Crystal face dependence of p-Cu2O stability as photocathode

CHED 71

Clifford Engel, cengel1@ithaca.edu, Kelly Sowers, ksowers1@ithaca.edu, Ian Weiss, iweiss1@ithaca.edu, and Akiko Fillinger, afillinger@ithaca.edu. Chemistry Department, Ithaca College, Ithaca, NY 14850
We have significantly increased the photon to current conversion efficiency of p-Cu2O by changing its morphology from an electrodeposited two-dimensional structure to a porous three- dimensional structure. Currently, we are trying to explain why polycrystalline p-Cu2O is stable while a single crystal Cu2O undergoes photocorrosion: Cu2O + H2O + 2e- → 2Cu + 2OH-. We have hypothesized that the stability of electrodeposited p-Cu2O is due to the Cu+-terminated (111) surface, where reduction of O2 occurs preferentially in an aqueous solution upon illumination. On the other hand, a single crystal p-Cu2O undergoes decomposition to Cu because of the predominant (211) and (311) surfaces, where H+ assisted reduction of Cu2O is inevitable. Testing our theory is crucial for achieving our ultimate goal, hydrogen generation at p-Cu2O surface. Preliminary results to examine our theory will be presented.
 

General Posters
7:30 PM-9:30 PM, Sunday, April 6, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008