Microscale Electrical Resistivity Measurements to Investigate Particle Distribution.

The functional performance of a particulate thin film depends greatly on the particle distribution that forms during drying. In situ methods for monitoring the impact of different processing parameters on the distribution of particles currently require expensive and specialized equipment. This work addresses this gap by miniaturizing a geophysical prospecting method to thin-film applications.

A Co-Doping Materials Design Strategy for Selective Ozone Electrocatalysts.

Catalysts for electrochemical ozone production (EOP) face inherent selectivity challenges stemming from thermodynamic constraints. This work establishes a design strategy for minimizing these limitations and inducing EOP activity in tin oxide, which is an intrinsically EOP-inactive material. We propose that selective ozone production using tin oxide catalysts can be broadly achieved by co-doping with two elements: first, n-type dopants to enhance electrical conductivity, and second, transition metal dopants that leach and homogeneously generate essential hydroperoxyl radical intermediates.

Interplay between Catalyst Corrosion and Homogeneous Reactive Oxygen Species in Electrochemical Ozone Production.

Electrochemical ozone production (EOP), a six-electron water oxidation reaction, offers promising avenues for creating value-added oxidants and disinfectants. However, progress in this field is slowed by a dearth of understanding of fundamental reaction mechanisms. In this work, we combine experimental electrochemistry, spectroscopic detection of reactive oxygen species (ROS), oxygen-anion chemical ionization mass spectrometry, and computational quantum chemistry calculations to determine a plausible reaction mechanism on nickel- and antimony-doped tin oxide (Ni/Sb-SnO, NATO), one of the most selective EOP catalysts.

Modifying the Electrocatalyst-Ionomer Interface via Sulfonated Poly(ionic liquid) Block Copolymers to Enable High-Performance Polymer Electrolyte Fuel Cells.

Polymer electrolyte membrane fuel cell (PEMFC) electrodes with a 0.07 mg cm Pt/Vulcan electrocatalyst loading, containing only a sulfonated poly(ionic liquid) block copolymer (SPILBCP) ionomer, were fabricated and achieved a ca. 2× enhancement of kinetic performance through the suppression of Pt surface oxidation.

Kinetic Isotope Effects Quantify pH-Sensitive Water Dynamics at the Pt Electrode Interface.

The pH-dependent kinetics of the hydrogen oxidation and evolution reactions (HERs and HORs) remain a fundamental conundrum in modern electrochemistry. Recent efforts have focused on the impact of the interfacial water network on the reaction kinetics. In this work, we quantify the importance of interfacial water dynamics on the overall hydrogen reaction kinetics with kinetic isotope effect (KIE) voltammetry experiments on single-crystal Pt(111) and Pt(110).

The Impotence of Non-Brownian Particles on the Gel Transition of Colloidal Suspensions.

The ability to predict transitions in the microstructure of mixed colloidal suspensions is of extreme interest and importance. The data presented here is specific to the case of battery electrode slurries whereby the carbon additive is reported to form strong colloidal gels. Using rheology, we have determined the effect of mixed particle systems on the critical gel transition ϕ gel .

Direct observation of active material interactions in flowable electrodes using X-ray tomography.

Understanding electrical percolation and charging mechanisms in electrochemically active biphasic flowable electrodes is critical for enabling scalable deionization (desalination) and energy storage. Flowable electrodes are dynamic material systems which store charge (remove ions) and have the ability to flow. This flow process can induce structural changes in the underlying material arrangement and result in transient and non-uniform material properties.

Nickel-silver alloy electrocatalysts for hydrogen evolution and oxidation in an alkaline electrolyte.

The development of improved catalysts for the hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) in basic electrolytes remains a major technical obstacle to improved fuel cells, water electrolyzers, and other devices for electrochemical energy storage and conversion. Based on the free energy of adsorbed hydrogen intermediates, theory predicts that alloys of nickel and silver are active for these reactions. In this work, we synthesize binary nickel-silver bulk alloys across a range of compositions and show that nickel-silver alloys are indeed more active than pure nickel for hydrogen evolution and, possibly, hydrogen oxidation.