Publication Date: Thu Jan 11 00:00: Research Org.: Energy Frontier Research Centers (EFRC) (United States). of North Carolina, Chapel Hill, NC (United States). The implications of these results for solar energy conversion are discussed. The potential onset followed the trend SnO 2/TiO 2 > SnO 2 > TiO 2, with TiO 2 closest to the vacuum level and SnO 2/TiO 2 the furthest away. The charge extraction technique was used to more » determine that the density of SnO 2/TiO 2 states was more similar to that of TiO 2 than SnO 2. Instead, the appearance of a single potential-independent absorption spectrum was observed and attributed to electrons present within an interfacial region between the core and the shell. In other words, upon reduction of SnO 2/TiO 2 there was no spectroscopic evidence for electrons residing in the SnO 2 core or in the TiO 2 shell. Significantly, standard addition of the spectra measured for SnO 2 and TiO 2 did not model that for SnO 2/TiO 2. For SnO 2, three unique spectra were required to model the potential dependent data while only one unique spectrum was needed to model the corresponding data for SnO 2/TiO 2 and TiO 2. Electrochemical reduction of these materials in aqueous electrolytes resulted in a blue shift of the fundamental VB → CB absorbance as well as a broad absorbance across the visible region. The mesoporous TiO 2 and SnO 2 films were synthesized by sol–gel techniques, and the core/shell material was created by atomic layer deposition of a TiO 2 shell on a SnO 2 core. A comparative spectroelectrochemical study of micron thick mesoporous thin films composed of TiO 2 and SnO 2 nanocrystallites was undertaken to identify the location and identity of electronic state(s) in core/shell SnO 2/TiO 2 films that have emerging applications in energy science.

Sno2 core shell