Electrochemical scanning probe microscopies for artificial photosynthesis

The rational design of efficient artificial photosynthetic components requires thorough understandings towards (photo)electrochemical properties and kinetic processes at the solid/liquid interface. Electrochemical scanning probe microscopy (EC-SPM), which enables the high-spatial resolution imaging in an electrolyte environment, becomes an indispensable experimental technique for operando studies of (photo)electrochemistry. This review summarizes the latest results of relevant EC-SPM techniques to study the interfacial properties of electrocatalysts and photoelectrodes. Covered methods include atomic force microscopy, Kelvin probe force microscopy, conductive atomic force microscopy, scanning tunneling microscopy, scanning electrochemical microscopy, and other advanced SPM-based operando techniques. Finally, we offer some perspectives on the future outlook in this fascinating research area.