ON ZERO-CHARGE POTENTIAL OF GALLIUM IN AQUEOUS SOLUTIONS AND ORIGIN OF HIGH CAPACITANCE AT GALLIUM/SOLUTION INTERFACE

The zero-charge potentials of gallium in water as determined from the position of the minimum on the differential capacitance in dilute solutions and from the electrocapillary curves in the absence of anion adsorption are shown to coincide and to be -0·97 to -0·98 V (nce). Evidence is presented supporting the assumption that the high capacitance values on gallium near the point of zero charge are due to the re-orientation of water dipoles on shifting from negative to more positive potentials. At potentials close to φ{symbol}o water is more strongly adsorbed on gallium than on mercury. © 1968.