Fabrication and application of tin oxide doped titanium dioxide nanofibers, lead sulfide QDS doped titanium dioxide nanotubes, silver vanadium oxide nanowires.

摘要

Both efficient light-to-energy conversion and photooxidation of organics require avoiding the accumulation of electrons on metal oxide semiconductors that would increase the recombination rate of electron hole pairs. When TiO2 is coupled with SnO2, SnO2 acts as a sink for photogenerated electrons, suppressing recombination. Mesoporous silica spheres were used as templates to prepare 5 ∼ 10 nm Sn-doped TiO 2 (TDT) nanofibers using SnCl4 and TiCl4 as precursors. The photodegradation of various dyes was catalyzed by the TDT nanofibers and was shown to be more effective than P25 and the undoped TiO2 nanofibers.; Multiple electron-hole pairs can be generated by an electron or hole with kinetic energy greater than that of the semiconductor band gap, which can improve photovoltaic conversion efficiency. This process is referred to as multiple electron generation (MEG). Lead sulfide (PbS) was received much attention because of the small band gap of 0.41 eV in the bulk form (galena) and a large exciton Bohr radius of 18 nm, which leads to extensive quantum size effects. PbS QDs coupled TiO2 anatase nanotubes were prepared using thiolactic acid molecular to bridge Pb2+ ions and the TiO2 nanotubes and followed by sodium surfide to precipitate. The size of QDs is controllable by changing the concentration of thiolactic acid.; The ease at which V2O5 can be reduced and ions intercalated into the layered structure makes it a promising material for applications such as lithium batteries, catalyst, electrochromic devices, and supercapacitors. Recently, silver doped V2O5 (SVO) was shown to significantly improve the intercalation rate, specific capacity and cycling performance in lithium ion batteries. It has also been used for implantable cardioverter defibrillators (ICDs) due to long-term stability. Silver vanadium oxide (SVO) bronze nanowires with layer structure have been hydrothermally synthesized. The as made nanowires are over 30 mum long and 10∼20 nm wide. The Li ion diffusion coefficient in the SVO nanowires was seven times higher than that in the V2O5 nanowires. An electrochromic device (ECD) was fabricated from the SVO nanowires which displayed a color switching time of 0.2s from bleached state (green) to colored state (red-brown) and 60% transmittance contrast.