We report the preparation of nanocomposites of OMC and CNTs and their successful application as novel, Pt-free, highly efficient and durable DSSC CEs. OMC?CNT nanocomposites have a unique structure wherein the primary particles of the OMC are interconnected via the CNTs, thus exhibiting a medusa-like morphology. Importantly, the OMC?CNT nanocomposites combine the advantageous properties of both OMC and CNTs. The high surface area of OMC provides numerous catalytically active sites for iodine reduction while its threedimensionally (3-D) interconnected mesoporous structure allows for the facile transport of ions and electrons. In addition, CNTs can function as electrical bridges that interconnect separated OMC primary particles, thus generating fast electrical networks. We show that the DSSC employing the OMC?CNT-based CE exhibits an excellent cell efficiency, which rivals that of the DSSC cell with a conventional Pt-based CE. Furthermore, we demonstrate that the DSSC with the OMC?CNTs-based CE shows remarkable stability in a long-term efficiency test.

Chem. Commun. Advance Article (2012)