Pure inorganic D-A type polyoxometalate/reduced graphene oxide nanocomposite for the photoanode of dye-sensitized solar cells

A pure inorganic donor-acceptor (D-A) type polyoxometalate K6H4[a-SiW9O37Co3(H2O)(3)]center dot 17H(2)O(SiW9Co3)/reduced graphene oxide (RGO) nanocomposite was employed to dye-sensitized solar cells (DSSCs) for the first time, building up a wide spectrum for the photoanode of a DSSC. Raman, XRD, TEM, and EDS have proved that SiW9Co3 was loaded on RGO, and then the SiW9Co3/RGO doped nanocomposite in P25 was applied to be the photoanode of the DSSCs. In this paper the performance of SiW9Co3/RGO-3@P25 is the best. The J(sc) of pure P25 is 13.74 mA cm(-2), V-oc is 0.679 V, FF is 0.598 and eta is 5.37%, while the J(sc) of SiW9Co3/RGO-3@ P25 is 17.5 mA cm(-2), V-oc is 0.705 V, FF is 0.558 and eta is enhanced to 6.88%, which is 28.05% higher than for a pure P25-based cell in a DSSC. OCVD indicates that SiW9Co3/RGO can delay the electron-hole recombination. In a Bode plot the electron lifetimes of SiW9Co3/RGO-3@P25 and P25 are 4.86 ms and 3.81 ms respectively, which also further clarifies that the SiW9Co3/RGO doped nanocomposite can extend the lifetime of electrons and also plays an important role in the photoanode of the DSSCs. This result is beneficial to the application of DSSCs in future industry.