Biography

Ph.D and Postdoctoral Opportunities

Competition funded Ph.D Position: Imido-Tungstate Photonic Materials: New Molecular Light Switches and Photosensitizers (Deadline Monday 27th November 2017)

Self-funded Ph.D Position: Polyoxothiometalates: The Primordial Answer to CO2 Mitigation (Deadline 31st May 2018)

To discuss possibilities for self-funded studentships, or post-doctoral fellowship applications in other areas please do not hesitate to contact me.

Biography

Dr. Fielden completed his MSci in Chemistry at the University of Bristol in 2000, before moving to the University of Glasgow where he graduated with a Ph.D in 2005 under the supervision of Prof. Leroy Cronin. He then spent two years working with Prof. Paul Kögerler at Ames Laboratory (Iowa State University) on the self-assembly and properties of polyoxometalates (POMs) and chiral magnetic materials. In 2007 he took up a postdoctoral position with Dr. Benjamin Coe at the University of Manchester, investigating redox-switchable NLO chromophores, and in 2010 was awarded a Marie Curie International Outgoing Fellowship. This took him back across the Atlantic to the laboratory of Prof. Craig Hill at Emory University, where he worked on POM functionalized photoelectrodes and the excited state properties of transition metal substituted POMs. He joined the UEA as a lecturer in 2012, transferring his Marie Curie reintegration year from Glasgow.

John is interested in the synthesis and optical and photophysical properties of coordination compounds and clusters, particularly relating to solar energy conversion and non-linear optics. Since joining UEA the main focus of his work has been the study of arylimido-polyoxometalates (a-POMs) as non-linear optical chromophores, and as sensitisers and coadsorbents for the p-type dye-sensitised solar cell, both applications making use of the POM's properties as an electron acceptor. He has also worked to develop new catalysts for small molecule activation, and new p-type semiconductor nanomaterials for use in dye-sensitized photocathodes.

Click here to go to the Energy Materials Laboratory homepage.

Selected Publications

Ahmed Al-Yasari, Nick Van Steerteghem, Hayleigh Kearns, Hani El Moll, Karen Faulds, Joseph A. Wright, Bruce S. Brunschwig, Koen Clays and John Fielden.
Organoimido-Polyoxometalate Non-Linear Optical Chromophores: A Structural, Spectroscopic and Computational Study
Inorg. Chem. 2017, 56, ASAP.
DOI:
 10.1021/acs.inorgchem.7b00708

Hani El Moll, Fiona A. Black, Christopher J. Wood, Ahmed Al-Yasari, Anil Reddy Marri, Igor V. Sazanovich, Elizabeth A. Gibson and John Fielden. 
Increasing p-type dye sensitised solar cell photovoltages using polyoxometalates
Phys. Chem. Chem. Phys. 2017, 19, 18831-18835.
DOI:
 10.1039/C7CP01558E

Elliot N. Glass, John Fielden, Zhuangqun Huang, Xu Xiang, Djamaladdin G. Musaev, Tianquan Lian and Craig L. Hill
Transition Metal Substitution Effects on Metal-to-Polyoxometalate Charge Transfer
Inorg. Chem. 201655, 4308-4319. DOI: 10.1021/acs.inorgchem.6b00060

Ahmed Al-Yasari, Nick Van Steerteghem, Hani El Moll, Koen Clays and John Fielden.
Donor-Acceptor Organo-Imido Polyoxometalates: High Transparency, High Activity Redox-Active NLO Chromophores
Dalton. Trans. 201645, 2818-2822.
DOI:
 10.1039/C6DT00115G

John Fielden, Jordan M. Sumliner, Nannan Han, Yurii Gueletii, Xu Xiang, Djamaladdin G. Musaev, Tianquan Lian, and Craig L. Hill.
Water Splitting with Polyoxometalate-Treated Photoanodes: Enhancing Performance through Sensitizer Design
Chem. Sci. 20156, 5531-5543.
DOI:
10.1039/C5SC01439E

Elliot N. Glass, John Fielden, Alexey L. Kaledin, Djamaladdin G. Musaev, Tianquan Lian, and Craig L. Hill.
Extending Metal-to-Polyoxometalate Charge Transfer Lifetimes: The Effect of Heterometal Location
Chem. Eur. J. 201420, 4297–4307.
DOI:
10.1002/chem.201304119 

Xu Xiang, John Fielden, William E. Rodríguez-Córdoba, Zhuangqun Huang, Naifei Zhang, Zhen Luo, Djamaladdin G. Musaev, Tianquan Lian, and Craig L. Hill.Electron Transfer Dynamics in Semiconductor–Chromophore–Polyoxometalate Catalyst Photoanodes
J. Phys. Chem. C 2013117, 918–926.
DOI: 10.1021/jp312092u

 

Career History

  • 2012 – Lecturer in Energy Materials, UEA School of Chemistry (confirmed spring 2016)
  • 2010 – 2013 Marie Curie International Outgoing Fellow, Emory University (Atlanta, USA) and UEA
  • 2007 – 2010 Post-Doctoral Research Associate, University of Manchester
  • 2005 – 2006 Post-Doctoral Research Associate, Ames Laboratory (US Department of Energy)
  • 2001 – 2004 Ph.D in Inorganic Chemistry, University of Glasgow
  • 1996 – 2000 MSci in Chemistry, University of Bristol

All Publications

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Al-Yasari, A., Van Steerteghem, N., Kearns, H., El Moll, H., Faulds, K., Wright, J. A., Brunschwig, B. S., Clays, K., Fielden, J.

(2017)

Organoimido-Polyoxometalate Nonlinear Optical Chromophores: A Structural, Spectroscopic, and Computational Study,

in Inorganic Chemistry

56

(17)

pp. 10181–10194

Full Text UEA Repository

(Article)

(Published)


El Moll, H., Black, F. A., Wood, C. J., Al-Yasari, A., Marri, A. R., Sazanovich, I. V., Gibson, E. A., Fielden, J.

(2017)

Increasing p-type dye sensitised solar cell photovoltages using polyoxometalates,

in Physical Chemistry Chemical Physics

19

pp. 18831-18835

Full Text UEA Repository

(Article)

(Published)


Glass, E., Fielden, J., Huang, Z., Xiang, X., Musaev, D., Lian, T., Hill, C.

(2016)

Transition Metal Substitution Effects on Metal-to-Polyoxometalate Charge Transfer,

in Inorganic Chemistry

55

(9)

pp. 4308-4319

Full Text UEA Repository

(Article)

(Published)


Al-Yasari, A., Van Steerteghem, N., El Moll, H., Clays, K., Fielden, J.

(2016)

Donor–acceptor organo-imido polyoxometalates: high transparency, high activity redox-active NLO chromophores,

in Dalton Transactions

45

(7)

pp. 2818-2822

Full Text UEA Repository

(Article)

(Published)


Fielden, J., Sumliner, J. M., Han, N., Geletii, Y., Xiang, X., Musaev, D. G., Lian, T., Hll, C. L.

(2015)

Water splitting with polyoxometalate-treated photoanodes: Enhancing performance through sensitizer design,

in Chemical Science

6

pp. 5531-5543

Full Text UEA Repository

(Article)

(Published)


Al-Yasari, A., Fielden, J.

(2014)

Polyoxometalates in visible-light photocatalysis and solar energy conversion,

in Reviews in Advanced Sciences and Engineering

3

(4)

article no. rase.2014.1077

pp. 304-319

Full Text UEA Repository

(Article)

(Published)


Tang, Y., He, W., Lu, Y., Fielden, J., Xiang, X., Yan, D.

(2014)

Assembly of ruthenium-based complex into metal-organic framework with tunable area-selected luminescence and enhanced photon-to-electron conversion efficiency,

in The Journal of Physical Chemistry C

118

(44)

article no. jp5092174

pp. 25365-25373

Full Text UEA Repository

(Article)

(Published)


Glass, E. N., Fielden, J., Kaledin, A. L., Musaev, D. G., Lian, T., Hill, C. L.

(2014)

Extending Metal-to-Polyoxometalate Charge Transfer Lifetimes: The Effect of Heterometal Location,

in Chemistry - A European Journal

20

(15)

pp. 4297-4307

Full Text UEA Repository

(Article)

(Published)


Sumliner, J. M., Lv, H., Fielden, J., Geletii, Y. V., Hill, C. L.

(2014)

Polyoxometalate multi-electron-transfer catalytic systems for water splitting,

in European Journal of Inorganic Chemistry

2014

pp. 635-644

Full Text UEA Repository

(Article)

(Published)


Xiang, X., Fielden, J., Rodríguez-Córdoba, W., Huang, Z., Zhang, N., Luo, Z., Musaev, D., Lian, T., Hill, C.

(2013)

Electron transfer dynamics in semiconductor–chromophore–polyoxometalate catalyst photoanodes,

in The Journal of Physical Chemistry C

117

(2)

pp. 918-926

Full Text UEA Repository

(Article)

(Published)


Fielden, J., Long, D., Speldrich, M., Kögerler, P., Cronin, L.

(2012)

[CoxCu1−x(DDOP)(OH2)(NO3)](NO3): hydrogen bond-driven distortion of cobalt(ii) by solid solution ‘network mismatch’,

in Dalton Transactions

41

(16)

pp. 4927-4934

Full Text UEA Repository

(Article)

(Published)


Fielden, J., Quasdorf, K., Cronin, L., Kögerler, P.

(2012)

A fluorophosphate-based inverse Keggin structure,

in Dalton Transactions

41

(33)

pp. 9876-9878

Full Text UEA Repository

(Article)

(Published)


Fielden, J., Speldrich, M., Besson, C., Kögerler, P.

(2012)

Chiral Hexanuclear Ferric Wheels,

in Inorganic Chemistry

51

(5)

pp. 2734-2736

Full Text UEA Repository

(Article)

(Published)


Tennant, D., Lake, B., James, A., Essler, F., Notbohm, S., Mikeska, H., Fielden, J., Kögerler, P., Canfield, P., Telling, M.

(2012)

Anomalous dynamical line shapes in a quantum magnet at finite temperature,

in Physical Review B

85

(1)

pp. 014402-014413

Full Text UEA Repository

(Article)

(Published)


Coe, B., Fielden, J., Foxon, S., Asselberghs, I., Clays, K., Van Cleuvenbergen, S., Brunschwig, B.

(2011)

Ferrocenyl Diquat Derivatives: Nonlinear Optical Activity, Multiple Redox States, and Unusual Reactivity,

in Organometallics

30

(21)

pp. 5731-5743

Full Text UEA Repository

(Article)

(Published)


Blackburn, O., Coe, B., Fielden, J., Helliwell, M., McDouall, J., Hutchings, M.

(2010)

Nickel(II) and Palladium(II) Complexes of Azobenzene-Containing Ligands as Dichroic Dyes,

in Inorganic Chemistry

49

(20)

pp. 9136-9150

Full Text UEA Repository

(Article)

(Published)


Clays, K., Docherty, R., Fielden, J., Helliwell, M., Raftery, J., Shaw, R., Swanson, C., Coe, B.

(2010)

Designing organic molecules for terahertz radiation generation in robust crystals,

Full Text UEA Repository

(Paper)

(Published)


Coe, B., Fielden, J., Foxon, S., Asselberghs, I., Clays, K., Brunschwig, B.

(2010)

Two-Dimensional, Pyrazine-Based Nonlinear Optical Chromophores with Ruthenium(II) Ammine Electron Donors,

in Inorganic Chemistry

49

(22)

pp. 10718-10726

Full Text UEA Repository

(Article)

(Published)


Coe, B., Fielden, J., Foxon, S., Brunschwig, B., Asselberghs, I., Clays, K., Samoc, A., Samoc, M.

(2010)

Combining Very Large Quadratic and Cubic Nonlinear Optical Responses in Extended, Tris-Chelate Metallochromophores with Six π-Conjugated Pyridinium Substituents,

in Journal of the American Chemical Society

132

(10)

pp. 3496-3513

Full Text UEA Repository

(Article)

(Published)


Coe, B., Fielden, J., Foxon, S., Harris, J., Helliwell, M., Brunschwig, B., Asselberghs, I., Clays, K., Garín, J., Orduna, J.

(2010)

Diquat Derivatives: Highly Active, Two-Dimensional Nonlinear Optical Chromophores with Potential Redox Switchability,

in Journal of the American Chemical Society

132

(30)

pp. 10498-10512

Full Text UEA Repository

(Article)

(Published)


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Key Research Interests

The Fielden group is currently working in the following areas:

  • Polyoxometalate-based non-linear optical chromophores and electropolymers. We have recently obtained a series of donor-acceptor chromophores based on polyoxometalates, including systems based on electropolymerizable pyrrole units.  The resulting materials obtain unusually high activity from moderate donor groups and short pi-systems, due to extension of charge transfer onto the POM. We are now working to develop ways of including these materials in films with bulk NLO activity and switchable responses.
  • New catalysts: We are using small, heteroleptic tripodal ligands as a platform to build catalysts for small molecule activation.  The ligands can coordinate a transition metal in a bidentate or tetradentate coordination pocket, while providing a pendant group for introduction of proton or electron relays.  These will allow controlled study of secondary coordination sphere effects. 
  • POM-derivatives as photosensitizers: We are investigating the use of POMs as electron acceptor units in push-pull chromophores.  These are designed to improve the efficiency of p-type dye-sensitized solar cells by retarding recombination of photo-excited electrons to NiO, one of the major sources of inefficiencies in these systems.  
  • New p-type semiconductor nanomaterials: In this project, supported by EU Marie Curie fellowship NanoCuI to Dr. Anil Reddy Marri, we are developing nanoporous copper iodide substrates as a replacement of the NiO p-type semiconductor in the p-type dye-sensitized solar cell (p-DSSC, collaboration with Dr. Andrew Mayes, UEA and Dr Elizabeth Gibson, Newcastle). p-DSSCs, in combination with conventional n-type DSSCs, could be used to make tandem DSSCs with better spectral coverage (light absorption at both electrodes) and photovoltage. However, at present p-DSSCs do not perform well enough to realise this promise, because the conductivity of the NiO substrate is poor. Gamma-CuI has an intrinsically much higher conductivity than NiO, so could produce much better devices, but the high surface area nanoporous electrodes needed for efficient dye sensitization do not yet exist. We are using chemical and electrochemical deposition methods to develop them.

Research Group Membership

The Fielden Group, February 2015

From left to right: Simon Child, John Fielden, Natalia Sanchez Moreno, David Miko, Phil Spence, Hani El-Moll, Ahmed Al-Yasari

From left to right: Simon Child, John Fielden, Natalia Sanchez Moreno, David Miko, Phil Spence, Hani El-Moll, Ahmed Al-Yasari

And among the Ziggurats...

Fielden group outside the UEA Ziggurat buildings

Fielden group outside the UEA Ziggurat buildings

 

 

External Activities and Indicators of Esteem

  • School Visits - The Deepings School, March 2017; Trent College, February 2016
  • Invited Research Talks: University of Glasgow (2017), FMOCS-PoCheMon (2016), University of Newcastle (2016), University of Southampton (2016); Emory University (2015), University of Central Lancashire (2015)
  • Outreach - Norwich Science Cafe 2013 - Talk on Artificial Photosynthesis
  • Outreach - Photon Science Institute/Manchester Museum of Science and Industry 2010 - Meet the Photon Scientist

Administrative Posts

Module Organiser: Year 2 Inorganic Chemistry (CHE-5301B)

Head of Second Year Chemistry

Chemistry Representative: Science Faculty Analytical Facilities User Group