Density functional calculation of the infrared spectrum of surface hydroxyl groups on goethite ( -FeOOH)

2010 ◽  
Vol 95 (2-3) ◽  
pp. 414-417 ◽  
Author(s):  
J. R. Rustad ◽  
J.-F. Boily
Keyword(s):  
Infrared Spectrum ◽  
Density Functional ◽  
Hydroxyl Groups ◽  
Density Functional Calculation ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

Infrared spectra in the Ag2O-CO2-Ag2CO3 system

1966 ◽  
Vol 19 (5) ◽  
pp. 715 ◽  
Author(s):  
JA Allen ◽  
PH Scaife
Keyword(s):  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Silver Oxide ◽  
Broad Band ◽  
Hydroxyl Groups ◽  
Silver Carbonate ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

The infrared spectrum of silver oxide, Ag2O, has been clarified by comparison with that of silver carbonate. In the region 4000-400 cm-l the spectrum consists of one broad band centred around 530 cm-l, other bands being accounted for in terms of normal, basic, and complex carbonates and surface hydroxyl groups, which are frequently present as contaminants. Conditions for the preparation, storage, and purification of silver oxide to minimize carbonate contamination are defined.

Chemical Stability of 2D-Nanostructured WO3 in Hydrogen Sensing Under Varied Operation Temperature

NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650092 ◽  
Author(s):  
Taisheng Yang ◽  
Hui Tian ◽  
Yue Zhang ◽  
Chen Li
Keyword(s):  
Water Molecule ◽  
Chemical Stability ◽  
Density Functional ◽  
Stable State ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Hydrogen Sensing ◽  
Operation Temperature ◽  
Surface Hydroxyl Groups

Nanostructured metal oxide-based resistive-type gas sensors are of high research interest. Chemical stability is the most critical issue due to the surface electron species and density. In the present paper, 2D-nanostructured WO3 was prepared and characterized, and a WO3-based sensor was fabricated and analyzed. The results showed that the synthesized WO3 material exhibited nanosheet structure, and during hydrogen sensing testing, the current baseline shifted with various tendencies, even completely opposite directions under different operation temperatures. The chemistry analysis results indicated that water molecule and hydroxyl group were formed under low operation temperature but further oxidation occurred at higher temperatures. The adsorption of H2 on oxygen terminated WO3(0 0 1) surfaces by density functional theory (DFT) method indicated that a water molecule formed by adsorption of a hydrogen molecule at the O site with the most thermodynamically stable state, and two surface hydroxyl groups formed by dissociative adsorption with a thermodynamically less stable state. The water molecule and surface hydroxyl groups increased the conductivity of the WO3 film while that was decreased as the oxidation occurred.

The synthesis and structure of silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complexes

1986 ◽  
Vol 51 (7) ◽  
pp. 1430-1438 ◽  
Author(s):  
Alena Reissová ◽  
Zdeněk Bastl ◽  
Martin Čapka
Keyword(s):  
Free Surface ◽  
Hydroxyl Groups ◽  
Titanium Complex ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Free Hydroxyl ◽  
Cyclopentadienyl Anion

The title complexes have been obtained by functionalization of silica with cyclopentadienylsilanes of the type Rx(CH3)3 - xSi(CH2)nC5H5 (x = 1-3, n = 0, 1, 3), trimethylsilylation of free surface hydroxyl groups, transformation of the bonded cyclopentadienyl group to the cyclopentadienyl anion, followed by coordination of (h5-cyclopentadienyl)trichlorotitanium. The effects of single steps of the above immobilization on texture of the support, the number of free hydroxyl groups, the coverage of the surface by cyclopentadienyl groups and the degree of their utilization in anchoring the titanium complex have been investigated. ESCA study has shown that the above anchoring leads to formation of the silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complex.

Controllable synthesis of phosphate-modified BiPO4 nanorods with high photocatalytic activity: surface hydroxyl groups concentrations effects

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99712-99721 ◽  
Author(s):  
Yan Li ◽  
Yawen Wang ◽  
Yu Huang ◽  
Junji Cao ◽  
Wingkei Ho ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Surface Modification ◽  
Photocatalytic Performance ◽  
High Photocatalytic Activity ◽  
Hydroxyl Groups ◽  
Controllable Synthesis ◽  
Surface Hydroxyl ◽  
Methylene Orange ◽  
Surface Hydroxyl Groups

Surface modification by phosphate efficiently improves the photocatalytic performance of BiPO4 for the degradation of methylene orange (MO), by enhancing the concentration of surface hydroxyl groups and improving its hydrophilicity.

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