In Operando Surface Potential Sensing of Photo-electrochemical Anodes

July 25, 2018 ─ Get the latest solar water splitting research from the Boettcher group at University of Oregon, as well as Bruker’s recent Nanoelectrode probe and Data Cube developments. We start with interfacial charge transfer at the semiconductor-catalyst interface – an issue that is central for solar water splitting yet has been poorly understood. New insights require unique experimental approaches- such as using a nanoelectrode AFM-SECM probe, scanning the surface of at water splitting photoanode, and making local surface potential measurements, in operando. In this presentation, we will discuss fundamental aspects and capabilities of the probes used.

We then show how the technique allows for measurement of the surface potential and thickness-dependent electronic properties of cobalt (oxy)hydroxide phosphate (CoPi). We show that when CoPi is deposited on illuminated photoanodes like hematite (a-Fe2O3), it acts as both a hole collector and an oxygen evolution catalyst. The versatility of the technique is highlighted by comparing surface potentials of CoPi-decorated hematite and bismuth vanadate photoelectrodes. Watch the webinar.