TY - JOUR
T1 - Supramolecular semiconductor receptor assemblies
T2 - Improved electron transfer at TiO2-β-cyclodextrin colloid interfaces
AU - Willner, I.
AU - Eichen, Y.
AU - Willner, B.
PY - 1994/1
Y1 - 1994/1
N2 - Semiconductor TiO2-colloids are stabilized by ß-cyclodextrin (ß-CD). Photoinduced electron transfer at the semiconductor (S.C.) solution interface is controlled in the S.C.-receptor assembly TiO2-β-CD. Trapping of TiO2-ß-CD photoexcited conduction-band electrons by N,N’-dioctyl-4,4’-bipyridinium, C8V2+, is 4.4 fold more effective than by N,N’-dimethyl-4,4’-bipyridinium. The kinetics of C8V2+ reduction, inhibition experiments and laser flash photolysis studies reveal that the effective trapping of conduction-band electrons by C8V2+ originates from its association to the ß-CD receptor. Electron transfer from dye, proflavine, Pfl, to the S.C., is similarly controlled by the S.C.-receptor assembly. In the presence of the Pt modified semiconductor-receptor colloid, Pt-TiO2-ß-CD, effective photoinduced H2-evolution occurs using Pfl as photosensitizer. Inhibition experiments and flow-dialysis measurements indicate that the effective H2-evolution originates from the association of Pfl to the ß-CD receptor sites.
AB - Semiconductor TiO2-colloids are stabilized by ß-cyclodextrin (ß-CD). Photoinduced electron transfer at the semiconductor (S.C.) solution interface is controlled in the S.C.-receptor assembly TiO2-β-CD. Trapping of TiO2-ß-CD photoexcited conduction-band electrons by N,N’-dioctyl-4,4’-bipyridinium, C8V2+, is 4.4 fold more effective than by N,N’-dimethyl-4,4’-bipyridinium. The kinetics of C8V2+ reduction, inhibition experiments and laser flash photolysis studies reveal that the effective trapping of conduction-band electrons by C8V2+ originates from its association to the ß-CD receptor. Electron transfer from dye, proflavine, Pfl, to the S.C., is similarly controlled by the S.C.-receptor assembly. In the presence of the Pt modified semiconductor-receptor colloid, Pt-TiO2-ß-CD, effective photoinduced H2-evolution occurs using Pfl as photosensitizer. Inhibition experiments and flow-dialysis measurements indicate that the effective H2-evolution originates from the association of Pfl to the ß-CD receptor sites.
UR - http://www.scopus.com/inward/record.url?scp=0038854523&partnerID=8YFLogxK
U2 - 10.1163/156856794X00487
DO - 10.1163/156856794X00487
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AN - SCOPUS:0038854523
SN - 0922-6168
VL - 20
SP - 681
EP - 700
JO - Research on Chemical Intermediates
JF - Research on Chemical Intermediates
IS - 7
ER -