Lecture

LIC Lecture + drinks

• Sheena Louisia
• Julia Villalva Fernandez

Date

Monday 27 March 2023

Time

15:30 - 18:00 hour

Address

Gorlaeus Building
Einsteinweg 55
2333 CC Leiden

Room

LMUY Havinga Lecture Room, Atrium ground floor

With this event we celebrate the Marie Skłodowska-Curie postdoctoral fellowships of both Sheena Louisia and Julia Villalva Fernández.

Pogramme

15:30-16:30 | LMUY Havinga Lecture Room
Introduction
Lectures

16:30-18:00 | Atrium ground floor
Drinks

Sheena Louisia: Using X-rays to investigate the electrode-electrolyte interface

Biography
Sheena Louisia (Nouméa, New Caledonia, 1995) is a post-doctoral researcher in the Catalysis and Surface Science (CASC) group at Leiden University. She received her B.Sc. in Chemistry from McGill University, Montreal, in 2016 and her Ph.D. in Chemistry from the University of California, Berkeley in 2021. There, she developed her interest in electrocatalysis through the investigation of nanomaterial design for the electroconversion of CO₂ to energy-dense products under the supervision of Prof. Peidong Yang. Her expertise in this field was decisive in winning the first prize of NASA’s CO₂ Conversion Challenge in 2021 where the abiotic production of sugars from CO₂ was successfully optimized. Her work has resulted in more than 15 publications in top scientific journals.
Her interest in determining a better structure-activity understanding in electrocatalysis through operando characterization led her to continue her postdoctoral research under the supervision of Prof. Marc Koper and Prof. Rik Mom at Leiden University in 2022. Her research today focuses on the development of X-ray spectroscopy techniques for the investigation of electrochemical interfaces. To carry out this work, she was awarded this year with a Marie Skłodowska-Curie Actions Postdoctoral fellowship.

Abstract
The successful transition of a high-energy consuming society to a sustainable model relies on our ability to harvest, store, and utilize renewable but intermittent energy sources. The management of this energy in the form of electricity implies the importance of understanding the factors that govern electron transfers at the junction of several materials. In the field of electrocatalysis, these transfers are buried in the electrolyte and confined to a solid-liquid interface which presents numerous characterization challenges for electrochemists.

Here, we will show how X-ray spectroscopy techniques can overcome some of these challenges to offer new insights into the electron transfers that take place at the electrode-electrolyte interface. We will discuss how in a dip-and-pull geometry, X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS), can provide interface-sensitive information about a variety of electrochemical systems. From supporting fundamental modeling to improving the performance of carbon-free fuel electroproduction, we foresee the presented method will become a valuable tool in the field of electrochemistry at large.

 

Overview of the sensitization of stiff stilbene based receptors for the transport of anions across a lipid bilayer membrane.

Julia Villalva Fernández: Visible-light-activated transmembrane transport by photosensitized isomerization of stiff-stilbene based anion receptors

Biography
Julia Villalva carried out her bachelor’s and master’s thesis in Prof. J. C. Carretero group, at the Universidad Autónoma de Madrid, focusing on C-H bond functionalization using transition metal catalysts. She then moved to IMDEA Nanoscience Institute, where she obtained her PhD. During her PhD studies, she functionalized and studied the properties of 2D materials (MoS₂, franckeite or cylindrite) and single-wall carbon nanotubes. During this period, she started gaining interest in the supramolecular field. She obtained a short-term stay grant from the DAAD in order to develop a project in M. von Delius group (Ulm University) merging his expertise in dynamic covalent chemistry and supramolecular chemistry and her expertise in nanomaterials functionalization and characterization.

In 2020, after defending her PhD, she started working as a scientific consultant. Her main project (with Nanocore ApS) was focused on the reinforcement of polymeric materials with carbon nanotubes and the writing of several patents derived from it. In 2022, she joined the Wezenberg group at the Leiden Institute of Chemistry as a post-doctoral researcher to work on the development of photoresponsive anion receptors and transporters.

Abstract
Stimuli-responsive transmembrane anion transport proteins are essential for cellular life due to their implication in important biological functions. Supramolecular systems with analogous properties have been developed, however, most of them rely on the use of damaging UV light. The granted MSCA project (SENSiTRANS) will explore the activation of anion transporters using visible light by means of a sensitization strategy. The project will focus on the employment of photosensitizers able to trigger the isomerization of stiff-stilbene based anion receptors located in the lipid bilayer, allowing activation of passive transmembrane transport (down a concentration gradient). In addition, insertion of the photosensitizer in a vectorial manner into the lipid bilayer will be explored towards light-driven active transport (against a concentration gradient).