Photoinduced electron transfer (PET) has been investigated in surface-bound donor-π-acceptor dyes; thiophene, 1 and its furan, 2 analogue with In2O3 nanocrystals (NCs). The synthesized In2O3 NCs (~6 nm) are fully dispersed in the organic solvent e.g. dichloromethane that allows systematic control over the dye:NC stoichiometric ratio. Steady-state fluorescence quenching by In2O3 NCs provided dependence of quenching on the dye:NC ratio, and studies of the dye adsorption to the NCs will be discussed. The ultrafast pump-probe measurement (λex: 500 nm) of pristine dyes 1 and 2 show decay lifetimes of the singlet excited states in the range of 1.6 ns. Attachment of the dyes to the In2O3 NCs in a 2:1 mole ratio results in rapid disappearance of the excited states of 1 and 2 (t = 7.89 ± 0.29 ps and 7.02 ± 0.14 ps, respectively) with concomitant formation of the oxidized dye molecules. These PET rate constants are 1.6 - 1.9 times larger than those reported for the same dyes bound to ZnO NCs. This is consistent with the expected increase in the NC density of states satisfying barrierless electron transfer.

Interfacial electron transfer from photoexcited chromophores to indium oxide (In2O3) nanocrystals

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.