A year of water splitting from one device

 Abigail Hallowes writes about an EES article in Chemistry World


Researchers from the US have optimised a photoelectrochemical cell (PEC) so that it can continuously split water into clean burning hydrogen and oxygen for over 2200 hours – the equivalent to one year of outdoor operation.

In order for PECs to be a competitive energy provider, they should efficiently covert solar into chemical energy, whilst remaining stable for years of continuous operation. The condition of the electrodes in PECs is a major concern as they immediately start to corrode once immersed in the electrolyte. Previous PEC researchers have only been able to produce systems that are either stable for 4–100 hours but inefficient, or efficient but only stable for a few minutes; they have not been able to incorporate both required properties.

Scanning-electron micrograph image of a microwire array with its protective coating

Scanning-electron micrograph image of a microwire array with its protective coating

 
Electrode instability is brought on when the energy required to excite an electron is within the same energy range that causes electrode corrosion; photocorrosion then becomes competitive with water splitting. In these cases, it is most likely that photocorrosion is thermodynamically more favourable which therefore leads to unstable electrodes. Now, a team led by Nathan Lewis at the California Institute of Technology have drastically increased PEC stability whilst achieving a 100% Faradaic efficiency for oxygen evolution.
 
Their approach increased the electrochemically active sites versus the surface area of the electrode through the use of silicon microwire arrays; this led to a decrease in the effective current density at the electrode–electrolyte interface, increasing the energy required for photocorrosion, which decreased the rate of photocorrosion. They also coated the arrays in a protective but conductive layer, to act as a corrosion-resistant barrier while maintaining efficient charge transfer to the reaction sites, as well as with an oxygen evolution catalyst to promote water oxidation.
 
Brian Seger, a photoelectrochemist at the Technical University of Denmark, explains that water splitting provides some very corrosive conditions so stability has been a large hurdle in this field: ‘The fact that the Lewis group could test their device for three months with no noticeable corrosion indicates that this hurdle is surmountable.’
 
Materials scientist, Dongyuan Zhao, of Fudan University, China, describes the work was a breakthrough and says it ‘shows great potential for industrial application.’

Interested to find out more? Read the full article by Abigail Hallowes in Chemistry World.

Read the original article in Energy and Environmental Science:

Stabilization of Si microwire arrays for solar-driven H2O oxidation to O2(g) in 1.0 M KOH(aq) using conformal coatings of amorphous TiO2
Matthew R. Shaner,ab   Shu Hu,ab   Ke Sunab and   Nathan S. Lewis
Energy Environ. Sci., 2015, Advance Article
DOI: 10.1039/C4EE03012E

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Emma Stephen writes about an EES article in Chemistry World

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Read the full news article on the work from Bert Sels et al. online at Chemistry World.

The original research article is also free to access for a limited time – download it here:

Direct catalytic conversion of cellulose to liquid straight-chain alkanes
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Redirecting electrons boosts algal hydrogen generation

Jonathan Midgley writes about an EES article in Chemistry World

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Hydrogen is increasingly being touted as an environmentally friendly alternative to conventional fossil fuels, but, ‘at present, hydrogen is mainly produced from natural gas, which makes it a “wolf in sheep’s clothing”,’ comments Oliver Inderwildi, a senior policy fellow at the Smith School of Enterprise and the Environment, University of Oxford, UK. Natural microalgae produce hydrogen by harnessing energy from sunlight, but their low production rate limits their practical application. Organisms typically use most of the electrons they generate to make the carbohydrates they need to live.

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Interested to find out more? Read the full article by Jonathan Midgley in Chemistry World.

Read the original article in Energy & Environmental Science:

Enhancing hydrogen production of microalgae by redirecting electrons from photosystem I to hydrogenase
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Energy Environ. Sci., 2014, Advance Article
DOI: 10.1039/C4EE01444H

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Wind-powered lighting is almost a breeze

Stephen McCarthy writes about an EES article in Chemistry World

Scientists in South Korea have created a material that emits bright white light when a stream of nitrogen is blown over it. The discovery paves the way for eco-friendly displays and lighting systems powered by natural winds.A stream of air causes the rods to bend, emitting light from the phosphors

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Interested to find out more? Read the full article by Stephen McCarthy in Chemistry World.

Read the original article in Energy & Environmental Science:

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DOI: 10.1039/C4EE01776E

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Vicki Marshall writes about an EES article in Chemistry World

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Interested to find out more? Read the full article by Vicki Marshall in Chemistry World.

Read the original article in Energy and Environmental Science:

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DOI: 10.1039/C4EE01546K 

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EES Impact Factor climbs even higher – 15.49

We are delighted to announce a huge rise in the Impact Factor* of Energy & Environmental Science to a record high of 15.49.

This increase means Energy & Environmental Science remains the #1 ranking journal (of all 205 journals) in its ISI subject category.

This great news demonstrates that the journal continues to attract and publish outstanding research, which appeals to its community-spanning international readership.ees cover

We wish to thank all our Board members, authors and referees for their continuing support – Energy & Environmental Science is your journal.

Please do continue to submit your best work to Energy & Environmental Science. We look forward to further success in the months and years ahead.

Read more about the 2013 Impact Factors from across RSC Publishing on the RSC Publishing Blog.

*The Impact Factor provides an indication of the average number of citations per paper. Produced annually, Impact Factors are calculated by dividing the number of citations in a year by the number of citeable articles published in the preceding two years. Data based on 2013 Journal Citation Reports®, (Thomson Reuters, 2014).

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Aaron Wheeler interviewed in Chemistry World

Energy and Environmental Science author Aaron Wheeler (University of Toronto) was recently interviewed in Chemistry World about his recent paper describing a technique that can screen algae with the aim of generating more efficient biofuels.

Here’s the beginning of the interview:

You recently reported an exciting technique that can screen algae grown under different wavelengths with the aim of generating more efficient biofuels.1 Can you tell me more about this work?

Sure, this was the first time we have developed a method for the area of renewable energy. I had a student, Steve Shih, who is now a postdoc at the Joint BioEnergy Institute in California, who became interested in the idea that we can cultivate algae to produce biofuel. Of course this is an idea that has been around for a while.

So, in looking at the problem it seems that the biofuel we can collect from algae does not have the required energy density relative to the cost needed to extract and generate fuel, to compete with non-renewable resources. There are ongoing efforts to develop ways to encourage algae to generate more lipids. The idea is that the algae generate stores of lipids that we can then extract and refine into fuel.

We saw an opportunity; we thought we might be able to build a microfluidic device that could rapidly screen for conditions that folks haven’t looked at before just to see if we could find some conditions that encouraged the algae to produce more lipids. A lot of time we start these projects but don’t end up with an exciting result, but this one was really exciting in that we believe we have identified a brand new phenomenon which is that, at least for this particular algae, if you culture them under yellow light they experience some sort of stress which causes them to increase lipid production!

Visit Chemistry World now to read the rest!

1. S C C Shih et al, Energy Environ. Sci., 2014, 7, 2366 (DOI: 10.1039/c4ee01123f)

Aaron Wheeler

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3D printing cuts fuel cell component costs

Energy and Environmental Science article featured in Chemistry World.

By using 3D printing researchers in the UK have cut the cost of manufacturing devices that produce hydrogen fuel by splitting water. The 3D printed plastic components developed by Lee Cronin and co-workers at the University of Glasgow, UK, allow for the construction of light weight and low-cost electrolysers that could make the currently expensive devices available to a wider audience. Hardware hackers in the scientific community are also encouraged to use the new manufacturing approach in open source developments.

Interested to find out more? For the full article visit Chemistry World.

Read the original article in Energy and Environmental Science – free to access until August 15th!

3D Printed Flow Plates for the Electrolysis of Water: an Economic and Adaptable Approach to Device Manufacture

Lee Cronin, Greig Chisholm, Philip Kitson, Niall Kirkaldy and Leanne Bloor

Energy Environ. Sci., 2014, Accepted Manuscript

DOI: 10.1039/C4EE01426J, Paper
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Solar cells: Tiny balls of fire – EES article featured in The Economist

A recent article in EES on how to increase the light-absorbing capability of a photoelectrochemical cell by arranging spheres of tungsten oxide has been selected as one of the three science articles featured in this week’s issue of The Economist. The article is written by Florent Boudoire and co-workers at the Swiss Federal Laboratories for Materials Science and Technology, where the group’s research efforts are concentrated on high performance ceramic materials for energy and the environment.

The Economist offers authoritative insight and opinion on international news, politics, business, finance, science, technology and the connections between them.

Read the full article on the website now!

Also check out the original research article which has been made free to access for a limited period of time! –

Florent Boudoire et al., Energy Environ. Sci., 2014, DOI: 10.1039/C4EE00380B

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