Scientific Reports Paper 2017

SUMMARY: A novel, non-hazardous photocatalytic material developed by scientists in the Energy Safety Research Institute (ESRI) at Swansea University is shown to effectively remove dye pollutants from water, adsorbing more than 90% of the dye and enhancing the rate of dye breakdown by almost ten times using visible light.

 

 

Rapid removal of harmful dye pollutants by a novel, non-hazardous composite

Exciting new material developed by Swansea scientists uses solar energy to remove man-made dye pollutants from water

 

 

Swansea – (June 22, 2017) – A novel composite material has been developed which shows promise as a catalyst for the degradation of environmentally-harmful synthetic dye pollutants, which are released at a rate of nearly 300,000 tonnes a year into the world’s water.  

The researchers, led by Dr. Charles W. Dunnill and Dr. Daniel Jones at the Energy Safety Research Institute in Swansea University, reported their discovery in the Nature open access journal Scientific Reports (https://www.nature.com/articles/s41598-017-04240-4).

By heating the reaction mixture at high pressures inside a sealed container, the composite is synthesised by growing ultra-thin “nanowires” of tungsten oxide on the surface of tiny particles of tantalum nitride.  As a result of the incredibly small size of the two material components – both the tantalum nitride and tungsten oxide are typically less than 40 billionths of a metre in diameter – the composite provides a huge surface area for dye capture.  The material then proceeds to break the dye down into smaller, harmless molecules using the energy provided by sunlight, in a process known as “photocatalytic degradation”.  Having removed the harmful dyes, the catalyst may simply be filtered from the cleaned water and reused.

While the photocatalytic degradation of dyes has been investigated for several decades, it is only relatively recently that researchers have developed materials capable of absorbing the visible part of the solar spectrum – other materials, such as titanium dioxide, are also able to break down dyes using solar energy, but their efficiency is limited as they only absorb higher energy, ultra-violet light.  By making use of a much greater range of the spectrum, materials such as those used by the ESRI team at Swansea University team are able to remove pollutants at a far superior rate.

Both of the materials used in the study have attracted significant interest in recent years.  Tungsten oxide, in particular, is considered one of the most promising materials for a range of photocatalytic applications, owing to its high electrical conductivity, chemical stability and surface activity, in addition to its strong light absorbance.  As a low band-gap semiconductor, tantalum nitride is red in colour due to its ability to absorb almost the entire spectrum of visible light and therefore extracts a high amount of energy from sunlight to power the degradation processes. 

However, the true potential of the two materials was only realised once they were combined into a single composite.  Due to the exchange of electrons between the two materials, the test dye used within the study was broken down by the composite at around double the rate achieved by tantalum nitride on its own, while tungsten oxide alone was shown to be incapable of dye degradation.  In contrast to other leading photocatalytic materials, many of which are toxic to both humans and aquatic life, both parts of the composite are classed as non-hazardous materials.

The scientists responsible for the study believe that their research provides just a taster of the material’s potential.  “Now that we’ve demonstrated the capabilities of our composite, we aim to not just improve on the material further, but to also begin work on scaling up the synthesis for real-world application.” said Dr. Jones.  “We’re also exploring its viability in other areas, such as the photocatalysed splitting of water to generate hydrogen.”

In addition to Drs. Dunnill and Jones, co-authors of the paper are Drs. Virginia Gomez, James McGettrick and Serena Margadonna and PhD students Bertrand Rome, Francesco Mazzali and Aled Lewis, who are all fellow researchers in the College of Engineering at Swansea University, in collaboration with Dr. Joseph Bear from the Materials Chemistry Centre at University College London and Dr. Waheed Al-Masry from the Department of Chemical Engineering at King Saud University, Saudi Arabia.  Financial support for the study was provided by the Welsh Government Sêr Cymru Programme and the FLEXIS project, which is part-funded by the European Regional Development Fund (ERDF) through the Welsh Government, as well as through collaboration with King Saud University.

The Energy Safety Research Institute (www.esri-swansea.org) is positioned to discover and implement new technology for a sustainable, affordable, and secure energy future and is housed on Swansea University’s new world class Bay Campus. ESRI provides an exceptional environment for delivering cutting edge research across energy and energy safety-related disciplines with a focus on renewable energy, hydrogen,  carbon capture and utilisation as well as new oil and gas technologies.

Read the open access article at https://www.nature.com/articles/s41598-017-04240-4.

Big Bang Fair 2017

This report concerns the activities of the Human to Hydrogen Experience @TheHydrogenBike at the Big Bang Fair 2017 in March 2017.

We attended the fair with a sponsorship from the RSC who gave us £4000 towards the stand in the Birmingham NEC.

The Hydrogen Bike is an outreach project by Swansea University that enables participants to donate their energy via a static bike and observe in real time their energy stored as hydrogen gas.  It facilitates real understanding and discussion as to the issues surrounding our renewable energy future and the use of hydrogen to store and move energy.

The team of chemists and engineers were amazing and full of enthusiasm for the full 4 days of intense activity.  6 of us went up and we spoke to more than 1500 people every day with at least a third of them actually getting on the bike.  The event was totally exhausting in a good way with at times groups of 20 small children peddling for 30 seconds, seeing their bubbles and then jumping off. While others spent longer on the bike making a substantial amount of hydrogen. The flame was well behaved and really opened the eyes of loads of people as to the cutting edge science that we do at Swansea and the benefits of Hydrogen as a potential store for renewable energy.

We counted people in two categories those on the bike and those actively watching the display and discussions.  Broken down daily:

  • Wednesday –  1193 recorded interactions with an additional 359 on the bike
  • Thursday – 1451 recorded interactions with an additional 679 on the bike
  • Friday – 965 recorded interactions with an additional 549 on the bike
  • Saturday ~1000 recorded interactions with an additional 500 on the bike

Giving us a total of more than 6500 interactions with people.

The age range was across the board with most being of school age.  The youngest child on the bike was probably about 3 years old and sat on the bike seat while here brothers turned the peddles long below her feet, while the oldest interaction would have been one of the grandparents taking their grandchildren to the show.  There were people from all backgrounds and ethnicities involved, reflecting the diverse backgrounds from which our school children originate.

There were a number of highlights for me. People declaring that we were the “Best event at the whole show” were pretty touching, as was the young lad who climbed out of his wheel chair and onto the bike in order to see his own hydrogen bubbles. Some of the more in-depth conversations about sustainable living and energy transfer were great, as was the animated argument about how we should ignore the laws of physics and run the bike off the hydrogen energy in order to make more hydrogen…..

We also came up with loads of improvements for the display and are now trying to implement them before our next outing.

I am extremely grateful to the RSC for their contribution and to the dedicated helpers on our team and look forward to the next encounter for The Hydrogen Bike.

 

Charlie Dunnill                                                                               @TheHydrogenBike

HEA Fellowship Application

I was bored, so I did a wordle of my HEA Fellowship application.

wordle-hea

Gas Safety

Gas safety gassafe

Joseph Bear’s poster MC12

S-Polymers MC12_2MB

Tower of London guide

This must be the best tour guide for the Tower of London ever..

Right click the mouse and select play.

 

 

I didn’t take this video and I make no claim to it, or the accuracy of it’s contents.  It is just funny..

Why space should not be measured in metric

Space in mteric

PhD in Renewable Energy Storage and Vectoring

With the modern shift to renewable energy supplies, there remains a significant problem in the buffering of supply and demand. Traditional renewable forms of energy such as wind wave and solar do not correlate in their supply with the demand for energy. Electricity is very difficult to store on a large scale so new forms of energy storage are required to smooth the supply and demand issues. Hydrogen is a fantastic possibility.

The project will look into the application of water splitting devices for the implementation of renewable energy storage in the form of hydrogen gas. Alkaline electrolysers will be engineered and modified with Matlab modelling used to guide the process.

Test cell2 Tests cell

This project will also  have an outreach element where members of the public can be enthused as to the benefits of hydrogen.

More details from the Swansea Post graduate pages HERE

Apply for the post by sending a CV and cover letter to me. C.Dunnill@Swansea.ac.uk

PhD in Solar Energy Harvesting

Fig 1

Solar energy harvesting is the direct conversion of sunlight to fuels.  My methods involve the use of bi-phasic catalysts to split water when under the influence of sunlight.

TiO2 has for many years been the pinnacle of photocatalytic research.  Doped TiO2 has shown much promise in applications with wide ranging consequence.  Another source of interest is in pure TiO2 but using the synergistic relationship between the different crystal structures.  Mixtures of both anatase and rutile have shown promise and are indeed the main composition of the commercial P25.

My new synthetic procedures allows for the production of bi-phasic nanoparticles.  Single particles consisting of half anatase and half rutile. These nanoparticles have allowed some interesting measurements to be carried out and helped to answer one of the big questions of semiconductor photocatalysis.  This is regarding the band alignment in a composite system of Anatase and Rutile.  Our Nature Materials paper on the revision of the band alignments of anatase and rutile we showed how this works.2015-01-16 10.20.43

This project will explore the plethora of different materials that could be married together using this synthetic technique and assess the composites for the use as solar energy harvesting photocatlaysts.

This project will also involve the design modification and optimization of an engineering device that will measure hydrogen produced in these reactions.  as well as having an outreach element where members of the public can be enthused as to the benefits of hydrogen.

More details from the Swansea Post graduate pages HERE

Apply for the post by sending a CV and cover letter to me. C.Dunnill@Swansea.ac.uk

Capitalism

capatalism

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