Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy
Laser reduction of graphene oxide (GO) offers unique opportunities for the rapid, nonchemical production of graphene. By tuning relevant reduction parameters, the band gap and conductivity of reduced GO can be precisely controlled. In situ monitoring of single layer GO reduction is therefore essenti...
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15306984_v14_n6_p3172_Sokolov http://hdl.handle.net/20.500.12110/paper_15306984_v14_n6_p3172_Sokolov |
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paper:paper_15306984_v14_n6_p3172_Sokolov2025-07-30T18:55:28Z Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy Hodak, Jose Hector absorption absorption coefficient emission Graphene oxide photolysis reduced graphene oxide Absorption Activation energy Neutron emission Photolysis Rate constants Absorption and emissions Absorption co-efficient Graphene oxides Nonchemical production Photoreduction mechanisms Reduced graphene oxides Spatial heterogeneity Two-dimensional materials Graphene Laser reduction of graphene oxide (GO) offers unique opportunities for the rapid, nonchemical production of graphene. By tuning relevant reduction parameters, the band gap and conductivity of reduced GO can be precisely controlled. In situ monitoring of single layer GO reduction is therefore essential. In this report, we show the direct observation of laser-induced, single layer GO reduction through correlated changes to its absorption and emission. Absorption/emission movies illustrate the initial stages of single layer GO reduction, its transition to reduced-GO (rGO) as well as its subsequent decomposition upon prolonged laser illumination. These studies reveal GO's photoreduction life cycle and through it native GO/rGO absorption coefficients, their intrasheet distributions as well as their spatial heterogeneities. Extracted absorption coefficients for unreduced GO are α405 nm ≈ 6.5 ± 1.1 × 104 cm-1, α 520 nm ≈ 2.1 ± 0.4 × 104 cm-1, and α640 nm ≈ 1.1 ± 0.3 × 104 cm-1 while corresponding rGO α-values are α 405 nm ≈ 21.6 ± 0.6 × 104 cm-1, α520 nm ≈ 16.9 ± 0.4 × 104 cm -1, and α640 nm ≈ 14.5 ± 0.4 × 104 cm-1. More importantly, the correlated absorption/emission imaging provides us with unprecedented insight into GO's underlying photoreduction mechanism, given our ability to spatially resolve its kinetics and to connect local rate constants to activation energies. On a broader level, the developed absorption imaging is general and can be applied toward investigating the optical properties of other two-dimensional materials, especially those that are nonemissive and are invisible to current single molecule optical techniques. © 2014 American Chemical Society. Fil:Hodak, J.H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2014 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15306984_v14_n6_p3172_Sokolov http://hdl.handle.net/20.500.12110/paper_15306984_v14_n6_p3172_Sokolov |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
absorption absorption coefficient emission Graphene oxide photolysis reduced graphene oxide Absorption Activation energy Neutron emission Photolysis Rate constants Absorption and emissions Absorption co-efficient Graphene oxides Nonchemical production Photoreduction mechanisms Reduced graphene oxides Spatial heterogeneity Two-dimensional materials Graphene |
| spellingShingle |
absorption absorption coefficient emission Graphene oxide photolysis reduced graphene oxide Absorption Activation energy Neutron emission Photolysis Rate constants Absorption and emissions Absorption co-efficient Graphene oxides Nonchemical production Photoreduction mechanisms Reduced graphene oxides Spatial heterogeneity Two-dimensional materials Graphene Hodak, Jose Hector Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy |
| topic_facet |
absorption absorption coefficient emission Graphene oxide photolysis reduced graphene oxide Absorption Activation energy Neutron emission Photolysis Rate constants Absorption and emissions Absorption co-efficient Graphene oxides Nonchemical production Photoreduction mechanisms Reduced graphene oxides Spatial heterogeneity Two-dimensional materials Graphene |
| description |
Laser reduction of graphene oxide (GO) offers unique opportunities for the rapid, nonchemical production of graphene. By tuning relevant reduction parameters, the band gap and conductivity of reduced GO can be precisely controlled. In situ monitoring of single layer GO reduction is therefore essential. In this report, we show the direct observation of laser-induced, single layer GO reduction through correlated changes to its absorption and emission. Absorption/emission movies illustrate the initial stages of single layer GO reduction, its transition to reduced-GO (rGO) as well as its subsequent decomposition upon prolonged laser illumination. These studies reveal GO's photoreduction life cycle and through it native GO/rGO absorption coefficients, their intrasheet distributions as well as their spatial heterogeneities. Extracted absorption coefficients for unreduced GO are α405 nm ≈ 6.5 ± 1.1 × 104 cm-1, α 520 nm ≈ 2.1 ± 0.4 × 104 cm-1, and α640 nm ≈ 1.1 ± 0.3 × 104 cm-1 while corresponding rGO α-values are α 405 nm ≈ 21.6 ± 0.6 × 104 cm-1, α520 nm ≈ 16.9 ± 0.4 × 104 cm -1, and α640 nm ≈ 14.5 ± 0.4 × 104 cm-1. More importantly, the correlated absorption/emission imaging provides us with unprecedented insight into GO's underlying photoreduction mechanism, given our ability to spatially resolve its kinetics and to connect local rate constants to activation energies. On a broader level, the developed absorption imaging is general and can be applied toward investigating the optical properties of other two-dimensional materials, especially those that are nonemissive and are invisible to current single molecule optical techniques. © 2014 American Chemical Society. |
| author |
Hodak, Jose Hector |
| author_facet |
Hodak, Jose Hector |
| author_sort |
Hodak, Jose Hector |
| title |
Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy |
| title_short |
Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy |
| title_full |
Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy |
| title_fullStr |
Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy |
| title_full_unstemmed |
Direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy |
| title_sort |
direct observation of single layer graphene oxide reduction through spatially resolved, single sheet absorption/emission microscopy |
| publishDate |
2014 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15306984_v14_n6_p3172_Sokolov http://hdl.handle.net/20.500.12110/paper_15306984_v14_n6_p3172_Sokolov |
| work_keys_str_mv |
AT hodakjosehector directobservationofsinglelayergrapheneoxidereductionthroughspatiallyresolvedsinglesheetabsorptionemissionmicroscopy |
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1840327266025865216 |