Role of hydrogen co-doping on opto-electronic behaviors of Na-H co-doped zinc oxide: a first principle study

Elements doping is a powerful way to alter the electronic structure and enhancing the photo catalytic activity of materials by relaxing the surrounding chemical bonds and forming new chemical bond. In this work, we have performed, the first principle density functional theory calculations to investigate the geometric, electronic and optical properties of pristine, Na-doped and P-doped as well as Na and P (Na/P) co-doped heptazine based monolayer graphitic carbon nitride (g-C3N4). The co-doping process results in significantly narrow band gap of g-C3N4. The optical absorption shows better visible-light response compare to pristine g-C3N4. After doping the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) show strong delocalization and indicates photo generated electron/hole (e-/h+) pair disunion abilities of doped systems are superior than pristine heptazine based monolayer g-C3N4. Thus the co-doping with Na and P elements is an effective technique to boost the photocatalytic performance of heptazine based monolayer g-C3N4.

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First-principles Calculation of the Electronic Structure and Optical Properties of ZnO Co-doped with Nb and Ta

Materials Science ◽

10.5755/j01.ms.25.3.19956 ◽

2019 ◽

Vol 25 (3) ◽

pp. 238-245 ◽

Cited By ~ 1

Author(s):

Jinpeng WANG ◽

Tao SHEN ◽

Hongchen LIU

Keyword(s):

Optical Properties ◽

Electronic Structure ◽

First Principles ◽

First Principles Calculation ◽

Ultraviolet Region ◽

First Principle ◽

Co Doping ◽

First Principle Calculations ◽

Function Loss ◽

Co Doped

First-principle calculations have been performed to investigate the electronic structure and optical properties of ZnO co-doped with Nb and Ta. The three doping structures are set to: Zn0.9375Nb0.0625O, Zn0.9375Ta0.0625O and Zn0.875Nb0.0625Ta0.0625O. The experiments show that co-doping with Nb and Ta narrows the band gap. And it causes the Fermi level to shift upwards and enter the conduction band, while enhancing the conductivity of the doped system. In addition, it has been determined that the dielectric imaginary part of the dopant system is larger than that of the pure ZnO in the low energy region. The absorption side of the dopant system, on the other hand, exhibits a redshift. Furthermore, the transmittance of the ultraviolet region is significantly increased, and the function loss spectrum appears to redshift. This will provide a good theoretical basis for the study and the applications of photoelectric materials co-doped with Nb and Ta. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19956

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Surface Rumpling Behavior of Hf/Zr Single-Doped and Co-Doped β-NiAl Coatings during High-Temperature Cyclic Oxidation

Coatings ◽

10.3390/coatings10090874 ◽

2020 ◽

Vol 10 (9) ◽

pp. 874

Author(s):

Shixing Wang ◽

Jian He ◽

Honghai Song ◽

Sijia Liang ◽

Hui Peng ◽

...

Keyword(s):

Phase Transformation ◽

Vapor Deposition ◽

Physical Vapor Deposition ◽

Cyclic Oxidation ◽

Protective Coatings ◽

Thermal Expansion Mismatch ◽

Promising Candidate ◽

Co Doping ◽

Co Doped

Reactive elements like Hf- and Zr-doped β-NiAl are considered to be promising candidate materials for protective coatings used at ultra-high temperatures. However, the role of reactive element co-doping on cyclic oxidation behavior and the surface rumpling of β-NiAl coatings remains unclear. Thus, in this paper, Hf and Zr single-doped and co-doped β-NiAl coatings were deposited on a single crystal superalloy by electron beam physical vapor deposition and the cyclic oxidation at 1150 °C was investigated. The coatings yielded a similar oxidation rate during cyclic oxidation. Obvious surface rumpling appeared in the single-doped coatings, whereas it was effectively alleviated in the co-doped coating. Related mechanisms were discussed, including thermal expansion mismatch, martensitic transformation and phase transformation from β-NiAl to γ′-Ni3Al. The non-uniform phase transformation from β to γ′ was finally believed to be responsible for the discrepancy in the rumpling extents between the single-doped and co-doped coatings.

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Freedom and Responsibility in Neoplatonist Thought

10.1093/oso/9780198824831.001.0001 ◽

2020 ◽

Author(s):

Ursula Coope

Keyword(s):

First Principle ◽

Human Beings ◽

Human Soul ◽

The One ◽

Freedom And Responsibility

The Neoplatonists have a perfectionist view of freedom: an entity is free to the extent that it succeeds in making itself good. Free entities are wholly in control of themselves: they are self-determining, self-constituting, and self-knowing. Neoplatonist philosophers argue that such freedom is only possible for nonbodily things. The human soul is free insofar as it rises above bodily things and engages in intellection, but when it turns its desires to bodily things, it is drawn under the sway of fate and becomes enslaved. This book discusses this notion of freedom, and its relation to questions about responsibility. It explains the important role of notions of self-reflexivity in Neoplatonist accounts of both freedom and responsibility. Part I sets out the puzzles Neoplatonist philosophers face about freedom and responsibility and explains how these puzzles arise from earlier discussions. Part II looks at the metaphysical underpinnings of the Neoplatonist notion of freedom (concentrating especially on the views of Plotinus and Proclus). In what sense (if any) is the ultimate first principle of everything (the One) free? If everything else is under this ultimate first principle, how can anything other than the One be free? What is the connection between freedom and nonbodiliness? Part III looks at questions about responsibility, arising from this perfectionist view of freedom. Why are human beings responsible for their behaviour, in a way that other animals are not? If we are enslaved when we act viciously, how can we be to blame for our vicious actions and choices?

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Promoting Hydrogen Evolution of g-C3N4 Based Photocatalyst by Indium and Phosphorus Co-doping

New Journal of Chemistry ◽

10.1039/d1nj00585e ◽

2021 ◽

Author(s):

Xiao-Hang Yang ◽

Chi Cao ◽

Zilong Guo ◽

Xiaoyu Zhang ◽

Yaxin Wang ◽

...

Keyword(s):

Hydrogen Evolution ◽

Post Treatment ◽

Experimental Results ◽

Indium Chloride ◽

Co Doping ◽

In Situ Copolymerization ◽

Co Doped

Indium and phosphorus co-doped g-C3N4 photocatalyst (In,P-g-C3N4) was prepared by K2HPO4 post-treatment of indium doped g-C3N4 photocatalyst (In-g-C3N4) derived from in-situ copolymerization of dicyandiamide and indium chloride. The experimental results...

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Synthesis of Zinc Oxide Nanostructures Growth by the role of pH variation

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/596/1/012040 ◽

2020 ◽

Vol 596 ◽

pp. 012040

Author(s):

Arlina Ali ◽

Mahani Yusoff ◽

An’amt Mohamed Noor ◽

Pao Ter Teo ◽

Sarizam Mamat ◽

...

Keyword(s):

Zinc Oxide ◽

Zinc Oxide Nanostructures ◽

Ph Variation ◽

Oxide Nanostructures

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Cobalt-doped bioceramic scaffolds fabricated by 3D printing show enhanced osteogenic and angiogenic properties for bone repair

BioMedical Engineering OnLine ◽

10.1186/s12938-021-00907-2 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Jungang Li ◽

Chaoqian Zhao ◽

Chun Liu ◽

Zhenyu Wang ◽

Zeming Ling ◽

...

Keyword(s):

Compressive Strength ◽

3D Printing ◽

Bone Regeneration ◽

Doping Concentration ◽

Artificial Bone ◽

Bone Defect Repair ◽

Co Doping ◽

Defect Repair ◽

Co Doped

Abstract Background The bone regeneration of artificial bone grafts is still in need of a breakthrough to improve the processes of bone defect repair. Artificial bone grafts should be modified to enable angiogenesis and thus improve osteogenesis. We have previously revealed that crystalline Ca10Li(PO4)7 (CLP) possesses higher compressive strength and better biocompatibility than that of pure beta-tricalcium phosphate (β-TCP). In this work, we explored the possibility of cobalt (Co), known for mimicking hypoxia, doped into CLP to promote osteogenesis and angiogenesis. Methods We designed and manufactured porous scaffolds by doping CLP with various concentrations of Co (0, 0.1, 0.25, 0.5, and 1 mol%) and using 3D printing techniques. The crystal phase, surface morphology, compressive strength, in vitro degradation, and mineralization properties of Co-doped and -undoped CLP scaffolds were investigated. Next, we investigated the biocompatibility and effects of Co-doped and -undoped samples on osteogenic and angiogenic properties in vitro and on bone regeneration in rat cranium defects. Results With increasing Co-doping level, the compressive strength of Co-doped CLP scaffolds decreased in comparison with that of undoped CLP scaffolds, especially when the Co-doping concentration increased to 1 mol%. Co-doped CLP scaffolds possessed excellent degradation properties compared with those of undoped CLP scaffolds. The (0.1, 0.25, 0.5 mol%) Co-doped CLP scaffolds had mineralization properties similar to those of undoped CLP scaffolds, whereas the 1 mol% Co-doped CLP scaffolds shown no mineralization changes. Furthermore, compared with undoped scaffolds, Co-doped CLP scaffolds possessed excellent biocompatibility and prominent osteogenic and angiogenic properties in vitro, notably when the doping concentration was 0.25 mol%. After 8 weeks of implantation, 0.25 mol% Co-doped scaffolds had markedly enhanced bone regeneration at the defect site compared with that of the undoped scaffold. Conclusion In summary, CLP doped with 0.25 mol% Co2+ ions is a prospective method to enhance osteogenic and angiogenic properties, thus promoting bone regeneration in bone defect repair.

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