Long-lasting hydrogen evolution on and hydrogen entry into iron in an aqueous solution

Gajek, Arkadiusz; Zakroczymski, T.

doi:10.1016/j.jelechem.2004.12.038

Cited by 18 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As suggested in mechanism II (Scheme ), transition metal particles (photo)electrodeposited on the cathode surface from admixtures present in solutions might function as the required electrocatalytic sites. Such deposits are frequently observed in the field of electrocatalytic water splitting, − and charge-transfer between heterogeneous catalysts and dye molecules has also been previously reported. ,,, Common transition metals capable of catalyzing H 2 evolution include cobalt, nickel, iron, and molybdenum. ,, However, ICP-MS analysis of the electrolyte solutions used herein did not show significant presence of admixtures except for iron in the phosphate and citrate buffers. Importantly, no clear correlation exists between the concentrations of iron in the solutions (Table ) and the corresponding photoelectrocatalytic performance of the photocathodes (Table ).…”

Section: Discussionsupporting

confidence: 66%

“…On the other hand, further ICP-MS analysis clearly demonstrates the presence of significant amounts of dissolved nickel (>10 1 μM), which is unsurprising given the instability of the underlying NiO semiconductor at pH < 10 (Figure S10). , At the same time, the reduction potential of the dye anion is −0.70 V vs NHE, , while the phase transition of the two-electron reduction of Ni 2+ to Ni 0 occurs at approximately −0.4 V vs NHE . Thus, a thermodynamic driving force of ∼0.3 V exists for nickel deposition, and resulting Ni 0 is expected to remain metastable (Figure S10).…”

Section: Discussionmentioning

confidence: 99%

“…59,60 At the same time, the reduction potential of the dye anion is −0.70 V vs NHE, 27,28 while the phase transition of the two-electron reduction of Ni 2+ to Ni 0 occurs at approximately −0.4 V vs NHE. 58 Thus, a thermodynamic driving force of ∼0.3 V exists for nickel deposition, and resulting Ni 0 is expected to remain metastable (Figure S10). This surface could then provide electrocatalytic sites for the observed generation of H 2 , similar to electrodeposited platinum metal in our previous work.…”

Section: ■ Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Origin of Photoelectrochemical Generation of Dihydrogen by a Dye-Sensitized Photocathode without an Intentionally Introduced Catalyst

et al. 2017

View full text Add to dashboard Cite

Dye-sensitized photocathodes have been observed on several occasions to sustain light-driven H 2 generation without intentionally introduced catalysts. Herein, plausible mechanisms addressing this phenomenon are probed by a combination of long-term photoelectrochemical measurements with concurrent gas chromatography, transient absorption spectroscopy, and inductively coupled mass spectrometry using a perylenemonoimide-sexithiophene-triphenylamine (PMI-6T-TPA) sensitized NiO electrode. The experimental evidence obtained discounts the possibility for direct reduction of hydrogen by the dye and demonstrates that the availability of interfaces between dye molecules and any electrically disconnected NiO particles exposed to the electrolyte solution is critical for photoelectrocatalytic H 2 generation. These interfaces are postulated to serve as photoactive sites for the formation of a hydrogen evolution catalyst, e.g., metallic nickel, which can accept photogenerated electrons from the excited dye molecules. The Ni 0 catalyst can form via photoelectroreduction of Ni 2+ , which has been found to slowly dissolve from the NiO support into the solutions during the photoelectrochemical measurements. Additionally, dependence of the H 2 generation rate on the anion within the electrolyte has been identified, with the highest rates of 35-40 nmol h -1 cm -2 achieved with acetate. The origin of this dependence remains unsolved at this stage but is clearly demonstrated to be not associated with the different rates of dissolution of NiO, the presence of other transition metal contaminants, nor electronic impacts of the anion on the NiO valence band. Overall, the results herein demonstrate that the effects of the chemical nature of the electrolyte, metallic nickel deposited from dissolved Ni 2+ , and availability of the interfaces between disconnected NiO and adsorbed dye should be considered when interpreting the photoelectrocatalytic performance of dye-sensitized photocathodes for dihydrogen evolution. × Our colleague, mentor and friend Prof. Leone Spiccia has passed away before this work could be published. Leone was an outstanding researcher and personality, and is sadly missed. ABSTRACTDye-sensitized photocathodes have been observed on several occasions to sustain light-driven H2 generation without intentionally-introduced catalysts. Herein, plausible mechanisms addressing this phenomenon are probed by a combination of long-term photo-electrochemical measurements with concurrent gas chromatography, transient absorption spectroscopy and inductively coupled mass spectrometry using a perelenmonoimid-sexithiophene-triphenylamine (PMI-6T-TPA) sensitized NiO electrode. The experimental evidence obtained discounts the possibility for direct reduction of hydrogen by the dye and demonstrates that the availability of interfaces between dye molecules and any electrically-disconnected NiO particles exposed to the electrolyte solution is critical for photo-electrocatalytic H2 generation. These interfaces are postulated to serve as photo-a...

show abstract

Section: Discussionsupporting

confidence: 66%

Section: Discussionmentioning

confidence: 99%

Section: ■ Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Origin of Photoelectrochemical Generation of Dihydrogen by a Dye-Sensitized Photocathode without an Intentionally Introduced Catalyst

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Hydrogen Diffusivity and Solubility. The analysis of the curves ( Figure 5) corresponding to the experimental results enabled us to determine the diffusivity ( eff ) by fitting hydrogen diffusion theoretical equation (2) into these curves. The apparent solubility of hydrogen measured in silicon steel is defined by using (3).…”

Section: Effect Of Thickness Reduction Degrees Onmentioning

confidence: 99%

“…It is readily available in abundance; therefore, in recent years, it is extensively used as a high-energy fuel. However, the entry of hydrogen into the metal surface is a serious problem encountered during many electrochemical processes, including corrosion of metals, pickling of metals, electroplating of metals, and metal welding [1][2][3]. The hydrogen which is introduced into the metal via electrochemical process or gaseous absorption leads to hydrogen embrittlement of the material which results in the decrease in the mechanical properties such as toughness and ductility.…”

Section: Introductionmentioning

confidence: 99%

Effect of Cold-Rolled Thickness Reduction Degree on Characteristics of Hydrogen Diffusion in Silicon Steel

Cai

Liu

et al. 2014

International Journal of Corrosion

View full text Add to dashboard Cite

The characteristic of hydrogen uptake and diffusion in the cold-rolled silicon steel was investigated by electrochemical hydrogen permeation technique performed under different cathodic charging current density and cold-rolled thickness reduction degree. The results indicated that anodic permeation current density increased with increasing cathodic charging current for the specimens. Moreover, the anodic steady state permeation current density and the solubility increased with an increase in the cold-rolled thickness reduction degrees. The breakthrough time of hydrogen in the specimens was shortened with increasing thickness reduction degrees, and the value of the hydrogen diffusivity decreased gradually with increasing thickness reduction degrees.

show abstract

In situ monitoring the effects of a magnetic field on the open-circuit corrosion states of iron in acidic and neutral solutions

Yang

2008

Corrosion Science

View full text Add to dashboard Cite

Long-lasting hydrogen evolution on and hydrogen entry into iron in an aqueous solution

Cited by 18 publications

References 28 publications

Origin of Photoelectrochemical Generation of Dihydrogen by a Dye-Sensitized Photocathode without an Intentionally Introduced Catalyst

Origin of Photoelectrochemical Generation of Dihydrogen by a Dye-Sensitized Photocathode without an Intentionally Introduced Catalyst

Effect of Cold-Rolled Thickness Reduction Degree on Characteristics of Hydrogen Diffusion in Silicon Steel

In situ monitoring the effects of a magnetic field on the open-circuit corrosion states of iron in acidic and neutral solutions

Contact Info

Product

Resources

About