MECHANOCHEMICAL SYNTHESIS OF GRAPHENE OXIDE WITH VARIABLE DEGREE
MECHANOCHEMICAL SYNTHESIS OF GRAPHENE OXIDE WITH VARIABLE DEGREE OF OXIDATION Magdalena Kralj,1 Irena Sovi1, Ivan Halasz1 1 Ruer Bokovi Institute, Zagreb, Croatia Division of Physical Chemistry Laboratory for Green Synthesis Acknowledgements This work was supported by the Ministry of Environment and Energy, the Ministry of Science and Education, the Environmental Protection and Energy Efficiency Fund and the Croatian Science Foundation under the project New Materials for Energy Storage, in the total amount of 1,962,100 HRK and by the Centre of Excellence for Advanced Materials and Sensing Devices, a project financed by the European Union through the European Regional Development Fund - the Competitiveness and Cohesion Operational Programme (KK.01.1.1.01.0001) Mechanochemical preparation and characterization of graphene oxide (GO) AIM Find optimal synthesis conditions Find influencing factors on the oxidation degree of GO PURPOSE Find new versatile and eco-friendly approach to prepare the large scale high quality graphene oxide with tunable degree of oxidation for further functionalization depending on its application Graphene oxide (GO) - single-atom carbon layer, combination of unsaturated benzene rings and aliphatic heterocycles containing range of reactive oxygen groups - Electronics optical materials supercapacitors lithium-ion batteries solar cells Potential use Mass production of graphene - Enviroment contaminant adsorption water decontamination solar desalination enviromental sensing - Biomedicine biosensors Drug delivery agents Variations of the Lerf-Klinowski model (Chem. Soc. Rev., 2010, 39, 228-240)
Oxidation of graphite and graphite oxide Method name Brodie method Staudenmeier method Year 1859. 1898. Hoffman method 1937. Hummers method 1958. Tour method 2010. Oxidation agents HNO3, > 90 %, KClO3 HNO3, > 90%, H2SO4, conc., KClO3 HNO3, > 65%., H2SO4, conc., KClO3 H2SO4, conc., NaNO3, KMnO4 H2SO4, conc., H3PO4, conc., KMnO4 Mechanochemistry Mechanochemical reaction - a chemical reaction that is induced by the direct absorption of mechanical energy - solvent free or with nominal amount of solvent (LAG, ILAG) Reflected better yield and selectivity Why? Better energy and atom - economy J.L. Howard, Q. Cao and D.L. Browne, Chem. Sci., 2018, 9, 30803094 reduce waste generation https://www.fritsch-international.com/sample-preparation/milling/planetary-m ills/details/product/pulverisette-6-classic-line/ https://www.insolidotech.com/ist600.html EXPERIMENTAL PART Mechanochemical synthesis of GO Chemical graphite, x > 400 m KMnO4 GO1 milled 3 1h with 10 min pause in between GO2, GO3, GO4 milled 3.5h 10min milling with 10
min pause in between Producer Graphenea E. Merch. H2SO4 (87%) Kemika HCl (10%) VWR Deionized water - Washing HCl (10%), deionized H2O, dialysis (2 days) sample G : H2SO4 : KMnO4 H2SO4 : KMnO4 GO1 GO2 GO3 GO4 1 : 3.2 : 4.4 1 : 3.2 : 4.4 1 : 4 : 5.7 1:5:7 1 : 1.40 1 : 1.40 1 : 1.43 1 : 1.40 Graphite oxide to graphene oxide 15 min sonication before and 45 min sonication after dialysis Reaction conditions - Planetary ball mill - PULVERISETTE 6 sample jar balls amount GO1 GO2 GO3 GO4 ZrO2 ZrO2 ZrO2 ZrO2
800 GO3 Ts(C) 34 30 100 150 94 6 300 75 19 600 65 10 800 60 5 degree of oxidation 150 C loss of physisorbed waterC loss of physisorbed water 200 C loss of physisorbed waterC main weight loss is due to the loss of carboxyl and epoxy func. groups 600 800 C loss of physisorbed waterC lactone, phenol, ether func. groups GO4 0 34 30 100 0 150 92 8
38 1613 cm-1 C=C stretching vibrations 1585 cm-1 stretching vibrations within graphitic domains 36 34 32 4000 3500 3000 2500 2000 1500 1000 500 Wavelenght (cm-1) FT-IR Spectometer PerkinElmer UATR Two 970-1260 cm-1 stretching vibrations C-OH and C-O bond Raman spectroscopy Sample ID/IG GO1 GO2 GO3 GO4 1.847 1.696 1.542 1.588 ID / IG - relative measure of the defects contrary to the standard sp2 materials for GO the following is true: structural defect I D / IG 0.077
GO1 GO2 GO3 GO4 0.375 GO1_1 GO1_2 14 Volume: 100% Mean value: 0.610 um Median: 0.381 um 12 10 0.721 8 6 GO2_1 GO2_2 25 Volume: 100% Mean value: 1.305 um Median: 1.470 um 20 Volume (%) 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 -2 Volume (%) Number (%) Dynamic Light Scattering
1.0 15 Volume: 100% Mean value: 0.749 um Median: 0.593 um 8 0.5 Diameter (um) GO3_1 GO3_2 10 Volume-weighted distribution represents relative proportion of multiple sizes in a particular sample based on their volume or size but not their intensity, while numberweighted distributions represent number of molecules in each bin in a given histogram 0.0 3.0 9 6 3 2 0 0 0.0 0.5 1.0 1.5 2.0 Diameter (um) 2.5 3.0 0.0 0.5 1.0
1.5 2.0 Diameter (um) 2.5 3.0 SEM ANALYSIS a) b)B) c)c) d) d) SEM images of a) GO1, b) GO2, c) GO3 and d) GO4 Conclusion Lately, market and research demands for GO grow tremendously, therefore it is necessary to find new synthesis paths that would reduce waste generation and reaction time, but still provide better or same quality GO XRD analysis shows that with increasing oxidation levels, the intensity of the peak at 26 decreases and for GO4 disappears entirely. Mechanocemical synthesis resulted with GO having an interlayer distance of 6.96 7.85 Furthermore, its clearly visible from TGA that obtained samples contain 30 62% of oxygen, where GO4 unlike other samples contains a higher amount of lactone, phenol and ether groups Presence of different oxygen functionalities in all samples are confirmed with FT-IR spectroscopy Moreover, from Raman spectroscopy, ID/IG ratio is calculated and amouts 1.5 1.9 indicating that GO3 has the most and GO1 the least defects Dynamic Light Scattering tells us that by planetary ball milling, graphite flakes reduce in size 10000 times and are in the range 77 - 721 nm SEM analysis shows morphology of all samples corresponding to the literature GO morfology. SEM analysis of particle size corresponds to DLS measurments. In summary, mechanochemical synthesis of graphene oxide is possible even though still in an early phase of its development. It has been shown that is possible to reduce explosive nature of reaction and eliminate emission of toxic gasses, using minimal amount of solvents, as well as greatly reduce the reaction time from 2-3 weeks to 3-4 days Literature 1. P. Ranjan et al. A Low-Cost Non-explosive Synthesis of Graphene Oxide for Scalable Applications, Sci. Rep. (2018) 2. X. Li et al. Graphene oxide-based efficient and scalable solar desalination under one sun with a confined 2D water path. Proc. Nat. Acad. Sci. 113(49), 1395313958 (2016) 3. Zhu, Y. et al. Graphene and graphene oxide: synthesis, properties, and applications. Advanced Materials 22, 39063924 (2010) 4. Dimiev, A. M. & Eigler, S., Graphene Oxide: Fundamentals and Applications. (Wiley, 2016) 5. S. L. James et al., Mechanochemistry: opportunities for new and cleaner synthesis, Chem. Soc. Rev., 41 , 413 (2012) 6. J. Chen et al., Water-enhanced oxidation of graphite to graphene oxide with controlled species of oxygenated groups, Chem. Sci. (2016) 7. W.L. Noorduin et al., Chem Soc.,130(4):1158-9 (2008) 8. K. Krishnamoorthy et al., The chemical and structural analysis of graphene oxide with different degrees of oxidation, Carbon, 53, 38 49 (2013) 9. J.L. Howard et al., Mechanochemistry as an emerging tool for molecular synthesis: what can it offer?, Chem. Sci. 9, 3080 (2018) 10. T. Ghosh et al., Solution-Processed Graphite Membrane from Reassembled Graphene Oxide, Chem. Mater., 24 (3), pp 594599 (2012)
DIBELS Maze (Daze) Text Reading and Comprehension (TRC) Text Reading and Comprehension (TRC) Phonics. Accurate and Fluent. Reading. Vocabulary & Language . Skills. Comprehension. This allows us to see how the mCLASS Reading 3D assessment system aligns with these big...
Denotation is the dictionary meaning, while connotation adds an emotional dimension. Cheap and inexpensive mean not costing a lot; however, cheap implies low quality whereas inexpensive does not. In the Wizard of OZ, for example, Dorothy says, " There's no...
To define employability. To learn the parts of employability. To learn employability skills. Employability. Is used to describe the positive work behaviors and personal qualities which make individuals more likely to gain employment and succeed in their chosen career.
Efter Balders død fanger aserne ham og straffer ham. Lænket fast til tre spidse sten. Slangen drypper edder i hans øjne. Sigyn holder et vaskefad under, og når hun tømmer det, får vi jordskælv. Loke slippe ikke fri før Ragnarok....
- ability to operate in 134 low and middle income countries, with a preferred creditor status in more than 65 countries. Responsive - understands project requirements, provides a wide product range and flexible with regard to project/country priorities.
Light & Eyes Vision begins when light comes into the eye Light: Focused by the cornea and the lens onto the retina (which is a thin layer of neural tissue at the back of the eye; contains photoreceptors)
How Sweet It Is! Cinnamon, Spices and Diabetes Catherine M. Champagne, PhD, RD Pennington Biomedical Research Center Focus of presentation: Cinnamon Health benefits of cinnamon Research A little is good, is more better?
Ready to download the document? Go ahead and hit continue!