Oxygen Evolution Reaction (Photo-)Electrocatalysts as studied by Scanning Electrochemical Microscopy and X-Ray Absorption Spectroscopies Seminar

Time:: 16:00
Date:: 3 March 2016
Venue:: Building 27, Room 2003, Chemistry, University of Southampton, SO17 1BJ

For more information regarding this seminar, please email Nuria Garcia-Araez at N.Garcia-Araez@soton.ac.uk .

Event details

Alessandro Minguzzi presents a seminar as part of the electrochemistry sections seminar series.

The research on new electrodes and photoelectrodes for energy conversion devices should in principle conjugate the selection of new materials and synthetic methods to the setup of new techniques for their faster and more accurate characterization and for a deeper understanding of the reaction mechanism. On this bases, the present talk will be focused on new methods for the rapid screening of (photo-) electrocatalysts activity using the scanning electrochemical microscope (1,2) and on the use of X-ray absorption spectroscopy for a better understanding of the (photo-) electrochemical behaviour of two model systems: IrO2 and α-Fe2O3/IrO2.

In this framework, the introduction of the Fixed Energy X-Ray Absorption Voltammetry (3) represents a key step for fast and easy preliminary characterization of electrodes and photoelectrodes. In fact, FEXRAV consists in recording the absorption coefficient at a fixed energy while varying at will the electrode potential. The energy is chosen close to a core level absorption edge, in order to give the maximum contrast between different oxidation states of an element. It follows that any shift from the initial oxidation state determines a variation of the X-ray absorption coefficient. FEXRAV allows to quickly map the variation of the oxidation states of the element under consideration in a desired potential window.

As a result, FEXRAV gives important information by itself but can also serve as a preliminary screening of the potential window or, more generally, for choosing the best experimental conditions for a better targeted XAS analysis. This led, for example, to the observation (4,5) of more than one Ir oxidation state at E >1.23V (RHE), which is consistent with its role in the water oxidation catalytic cycle. More recently, studies by time-resolved energy dispersive and pump-and-probe XAS have been carried out with the aim of studying the time-dependence of interfacial phenomena, also in the framework of photoelectrochemical water splitting.

(1) Minguzzi, A., Apulche-Aviles, M. A., Rodriguez Lopez, J., Rondinini, S., Bard, A.J. Anal. Chem.2008, 80, 4055.

(2) Minguzzi A., Battistel D., Rodriguez-Lopez J., Vertova A., Rondinini S., Bard A.J., Daniele S., J.Phys. Chem. C, 2015, 119, 2941–2947

(3) Minguzzi, A.; Lugaresi, O.; Locatelli, C.; Rondinini S.; d'Acapito, F.; Achilli, E.; Ghigna, P. Anal.Chem. 2013, 85, 7009-7013.

(4) Minguzzi A., Lugaresi O., Achilli E., Locatelli C., Vertova A., Ghigna P., Rondinini S., Chem. Sci.2014. 5, 3591.

(5) Minguzzi A., Locatelli C., Lugaresi O., Achilli E., Cappelletti G., Scavini M., Coduri M., Masala P.,Sacchi B., Vertova A., Ghigna P., Rondinini S., ACS Catalysis, 2015, 5, 5104−5115

Speaker information

Alessandro Minguzzi, Department of Chemistry, the University of Milan. Assistant Professor since 2013. Research activities: Physical-Chemistry and electrochemistry of materials. Electrocatalysis. Innovative methods in electrocatalysis and photoelectrochemistry. 37 Publications on international, peer-reviewed journals, more than 60 presentation and conferences, 5 invited seminars/oral communications, reviewer of high ranked journals (Nature, JACS, Advanced Energy Materials, ACS Nano, Chemical Science, ACS Catalysis ...). Carreer: PhD (2007) and post doc at the University of Milan (2008-2013); visiting researcher at (2006) the Laboratoire de Electrochimie et Synthèse Organique, Institut de Chimie et des Matériaux Paris Est, CNRS, Parigi (funded by COST D29 project); (2008) Prof. S. Daniele group (Università “Ca’ Foscari”, Venezia); (2007 and 2010) Prof. A.J. Bard group (University of Texas at Austin, TX, USA). 2011 – invited at the University of Alicante, Spain, to spend a research period and to give a seminar as expert in electrocatalysis and innovative electrochemical investigation methods. 2013 – elected member of the board of the Electrochemical Division of the Italian Chemical Society Awards: - 2006 “AMEL s.r.l.” prize, Electrochemical Division of the Italian Chemical Society - 2010 “F.I.A.M.M. S.p.A.” prize, Electrochemical Division of the Italian Chemical Society - “ISE Travel Award for Young Electrochemists”, by the International Society of Electrochemistry - ”Poster award" at the 7th Workshop on SECM and related techniques (Ein Gedi, Israel) - "Primo Levi Prize 2014", Italian Chemical Society. Fundings: Ministry of Education, Universities and Research (Italy)- Futuro in Ricerca 2013, head of the UniMI research unit for a project on “Low-cost photoelectrodes architectures based on the redox cascade principle for artificial photosynthesis" - Oronzio and Niccolò De Nora fellowship (2007) - 6 proposals funded by ESRF as main proposer, 2 as co-proposer - PI for a 2-year Block Allocation Group Proposal at Beamline 08, ESRF. - Piano di Sostegno alla Ricerca 2015, Principal Investigator, University of Milan Selected Publications • A. Minguzzi, D. Battistel, J. Rodríguez-‐López, A.Vertova, S. Rondinini, A.J. Bard, S. Daniele “Rapid characterization of oxygen-‐evolving electrocatalyst spot arrays by the substrate generation/tip collection mode of scanning electrochemical microscopy with decreased O2 diffusion layer overlap” Journal of Physical Chemistry C, 119 (2015) 2941-‐2947 • A. Minguzzi, C. Locatelli, O. Lugaresi, E. Achilli, G. Cappelletti, M. Scavini, M. Coduri, P. Masala, B. Sacchi, A. Vertova, P. Ghigna, S. Rondinini, “Easy Accommodation of Different Oxidation States in Iridium Oxide Nanoparticles with Different Hydration Degree as Water Oxidation Electrocatalysts” ACS Catalysis, 5 (2015) 5104−5115 • F. Malara, A. Minguzzi, M. Marelli, S. Morandi, R. Psaro, V. Dal Santo, A. Naldoni “α‑Fe2O3/NiOOH: An Effective Heterostructure for Photoelectrochemical Water Oxidation” ACS Catalysis, 5 (2015) 5292−5300 • S. Morandi, A. Minguzzi “The cavity-‐microelectrode as a tip for scanning electrochemical microscopy” Electrochemistry Communications, 59 (2015) 100–103 • A. Minguzzi, O. Lugaresi, E. Achilli, C. Locatelli, A. Vertova, P. Ghigna, S. Rondinini. “Observing the Oxidation State Turnover in Heterogeneous Iridium-‐Based Water Oxidation Catalysts”, Chemical Science 5 (2014), 3591-‐3597 • A. Minguzzi, O. Lugaresi, C. Locatelli, S. Rondinini, F. D’Acapito, E. Achilli, Paolo Ghigna “Fixed Energy X-‐Ray Absorption Voltammetry (FEXRAV)” Analytical Chemistry 85 (2013) 7009−7013