TiO 2 nanoparticles are commonly used as versatile precursors to make functional nanocomposite materials. However, the surface defects at grain boundaries of TiO 2 nanoparticles significantly affect the photoelectric properties of TiO 2 nanomaterials . In this work, we firstly prepared nanocomposites of TiO 2 and polyoxometalates (POMs) in which different POMs, including titanium-substituted POMs K 5 [PW 11 TiO 40 ] and K 7 [PW 10 Ti 2 O 40 ], are incorporated with TiO 2 nanoparticles so as to make an interface modification on grain boundaries of TiO 2 nanoparticles. Then the photoconductivities of the TiO 2 /POM nanocomposites were investigated through measurement of photocurrent responses, current-voltage curves, Mott-Schottky plots and surface photocurrent spectra. Compared with pure TiO 2 nanoparticles, TiO 2 /POM nanocomposites exhibit superior photoelectric properties, benefitting from the interface modification from different POMs. The gas sensing performance for acetone was also explored by use of the as-prepared photoconductive devices, and TiO 2 /PW 11 Ti exhibited a high gas sensing performance.
Dye-sensitized solar cells (DSSCs) on flexible plastic substrates usually suffer from a slower electron diffusion rate and insufficient surface area due to no sintering process . Therefore, the conversion efficiency (ƞ) of such flexible DSSCs is normally below 6%. Here, the highly flexible DSSCs with enhanced performance are fabricated at room temperature, employing 3D graphene decorated nanocrystalline TiO 2 films (3DGT) as anode on plastic substrates. Owing to the enhanced charge transportation and increased surface area from 3D conductive graphene skeleton, the 13 μm-thick 3DGT-0.85 (0.85 wt% 3D graphene plus TiO 2 nanoparticles) anode achieves a power conversion efficiency of 6.41%, which is 56% higher than pristine TiO 2 based anode. This efficiency is among the highest values for the previously reported TiO 2 photoanodes on plastic substrates.