Photoelectrochemistry of Porous p-Cu[sub 2]O Films

Porous films were prepared on transparent conductive glass from a dispersion of powder in ethanol. Upon illumination with a tungsten lamp, the photocurrent of the porous film was appreciably greater when compared to electrodeposited films. The enhancement is attributed to the increased interfacial area between the film and the solution due to the three-dimensional nature of the film. No chemical change was detected by visual examination and X-ray diffraction of the porous film after illumination for in the aqueous solution at vs saturated calomel electrode. The reported stability of electrodeposited films is attributed to the effect of -terminated (111) surface, where the -assisted photoreduction of is less likely to occur. The well-known instability of single-crystal is hypothesized to be due to the predominating (211) and (311) surfaces, where the photodecomposition to Cu is inevitable at the exposed sites.