Synthesis of Sn-porphyrin-intercalated trititanate nanofibers: Optoelectronic properties and photocatalytic activities

A new class of nanostructures were fabricated by one-step hydrothermal reaction of a mixture solution of TiO2 anatase powder and a Sn-porphyrin, trans-dihydroxo[5,10,15,20-tetrakis(p-tolyl)porphyrinato]tin(IV) [SnTTP], and they were found to be well-crystalline trititanate (H2Ti3O7)-type multilayered nanofibers (TiNFs) intercalated by SnTTP which have lengths in the range of 0.5-1 mu m with an average diameter of approximately 50 nm. Based on the femtosecond-diffuse reflectance transient absorption and photoluminescence spectroscopic measurements, the SnTTP-intercalated TiNFs were observed to exhibit efficient optoelectronic properties such as photoinduced electron transfer from deep surface states of trititanate layer to SnTTP, forming an anion radical SnTTP..- rapidly in a few picoseconds. These results infer that electrons and holes are effectively separated in the SnTTP-TiNFs upon illumination, and consequently remarkable UV-visible light-sensitive photocatalytic activities as compared to those of free TiNFs and SnTTP, suggesting that the SnTTP-intercalated TiNFs have potential application in development of efficient artificial photosynthetic systems and photoelectronic materials.