TiO₂ nanotubes (TNTs) with large aspect ratio and large specific surface area were prepared from P25 (Nippon Aerosil) and applied to dye-sensitized titanium dioxide solar cells (DSSCs). Optimization of fabrication conditions, i.e., pH of the starting paste, sintering temperature for the TiO₂ electrodes, electrolyte compositions of DSSCs gave the high conversion efficiency with improved open circuit voltage (V_oc) and fill factor (FF) when compared to DSSCs made of P25. The evaluation of dye adsorption and the photo-injected electron transport such as electron diffusion coefficient (D) and electron lifetime (τ) in TNTs electrodes revealed that the higher efficiency resulted from increase of electron density with keeping much longer τ in TNTs electrodes than in P25 electrodes.

To improve the thermal conductivity of epoxy resins without losing the insulation, epoxy/silicon nitride (Si₃N₄) nanowire composites were produced. β-Si₃N₄ nanowires were synthesized by the carbothermal reduction and nitridation of a homogeneous mixture of silica (SiO₂), carbon, and a small amount of cobalt via the vapor–liquid–solid (VLS) mechanism. The ratio of β to α phase in the product Si₃N₄ increased with heat-treatment temperature; however, the undesirable SiC also increased. By increasing the nitrogen gas pressure in the heat treatment, the ratio of β- to α-Si₃N₄ increased without producing SiC. The epoxy composite containing Si₃N₄ nanowires of 60 vol% showed a high thermal conductivity of 9.2 W m⁻¹ K⁻¹ along the preferred orientation of the nanowires.