ABSTRACT
The transfer of a metal ion from the solid to bulk solution in the form of a monomeric M(OH)n(H2O)m(z-n)+ ion necessarily involves the breakage of M-O-M bonds, assisted by the attack by solvent molecules and/or by dissolved ions. The discussion is based on the assumption of the establishment of a dissolving interface characterized by a steady-state composition: upon transfer of one dissolving ion to the solution, the interface left behind achieves a configuration that is identical to the configuration it had before the ion was transferred. In the case of semiconductors, two types of limiting approaches can be envisaged. The first one, corresponding to the classic Gerischer formulation of electrochemical kinetics, assumes that charge transfer between redox couples in solution and the solid is described on the basis of the band structure of the solid. The second approach focuses on the surface complexes; these complexes are electronically decoupled from the band structure and, therefore, the semiconducting properties are less important.
