PCCP Blog

Understanding defects in graphene

09 May 2013

The products of making graphene by thermally exfoliating graphite oxide are much more complex than previously thought, new research shows.

The most common way to prepare graphene is by thermally reducing – or ‘exfoliating’ – graphite oxide. But the graphene produced in the process often contains defects and lacks the perfect ‘honeycomb’ structure. One explanation is that these defects may be the result of organic by-products forming and escaping as gases during the reaction.

Scientists from Singapore and the Czech Republic allowed exfoliation to take place in an autoclave at 500 degrees for two hours then analysed the gases produced using gas chromatography–mass spectrometry (GC-MS). They detected many other volatiles in addition to H₂O, CO and CO₂, including polycyclic aromatic molecules, and those containing sulphur and nitrogen heteroatoms that are present as contaminants in the graphite oxide.

Moreover, the nature of the volatiles released varies hugely depending on pressure (2 bar versus 100 bar) and the gaseous atmosphere in which the exfoliation was carried out (hydrogen versus inert argon). The method by which the graphite oxide itself was prepared also had an effect – the Hummers method yielded the highest number of volatiles.

Understanding these by-products is crucial as they can affect the structure of the resultant graphene which influences its future use. The team suggest that measuring the volatiles produced during exfoliation could help determine the nature of defects.

Read this HOT PCCP article in full today:

Complex organic molecules are released during thermal reduction of graphite oxides
Z Sofer, P Šimek and M Pumera
DOI: 10.1039/C3CP51189H

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The Gordon F. Kirkbright Bursary Award 2014

08 May 2013

By Rowan Frame, Commissioning Editor.

The Gordon F. Kirkbright bursary award is a prestigious annual award that enables a promising student/non-tenured young scientist of any nation to attend a recognised scientific meeting or visit a place of learning.

Applications are invited for the 2014 Gordon Kirkbright Bursary.

For further information contact John Chalmers at, email: vibspecconsult@aol.com

The closing date for entries is 31 December 2013.

The fund for this bursary was established in 1985 as a memorial to Professor Gordon Kirkbright in recognition of his contributions to analytical spectroscopy and to science in general. Although the fund is administered by the Association of British Spectroscopists (ABS) Trust, the award is not restricted to spectroscopists.

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DNP SENS – a fast method to probe surface functionality

07 May 2013

By Heather Montgomery, Deputy Editor.

We are delighted to welcome Alexander Forse as a new guest web-writer for PCCP, Nanoscale, and Energy and Environmental Science. Alexander is a PhD student in Professor Clare Grey’s group at the University of Cambridge. When not in the lab, he enjoys playing football, skateboarding and producing electronic music.

The development of new experimental methods to probe surface functionality is crucial to the understanding of functional materials. For the typically low concentrations of surface functional groups, traditional nuclear magnetic resonance (NMR) spectroscopy lacks the sensitivity to provide chemical information quickly.

In dynamic nuclear polarisation surface enhanced NMR spectroscopy (DNP SENS), a porous or particulate sample is wetted with a radical solution. The large polarisation of the radicals’ unpaired electrons is then transferred to surrounding nuclear spins, with a typical signal enhancement of between 10 and 100. This can decrease experimental time dramatically, whilst probing specifically the surface functionality.

In their recent communication in PCCP, the research groups of Professor Lyndon Emsley and Professor Christophe Copéret collaborated to characterise the organic part of a periodic mesoporous organosilicate (PMO). Structural changes following functionalisation with an organoiridium compound were studied using DNP SENS. Remarkably, ¹⁵N (0.37% natural abundance) DNP SENS spectra revealed the appearance of a new chemical environment following functionalisation, corresponding to nitrogen atoms (in the PMO) bonded to Iridium (III). This key piece of evidence allowed the authors to elucidate a layered structure in which only the surface layers were available for functionalisation.

Whilst the ¹⁵N spectra would have taken weeks to acquire using conventional NMR methods, DNP SENS experiments took only a matter of hours, highlighting the power of this fascinating method.

Full details can be found in the PCCP communication:

Molecular-level characterization of the structure and the surface chemistry of periodic mesoporous organosilicates using DNP-surface enhanced NMR spectroscopy
Wolfram R. Grüning, Aaron J. Rossini, Alexandre Zagdoun, David Gajan, Anne Lesage, Lyndon Emsley and Christophe Copéret
DOI: 10.1039/C3CP00026E

By Alexander Forse

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Water of life

02 May 2013

By Heather Montgomery, Deputy Editor.

Thomas Just Sørensen is a guest web-writer for PCCP. He is currently a post-doctoral researcher at the University of Copenhagen, Denmark.

More than 50 % of our bodies are water. Plain and simple, we are more water than anything else. Following that statement it must be said that none of the water in our body is simply water. Excluding the content of your bladder, none of the water in your body is water as you have come to know it from your glass, rain, your local river and the oceans. Your body water surrounds cell membranes, microtubule, proteins, sugars, bones; all the smaller and larger biomolecules that make up our bodies. Not to mention the specific concentrations of salts and inorganic molecules that are required to run our bodies. We are beginning to understand the structure of water itself, and when water solvates simple ions. The work of Takis and co-workers increases the stakes and opens our mind to the specific solvations of small protein fragments.

The research from the groups of Troganis and Melissas at the University of Ioannina is focused on simple dipeptides, and exploits molecular dynamic simulations, density functional theory based calculations and advanced nuclear magnetic resonance spectroscopy. This combination allows them to probe the solvation of the small peptide experimentally, and rationalize the findings by the theoretical approach. Specifically the distances between selected carbon atoms in the peptide structure and water molecules can be measured. The challenge in this approach is the continuous and rapid exchange of the water molecules.

To me, the most readily accessible data is the plots showing the probability of finding water oxygen and hydrogen atoms at a specific distance to selected groups in the peptide structure. Here, extracted from MD simulations. When experimental data can yield similar results, we will be able to start directly investigating how more than half of our bodies are made up.

The excellent work on the solvation of dipeptides is published in the PCCP paper titled:

Probing micro-solvation in “numbers”: the case of neutral dipeptides in water
Panteleimon G. Takis, Konstantinos D. Papavasileiou, Loukas D. Peristeras, Vasilios S. Melissas and Anastassios N. Troganis
Phys. Chem. Chem. Phys., 2013, 15, 7354-7362
DOI: 10.1039/C3CP44606A

by Thomas Just Sørensen

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Playing with liquid crystalline water balloons

02 May 2013

By Heather Montgomery, Deputy Editor.

Thomas Just Sørensen is a guest web-writer for PCCP. He is currently a post-doctoral researcher at the University of Copenhagen, Denmark.

Sometimes you just have to sit back, read, and enjoy the ride. This is exactly the case with the work of Kirsten Harth and Ralf Stannarius from the Institute of Experimental Physics at the Otto von Guericke University Magdeburg. The have investigated the interface tension between soapy water and a smectic liquid crystal.

Apparently, thin films of smectic—and only smectic—liquid crystals readily form in water, where they can form bubbles. In an ingenious experimental set-up Harth and Stannarius can measure the surface tension by letting a single air bubble put the smectic film bubble under tension. Amazing as it sounds, it is a viable procedure and the interface tension can be accurately determined.

The generic appeal of this study makes it one of the more enjoyable reads I have had in a while. The images were just so interesting that my curiosity forced me to download and read the paper.

If you are equally enticed, the paper is published in PCCP:

Measurement of the interface tension of smectic membranes in water
Kirsten Harth and Ralf Stannarius
Phys. Chem. Chem. Phys., 2013, 15, 7204-7209
DOI: 10.1039/C3CP44055A

by Thomas Just Sørensen

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Using NMR to study ion adsorption in porous carbide-derived carbons

26 Apr 2013

By Rowan Frame, Commissioning Editor.

Nuclear magnetic resonance study of ion adsorption on microporous carbide-derived carbon Developing alternative energy storage devices, such as supercapacitors, is of rising importance when facing today’s challenges of climate change and fossil fuel depletion. Supercapacitors typically employ porous carbon electrodes as they have large surface areas for ion electrosorption, good electronic conductivities and relatively low production cost. The design and improvement of supercapacitors is only possible with a detailed understanding of ion adsorption within porous carbon.

A group of Scientists from the UK, Germany, the USA and France have used NMR spectroscopy to systematically study ion adsorption in porous carbide-derived carbons. Their results provide insight into the different electrolyte environments present in the carbon, and how they are affected by pore size. The group, led by Prof. Clare Grey, also explored the effects of sample orientation, and developed 13C-1H CP NMR experiments to select the ions adsorbed in the pores.

These techniques presented in their recent PCCP paper will be useful for future investigations into adsorption on porous carbons.

Read this HOT article today:

Nuclear magnetic resonance study of ion adsorption on microporous carbide-derived carbon
Alexander C. Forse, John M. Griffin, Hao Wang, Nicole M. Trease, Volker Presser, Yury Gogotsi, Patrice Simon and Clare P. Grey
DOI: 10.1039/C3CP51210J

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PCCP Communications: fast publication of high impact research

24 Apr 2013

By Rowan Frame, Commissioning Editor.

Physical Chemistry Chemical Physics (PCCP) publishes high impact Communications on the most important new research.

We provide our authors with a fast publication service: the average time from receipt to first publication in March 2013 was just 36 days for Communication Articles. Now PCCP’s Accepted Manuscript service means your research is available, in citable form, on average within one day of acceptance.

Why publish in PCCP?

•             Committed to publishing the best research across physical chemistry, chemical physics and biophysical chemistry
•             Large community-spanning international readership
•             Very efficient, rigorous and fair peer review procedure
•             High impact factor: 3.57
•             No author page charges or colour charges
•             Society publishing, and fully open-access compatible

Submit your best research today and see your Communication published on average five weeks after submission.

Below is a collection of our very recent high impact Communications, with a selection available to read for free for a limited period:

FREE: Screened-exchange density functionals with broad accuracy for chemistry and solid-state physics
Roberto Peverati and Donald G. Truhlar
DOI: 10.1039/C2CP42576A

FREE: Integrated microfluidic test-bed for energy conversion devices
Rachel A Segalman, Miguel A. Modestino, Joel W. Ager III, Sophia Haussener, Rafael Gomez-Sjoberg and Camilo Diaz-Botia
DOI: 10.1039/C3CP51302E

FREE: Characterization of an activated iridium water splitting catalyst using infrared photodissociation of H2 tagged ions
Etienne Garand, Joseph A. Fournier, Michael Z. Kamrath, Nathan D. Schley, Robert H. Crabtree and Mark A. Johnson
DOI: 10.1039/C2CP41490B

FREE: Bioelectrocatalytic oxidation of glucose with antibiotic channel-containing liposomes
Shuji Fujita, Ryuhei Matsumoto, Kenichi Ogawa, Hideki Sakai, Akihiro Maesaka, Yuichi Tokita, Seiya Tsujimura, Osamu Shirai and Kenji Kano
DOI: 10.1039/C3CP43998D

FREE: Synthesis, Characterization and Organic Field Effect Transistor Performance of Diketopyrrolopyrrole- Fluorenone Copolymer
Prashant Murlidhar Sonar, Taejun Ha and Ananth Dodabalapur
DOI: 10.1039/C3CP50286D

FREE: Surface oxidation of gold nanoparticles supported on a glassy carbon electrode in sulphuric acid medium: contrasts with the behaviour of ‘macro’ gold
Ying Wang, Eduardo Laborda, Alison Crossley and Richard G. Compton
DOI: 10.1039/C3CP44615H

FREE: Supramolecular H-bonded porous networks at surfaces: exploiting primary and secondary interactions in a bi-component melamine–xanthine system
Artur Ciesielski, Sébastien Haar, Gábor Paragi, Zoltán Kupihár, Zoltán Kele, Stefano Masiero, Célia Fonseca Guerra, F. Matthias Bickelhaupt, Gian Piero Spada, Lajos Kovács and Paolo Samorì
DOI: 10.1039/C3CP50891A

The influence of thermal degradation on the electrodeposition of aluminium from an air- and water-stable ionic liquid
Jean-Pierre Marcel Veder, Thomas Ruether, Mike Horne, Alan M Bond and Theo Rodopoulos
DOI: 10.1039/C3CP50690H

Accurate quantum chemical energies for tetrapeptide conformations: why MP2 data with an insufficient basis set should be handled with caution
Lars Goerigk, Amir Karton, Jan M. L. Martin and Leo Radom
DOI: 10.1039/C3CP00057E

Operando XAFS study of catalytic NO reduction over Cu/CeO2: the effect of copper–ceria interaction under periodic operation
Yasutaka Nagai, Kazuhiko Dohmae, Yusaku F. Nishimura, Hitoshi Kato, Hirohito Hirata and Naoki Takahashi
DOI: 10.1039/C3CP44316G

Other origins for the fluorescence modulation of single dye molecules in open-circuit and short-circuit devices
Jefri S. Teguh, Michael Kurniawan, Xiangyang Wu, Tze Chien Sum and Edwin K. L. Yeow
DOI: 10.1039/C2CP43284F

Roughening of Pt nanoparticles induced by surface-oxide formation
Tianwei Zhu, Emiel J. M. Hensen, Rutger A. van Santen, Na Tian, Shi-Gang Sun, Payam Kaghazchi and Timo Jacob
DOI: 10.1039/C2CP44252C

ZnO nanoparticle based highly efficient CdS/CdSe quantum dot-sensitized solar cells
Chunhui Li, Qingbo Meng and Bo Brummerstedt Iversen
DOI: 10.1039/C3CP50365H

Natural mineral tetrahedrite as a direct source of thermoelectric materials
Xu Lu and Donald T. Morelli
DOI: 10.1039/C3CP50920F

Attenuated total reflectance infrared spectroelectrochemistry at a carbon particle electrode; unmediated redox control of a [NiFe]-hydrogenase solution
Adam J. Healy, Philip A. Ash, Oliver Lenz and Kylie A. Vincent
DOI: 10.1039/C3CP00119A

Using waste Li ion batteries as cathodes in rechargeable Li–liquid batteries
Jinyoung Chun, Moonsik Chung, Jinwoo Lee and Youngsik Kim
DOI: 10.1039/C3CP00006K

Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes
ZhenHua Zeng, Mårten E. Björketun, Sune Ebbesen, Mogens B. Mogensen and Jan Rossmeisl
DOI: 10.1039/C3CP51099A

Critical solution behavior of poly(N-isopropyl acrylamide) in ionic liquid–water mixtures
Purnendu K. Nayak, Adam P. Hathorne and Harry Bermudez
DOI: 10.1039/C2CP44205A

Resonance Raman studies of excited state structural displacements of conjugated polymers in donor/acceptor charge transfer complexes
Adam J. Wise and John K. Grey
DOI: 10.1039/C2CP41748K

The bulk and the gas phase of 1-ethyl-3-methylimidazolium ethylsulfate: dispersion interaction makes the difference
Friedrich Malberg, Alfonso S. Pensado and Barbara Kirchner
DOI: 10.1039/C2CP41878A

Resonant X-ray emission spectroscopy reveals d–d ligand-field states involved in the self-assembly of a square-planar platinum complex
Claudio Garino, Erik Gallo, Nikolay Smolentsev, Pieter Glatzel, Roberto Gobetto, Carlo Lamberti, Peter J. Sadler and Luca Salassa
DOI: 10.1039/C2CP42451G

Well-defined lipid interfaces for protein adsorption studies
Cristina Satriano, Sofia Svedhem and Bengt Kasemo
DOI: 10.1039/C2CP43254D

Charge localization increases chemical expansion in cerium-based oxides
Dario Marrocchelli, Sean R. Bishop, Harry L. Tuller, Graeme W. Watson and Bilge Yildiz
DOI: 10.1039/C2CP40754J

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Computational chemistry: predicting or understanding measurements?

23 Apr 2013

By Heather Montgomery, Deputy Editor.

Thomas Just Sørensen is a guest web-writer for PCCP. He is currently a post-doctoral researcher at the University of Copenhagen, Denmark.

In my understanding, science is the search for answers. The validity of the research is then defined by the nature of the question.

Computational chemistry is a two-headed scientist, where one head is constantly trying to find cost-effective methods for screening molecular interactions, lock-and-key matches of drug candidates etc. While the other head is busy creating a theoretical model able to emulate nature as close as possible. Either head is plagued by the need to understand nature and benchmark against experimental data. The computational results must constantly be contrasted to experiments, as not to lose the contact with reality and be caught in the virtual world. This is highlighted in the excellent report by Vöhringer and Kirchner on the computing of vibrational spectra.

Martin Thomas and co-workers makes a thorough review of the field of calculating vibrational spectra, followed by an easily approached walk-through of the theory they use when generating vibrational spectra from MD simulations. Reading the paper, I must admit I gained high expectations as to the results. I have been away from the field a couple of years. So instead of the being impressed by the results, I was slightly disappointed, which is completely unfair. Not only does the work move from the static system and the harmonic approximation, it also takes us from the gas phase to solvated molecules. Well, the experimental data is not matched, but we are getting closer.

by Dr Thomas Just Sørensen

Read more details of this fascinating article which is part of the themed collection “Theory meets spectroscopy“:

Computing vibrational spectra from ab initio molecular dynamics
Martin Thomas, Martin Brehm, Reinhold Fligg, Peter Vöhringer and Barbara Kirchner
DOI: 10.1039/C3CP44302G

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PCCP themed collection: Theory meets spectroscopy – out now!

23 Apr 2013

By Hannah Porter, Publishing Assistant.

We are delighted to announce that the PCCP themed collection on Theory meets spectroscopy has now been published online – take a look today!

The themed collection was Guest Edited by Manfred Kappes and Wim Klopper.

The outside front cover features a perspective article on Comparing molecular photofragmentation dynamics in the gas and liquid phases by Stephanie J. Harris, Daniel Murdock, Yuyuan Zhang, Thomas A. A. Oliver, Michael P. Grubb, Andrew J. Orr-Ewing, Gregory M. Greetham, Ian P. Clark, Michael Towrie, Stephen E. Bradforth and Michael N. R. Ashfold.

Theory meets spectroscopy themed collection features a broad range of Papers and Communications and includes the following Perspective articles:

Modeling environment effects on spectroscopies through QM/classical models
DOI: 10.1039/C3CP44417A
Rotational spectroscopy meets theory
DOI: 10.1039/C3CP44301A

Take a look at the issue today!

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Understanding defects in graphene

The Gordon F. Kirkbright Bursary Award 2014

DNP SENS – a fast method to probe surface functionality

Top 10 most accessed PCCP articles in March

Water of life

Playing with liquid crystalline water balloons

Using NMR to study ion adsorption in porous carbide-derived carbons

PCCP Communications: fast publication of high impact research

Computational chemistry: predicting or understanding measurements?

PCCP themed collection: Theory meets spectroscopy – out now!

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