scholarly journals Facile Fabrication of Macroscopic Self-Standing Ni or Co-doped MnO2 Architectures as Catalysts for Propane Oxidation

Technologies ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 81 ◽  
Author(s):  
Long Chen ◽  
Xiping Song
Keyword(s):  
Hydrothermal Reaction ◽  
Ambient Pressure ◽  
Ambient Pressure Drying ◽  
Propane Oxidation ◽  
Practical Applications ◽  
Catalytic Activities ◽  
Co Doping ◽  
Facile Fabrication ◽  
Co Doped ◽  
Mno2 Nanowires

The fabrication of macroscopic self-standing architectures plays a key role in the practical applications of nanomaterials. A facile strategy to assemble MnO2 nanowires into macroscopic self-standing architectures via hydrothermal reaction followed by ambient pressure drying was developed. The obtained sample was robust and showed excellent mechanical strength with a Young’s modulus of 127 MPa, which had the possibility for practical applications. In order to promote the catalytic activity for propane oxidation, Ni or Co doping into MnO2 was studied. The results showed that the obtained macroscopic self-standing Ni-MnO2 and Co-MnO2 architectures exhibited enhanced catalytic activities for propane oxidation. Specifically, the conversions of propane over Co-MnO2 and Ni-MnO2 samples at 400 °C were 27.3% and 25.7% higher than that over pristine MnO2 sample.

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.

High thermochromic performance of Fe/Mg co-doped VO2 thin films for smart window applications

2018 ◽  
Vol 6 (24) ◽  
pp. 6502-6509 ◽  
Author(s):  
Chunhui Ji ◽  
Zhiming Wu ◽  
Lulu Lu ◽  
Xuefei Wu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
New Method ◽  
Smart Window ◽  
Smart Windows ◽  
Practical Applications ◽  
Co Doping ◽  
Window Applications ◽  
Vo2 Thin Films ◽  
First Time ◽  
Co Doped

A new method, Fe/Mg co-doping, is proposed for the first time to optimize thermochromic VO2 and the promising performance of VO2-based smart windows for practical applications is successfully achieved.

scholarly journals Interior and Exterior Decoration of Transition Metal Oxide Through Cu0/Cu+ Co-Doping Strategy for High-Performance Supercapacitor

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weifeng Liu ◽  
Zhi Zhang ◽  
Yanan Zhang ◽  
Yifan Zheng ◽  
Nishuang Liu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Electrochemical Performance ◽  
Electrode Materials ◽  
Theoretical Calculations ◽  
Synergetic Effect ◽  
Transition Metal Oxide ◽  
Practical Applications ◽  
Co Doping ◽  
Co Doped

AbstractAlthough CoO is a promising electrode material for supercapacitors due to its high theoretical capacitance, the practical applications still suffering from inferior electrochemical activity owing to its low electrical conductivity, poor structural stability and inefficient nanostructure. Herein, we report a novel Cu0/Cu+ co-doped CoO composite with adjustable metallic Cu0 and ion Cu+ via a facile strategy. Through interior (Cu+) and exterior (Cu0) decoration of CoO, the electrochemical performance of CoO electrode has been significantly improved due to both the beneficial flower-like nanostructure and the synergetic effect of Cu0/Cu+ co-doping, which results in a significantly enhanced specific capacitance (695 F g−1 at 1 A g−1) and high cyclic stability (93.4% retention over 10,000 cycles) than pristine CoO. Furthermore, this co-doping strategy is also applicable to other transition metal oxide (NiO) with enhanced electrochemical performance. In addition, an asymmetric hybrid supercapacitor was assembled using the Cu0/Cu+ co-doped CoO electrode and active carbon, which delivers a remarkable maximal energy density (35 Wh kg−1), exceptional power density (16 kW kg−1) and ultralong cycle life (91.5% retention over 10,000 cycles). Theoretical calculations further verify that the co-doping of Cu0/Cu+ can tune the electronic structure of CoO and improve the conductivity and electron transport. This study demonstrates a facile and favorable strategy to enhance the electrochemical performance of transition metal oxide electrode materials.

Preparation of Hydrophobic Silica Aerogels from Industrial Microsilica and its Oil Adsorption Properties

2012 ◽  
Vol 531-532 ◽  
pp. 103-107 ◽  
Author(s):  
Fei Shi ◽  
Jing Xiao Liu ◽  
Xiao Li Dong ◽  
Zhi Wei Zhang ◽  
Peng Cheng Du ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Hydrothermal Reaction ◽  
Ambient Pressure ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Silica Aerogels ◽  
Ambient Pressure Drying ◽  
Mixed Solution ◽  
Hydrophobic Silica ◽  
Oil Adsorption

Hydrophobic silica aerogels were prepared from industrial microsilica via ambient pressure drying. The process consists of two stages, synthesis of sodium silicate solution from microsilica by hydrothermal reaction with sodium hydroxide, and preparation of silica aqueous gel and porous silica aerogels from the obtained sodium silicate solution. The mixed solution of hexane/ethanol/trimethylchlorosilane was used to modify the sol-gel derived silica aqueous gel so as to obtain porous structure by ambient pressure drying. The microstructure, pore properties of the silica aerogels were analyzed by FTIR and N2 adsorption-desorption methods, and the oil adsorption of the synthesized silica aerogels was investigated. The results indicate that the obtained silica aerogels are light-weight and hydrophobic porous materials, with the specific surface area of 767~828 m2•g-1, porosity of 91.5~95.1% and the average pore diameter of 5.22~8.02 nm. The synthesized silica aerogels have good oil adsorption capacity and the highest saturated oil adsorption rate can achieve 1105%.

scholarly journals First-principles study of atomic structure and electronic properties of Si and F doped anatase TiO2

2015 ◽  
Vol 33 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Hongping Li ◽  
Lin Chen ◽  
Shuai Liu ◽  
Changsheng Li ◽  
Jian Meng ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Chemical Doping ◽  
Geometrical Structures ◽  
Practical Applications ◽  
Co Doping ◽  
Si Doped ◽  
Theory Calculation ◽  
Co Doped

Abstract Chemical doping represents one of the most effective ways in engineering electronic structures of anatase TiO2 for practical applications. Here, we investigate formation energies, geometrical structures, and electronic properties of Si-, F-doped and Si/F co-doped anatase TiO2 by using spin-polarized density functional theory calculation. We find that the co-doped TiO2 is thermodynamically more favorable than the Si- and F-doped TiO2- Structural analysis shows that atomic impurity varies crystal constants slightly. Moreover, all the three doped systems show a pronounced narrowing of band gap by 0.33 eV for the F-doped TiO2, 0.17 eV for the Si-doped TiO2, and 0.28 eV for the Si/F-co-doped TiO2, which could account for the experimentally observed redshift of optical absorption edge. Our calculations suggest that the Si/F-co-doping represents an effective way in tailoring electronic structure and optical properties of anatase TiO2.

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

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...

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

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.

Transport mechanisms in Co-doped ZnO (ZCO) and H-irradiated ZCO polycrystalline thin films

2021 ◽  
Vol 23 (3) ◽  
pp. 2368-2376
Author(s):  
A. Di Trolio ◽  
A. Amore Bonapasta ◽  
C. Barone ◽  
A. Leo ◽  
G. Carapella ◽  
...  
Keyword(s):  
Thin Films ◽  
Opposite Effect ◽  
Transport Mechanisms ◽  
Co Doping ◽  
Polycrystalline Thin Films ◽  
Doped Zno ◽  
Co Doped

Co doping increases the ZnO resistivity (ρ) at high T (HT), whereas it has an opposite effect at low T (LT). H balances the Co effects by neutralizing the ρ increase at HT and strengthening its decrease at LT.

Transparent, ultraflexible, and superinsulating nanofibrous biocomposite aerogels via ambient pressure drying

2021 ◽  
Author(s):  
Guoqing Zu ◽  
Sheng Zeng ◽  
Ben Yang ◽  
Jia Huang
Keyword(s):  
Ambient Pressure ◽  
Ambient Pressure Drying ◽  
Oxidized Starch ◽  
Nanofibrous Structure ◽  
First Time ◽  
Highly Porous

We report transparent, flexible, and superinsulating biocomposite aerogels with a homogeneous, highly porous, and nanofibrous structure based on oxidized starch and polyorganosiloxane via facile ambient pressure drying for the first time.

scholarly journals Rapid Fabrication of Monolithic Carbon Aerogels Based on Resorcinol-Formaldehyde by Ambient Pressure Drying

2013 ◽  
Vol 25 (10) ◽  
pp. 5395-5398
Author(s):  
Seung-Kyu Park ◽  
Heon-Chang Kim ◽  
Chang-Sup Oh ◽  
Yong-Ha Kim
Keyword(s):  
Ambient Pressure ◽  
Ambient Pressure Drying ◽  
Carbon Aerogels ◽  
Resorcinol Formaldehyde ◽  
Rapid Fabrication
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