Evaluating the electric property of different crystal faces and enhancing the Raman scattering of Cu2O microcrystal by depositing Ag on the surface

The surface electric property of Cu2O microcrystal affects the interaction of facets with substance in the aqueous solution, and hence plays a key role in determining the photocatalytic activity. In this paper, the capability of Cu2O microcrystals with exclusive {111}, {110} or both lattice surfaces in reducing Ag+ to Ag0 were investigated. Ag particles selectively deposited on {111} surfaces of Cu2O, while not on {110} surfaces. The different behaviors of the two surfaces are mainly attributed to their different electric properties: negatively-charged {111} surfaces absorb Ag+ ions while positively-charged {110} surfaces repel them. Raman scattering of Cu2O {111} surfaces was enhanced by the photo-deposition of Ag particles.