Search results for "GRAPHENE"

PREPARATION OF MULTIFUNCTIONAL NANO-STRUCTURED POLYMER NANOHYBRIDS CONTAINING CARBON COMPOUNDS

Raw data for the publication "Effect of graphene substrate type on formation of Bi2Se3 nanoplates", Sci. Rep. 9, 4791, 2019. https://doi.org/10.1038/…

2020

This dataset contains the raw AFM and SEM measurement data used for the study of stages of formation of Bi2Se3 nanoplates on different substrates and for the statistical analysis of sizes and thicknesses of the nanoplates. The results are published in Sci. Rep. 9, 4791, 2019. https://doi.org/10.1038/s41598-019-41178-1

Manufacturing of graphene nanodisks for surface plasmon measurements

2017

Grafeeni on ilmestynyt tieteen rintamalle kovalla ryminällä vasta viimeisen 13 vuoden aikana, mutta on jo nyt yksi mielenkiintoisimmista tutkimuskohteista, jolla voisi olla lukuisia sovelluksia tulevaisuudessa. Grafeeni on ilmestynyt myös plasmoniikan tutkimuskohteeksi sen lukuisten ainutlaatuisten sähköisten ja optisten ominaisuuksien takia ja sen ominaisuuksien muokattavuuden helppouden takia. Grafeeni voisi mahdollisesti korvata yleisesti käytössä olleet jalot metallit kuten kullan ja hopean pintaplasmonien tuotossa ja tutkimuksessa ja voisi johtaa uudenlaiseen valon kontrollointiin nanoskaalassa ja optiikan ja elektroniikan yhdistämiseen tässä pienessä mittakaavassa. Tässä työssä tavoit…

Photocatalytic H2 evolution from aqueous solutions of oxygenated organic compounds in the presence of C3N4/reduced graphene oxide based photocatalysts

2022

Composites of C3N4/reduced graphene oxide have been used as a cheap and promising photocatalysts for triethanolamine and ethanol photo-reforming with H2 generation in aqueous solution. The rate of H2 production over the best performing photocatalysts reached 1,415 μmol·h-1·g-1 which increases up to 57,306 in the presence of 1% of Pt. The apparent quantum efficiency of the optimal material was 7 % by using both LED and natural sunlight irradiation

Strongly Coupled Coherent Phonons in Single-Layer MoS 2

2019

We present a transient absorption setup combining broadband detection over the visible-UV range with high temporal resolution ($\sim$20fs) which is ideally suited to trigger and detect vibrational coherences in different classes of materials. We generate and detect coherent phonons (CPs) in single layer (1L) MoS$_2$, as a representative semiconducting 1L-transition metal dichalcogenide (TMD), where the confined dynamical interaction between excitons and phonons is unexplored. The coherent oscillatory motion of the out-of-plane $A'_{1}$ phonons, triggered by the ultrashort laser pulses, dynamically modulates the excitonic resonances on a timescale of few tens fs. We observe an enhancement by…

Photoresponse of graphene ruthenium-complex heterostructures

2015

The aim of this study is to understand the photoresponse of a Ruthenium-complex/graphene heterostructure. Early work demonstrated that light detection by graphene field effect devices was enhanced by dropcasting Ruthenium Complex molecules. Here we proposed to fabricate a new class of devices where the Ruthenium-complex molecules are embedded between two layer of CVD monolayer graphene.

Silica as a green exfoliant agent for graphene oxidepolymer nanocomposites prepared in the melt

2017

For the first time, solid-state exfoliant agents were used to hinder the re-aggregation of graphene oxide (GO) during melt processing with polyamide 6 (PA6). This technique drastically reduces the time and difficulty related to solvent (removal, disposal, etc.), and avoids water consumption, since in this case 150 mL of water under mild operative conditions are enough to prepare the amount of GOS necessary for the realization of almost 100 grams of PA6- GOS nanocomposites with outstanding ultimate properties.

Pulicaria glutinosa Extract: A Toolbox to Synthesize Highly Reduced Graphene Oxide-Silver Nanocomposites

2015

A green, one-step approach for the preparation of graphene/Ag nanocomposites (PE-HRG-Ag) via simultaneous reduction of both graphene oxide (GRO) and silver ions using Pulicaria glutinosa plant extract (PE) as reducing agent is reported. The plant extract functionalizes the surfaces of highly reduced graphene oxide (HRG) which helps in conjugating the Ag NPs to HRG. Increasing amounts of Ag precursor enhanced the density of Ag nanoparticles (NPs) on HRG. The preparation of PE-HRG-Ag nanocomposite is monitored by using ultraviolet-visible (UV-Vis) spectroscopy, powder X-ray diffraction (XRD), and energy dispersive X-ray (EDX). The as-prepared PE-HRG-Ag nanocomposities display excellent surfac…

Measuring optical anisotropy in poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) films with added graphene

2015

Abstract Graphene is a 2D nanomaterial having a great potential for applications in electronics and optoelectronics. Composites of graphene with conducting polymers have shown high performance in practical devices and their solution-processability enables low-cost and high-throughput mass manufacturing using printing techniques. Here we measure the effect of incorporation of graphene into poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) to the optical anisotropy, absorbance and conductivity of the film. Uniaxial anisotropy in PEDOT:PSS films has been thought to be caused by the spin-coating process used in fabrication. We have characterized spray- and spin-coated films …

Optical properties of conductive carbon-based nanomaterials

2016

The interaction of light with carbon nanomaterials is the main focus of this thesis. I explore several nanostructured systems involving different allotropes of carbon, and characterize them both electrically, if applicable, and optically. Special attention is paid to search for plasmon-like excitations on the systems, or utilizing surface plasmons on characterization. The first objective is to achieve control of carbon nanotube (CNT) conductivity with surface plasmon polaritons (SPPs), which resulted in the first CNT field-effect transistor (FET) that can be gated definitively with SPPs. The second objective is the investigation of optical properties of various thin carbon-based molecular n…