scholarly journals The Effects of Crystal Structure and Electronic Structure on Photocatalytic H2 Evolution and CO2 Reduction over Two Phases of Perovskite-Structured NaNbO3

2012 ◽  
Vol 116 (14) ◽  
pp. 7621-7628 ◽  
Author(s):  
Peng Li ◽  
Shuxin Ouyang ◽  
Guangcheng Xi ◽  
Tetsuya Kako ◽  
Jinhua Ye
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Co2 Reduction ◽  
H2 Evolution ◽  
Two Phases ◽  
Photocatalytic H2 Evolution

Facile fabrication of oxygen and carbon co-doped carbon nitride nanosheets for efficient visible light photocatalytic H2 evolution and CO2 reduction

2019 ◽  
Vol 48 (32) ◽  
pp. 12070-12079 ◽  
Author(s):  
Shipeng Wan ◽  
Man Ou ◽  
Xinming Wang ◽  
Yanan Wang ◽  
Yiqing Zeng ◽  
...  
Keyword(s):  
Carbon Nitride ◽  
Co2 Reduction ◽  
Mechanistic Study ◽  
H2 Evolution ◽  
Co Doping ◽  
Facile Fabrication ◽  
Carbon Nitride Nanosheets ◽  
Co Doped ◽  
Photocatalytic H2 Evolution ◽  
Visible Light Photocatalytic

C3N4 nanosheets with oxygen and carbon co-doping were successfully designed for H2 evolution and CO2 reduction. A mechanistic study was also performed.

scholarly journals Photocatalytic H2 Evolution, CO2 Reduction, and NOx Oxidation by Highly Exfoliated g-C3N4

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1147
Author(s):  
Nadia Todorova ◽  
Ilias Papailias ◽  
Tatiana Giannakopoulou ◽  
Nikolaos Ioannidis ◽  
Nikos Boukos ◽  
...  
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Co2 Reduction ◽  
H2 Production ◽  
Thermal Treatments ◽  
H2 Evolution ◽  
Photocatalytic H2 Evolution

g-C3N4, with specific surface area up to 513 m2/g, was prepared via three successive thermal treatments at 550 °C in air with gradual precursor mass decrease. The obtained bulk and exfoliated (1ex, 2ex and 3ex) g-C3N4 were characterized and tested as photocatalysts for H2 production, CO2 reduction and NOx oxidation. The exfoliated samples demonstrated graphene-like morphology with detached (2ex) and sponge-like framework (3ex) of layers. The surface area increased drastically from 20 m2/g (bulk) to 513 m2/g (3ex). The band gap (Eg) increased gradually from 2.70 to 3.04 eV. Superoxide radicals (·O2−) were mainly formed under UV and visible light. In comparison to the bulk, the exfoliated g-C3N4 demonstrated significant increase in H2 evolution (~6 times), CO2 reduction (~3 times) and NOx oxidation (~4 times) under UV light. Despite the Eg widening, the photocatalytic performance of the exfoliated g-C3N4 under visible light was improved too. The results were related to the large surface area and low e−-h+ recombination. The highly exfoliated g-C3N4 demonstrated selectivity towards H2 evolution reactions.

scholarly journals Reversible structure manipulation by tuning carrier concentration in metastable Cu2S

2017 ◽  
Vol 114 (37) ◽  
pp. 9832-9837 ◽  
Author(s):  
Jing Tao ◽  
Jingyi Chen ◽  
Jun Li ◽  
Leanne Mathurin ◽  
Jin-Cheng Zheng ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electronic Structure ◽  
Material Properties ◽  
Driving Force ◽  
The Other ◽  
Charge Generation ◽  
Control Material ◽  
Two Phases ◽  
Induced Changes

The optimal functionalities of materials often appear at phase transitions involving simultaneous changes in the electronic structure and the symmetry of the underlying lattice. It is experimentally challenging to disentangle which of the two effects––electronic or structural––is the driving force for the phase transition and to use the mechanism to control material properties. Here we report the concurrent pumping and probing of Cu2S nanoplates using an electron beam to directly manipulate the transition between two phases with distinctly different crystal symmetries and charge-carrier concentrations, and show that the transition is the result of charge generation for one phase and charge depletion for the other. We demonstrate that this manipulation is fully reversible and nonthermal in nature. Our observations reveal a phase-transition pathway in materials, where electron-induced changes in the electronic structure can lead to a macroscopic reconstruction of the crystal structure.

Improved Photocatalytic H2 Evolution from Inorganic/Organic Sacrificial Solution over Ni-Doped (CuIn)0.2Zn1.6S2 Photocatalysts

2011 ◽  
Vol 1326 ◽  
Author(s):  
Xianghui Zhang ◽  
Dengwei Jing ◽  
Liejin Guo
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Hydrothermal Method ◽  
H2 Evolution ◽  
Doping Amount ◽  
Ni Doping ◽  
Sem Images ◽  
Xrd Pattern ◽  
Environmental Friendly ◽  
Photocatalytic H2 Evolution

ABSTRACTThe Ni-doped (CuIn)0.2Zn1.6S2 photocatalysts were prepared via a two-step ultrasonic-hydrothermal method under an environmental-friendly condition. XRD pattern profiles suggested that Ni2+ successfully doped into (CuIn)0.2Zn1.6S2 lattice. UV-Vis spectra indicated that the optical properties of the photocatalysts greatly depended on the amount of Ni doped. SEM images show that the samples were microspheres. The microsphere structures were gradually damaged with the increment of Ni doping amount. The photoactivity of (CuIn)0.2Zn1.6S2 was enhanced when Ni2+ was doped into the crystal structure. The H2 evolution performance over the prepared samples from inorganic/organic sacrificial solution was systematic investigated.

Tuning the interfacial electronic structure via Au clusters for boosting photocatalytic H2 evolution

2021 ◽  
Author(s):  
Wenhui Feng ◽  
Yanhua Lei ◽  
Xishuang Wu ◽  
Jie Yuan ◽  
Jianhong Chen ◽  
...  
Keyword(s):  
Electronic Structure ◽  
H2 Evolution ◽  
Au Clusters ◽  
Interfacial Electronic Structure ◽  
Photocatalytic H2 Evolution

Gold (Au) clusters are arranged at the interface of Zn0.5Cd0.5S and Mo2C, achieving (Mo2C/Au)@Zn0.5Cd0.5S configuration, where numerous Au-mediated link points can serve as multifunctional mediators for boosting photocatalytic H2 production.

Structural/Property Relationships for Optical Materials

1993 ◽  
Vol 329 ◽  
Author(s):  
Vivien D.
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Electronic Structure ◽  
Chemical Composition ◽  
Field Strength ◽  
Optical Materials ◽  
Site Occupancy ◽  
Laser Materials ◽  
Crystal Field Strength ◽  
The Matrix

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.

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