inside the metal wire, would contribute to the formation of the oxide layer with micro and nanostructures by favoring diffusion processes towards the surface. Results on the synthesis of Cu nanowires under a STM tip 24 and on CuO nanowires 25 by heating Cu foils at 400 C on a hotplate indicated that the process is favored by the application of an external electric eld, which promotes the diffusion/electromigration of Cu ions. 25 In the case of Mo, a thermal assisted electromigration process would enhance the out diffusion of Mo ions in the metal wire leading to the rapid growth of MoO 3 plates.…”

Section: Structures Formed On the Mo Wirementioning

confidence: 99%

Influence of an external electric field on the rapid synthesis of MoO₃ micro- and nanostructures by Joule heating of Mo wires

et al. 2020

View full text Add to dashboard Cite

show abstract

Field-induced cation migration in Cu oxide films by in situ scanning tunneling microscopy

Cited by 13 publications

References 25 publications

Bifunctional CoFeVO_x Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Bifunctional CoFeVO_x Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Growth of Metal Oxide Nanostructures by Thermal Oxidation of Metals Under Influence of External Electric Fields and Electric Current Flow

Influence of an external electric field on the rapid synthesis of MoO₃ micro- and nanostructures by Joule heating of Mo wires

Contact Info

Product

Resources

About

Field-induced cation migration in Cu oxide films by in situ scanning tunneling microscopy

Cited by 13 publications

References 25 publications

Bifunctional CoFeVOx Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Bifunctional CoFeVOx Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Growth of Metal Oxide Nanostructures by Thermal Oxidation of Metals Under Influence of External Electric Fields and Electric Current Flow

Influence of an external electric field on the rapid synthesis of MoO3 micro- and nanostructures by Joule heating of Mo wires

Contact Info

Product

Resources

About

Bifunctional CoFeVO_x Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Bifunctional CoFeVO_x Catalyst for Solar Water Splitting by using Multijunction and Heterojunction Silicon Solar Cells

Influence of an external electric field on the rapid synthesis of MoO₃ micro- and nanostructures by Joule heating of Mo wires