PHOTOELECTROCHEMISTRY AND SURFACE STUDIES OF COPPER INTERACTION WITH ROUGH SURFACES OF P-MOSE2

Layered materials of the type MoX2, where X is a chalcogenide, have been widely used in photoelectrochemical cells. Their two-dimensional structure makes these materials highly anisotropic in their electronic properties. The interaction of Cu2+ with the axial planes of p-MoSe2 have been studied by Auger electron spectroscopy as by photoelectrochemical methods. We present results on the photoelectrodeposition of Cu at rough surfaces (R) of p-MoSe2, i.e., surfaces having a high degree of axial planes exposed to the electrode/electrolyte interface. Cyclic voltammetry of Cu2+ at p-MoSe2 (R) showed a quasireversible electron transfer process at ca. 350 mV vs. SCE. Photoelectrodeposition of Cu at rough surfaces of p-MoSe2- was performed at 170 and 0 mV vs. saturated calomel electrode while the semiconductor was under illumination. Auger electron spectroscopy depth profiles of the surface, after the photoelectrodeposition of CU2+, indicates that at both potentials, and for long times of photoelectrodeposition, intercalation of Cu is occurring.