scholarly journals ANTIBONDING STATE AND RELATED PROPERTIES OF Fe-ACCEPT OR IN GaP AND GaAs

1987 ◽  
Vol 36 (11) ◽  
pp. 1481
Author(s):  
HUANG QI-SHENG
Keyword(s):  
Antibonding State

scholarly journals Photoinduced hydrogen release from hydrogen boride sheets

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Reiya Kawamura ◽  
Nguyen Thanh Cuong ◽  
Takeshi Fujita ◽  
Ryota Ishibiki ◽  
Toru Hirabayashi ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Density Functional ◽  
Electron Transition ◽  
Hydrogen Release ◽  
Acetonitrile Solution ◽  
Bandgap Energy ◽  
Ambient Conditions ◽  
Functional Theory ◽  
Antibonding State ◽  
Bonding State

Abstract Hydrogen boride nanosheets (HB sheets) are facilely synthesized via ion-exchange treatment on magnesium diboride (MgB2) in an acetonitrile solution. Optical absorption and fluorescence spectra of HB sheets indicate that their bandgap energy is 2.8 eV. According to first-principles calculations, optical absorption seen at 2.8 eV is assigned to the electron transition between the σ-bonding states of B and H orbitals. In addition, density functional theory (DFT) calculations suggest the other allowed transition from the σ-bonding state of B and H orbitals to the antibonding state with the gap of 3.8 eV. Significant gaseous H2 release is found to occur only under photoirradiation, which causes the electron transition from the σ-bonding state to the antibonding state even under mild ambient conditions. The amount of H2 released from the irradiated HB sheets is estimated to be 8 wt%, indicating that the sheets have a high H2-storage capacity compared with previously reported metal H2-storage materials.

Photo-induced Dissociation and Optical Cross Section of Si-H and S-H Complexes in GaAs and AlGaAs

2002 ◽  
Vol 719 ◽  
Author(s):  
M. Barbé ◽  
F. Bailly ◽  
J. Chevallier ◽  
S. Silvestre ◽  
D. Loridant-Bernard ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Cross Section ◽  
Cross Sections ◽  
Electronic Excitation ◽  
Surface States ◽  
Antibonding State ◽  
Free Carriers ◽  
Bonding State ◽  
Uv Illumination ◽  
Optical Cross Section

AbstractIn GaAs, (Si,H) complexes are efficiently dissociated at 300 K by photons with energies above 3.5 eV. Their optical cross-section is 10-19-10-18 cm2. This dissociation is the result of an electronic excitation of the Si-H bond of the complex from a bonding state to an antibonding state. (Si,H) and (S,H) complexes in AlGaAs alloys are also dissociated under UV illumination with optical cross-sections similar to GaAs. In passivated 2D AlGaAs-GaAs heterostructures, the evolution of the extra sheet carrier concentration at low photon densities presents a loss of free carriers attributed to the filling of surface states. In AlGaAs and in 2D AlGaAs-GaAs heterostructures, the replacement of hydrogen by deuterium in the complexes shows that the (Si,D) and (S,D) complexes are significantly more stable than the (Si,H) and (S,H) complexes as previously found in GaAs:Si,H.

Computational Study of Organometallic Structures for Hydrogen Storage, Effects of Ligands

2009 ◽  
Vol 5 ◽  
pp. 113-119 ◽  
Author(s):  
Arturo I. Martinez
Keyword(s):  
Hydrogen Storage ◽  
Density Functional ◽  
Storage Capacity ◽  
Computational Study ◽  
Density Functional Theory Calculations ◽  
Hydrogen Storage Capacity ◽  
Functional Theory ◽  
Antibonding State ◽  
Storage Effects ◽  
Back Donation

Density functional theory calculations of hydrogen storage capacity for different organometallic structures have been carried out. Complexes involving Sc, Ti and V bound to C4H4, C5H5, C5F5 and B3N3H6 molecules have been considered, and all present a hydrogen storage capability limited by the 18-electron rule. In order to stabilize the complexes, which the 18-electron rule is not completed, additional ligands are considered, namely -H, -CH3, -NH2, -OH and -F. These ligands affect the H2-metal bond; particularly the back donation effect from the metal atom to the * antibonding state of H2 and then its H2 storage capacity.

Bonding–antibonding state transition induces multiple electron modulations toward oxygen reduction reaction electrocatalysis

2020 ◽  
Vol 44 (20) ◽  
pp. 8191-8197
Author(s):  
Qi Zhang ◽  
Haixia Zhong ◽  
Can Chen ◽  
Juexian Cao ◽  
Liwen Yang ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
State Transition ◽  
Reduction Reaction ◽  
Antibonding State ◽  
Bonding State ◽  
Orr Activity ◽  
B Doping

B doping induces the transformation from the bonding state to the antibonding state of an Ni–N bond, resulting in enhanced ORR activity.

Sign in / Sign up

Export Citation Format

Share Document