(Invited) Soapy Molecules for Photocatalysis in Soft Membranes: A Multidisciplinary Approach Towards Solar Fuels

Abstract

Natural photosynthesis takes place at lipid bilayers. Although major progress has been achieved in understanding how it works, science is still unable to re-create an efficient, lipid-based photocatalytic membrane that can generate solar fuels. To understand what happens when a photocatalytic system is embedded in a soft membrane, a multidisciplinary approach is needed. In this presentation I will discuss how to synthesize and characterize “soapy” photosensitizers and catalysts that can be used to functionalize soft interfaces. Using these molecules, my group has been able to study water oxidation and proton reduction in liposomes and foams. To understand the influence of the soft matter interface on photocatalysis, and notably compare it to homogeneous conditions, it is necessary to measure the diffusion of molecules in the membrane as well as electron transfer rates using time-resolved spectroscopy. On the one hand these studies highlighted the exceptional lifetimes of a selection of spectroscopically visible photoreduced and photooxidized catalytic intermediates; on the other hand, full understanding of the role of the soft interface on photocatalysis is still hindered by the spectroscopic invisibility of other intermediates, as well as by the challenge of modelling photocatalytic interfaces. Figure 1