Microfluidic fuel cells on paper

Jennifer Newton writes about a HOT EES article in Chemistry World

Instrument-free point-of-care diagnostic devices could be taken to the next level with the development of microfluidic fuel cells on paper.

Paper is cheap, biodegradable, thin and flexible, making it an ideal base material for single-use tests. The paper-based microfluidic fuel cells created by Juan Pablo Esquivel, at the Barcelona Microelectronics Institute of the National Microelectronics Centre, IMB-CNM (CSIC), in Spain, and colleagues, were inspired by the convenience and simplicity of lateral flow test strips – pregnancy tests are probably the most well-known example of these – and take advantage of capillary diffusion to transport reactants without external pumps.

Interested to know more? Read the full news article by Jennifer Newton on Chemistry World here…

Read the original article in EES – it’s open access

Microfluidic fuel cells on paper: meeting the power needs of next generation lateral flow devices
Juan Pablo Esquivel Bojorquez, Javier Del Campo, de la Fuente José Luis, Sergio Rojas and Neus Sabaté
Energy Environ. Sci., 2014, Accepted Manuscript
DOI: 10.1039/C3EE44044C, Paper

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EES Issue 3 of 2014 out now!

Graphical abstract: Front coverThe latest issue of EES is now online. You can read the full issue here.

The outside front cover features the paper Optical designs that improve the efficiency of Cu2ZnSn(S,Se)4 solar cells by Mark T. Winkler, Wei Wang, Oki Gunawan, Harold J. Hovel, Teodor K. Todorov and David B. Mitzi.

Visible light driven photocatalysis mediated via ligand-to-metal charge transfer (LMCT): an alternative approach to solar activation of titania is the paper highlighted on the inside front cover by Guan Zhang, Gonu Kim and Wonyong Choi.

Issue 3 contains a number of excellent Opinion, Analysis, Review, and Perspective articles:

Solar energy: setting the economic bar from the top-down
E. W. McFarland

Large scale deployment of polymer solar cells on land, on sea and in the air
Nieves Espinosa, Markus Hösel, Mikkel Jørgensen and Frederik C. Krebs

Capacitive energy storage in micro-scale devices: recent advances in design and fabrication of micro-supercapacitors
Majid Beidaghi and Yury Gogotsi

Spin caloritronics
Stephen R. Boona, Roberto C. Myers and Joseph P. HeremansGraphical abstract: Inside front cover

Towards sustainable wastewater treatment by using microbial fuel cells-centered technologies
Wen-Wei Li, Han-Qing Yu and Zhen He

From lab to fab: how must the polymer solar cell materials design change? – an industrial perspective
Riccardo Po, Andrea Bernardi, Anna Calabrese, Chiara Carbonera, Gianni Corso and Andrea Pellegrino

Interfacial reactions in ceramic membrane reactors for syngas production
A. S. Yu, J. M. Vohs and R. J. Gorte

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This week’s HOT articles

Take a look at this week’s selection! These articles are available free for a limited time: Graphical abstract: Na0.67Mn1−xMgxO2 (0 ≤ x ≤ 0.2): a high capacity cathode for sodium-ion batteries

Na0.67Mn1−xMgxO2 (0 ≤ x ≤ 0.2): a high capacity cathode for sodium-ion batteries
Juliette Billaud, Gurpreet Singh, A. Robert Armstrong, Elena Gonzalo, Vladimir Roddatis, Michel Armand, Teófilo Rojo and Peter G. Bruce
DOI: 10.1039/C4EE00465E, Communication

Energy storage applications of activated carbons: supercapacitors and hydrogen storage
Marta Sevilla and Robert Mokaya
Energy Environ. Sci., 2014, Advance Article
DOI: 10.1039/C3EE43525C, Review Article

Novel “3-D spacer” all fibre piezoelectric textiles for energy harvesting applications
Navneet Soin, Tahir H. Shah, Subhash C. Anand, Junfeng Geng, Wiwat Pornwannachai, Pranab Mandal, David Reid, Surbhi Sharma, Ravi L. Hadimani, Derman Vatansever Bayramol and Elias Siores
Energy Environ. Sci., 2014, Advance Article
DOI: 10.1039/C3EE43987A, Paper

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Revealing electron transfer in current-producing bacteria

Bhavin Siritanaratkul is a guest web-writer for EES. Bhavin is a PhD student in Inorganic Chemistry at Oxford, under the supervision of Prof. Fraser Armstrong. In his spare time, he enjoys playing the piano and reading science fiction.

Researchers from Japan and the USA have found the first clue to the electron transfer mechanism in a species of current-producing bacteria.

Some bacteria can generate electrical energy from its metabolic systems, and they are used in microbial fuel cells and bioremediation processes. Geobacter sulfurreducens is the most efficient current-producing bacteria found so far, but there is no conclusive mechanism for electron transfer from the bacteria to the electrode.

In this paper, Ryuhei Nakamura et al. the authors identify self-secreted flavin as the electron shuttle involved in this extracellular electron transfer (EET). For this bacteria, free-floating flavin in the solution does not contribute to EET, as changing the solution to a fresh one did not impact current production. Instead, electron transfer occurs through flavin bound to c-type cytochromes (c-Cyts) on the outer membrane.

The authors confirmed flavin secretion by spectroscopy and mass chromatography, and voltammetry showed that current production was influenced by the amount of flavin present. The importance of c-Cyts was revealed by a mutant comparison experiment, in which a mutant lacking several major c-Cyts produced less current than the wild type.

Extracellular electron transfer (EET) is a key step in current production from bacteria, and understanding the mechanisms involved can lead to optimization of microbial fuel cells.

by Bhavin Siritanaratkul

For more information read this Energy & Environmental Science article:

Uptake of self-secreted flavins as bound cofactors for extracellular electron transfer in Geobacter species
Akihiro Okamoto, Koichiro Saito, Kengo Inoue, Kenneth H. Nealson, Kazuhito Hashimoto and Ryuhei Nakamura
DOI: 10.1039/C3EE43674H

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A Neutral Solution: Reliable PEC H2 Production at Near Neutral pH

In an exciting breakthrough in photoelectrochemical (PEC) solar generator development, a new report describes a methodology for robust H2 production in a near neutral environment.

Robust production of purified H2 in a stable, self-regulating, and continuously operating solar fuel generator

The development of practical, sustainable solar fuel generators comes with many challenges. Not only do the materials and components used need to be cost-effective and abundant, but the devices also need to be able to consistently produce purified fuels over long periods of time under environmentally benign conditions. A challenge to meeting all of these requirements has been in the creation of devices that are stable using either strong acid or basic electrolytes. A recent EES paper by Modestino et al. describes the development of a controlled recirculating stream across reactions sites to yield continuous solar-hydrogen generation in near neutral pH electrolytes.

In this report, researchers from the Joint Center for Artificial Photosynthesis and collaborating institutions describe alternate ion transport pathways that allow for operation under a near neutral pH. By creating a recirculation scheme to balance the concentration across the membrane in a membrane-separated photoelectrochemical (PEC) system, the authors achieved robust production of separated product streams (pure hydrogen and oxygen) via their ion-transport membrane components.

Designing a PEC device that operates using neutral pH electrolytes enables the use of catalytic and light absorbing components that would degrade in acidic or basic environments. The methodology described in this paper can provide researchers with a platform to experiment with different materials and hopefully optimize solar-to-hydrogen efficiency. It will be interesting to see the implementation of this methodology in future research, and if this approach ultimately provides a good solution to one major obstacle in the creation of scalable, sustainable, and robust solar fuel generators.

Read more in the full EES article here:

Robust production of purified H2 in a stable, self-regulating, and continuously operating solar fuel generator
Miguel A. Modestino, Karl A. Walczak, Alan Berger, Christopher M. Evans, Sophia Haussener, Carl Koval, John S. Newman, Joel W. Ager and Rachel A. Segalman
Energy Environ. Sci., 2014,7, 297-301
DOI: 10.1039/C3EE43214A

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This week’s HOT articles

Take a look at this week’s selection! These articles are available free for a limited time: Graphical abstract: Uptake of self-secreted flavins as bound cofactors for extracellular electron transfer in Geobacter species

Transforming an oxygen-tolerant [NiFe] uptake hydrogenase into a proficient, reversible hydrogen producer
Bonnie J. Murphy, Frank Sargent and Fraser A. Armstrong
DOI: 10.1039/C3EE43652G, Paper

Uptake of self-secreted flavins as bound cofactors for extracellular electron transfer in Geobacter species
Akihiro Okamoto, Koichiro Saito, Kengo Inoue, Kenneth H. Nealson, Kazuhito Hashimoto and Ryuhei Nakamura
DOI: 10.1039/C3EE43674H, Communication

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Top 10 most-read EES articles – Q4 2013

This month sees the following articles in Energy & Environmental Science that are in the top 10 most accessed from October –December:

The energetic implications of curtailing versus storing solar- and wind-generated electricity
Charles J. Barnhart, Michael Dale, Adam R. Brandt and Sally M. Benson
Energy Environ. Sci., 2013,6, 2804-2810
DOI: 10.1039/C3EE41973H, Analysis

Low-temperature processed meso-superstructured to thin-film perovskite solar cells
James M. Ball, Michael M. Lee, Andrew Hey and Henry J. Snaith
Energy Environ. Sci., 2013,6, 1739-1743
DOI: 10.1039/C3EE40810H, Communication

Electrochemical energy storage in a sustainable modern society
John B. Goodenough
Energy Environ. Sci., 2014,7, 14-18
DOI: 10.1039/C3EE42613K, Opinion

Challenges in the development of advanced Li-ion batteries: a review
Vinodkumar Etacheri, Rotem Marom, Ran Elazari, Gregory Salitra and Doron Aurbach
Energy Environ. Sci., 2011,4, 3243-3262
DOI: 10.1039/C1EE01598B, Review Article

Graphene-based nanocomposites: preparation, functionalization, and energy and environmental applications
Haixin Chang and Hongkai Wu
Energy Environ. Sci., 2013,6, 3483-3507
DOI: 10.1039/C3EE42518E, Review Article

Lithium ion battery applications of molybdenum disulfide (MoS2) nanocomposites
Tyler Stephenson, Zhi Li, Brian Olsen and David Mitlin
Energy Environ. Sci., 2014,7, 209-231
DOI: 10.1039/C3EE42591F, Review Article

Assessing the drivers of regional trends in solar photovoltaic manufacturing
Alan C. Goodrich, Douglas M. Powell, Ted L. James, Michael Woodhouse and Tonio Buonassisi
Energy Environ. Sci., 2013,6, 2811-2821
DOI: 10.1039/C3EE40701B, Analysis

Highly efficient organic tandem solar cells: a follow up review
Tayebeh Ameri, Ning Li and Christoph J. Brabec
Energy Environ. Sci., 2013,6, 2390-2413
DOI: 10.1039/C3EE40388B, Review Article

Depleted hole conductor-free lead halide iodide heterojunction solar cells
Waleed Abu Laban and Lioz Etgar
Energy Environ. Sci., 2013,6, 3249-3253
DOI: 10.1039/C3EE42282H, Communication

3D carbon based nanostructures for advanced supercapacitors
Hao Jiang, Pooi See Lee and Chunzhong Li
Energy Environ. Sci., 2013,6, 41-53
DOI: 10.1039/C2EE23284G, Review Article

Why not take a look at the articles today and blog your thoughts and comments below

Fancy submitting an article to EES? Then why not submit to us today!

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Putting the power in power-dressing – EES article in Chemistry World

Scientists in the UK developing wearable electronics have knitted a flexible fabric that delivers twice the power output of current energy harvesting textiles.

There is considerable interest and research into wearable piezoelectric energy harvesters that use waste energy from human movement or the ambient environment to power low-energy consuming wearable devices, such as wireless sensors and consumer electronics. Typically these materials are ceramic-based with limited flexibility, so aren’t that comfortable to wear, and include toxic elements like lead. They also involve charge-collecting metallic electrodes with poor fatigue resistance that fail after repeated use. New, less rigid materials with sufficient mechanical strength and an all-in-one design are therefore highly sought after.

The polymeric piezoelectric fibres created by Navneet Soin at the University of Bolton and colleagues in the laboratory of Elias Siores fulfill all of the above: they are flexible, strong and breathable.

Interested to know more? Read the full news article by Polly Wilson on Chemistry World here…

Read the article by N Soin et al. in EES:

Novel “3-D spacer” all fibre piezoelectric textiles for energy harvesting applications
Navneet Soin, Tahir Shah, Subhash Anand, Junfeng Geng, Wiwat Pornwannachai, Pranab Mandal, David Reid, Surbhi Sharma, Ravi Hadimani, Derman Vatansever Bayramol and Elias Siores
Energy Environ. Sci., 2014, Accepted Manuscript
DOI: 10.1039/C3EE43987A, Paper

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This week’s HOT article

Take a look at this week’s selection! This article is available free for a limited time: Graphical abstract: Spin caloritronics

Spin caloritronics
Stephen R. Boona, Roberto C. Myers and Joseph P. Heremans
DOI: 10.1039/C3EE43299H, Review Article

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EES Issue 2 of 2014 out now!

Graphical abstract: Front coverThe latest issue of EES is now online. You can read the full issue here.

The outside front cover features the paper Exciton diffusion in organic photovoltaic cells by S. Matthew Menke and Russell J. Holmes.

Lead candidates for high-performance organic photovoltaics from high-throughput quantum chemistry – the Harvard Clean Energy Project is the paper highlighted on the inside front cover by Johannes Hachmann, Roberto Olivares-Amaya, Adrian Jinich, Anthony L. Appleton, Martin A. Blood-Forsythe, László R. Seress, Carolina Román-Salgado, Kai Trepte, Sule Atahan-Evrenk, Süleyman Er, Supriya Shrestha, Rajib Mondal, Anatoliy Sokolov, Zhenan Bao and Alán Aspuru-Guzik.

Issue 2 contains a number of excellent Analysis, Review and Perspective articles:

Energy demand and emissions of the non-energy sector
Vassilis Daioglou, Andre P. C. Faaij, Deger Saygin, Martin K. Patel, Birka Wicke and Detlef P. van Vuuren

Lithium metal anodes for rechargeable batteries
Wu Xu, Jiulin Wang, Fei Ding, Xilin Chen, Eduard Nasybulin, Yaohui Zhang and Ji-Guang ZhangGraphical abstract: Inside front cover

Recent progress on flexible lithium rechargeable batteries
Hyeokjo Gwon, Jihyun Hong, Haegyeom Kim, Dong-Hwa Seo, Seokwoo Jeon and Kisuk Kang

Enhancing SOFC cathode performance by surface modification through infiltration
Dong Ding, Xiaxi Li, Samson Yuxiu Lai, Kirk Gerdes and Meilin Liu

Heterogeneous nanocarbon materials for oxygen reduction reaction
Da-Wei Wang and Dangsheng Su

Directing the film structure of organic semiconductors via post-deposition processing for transistor and solar cell applications
Anna M. Hiszpanski and Yueh-Lin Loo

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