In situ measurement of pH value on the cathode/solution interface

In this paper, a pH microprobe technique was developed to measure in situ t he pH value on the cathode /solution interface, and iridium oxide was used as a pH sensitive material which is of a good response behavior in the meas ured solutions. During electrodeposition process of bioceramic coatings of calcium phosphates, the interfacial pH change, for example, was first measu red. The experimental results indicated that the pH value on the cathode /s olution interface first jumped to a maximum, then slowly decreased with the increase of the electrodeposition time. The interfacial pH value was incre ased with the applied current density or cathode overpotential.