A TiO₂@{Mo₃₆₈} composite: synthesis, characterization, and application in dye-sensitized solar cells

<div><p>The high-nuclear cluster compound Na₄₈[H_xMo₃₆₈O₁₀₃₂(H₂O)₂₄₀(SO₄)₄₈]·ca.1000H₂O (denoted as {Mo₃₆₈}) represents the known nanoscale hedgehog-type cluster anion with the diameter of approximately 6 nm. Herein, a TiO₂@{Mo₃₆₈} composite was prepared through a sol–gel process for the first time. SEM, XPS, and UV–vis spectra were employed to characterize their chemical composition and structures. Meanwhile, the as-obtained composite was further mixed with P25 (Degussa P25 titania photocatalyst) then applied as the photoanodes of dye-sensitized solar cells (DSSCs); the results showed that DSSCs with the P25-TiO₂@{Mo₃₆₈}-based photoanodes exhibited better performance than that with pure P25-based photoanodes, which was due to less carrier recombination and longer electron lifetime in the former DSSCs by the results from analysis of dark current measurement, electrochemical impedance spectroscopy, and open-circuit voltage decay curve.</p></div

A Novel Carboxyethyltin Functionalized Sandwich-type Germanotungstate: Synthesis, Crystal Structure, Photosensitivity, and Application in Dye-Sensitized Solar Cells

A novel sandwich-type germanotungstate [C­(NH₂)₃]₁₀[Mn₂{Sn­(CH₂)₂COOH}₂(B-α-GeW₉O₃₄)₂]·8H₂O (<b>1</b>) represents the first single crystalline polyoxometalate (POM) functionalized by open chain carboxyethyltin, which was designed and synthesized in aqueous solution and applied to a dye-sensitized solar cell (DSSC) for the first time. Its photosensitivity was explored through a fluorescence spectrum (FL), surface photovoltage spectrum (SPV), electrochemical method, and solid diffuse spectrum. <b>1</b> displays the primary features of sensitizers in DSSCs, and the efficiency of the solar cell is 0.22%. Delightedly, when <b>1</b> was employed to assemble a cosensitized solar cell configuration by preparing a <b>1</b>-doped TiO₂ electrode and additionally adsorbing N719 dyes, a considerably improved efficiency was achieved through increasing spectral absorption and accelerating electron transport, which is 19.4% higher than that of single N719 sensitization. This result opens up a new way to position different dyes on a single TiO₂ film for cosensitization