Nanostructured Water Splitting Photocatalysts

Photocatalytic water splitting with colloidal suspensions is conceptually the most simple and inexpensive pathway to hydrogen fuel from solar energy. Nanoscaling is widely considered to improve the efficiency of such catalysts, but as a detailed analysis shows, nanostructures also have considerable disadvantages.  Using recent examples from this laboratory, this talk discusses the effects of nanostructuring on carrier generation, separation, and recombination, as well as the possibility of controlling nanostructure energetics and reactivity via potential determining ions and quantum size effects. The use of Surface Photovoltage Spectroscopy to probe photochemical charge separation on the nanoscale is also discussed.