Enhancement of electrochemical transfer junction for cation extraction

Electrochemical transfer junctions (ETJs) were synthesized via a physical or chemical covering method onto a porous ceramic substrate (mullite and alumina). The Mo6S8 layer thickness ranged from 10 to 100 μm. The ETJ composites placed between two tanks lead to a cobalt transfer by applying a current density between electrodes placed in both tanks. The thickness decrease compared to a hot pressed junction allows imposing current densities equal to 7 or 9 mA cm−2 inducing 4–6 fold faster Co2+ fluxes (1.3.10−4 and 1.7.10−4 mol h−1 cm−2 for physical and chemical covering respectively, versus 2.9.10−5 mol h−1 cm−2 for hot pressed junctions).