2D Materials for the Electrocatalytic Conversion of CO₂ and Water Depollution

Mitigating climate change and securing water resources are two of the major challenges of the century^1,2. In this context, membranes and electrocatalysis process are promising avenues to reduce the energy footprint, while mitigating carbon dioxide emissions. Our research aims to evaluate the potential of low dimensional materials for membrane and electrocatalytic applications.<br/>Due to their atomic thickness and confined interlayer spacing, nanolaminate membranes made of re-stacked 2D nanosheets could theoretically enable improved separation performance. We developed a novel strategy to control the interlayer spacing and improve the separation performance of nanolaminate membranes using covalent functionalization of exfoliated nanosheets. The functionalized MoS₂ membranes demonstrated remarkable performance for water purification and desalination, while they have enabled to discriminate the role of the surface and stacking disorder on the nanofluidic behavior of water in the laminates³.<br/>We also investigated the influence of surface chemistry on the electrocatalytic behavior of low dimensional materials. In particular, we have developed a new strategy to enhance the conversion of CO₂ to hydrocarbon molecules with two or more carbon atoms (C₂₊) via molecular doping of a metal catalyst⁴. Specifically, we have identified electrophilic functional groups that can direct electrochemical reactions to produce C₂₊ species such as ethanol and ethylene and improve reaction rates at the catalyst surface.<br/>In my presentation, I will review our recent findings on understanding electrocatalytic and nanofluidic phenomena that take place on the surface of low dimensional materials.<br/><br/><u>References</u>:<br/>1. Shannon, M. A. <i>et al.</i> <i>Nature</i> <b>2008</b>, 452, 301–310 (2008).<br/>2. Voiry, D., Shin, H. S., Loh, K. P. & Chhowalla, M. Low dimensional catalysts fr hydrogen evolution and CO2 reduction. <i>Nat. Rev. Chem. </i><b>2017</b>, 9858, 0105<br/>3. Ries, L. <i>et al.</i> Enhanced sieving from exfoliated MoS₂ membranes via covalent functionalization. <i>Nature Materials</i> <b>2019</b>, 18, 1112–1117.<br/>4. Wu, H. <i>et al.</i> Improved electrochemical conversion of CO2 to multicarbon products by using molecular doping. <i>Nature Communications</i> <b>2012</b>, 12, 1–11.