文摘
The effects of coadsorbing the amphiphilic ruthenium-based dye Z907 (cis-bis(isothiocyanato)(2,20-bipyridyl-4,40-dicarboxylato)(4,40-dinonyl-20-bipyridyl)ruthenium(II)) with the coadsorbent DPA (n-decylphosphonic acid) and with the organic dye D35 ((E)-3-(5-(4-(bis(2′,4′-dibutoxybiphenyl-4-yl)amino)phenyl)thiophen-2-yl)-2-cyanoacrylic acid) on mesoporous TiOb>2b> were investigated using photoelectron spectroscopy (PES). Z907 is expected to adsorb to the TiOb>2b> surface via the carboxylic acid groups. However, Z907 also shows signs of interacting with the TiOb>2b> via the sulfur of the thiocyanate groups, and this interaction is affected by both the addition of DPA and D35. DPA, when added, exchanges with Z907 at the TiOb>2b> surface, and each Z907 is replaced by six DPA molecules, but it does not affect the energy level alignment between Z907 and TiOb>2b> substantially. Adding D35 to Z907 induces changes in the adsorption configuration of Z907 by the means of suppressing the interaction of the thiocyanate ligands and the TiOb>2b> surface. The HOMO level of Z907 is shifted by the addition of D35. Coadsorbing Z907 with D35 thus gives changes at a molecular level, meaning that this is an example of collaborative sensitization.