Role of Sodium Ion on TiO2 Photocatalyst: Influencing Crystallographic Properties or Serving as the Recombination Center of Charge Carriers?

2016 ◽  
Vol 120 (19) ◽  
pp. 10390-10399 ◽  
Author(s):  
Huan Xie ◽  
Neng Li ◽  
Baoshun Liu ◽  
Jingjing Yang ◽  
Xiujian Zhao
1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.


2021 ◽  
Vol 23 (3) ◽  
pp. 2038-2045
Author(s):  
Kyoungmin Min ◽  
Young-Han Shin

Prevention of the degradation of sodium-based layered cathode materials is the key to developing high-performance and high-stability sodium-ion batteries.


2009 ◽  
Vol 24 (08n09) ◽  
pp. 1721-1742 ◽  
Author(s):  
V. M. MOSTEPANENKO ◽  
R. S. DECCA ◽  
E. FISCHBACH ◽  
B. GEYER ◽  
G. L. KLIMCHITSKAYA ◽  
...  

The Lifshitz theory of dispersion forces leads to thermodynamic and experimental inconsistencies when the role of drifting charge carriers is included in the model of the dielectric response. Recently modified reflection coefficients were suggested that take into account screening effects and diffusion currents. We demonstrate that this theoretical approach leads to a violation of the third law of thermodynamics (Nernst's heat theorem) for a wide class of materials and is excluded by the data from two recent experiments. The physical reason for its failure is explained by the violation of thermal equilibrium, which is the fundamental applicability condition of the Lifshitz theory, in the presence of drift and diffusion currents.


2017 ◽  
Vol 23 (63) ◽  
pp. 15991-15996 ◽  
Author(s):  
Yang Liu ◽  
Gangya Wei ◽  
Mengyue Ma ◽  
Yun Qiao

1980 ◽  
Vol 21 (2) ◽  
pp. 123
Author(s):  
Yang Saeng Park ◽  
Seung Mook Lee
Keyword(s):  

2007 ◽  
Vol 60 (7) ◽  
pp. 457 ◽  
Author(s):  
Joel van Embden ◽  
Jacek Jasieniak ◽  
Daniel E. Gómez ◽  
Paul Mulvaney ◽  
Michael Giersig

Passivation of CdSe semiconductor nanocrystals can be achieved by overcoating the particles with a homogeneous shell of a second semiconductor. Shell layers are grown in monolayer steps to ensure homogeneous growth of the shell. The relative band edges of the two materials determine the photoreactiveity of the resultant core-shell nanocrystals. The critical role of ligands in minimizing nucleation of the shell material during the growth of the passivating layer is emphasized. The delocalization of charge carriers into the shell layers can be followed spectroscopically during the growth processes. The relative spectral shifts are directly correlated to the relative energies of the band edges.


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