Potential of zero charge (PZC) is fundamentally important in electrochemistry and affects the activity of many energy storage and conversion processes. PZC at solid electrodes can be determined on single crystal electrodes using the differential capacitance and laser-induced potential transient. However, the distribution of PZC on a polycrystalline electrode, often treated as patches of single crystals of different orientations, has been less studied. Herein, we used the approach of scanning electrochemical cell microscopy (SECCM) to measure the local PZC on polycrystalline solid electrodes. The principle is based on the potential-dependent charging current on the working electrode defined by a nanodroplet in SECCM. Co-localized maps of PZC, electrocatalytic activities, and crystal orientations on Pt and Au show that the PZC and electrocatalytic activity of the hydrogen evolution reaction (HER) is correlated with the local crystal orientation on a polycrystalline electrode. Our results demonstrate such a technique as a general method to map the PZC of solid material at the nanoscale.

Mapping the local potential of zero charge at the electrode/electrolyte interface

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.