Substrate and buffer layer effect on the structural and optical properties of graphene oxide thin films

Rani, J. R.; Lim, Jin Hong; Oh, Ji Hye; Kim, Dukhan; Lee, Dongil; Kim, Jung Ho; Shin, Hyeon Suk; Kim, Jae‐Hun; Jun, Seong Chan

doi:10.1039/c3ra00028a

Cited by 50 publications

(26 citation statements)

References 42 publications

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“…Of the remaining peaks, the 284.4-eV peak is assigned as described previously to the C¼C-C bonds and the 285.4-eV peak is related to 'defects' of carbon atoms: out of sp 2 configuration or in a partially sp 2 or sp 3 hybridised state. [43] In order to further confirm that no carbon-nitrogen bonds exist in the product, an examination essential for the next step when we intended to detect acrylamide, we took a closer look at the HR (high-resolution)-XPS of the N 1s region. Fig.…”

Section: Resultsmentioning

confidence: 99%

Can r-graphene oxide replace the noble metals in SERS studies: the detection of acrylamide

Segal

Gedanken

2016

Environ. Chem.

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Environmental context. The need for detecting and sensing hazardous materials that can contaminate our food and water is growing each and every year. Regulation of these contaminants to safeguard human health depends on the ability to detect them at ultra-low concentrations in the environment. This work proposes a simple and efficient substrate preparation for detecting acrylamide, a toxic and carcinogenic material usually found in drinking water.Abstract. Polyacrylamide acts as a very common water purifier worldwide. Unfortunately, it leaves hazardous and toxic residues of its monomer, acrylamide (C 3 H 5 NO), in water sources. The World Health Organization (WHO), the Food and Agriculture Organisation of the United Nations (FAO) and the European Union (EU) set the maximum contaminant level of acrylamide in drinking water to 0.1-0.5 mg L À1 . This environmental risk encouraged our efforts to develop surfaceenhanced Raman spectroscopy (SERS) probes that are easy and simple to fabricate, and also have superb detection ability. We report down to 0.071-mg L À1 acrylamide detection with good reproducibility, which is even lower than the WHO, FAO and EU requirements, and may be used as a powerful analytical alternative for detection. In this manuscript, we present a practical route to fabricate these detection substrates for detection of ultra-low concentrations of aqueous acrylamide solutions. The facile method is based on deposition of graphene oxide on Si wafers by ultrasonication, followed by surface reduction. These substrates require no adhesion layer or pretreatment with O 2 plasma or aminopropyl triethoxysilane for the coating process. Sonochemical deposition of silver nanoparticles on the substrates is also carried out and the product compared with the proposed Si-reduced graphene oxide wafers.

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Section: Resultsmentioning

confidence: 99%

Can r-graphene oxide replace the noble metals in SERS studies: the detection of acrylamide

Segal

Gedanken

2016

Environ. Chem.

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“…The thickness of the unreduced GO is ∼1.0 nm and that of chemically rGO is 0.6 nm. This difference in the thickness and the phase contrast arises from the hydrophilicity difference due to the distinct oxygen functional group in the reduction process as represented in Figure 1.6 [19,48].…”

Section: Afm (Atomic Force Microscopy)mentioning

confidence: 99%

“…Substrates significantly influence the properties because the interaction between substrate and GO modifies the electron band structure [19]. Graphene is semimetallic since its HOMO and LUMO are in contact, resulting in the zero band gap material [67].…”

Section: Substrate Effectmentioning

confidence: 99%

“…This process requires a scattering at defect sites in order to conserve the momentum. Photoluminescence (PL) in such carbon systems usually is a consequence of the recombination of localized e-h pairs in sp 2 clusters [19]. Excitation wavelength-dependent PL emission from the GO and graphene quantum dots were also observed and the PL peak shifted from 430 to 515 nm when the excitation wavelength was changed from 320 to 420 nm [13].…”

Section: Introductionmentioning

confidence: 99%

“…19 Oxygen functional group modification from epoxy to carbonyl and Raman spectra of oxygen plasma-treated graphene oxide dependent to oxygen pressure.…”

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Fundamental of Graphene

Jun

2015

Graphene‐based Energy Devices

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IntroductionGraphene, a single-atom-thick sheet of hexagonally arrayed sp 2 -bonded carbon atoms, has got a significant attention due to its unique electronic [1], mechanical [2], and thermal [3] properties all derived from the unique details of its electronic band structure. Due to its flexibility, graphene provides infinite possibilities in various fields [4,5] and the peculiar dispersion relation of carbon's π electrons is responsible for its unique properties [1].There are different ways to produce "pristine" graphene. The graphene synthesis can be mainly classified into exfoliation [6], chemical vapor deposition (CVD) [7], arc discharge [8], and reduction of graphene oxide (GO) [9]. One method for isolation of a sheet of graphene is through the mechanical exfoliation from a graphite crystal, but this is not scalable beyond one small flake of graphene, making graphene with lateral dimensions on the order of tens to hundreds of micrometers. But reports are also showing the development of patterned graphene through the mechanical exfoliation of patterned graphite.The important large-scale synthesis of graphene includes the thermal decomposition of silicon carbide [10] and CVD growth. The formation of carbon layers with sp 2 bonding, on the SiC substrate could be obtained through the sublimation of Si by heating the C-face or Si-face in ultrahigh vacuum (UHV) at temperatures ranging from 1000 to 1500 ∘ C and the thermal decomposition of hydrocarbons. CVD method has raised much attention for graphene synthesis due to high quality with large surface area. Gas-phase synthesis of graphene platelets and arc discharge synthesis of multilayered graphene are also reported.Exfoliation of graphite in solvents is a method for obtaining dispersions of GO to yield individual layers of GO and offers potential for the production of costeffective, large-scale production of graphene [9]. Based on recent studies, GO consists of phenol hydroxyl and epoxide functional groups on the top and bottom surfaces of each sheet and sp 2 -hybridized carbons containing carboxyl and carbonyl groups mostly at the sheet edges and these groups offer tremendous opportunities for access to functionalized graphene-based materials [11]. The oxidation Graphene-based Energy Devices, First Edition. Edited by A. Rashid bin Mohd Yusoff.

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Characterization of Surface and Structure of In Situ Doped Sol‐Gel‐Derived Silicon Carbide

et al. 2018

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Silicon carbide (SiC), is an artificial semiconductor used for high-power transistors and blue LEDs, for its extraordinary properties. SiC will be attractive for more applications, but large-scale or large-surface area fabrication, with control over defects and surface is challenging. Sol-gel based techniques are an affordable alternative toward such requirements. This report describes two types of microcrystalline SiC derived after carbothermal reduction from sol-gel-based precursors, one with nitrogen added, the other aluminum. Characterization of their bulk, structure, and surface shows that incorporation of dopants affects the formation of polytypes and surface chemistry. Nitrogen leads exclusively to cubic SiC, exhibiting a native oxide surface. Presence of aluminum instead promotes growth of hexagonal polytypes and induces self-passivation of the crystallites' surface during growth. This is established by hydrogenation of silicon bonds and formation of a protecting aluminum carbonate species. XPS provides support for the suggested mechanism. This passivation is achieved in only one step, solely by aluminum in the precursor. Hence, it is shown that growth, doping and passivation of SiC can be performed as "one-pot synthesis". Material without insulating oxide and a limited number of defects is highly valuable for applications involving surface-sensitive charge-transfer reactions, therefore the potential of this method is significant.

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Substrate and buffer layer effect on the structural and optical properties of graphene oxide thin films

Cited by 50 publications

References 42 publications

Can r-graphene oxide replace the noble metals in SERS studies: the detection of acrylamide

Can r-graphene oxide replace the noble metals in SERS studies: the detection of acrylamide

Fundamental of Graphene

Characterization of Surface and Structure of In Situ Doped Sol‐Gel‐Derived Silicon Carbide

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