High-Resolution Studies of Photo(electro)catalysts by Electrochemical Scanning Probe Microscopies

Abstract

Photocatalytic processes are central to many energy and environmental applications; however, mechanistic understanding of these processes is incomplete. Traditional techniques provide bulk-averaged data, missing crucial activity variations between and within individual photocatalyst particles, which due to their small size are challenging to probe. Scanning electrochemical microscopy (SECM) and related techniques provide a unique spatially resolved perspective, enabling deeper insights into photocatalyst performance at the micro- and nanoscale. In this Article, we review applications of electrochemical scanning probe techniques in studies of particulate and two-dimensional photo(electro)catalysts and advancements in quantitative kinetic measurements and high-resolution mapping of CT and catalytic activity. The characterization of heterogeneous photocatalysts and co-catalysts by recently developed tunnelling mode of photo-SECM and expected synergy between amperometric and potentiometric nanoelectrochemical techniques are also discussed.