Laser‐induced molecular desorption from size‐selected nickel cluster carbonyl ions: Kinetics of the adsorption–desorption equilibrium

1988 ◽  
Vol 89 (4) ◽  
pp. 2419-2426 ◽  
Author(s):  
C. Brechignac ◽  
Ph. Brechignac ◽  
P. Fayet ◽  
W. A. Saunders ◽  
L. Wöste
Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 326 ◽  
Author(s):  
Peng Sun ◽  
Jun Zhang ◽  
Wenxiu Liu ◽  
Qi Wang ◽  
Wenbin Cao

In this paper, the Langmuir-Hinshelwood (L-H) model has been used to investigate the kinetics of photodegradation of gaseous benzene by nitrogen-doped TiO2 (N-TiO2) at 25 °C under visible light irradiation. Experimental results show that the photoreaction coefficient kpm increased from 3.992 × 10−6 mol·kg−1·s−1 to 11.55 × 10−6 mol·kg−1·s−1 along with increasing illumination intensity. However, the adsorption equilibrium constant KL decreased from 1139 to 597 m3·mol−1 when the illumination intensity increased from 36.7 × 104 lx to 75.1 × 104 lx, whereas it was 2761 m3·mol−1 in the absence of light. This is contrary to the fact that KL should be a constant if the temperature was fixed. This phenomenon can be attributed to the breaking of the adsorption-desorption equilibrium by photocatalytically decomposition. To compensate for the disequilibrium of the adsorption-desorption process, photoreaction coefficient kpm was introduced to the expression of KL and the compensation form was denoted as Km. KL is an indicator of the adsorption capacity of TiO2 while Km is only an indicator of the coverage ratio of TiO2 surface. The modified L-H model has been experimentally verified so it is expected to be used to predict the kinetics of the photocatalytic degradation of gaseous benzene.


Author(s):  
Soojeong Choi ◽  
Tong-Ho Kim ◽  
Henry O. Everitt ◽  
April Brown ◽  
Maria Losurdo ◽  
...  

Author(s):  
Władysław Janusz ◽  
Ewa Skwarek

AbstractThe aim of the study was the basic incidence on the phenomenon of adsorption that occurs at the hydroxyapatite/malic acid interface, leading to a change in the surface properties of hydroxyapatite, Analytical methods used in the research: X-ray diffraction (XRD) as well as by the, adsorption–desorption of nitrogen (ASAP), potentiometric titration. The specific adsorption of malic acid ions at the hydroxyapatite interface was investigated by means of the radioisotope method. The zeta potential of hydroxyapatite dispersions was determined by electrophoresis with Zetasizer Nano ZS90 by Malvern. The particle sizes of hydroxyapatite samples were analyzed using Masteriszer 2000 Malvern. Studies on the kinetics of malic acid on hydroxyapatite from a solution with an initial concentration of 1 mmol/dm3 have shown that the adsorption process is initially fast, followed by a slow adsorption step. An increase in the pH of the solution causes a decrease in the malic acid adsorption as a result of competition with hydroxyl ions. The presence of adsorbed malic acid was confirmed by the FTIR measurements. The effect of malic acid adsorption on the zeta potential and particle size distribution of hydroxyapatite in the NaCl solution was investigated.


Soil Science ◽  
1988 ◽  
Vol 146 (4) ◽  
pp. 221-231 ◽  
Author(s):  
J. J. T. I. BOESTEN ◽  
L. J. T. VAN DER PAS

2019 ◽  
Vol 17 (2) ◽  
pp. 371-380 ◽  
Author(s):  
Mohamed El messoudi ◽  
Aicha Boukhriss ◽  
Omar Cherkaoui ◽  
M’hammed El kouali ◽  
Said Gmouh

Soft Matter ◽  
2019 ◽  
Vol 15 (8) ◽  
pp. 1890-1890 ◽  
Author(s):  
Ivan L. Minkov ◽  
Dimitrinka Arabadzhieva ◽  
Ibrahim E. Salama ◽  
Elena Mileva ◽  
Radomir I. Slavchov

Correction for ‘Barrier kinetics of adsorption–desorption of alcohol monolayers on water under constant surface tension’ by Ivan L. Minkov et al., Soft Matter, 2019, DOI: 10.1039/c8sm02076k.


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