Electrochemically generated atomic layers as building blocks of nanomaterials

A layer-by-layer approach in the assembly of nanomaterials from the atomic layers electrochemically generated by underpotential deposition was reinforced by the development of the method of multiparametric monitoring of surface-restricted electrochemical reactions based on frequency response analysis under nonstationary conditions. The upd in a wide meaning of this term is not restricted to deposition of a monolayer of one metal onto an electrode of different metal but involves also nonmetals, such as Se and Te, their compounds (CdSe, CdTe, CdS, PbTe, PbSe, Bi₂Te₃, etc.) and superlattices, such as (Bi₂)_m(Bi₂Te₃)_n. The experience acquired in the electrochemistry of the underpotential deposition and multilayer assembly can be also helpful in other fields of materials science, such as supercapacitor research, where the frequency response examination of the surface-restricted reactions enables the discrimination between capacitive and noncapacitive currents under conditions preventing from the use of classical impedance spectroscopy and evaluation of energy dissipation in the charge–discharge processes.