Cations promoting synthesis of self-supported nanoporous silver electrode and its catalytic activity for oxygen reduction reaction.

Graphical abstract Highlights • Cu2+ drives the spontaneous formation of AgCl on Ag surface via microcell reactions. • Potential bias promotes the process due to surface enrichment of Cu2+. • Self-supported nano-Ag were obtained from by electro-reduction of AgCl. • The nano-Ag shows good activity and stability to the oxygen reduction reaction. • The approach provides an alternative way to prepare self-supported nanoporous metals. Abstract Self-supported nanoporous metals are promising catalysts and battery materials due to their continuous channels, excellent conductivity and high surface area. In this work, we found that Cu2+ cations could promote the spontaneous formation of AgCl on Ag surface via microcell reactions. Applying a potential to the silver electrode promotes the surface enrichment of Cu2+ cations, and further speeds the formation of AgCl. After electro-reduced, AgCl was transformed to self-supported silver electrode with nanoporous structures, which shows good catalytic activity for the oxygen reduction reaction and electrochemical stability together with superior methanol tolerance property, compared to the pristine silver electrode. The approach used in this work provides an alternative way to prepare self-supported nanoporous metals. [ABSTRACT FROM AUTHOR]