Electrocatalysis and Plasmon-Induced Electrocatalysis
PhD students: Jintao Fu, Tim Lee,
Undergraduate students: Alexander Proschel
Post Doc: Dr. Pengtao sheng
This project is aimed at tailoring the nature and density of catalytic active sites (active facets, terraces, steps) at the interface of nanoporous metals, in order to significantly enhance their electrocatalytic activities toward CO2 reduction, O2 reduction, and N2 reduction reactions (see Figure 1). We also take advance of the plasmonic properties of nanoporous metals to further enhance their catalytic performance. Some examples of ongoing projects are provided below.
Lead student: Jintao Fu
- Tailoring the Electrocatalytic Activity of Nanoporous Metals by Defect and Facet Engineering
As an example of project, here we tuned the electrocatalytic activity of nanoporous bimetallic Au-Ag nanoparticles with composition Au40Ag60at. %, in order to boost its electrocatalytic performance. In doing so, surfactant-assistant facet-engineering was used to enrich the nanoporous nanoparticles surface with (100) facets and terraces. A significant improvement in the electrocatalytic activity of the facet-tailored porous Au40Ag60 nanoparticles was then observed, (see Figure 2) as evidenced by their smaller Tafel plot slope compared to that of pristine porous Au40Ag60 (68 mV/decade vs. 95 mV/decade), and a 48.8 % increase in the limiting current density compared to that of pristine porous Au40Ag60.
Reference: P. Sheng, Z. Wang, J. Fu and E. Detsi, Unpublished
- Visible Light Plasmonic Heating-Enhanced Electrochemical Activity
Taking advantage of the localized surface resonance effect to boost the performance of electrochemical cells has rarely been demonstrated using nanoporous metal films as photoactive electrodes. Rather, studies on plasmon-enhanced electrochemical processes use plasmonic metal nanoparticles loaded onto semiconductor or conductor substrates. In this project, we use visible light to significantly enhance the kinetics of a redox reactions. As a proof-of-concept, a 20-fold increase in the electrochemical current density associated with hydrogen evolution reaction on nanoporous Au cathode was demonstrated upon exposure of this nanoporous Au cathode to visible light (see Figure 3). We demonstrate that this significant current enhancement is associated with local heat generated in Au during localized surface plasmon resonance. This concept is exploited to develop high-performance heterogeneous plasmon-induced electrocatalysts based on plasmonic heating, for the conversion of renewable energy resources into fuels and value-added chemicals.
Reference: A. Pröschel, J. Chacko, R. Whitaker, M. A. U Chen, and E. Detsi, Journal of The Electrochemical Society 166, H146-H150, 2019