Electrochemical fabrication and characterizations of Ag/AgCl pseudo-reference electrode: a preliminary study

Abstract

Abstract In this work Ag/AgCl planar pseudo-reference electrodes (pREs) were fabricated and studied. The pRE was derived from typical copper-cladded flame retardant 4 (FR4) board, with layers of Ni, Au, and Ag electrochemically deposited sequentially. Lastly, the AgCl layer was obtained through electro-chlorination process. The morphology and Open Circuit Potential (OCP) of the samples were obtained from characterizations. It was revealed that the Au layer consisted of finer grains compare to that of Ag having larger granular structure. There was also morphological difference between as-prepared AgCl and post OCP run AgCl, where the later show signs of degradation. Based on the potential-transient curve of electro-chlorination, chlorination process took place on the surface of Ag, subsequently diffused into the bulk layer. Sample chlorinated for 1 min shows better stability in OCP test where the potential exhibit minimum changes. The duration of the sample being stable during electrochemical process was 10 minutes.