Engineering topics
Loney, Charles N.
Publications and source records attributed to Loney, Charles N..
Effects of Peptide-Functionalized Surfaces on the Electrochemical Hydrogen Evolution Reaction
Abstract This review outlines the approaches and mechanisms through which peptides and amino acids functionalize electrocatalytically active surfaces to promote or inhibit the electrochemical hydrogen evolution reaction (HER). HER is important in many electrochemical systems. For example, HER is highly desired in water electrolysis, which if driven by renewable energy could serve as a green alternative to the fossil-fuel-driven steam methane-reforming process. However, HER is often an undesired side reaction and thus limits the selectivity of promising electrochemical technologies such as electrochemical nitrogen reduction or carbon dioxide reduction. In pursuing higher product selectivity and yield in emerging and existing electrochemical systems, amino acids and short-chain peptides are promising molecules for the modification of electrochemically active surfaces. Peptides are attractive because they are highly tunable, which allows for versatility in their applications. This short review article summarizes literature that illustrates the mechanisms through which electrode-bound peptides can affect HER including via modulating surface binding and adsorbate coverage, altering the surface composition, and controlling proton transfer rates. Our goal is to motivate additional studies utilizing electrode-bound peptides to modulate electrochemical hydrogen evolution reactions.
Interactions of Polyproline II Helix Peptides with Iron(III) Oxide
Interactions of a peptide with polyproline II helical secondary structure with maghemite (iron(III) oxide, Fe 2 O 3 ) surfaces were characterized using a variety of surface techniques. A quartz crystal microbalance with dissipation was used to measure the hydrated mass and thickness (92 ± 29 ng/cm 2 and 0.89 ± 0.27 nm, respectively) of a layer which formed after a sensor coated with Fe 2 O 3 was exposed to the peptide in aqueous solution. The analysis revealed that the peptide formed a stable thin layer on the sensor. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy of the monolayer were employed to study the relationship between the metal and the peptide. Finally, Fe 2 O 3 nanoparticles were incubated with the peptide, and analysis of the settling and particle size revealed that the presence of the peptide reduced the occurrence of large aggregates in solution.