Photoinduced electron transfer from benzimidazole to nano WO3, CuO and Fe2O3. A new approach on LUMO–CB energy-binding efficiency relationship

The dynamics of photoinduced electron injection from 2-(4-fluorophenyl)-1-phenyl-1H-benzimidazole (FPPBI) to CuO, Fe2O3 and WO3 nanocrystals has been studied by FT-IR, absorption, fluorescence and lifetime spectroscopic methods. The association between nanoparticles and FPPBI is explained from both absorption and fluorescence quenching data. The distance between FPPBI and nanoparticles as well as the critical energy transfer distance has been obtained. The free energy change (ΔGet) for electron injection has also been deduced. Energy gap between LUMO and CB is correlated with the binding efficiency of the FPPBI with nanoparticles. The electron transfer between the FPPBI with nanosemiconductors is explained in detail.