| 1. |
- Mishra, Prashant, et al.
(författare)
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Electrocatalytic biofuel cell based on highly efficient metal-polymer nano-architectured bioelectrodes
- 2017
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Ingår i: Nano Energy. - : ELSEVIER SCIENCE BV. - 2211-2855 .- 2211-3282. ; 39, s. 601-607
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Tidskriftsartikel (refereegranskat)abstract
- Bioenergy based devices are rapidly gaining significant research interest because of growing quest for future alternative energy resources, but most of the existing technologies suffer from poor electron transfer and slow mass transport, which hinder the fabrication of realistic high-power devices. Using a versatile strategy, here we have demonstrated the fabrication of nanoparticle-polymer framework based bioelectrocatalytic interfaces which facilitate a high mass-transport and thus offers the simple construction of advanced enzyme-based biofuel cells. It has been shown that a gold nanoparticle-structured polyaniline network can be effectively used as an electrical cabling interface providing efficient electron transfer for bio-anode and cathode. The resulting bioelectrodes are capable of excellent diffusional mass-transport and thus can easily facilitate the design of new and highly efficient membrane-less advanced bioenergy devices. The biofuel cell delivers a high-power density of about 2.5 times (i.e., 685 mu W cm(-2)) and open circuit voltage of 760 mV compared to conventional conducting polymer-based biofuel cells.
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| 2. |
- Kaushik, Priya Darshni, et al.
(författare)
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Modifications in structural, optical and electrical properties of epitaxial graphene on SiC due to 100 MeV silver ion irradiation
- 2018
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Ingår i: Materials Science in Semiconductor Processing. - : Pergamon Press. - 1369-8001 .- 1873-4081. ; 74, s. 122-128
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial graphene (EG) on silicon carbide (SiC) is a combination of two robust materials that are excellent candidates for post silicon electronics. In this work, we systematically investigate structural changes in SiC substrate as well as graphene on SiC and explore the potential for controlled applications due to 100 MeV silver swift heavy ion (SHI) irradiation. Raman spectroscopy showed fluence dependent decrease in intensity of first and second order modes of SiC, along with decrease in Relative Raman Intensity upon ion irradiation. Similarly, Fourier-transform infrared (FTIR) showed fluence dependent decrease in Si-C bond intensity with presence of C = O, Si-O-Si, Si-Si and C-H bond showing introduction of vacancy, substitutional and sp(3) defects in both graphene and SiC. C1s spectra in XPS shows decrease in C = C graphitic peak and increase in interfacial layer following ion irradiation. Reduction in monolayer coverage of graphene after ion irradiation was observed by Scanning electron microscopy (SEM). Further, UV-Visible spectroscopy showed increase in absorbance of EG on SiC at increasing fluence. I-V characterization showed fluence dependent increase in resistance from 62.9 O in pristine sample to 480.1 Omega in sample irradiated at 6.6 x 10(12) ions/cm(2) fluence. The current study demonstrates how SHI irradiation can be used to tailor optoelectronic applicability of EG on SiC.
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| 3. |
- Kaushik, Priya Darshni, et al.
(författare)
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Surface functionalization of epitaxial graphene on SiC by ion irradiation for gas sensing application
- 2017
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Ingår i: Applied Surface Science. - : ELSEVIER SCIENCE BV. - 0169-4332 .- 1873-5584. ; 403, s. 707-716
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Tidskriftsartikel (refereegranskat)abstract
- In this work, surface functionalization of epitaxial graphene grown on silicon carbide was performed by ion irradiation to investigate their gas sensing capabilities. Swift heavy ion irradiation using 100 MeV silver ions at four varying fluences was implemented on epitaxial graphene to investigate morphological and structural changes and their effects on the gas sensing capabilities of graphene. Sensing devices are expected as one of the first electronic applications using graphene and most of them use functionalized surfaces to tailor a certain function. In our case, we have studied irradiation as a tool to achieve functionalization. Morphological and structural changes on epitaxial graphene layers were investigated by atomic force microscopy, Raman spectroscopy, Raman mapping and reflectance mapping. The surface morphology of irradiated graphene layers showed graphene folding, hillocks, and formation of wrinkles at highest fluence (2 x 10(13) ions/cm(2)). Raman spectra analysis shows that the graphene defect density is increased with increasing fluence, while Raman mapping and reflectance mapping show that there is also a reduction of monolayer graphene coverage. The samples were investigated for ammonia and nitrogen dioxide gas sensing applications. Sensors fabricated on pristine and irradiated samples showed highest gas sensing response at an optimal fluence. Our work provides new pathways for introducing defects in controlled manner in epitaxial graphene, which can be used not only for gas sensing application but also for other applications, such as electrochemical, biosensing, magnetosensing and spintronic applications. (C) 2017 Elsevier B.V. All rights reserved.
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