PhD position in Photo-electrochemistry (M/F)

Job Description

Thesis Subject

Quantitative imaging of Photoinjected electrons triggered redox reactions

Your Work Environment

Functional surfaces are of paramount importance in a variety fields such as energy, analytical chemistry, catalysis,.. Several approaches for covalently bonding organic moieties to surfaces exist, often relying on local generation of highly reactive radicals near the substrate where it should add. Most often, fragile molecules with labile leaving groups are chosen, facilitating local generation of radicals as response to external stimuli, such as surface potentials or photochemical excitation.
However, such choice makes indirect and unspecific methodologies. While efficient, these routes for surface modification are prone to artifacts such as non specific absorption, parasitic reactions, or diffusion based resolution loss.

In this project, we will design and control a surface modifcaiton process based on a double, photo electrochemical, activation process, along with the tools for analyzing and controlling it.
The strategy is based on the principle of the PhotoInjection of Electrons (PIE): using highly energetic irradiation (typically pulsed UV laser pulses) electrons can be extracted from suitably polarized electrodes (Eapp). This process leads to the formation of solvated electrons e_solv^-, which are strongly reducing and can activate even stable molecular substrates (RX), as sketched in Figure.

The goal of the project, a collaboration between the PPSM (CNRS ENS Paris-Saclay) and the Institute de Sciences Chimiques de Rennes (ISCR), is to design electrochemical and optical tools to analyze this process, enabling determination of optimal conditions for surface functionalization. This will require the development of two new tools: (i) a photopotentiostat , to measure the injected photocharge, and (ii) an optical nanometrology strategy to quantify in situ the amount of photografted material.

The objective of this PhD will be the development of the optical strategy and its integration with the electrochemical one. Besides optimizing a sensitive quantitative phase imaging setup for analysis of thin surface layers in reflection mode, it will require fulfilling the following objectives: (i) to determine suitable irradiation conditions (wavelength, pulse duration, energy, surface potential, etc. ) for generating photoinjected electrons (ii) develop a photoelectrochemical protocol for measuring photo injection rates, notably using optical methodologies, (iii) optimize conditions to engage photoinjectionelectrons in surface functionalization reactions.


The PhD project will take place in the PPSM (ENS Paris-Saclay) in close collaboration with the Institut de Sciences Chimiques de Rennes. The PhD will be co-supervised by Vitor Brasiliense and Fabien Miomandre.

Constraints and risks

Handling chemical products, work in chemistry laboratory, work with laser sources.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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