scholarly journals Non-destructive analysis on oxidation states of Ti atoms in the passivation film formed on SUS321 using hard X-ray photoelectron spectroscopy

2009 ◽  
Vol 34 (4) ◽  
pp. 617-620
Author(s):  
Shin Takahashi ◽  
Mitsutoshi Yokomizo ◽  
Masugu Sato ◽  
Masatake Machida ◽  
Son Jin-Young
2012 ◽  
Vol 101 (14) ◽  
pp. 143501 ◽  
Author(s):  
Thomas Bertaud ◽  
Malgorzata Sowinska ◽  
Damian Walczyk ◽  
Sebastian Thiess ◽  
Andrei Gloskovskii ◽  
...  

2019 ◽  
Vol 66 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Junzhe Liu ◽  
Jundi Geng ◽  
Hui Wang ◽  
Mingfang Ba ◽  
Zhiming He

Purpose This paper aims to study the influence of NaNO2 on the chemical composition of passivation film. Design/methodology/approach X-ray photoelectron spectroscopy and X-ray diffraction were selected to determine the composition of passivation film of steel bars in mortar. The specimens were exposed to the chloride solution, carbonation environment and the coupling effects of chloride solution and carbonation. The chemical composition and micro structures at 0 and 5 nm from the outer surface of the passivation film of steel bars were analyzed. Findings Results showed that the nitrite inhibitor improved the forming rate of the passivation film and increased the mass ratio of Fe3O4 to FeOOH on the surface of steel bars. The component of Fe3O4 at 5 nm of the steel passivation film was more than that at 0 nm. Sodium ferrite in the pore solution was easily hydrolyzed and then FeOOH was formed. Therefore, due to the nitrite inhibitor, a “double layer structure” of the passivation film was formed to prevent steels bars from corrosion. Originality/value This is original work and may help the researchers further understand the mechanism of rust resistance by nitrite inhibitor.


Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1909
Author(s):  
Ju Hyun Yang ◽  
So Jeong Park ◽  
Choong Kyun Rhee ◽  
Youngku Sohn

Energy recycling and production using abundant atmospheric CO2 and H2O have increasingly attracted attention for solving energy and environmental problems. Herein, Pt-loaded Ti sheets were prepared by sputter-deposition and Pt4+-reduction methods, and their catalytic activities on both photocatalytic CO2 reduction and electrochemical hydrogen evolution were fully demonstrated. The surface chemical states were completely examined by X-ray photoelectron spectroscopy before and after CO2 reduction. Gas chromatography confirmed that CO, CH4, and CH3OH were commonly produced as CO2 reduction products with total yields up to 87.3, 26.9, and 88.0 μmol/mol, respectively for 700 °C-annealed Ti under UVC irradiation for 13 h. Pt-loading commonly negated the CO2 reduction yields, but CH4 selectivity was increased. Electrochemical hydrogen evolution reaction (HER) activity showed the highest activity for sputter-deposited Pt on 400 °C-annealed Ti with a HER current density of 10.5 mA/cm2 at −0.5 V (vs. Ag/AgCl). The activities of CO2 reduction and HER were found to be significantly dependent on both the nature of Ti support and the oxidation states (0,II,IV) of overlayer Pt. The present result could provide valuable information for designing efficient Pt/Ti-based CO2 recycle photocatalysts and electrochemical hydrogen production catalysts.


1979 ◽  
Vol 33 (4) ◽  
pp. 380-384 ◽  
Author(s):  
J. A. Schreifels ◽  
A. Rodero ◽  
W. E. Swartz

A series of copper chromite catalysts have been studied by x-ray photoelectron spectroscopy. The data indicate that in the as-received form the copper is present as a mixture of Cu(OH)2 and CuO. After calcination at 500 °C only CuO is present. The chromium is present as Cr+3 and Cr+4 when no promoter is added. When a BaO promoter is added, the Cr+6 is stabilized. Calcination at 500°C for varying periods of time alter the relative amounts of Cr+3 and Cr+6 on the catalytic surface. In addition, the relative amounts of the various oxidation states are a function of calcination temperature. At a calcination temperature of 240°C a Cr+5 surface species is reproducibly observed in one of the catalysts.


Sign in / Sign up

Export Citation Format

Share Document