Photoinjection of High Potential Holes into Cu5Ta11O30 Nanoparticles by Porphyrin Dyes

I. SULLIVAN, C. L. BROWN, M. J. LLANSOLA-PORTOLES, G. KODIS, T. A. MOORE, D. GUST, A. L. MOORE, P. ; M. GERVALDO

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2015 vol. 119 p. 21294 - 21303

1932-7447

Excited-state hole injection into the valence band of Cu5Ta11O30 nanoparticles (NPCu5Ta11O30) was investigated through sensitization with zinc porphyrin dyes using simulated solar irradiance. The Cu5Ta11O30 nanoparticles were prepared by a flux-mediated synthesis and found to have an average particle size of ~10?15 nm by DLS and TEM. The zinc 4-(10,15,20-tris(4-pyridinyl)-porphin-5-yl)phenylphosphonic acid (D1) and its analog in which the pyridine groups are methylated (D2) were synthesized and found to have excited state reduction potentials appropriate for p-type dye sensitization of the nanoparticles. The dye-sensitized NP-Cu5Ta11O30 exhibited fluorescence quenching consistent with electron transfer from the NP-Cu5Ta11O30 to the dye; forward and recombination rates were obtained by transient absorption measurements.Hole injection times of 8 ps and