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Economical Pt-Free Catalysts for Counter Electrodes of Dye-Sensitized Solar Cells
journal contribution
posted on 2012-02-22, 00:00 authored by Mingxing Wu, Xiao Lin, Yudi Wang, Liang Wang, Wei Guo, Daidi Qi, Xiaojun Peng, Anders Hagfeldt, Michael Grätzel, Tingli MaThree classes (carbides, nitrides and oxides) of nanoscaled
early-transition-metal
catalysts have been proposed to replace the expensive Pt catalyst
as counter electrodes (CEs) in dye-sensitized solar cells (DSCs).
Of these catalysts, Cr3C2, CrN, VC(N), VN, TiC,
TiC(N), TiN, and V2O3 all showed excellent catalytic
activity for the reduction of I3– to
I– in the electrolyte. Further, VC embedded in mesoporous
carbon (VC–MC) was prepared through in situ synthesis. The
I3–/I– DSC based on
the VC–MC CE reached a high power conversion efficiency (PCE)
of 7.63%, comparable to the photovoltaic performance of the DSC using
a Pt CE (7.50%). In addition, the carbide catalysts demonstrated catalytic
activity higher than that of Pt for the regeneration of a new organic
redox couple of T2/T–. The T2/T– DSCs using TiC and VC–MC CEs showed
PCEs of 4.96 and 5.15%, much higher than that of the DSC using a Pt
CE (3.66%). This work expands the list of potential CE catalysts,
which can help reduce the cost of DSCs and thereby encourage their
fundamental research and commercial application.