Operando Electrochemical Raman Spectroscopy Studies of Working Electrodes in (Photo)electrocatalytic Water Splitting

Author: Timothy Lin

Faculty Supervisor: Jingjing Qiu

Department: Chemistry & Biochemistry

Operando Raman spectroscopy is an established vibrational spectroscopic technique with a wide range of applications in the field of chemical, material, and life sciences. Recently, the operando electrochemical Raman spectroscopy has received more research attention for the characterization of working electrodes in (photo)electrochemical catalysis. This technique allows for the characterization of the fate of electrocatalysts on the surface of working electrodes under electrochemical reaction conditions, which is crucial to determine the chemical identity of the electrocatalysts. We applied electrochemical Raman spectroscopy to study two electrodes in the (photo)electrocatalytic water splitting process, which is an important process to generate the clean energy hydrogen (H2) gas from water using solar energy and electricity. Specifically, we studied the stability of the electrocatalyst molybdenum sulfide (MoS2) on silicon (Si) photocathode for the hydrogen evolution reaction (HER) and the electrochemical transformation of the electrocatalyst cobalt hydroxide (Co(OH)2) on gold (Au) nanostructured photoanode for the oxygen evolution reaction (OER). We identified the correlation between the morphological changes and vibrational features of the MoS2 layer and detected the potential-dependent vibrational features of the Co(OH)2 film.