Rodney Smith1
University of Waterloo1
Defects within solid state materials can dramatically alter material properties, but direct analysis of such defects is particularly challenging. Such analysis is impeded by the low concentrations of defects relative to bulk sites, potential co-existence of multiple defect types in any given material, possibility of dynamic changes during catalysis, and fundamental limitations inherent in every characterization technique. We analyze distortions and defects in solids through indirect analysis, where changes in structural data for series of samples are monitored as a function of some perturbation. This talk will demonstrate how we have applied variable temperature Raman spectroscopy under controlled environments to analyze phase transitions in solid state materials commonly employed as (photo)electrocatalysts, with particular interest in how defects affect features such as the presence of phase transitions and the temperature at which they occur. Discussion will be focused on the analysis of protons trapped within hematite, a commonly employed photoelectrocatalyst for the oxygen evolution reaction, and the formation of disordered carbonate-containing overlayers on a family of perovskite electrocatalysts.