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High-Performance Stable Field Emission with Ultralow Turn on Voltage from rGO Conformal Coated TiO2 Nanotubes 3D Arrays.

Agrawal Y, Kedawat G, Kumar P, Dwivedi J, Singh VN, Gupta RK, Gupta BK - Sci Rep (2015)

Bottom Line: A facile method to produce conformal coated reduced graphene oxide (rGO) on vertically aligned titanium oxide (TiO2) nanotubes three dimensional (3D) arrays (NTAs) is demonstrated for enhanced field emission display applications.Moreover, these enhancements observed in nano arrays attribute to the contribution of low work function with non-rectifying barriers, which allow an easy injection of electrons from the conduction band of TiO2 into the Fermi level of reduced graphene oxide under external electric field.The obtained results are extremely advantageous for its potential application in field emission devices.

View Article: PubMed Central - PubMed

Affiliation: CSIR - National Physical Laboratory, Dr K S Krishnan Road, New Delhi, 110012, India.

ABSTRACT
A facile method to produce conformal coated reduced graphene oxide (rGO) on vertically aligned titanium oxide (TiO2) nanotubes three dimensional (3D) arrays (NTAs) is demonstrated for enhanced field emission display applications. These engineered nano arrays exhibit efficient electron field emission properties such as high field emission current density (80 mA/cm(2)), low turn-on field (1.0 V/μm) and field enhancement factor (6000) with high emission current stability. Moreover, these enhancements observed in nano arrays attribute to the contribution of low work function with non-rectifying barriers, which allow an easy injection of electrons from the conduction band of TiO2 into the Fermi level of reduced graphene oxide under external electric field. The obtained results are extremely advantageous for its potential application in field emission devices.

No MeSH data available.


The synthesis process for highly oriented architecture of TiO2NTAs via anodization technique with conformal coating of rGO on highly orientedannealed TiO2 3D NTAs samples (40 V, 4 hours,500 °C).
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f1: The synthesis process for highly oriented architecture of TiO2NTAs via anodization technique with conformal coating of rGO on highly orientedannealed TiO2 3D NTAs samples (40 V, 4 hours,500 °C).

Mentions: Herein, we report an approach to develop rGO-TiO2 NTAs hybrid nanostructuresas efficient field emitters. In the investigations, vertically aligned TiO2NTAs were grown on titanium (Ti) substrates via anodic oxidation method and thenconformal coating of rGO was transfer onto TiO2 NTAs. It shows much improvedFE properties than those obtained from pure TiO2 NTAs and rGO nanostructures.The morphology, dimensions and structural parameters of TiO2 NTAs are easilycontrolled by anodic oxidation parameters such as anodic voltage, oxidation time andelectrolyte composition383940. An anodic oxidation process has beenused extensively for the rapid production of aligned TiO2 nanotubes becauseit has a good controlled pore size, uniformity and conformability over large areas. Thisis a facile process at economic cost and the desired properties can easily be obtainedby tuning the dimensions. Moreover, in the present method, TiO2 nanotube hasbeen formed on Ti sheet with a chemical bond between the oxide and Ti sheet.TiO2 nanotubes are strongly attached with Ti substrate, which providesconvenience for TiO2 reusability. The field emission properties ofTiO2 NTAs were investigated before and after being modified with rGOconformal coating and it was found that rGO conformal coated TiO2 NTAs havelow turn-on field, high current density and uniform emission with better stability overa large area as compared to as-synthesized TiO2 NTAs. It is beingdemonstrated here that the incorporation of rGO through conformal coating onTiO2 NTAs greatly facilitates large surface area and charge carrierdynamics and improves the FE performance compared to other nanostructures such ascommercial TiO2 nanoparticles (NPs), as-synthesized TiO2 NTAs andannealed TiO2 NTAs samples, which is not reported so far. The schematicpresentation of synthesis process for highly oriented architecture of TiO2NTAs via anodization technique with conformal coating of rGO on highly oriented annealedTiO2 3D NTAs samples (40 V, 4 hours,500 °C) is shown in Fig. 1.


High-Performance Stable Field Emission with Ultralow Turn on Voltage from rGO Conformal Coated TiO2 Nanotubes 3D Arrays.

Agrawal Y, Kedawat G, Kumar P, Dwivedi J, Singh VN, Gupta RK, Gupta BK - Sci Rep (2015)

The synthesis process for highly oriented architecture of TiO2NTAs via anodization technique with conformal coating of rGO on highly orientedannealed TiO2 3D NTAs samples (40 V, 4 hours,500 °C).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495390&req=5

f1: The synthesis process for highly oriented architecture of TiO2NTAs via anodization technique with conformal coating of rGO on highly orientedannealed TiO2 3D NTAs samples (40 V, 4 hours,500 °C).
Mentions: Herein, we report an approach to develop rGO-TiO2 NTAs hybrid nanostructuresas efficient field emitters. In the investigations, vertically aligned TiO2NTAs were grown on titanium (Ti) substrates via anodic oxidation method and thenconformal coating of rGO was transfer onto TiO2 NTAs. It shows much improvedFE properties than those obtained from pure TiO2 NTAs and rGO nanostructures.The morphology, dimensions and structural parameters of TiO2 NTAs are easilycontrolled by anodic oxidation parameters such as anodic voltage, oxidation time andelectrolyte composition383940. An anodic oxidation process has beenused extensively for the rapid production of aligned TiO2 nanotubes becauseit has a good controlled pore size, uniformity and conformability over large areas. Thisis a facile process at economic cost and the desired properties can easily be obtainedby tuning the dimensions. Moreover, in the present method, TiO2 nanotube hasbeen formed on Ti sheet with a chemical bond between the oxide and Ti sheet.TiO2 nanotubes are strongly attached with Ti substrate, which providesconvenience for TiO2 reusability. The field emission properties ofTiO2 NTAs were investigated before and after being modified with rGOconformal coating and it was found that rGO conformal coated TiO2 NTAs havelow turn-on field, high current density and uniform emission with better stability overa large area as compared to as-synthesized TiO2 NTAs. It is beingdemonstrated here that the incorporation of rGO through conformal coating onTiO2 NTAs greatly facilitates large surface area and charge carrierdynamics and improves the FE performance compared to other nanostructures such ascommercial TiO2 nanoparticles (NPs), as-synthesized TiO2 NTAs andannealed TiO2 NTAs samples, which is not reported so far. The schematicpresentation of synthesis process for highly oriented architecture of TiO2NTAs via anodization technique with conformal coating of rGO on highly oriented annealedTiO2 3D NTAs samples (40 V, 4 hours,500 °C) is shown in Fig. 1.

Bottom Line: A facile method to produce conformal coated reduced graphene oxide (rGO) on vertically aligned titanium oxide (TiO2) nanotubes three dimensional (3D) arrays (NTAs) is demonstrated for enhanced field emission display applications.Moreover, these enhancements observed in nano arrays attribute to the contribution of low work function with non-rectifying barriers, which allow an easy injection of electrons from the conduction band of TiO2 into the Fermi level of reduced graphene oxide under external electric field.The obtained results are extremely advantageous for its potential application in field emission devices.

View Article: PubMed Central - PubMed

Affiliation: CSIR - National Physical Laboratory, Dr K S Krishnan Road, New Delhi, 110012, India.

ABSTRACT
A facile method to produce conformal coated reduced graphene oxide (rGO) on vertically aligned titanium oxide (TiO2) nanotubes three dimensional (3D) arrays (NTAs) is demonstrated for enhanced field emission display applications. These engineered nano arrays exhibit efficient electron field emission properties such as high field emission current density (80 mA/cm(2)), low turn-on field (1.0 V/μm) and field enhancement factor (6000) with high emission current stability. Moreover, these enhancements observed in nano arrays attribute to the contribution of low work function with non-rectifying barriers, which allow an easy injection of electrons from the conduction band of TiO2 into the Fermi level of reduced graphene oxide under external electric field. The obtained results are extremely advantageous for its potential application in field emission devices.

No MeSH data available.