Dye-Sensitization of Tin Dioxide via the Functionalization of Oxide Surfaces with Trialkynylorganotins

The surface modification of nanoporous tin dioxide materials was achieved with trialkynylorganotin(IV) (C 4 H 9 -C=C) 3 Sn-(CH 2 )n(C 10 H 20 ) (n = 4,6)1 endowed with a perylene dye to yield powders containing up to 0.13 mmol.g -1 of perylene unit or dye-modified thin films. Irreversible chemisorption occurred in solution at room temperature to give perylene dye grafted at the oxide surface via the cleavage of the three tin-alkynide bonds of the precursor and the formation of Sn bulk -O-Sn-C dye linkages. The photoelectrochemical cells made with the 1-modified films demonstrated maximum incident photon to current efficiency (IPCE) as high as 18% at 430 nm under white light illumination. The performances of the cells were interpreted in terms of the intrinsic properties of tin dioxide and aggregation of the perylene dye.