| Solar energy devices as an alternative to nonrenewable power sources have been widely used in various fields so far. Dye-sensitized solar cells (DSSCs) have been paid widespread attention due to their virtues such as low cost, friendly to the environment and easily manufacture. A DSSC is comprised of a dye-sensitized semiconductor photoanode as a working electrode, an electrolyte with an iodide/triiodide redox couple, and a Pt counter electrode (CE), which looks like "sandwich". The photoanode plays an important role in the DSSCs because it has a connection with the adsorption of dye and the electron transport. Polyoxometalates (POMs) have been widely applied in photovoltaic cells owing to better photoelectrochemical properties and stability.In this paper, POMs are respectively composited with TiO2 and graphene to get composite, which was introduced into the photoanode of the DSSCs to improve the performance of the cell effectively.1. A sol-gel method was adopted to make Keggin-type polyoxometalate [Ru(bipy)3]2[SiW12O40]·2C2H5OH·8H2O (1) load on TiO2 to get composite 1@TiO2, and then mixed 1@ TiO2 and P25 with different mass fractions to fabricate the photoanodes. By means of a series of representations such as current-voltage curve, voltage-time curve, electrochemical impedance spectroscopy and open circuit voltage decay curve, it can be seen that the performance of the DSSCs was best when the mass fraction was 0.1%(6.7683%), which is 20.4% higher than the pure P25 cell (5.6823%).2. Pure inorganic D-A type polyoxometalate K6H4[?-SiW9O37Co3(H2O)3]·17H2O (SiW9Co3) was composited with graphene to get SiW9Co3/RGO composite, which was mixed with P25 and then introduced into the photoanode of the DSSCs. In addition, the performance of DSSCs with composite different mass of POMs on graphene have been discussed, and the performance of the DSSCs was best when the mass was 30mg (6.88%), which was improved by 28.05% compared to the P25 photoanode (5.37%). |
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