This document summarizes research on using early transition metal-based catalysts in dye-sensitized solar cells as alternatives to platinum. It describes testing various metal oxides, nitrides, sulfides and carbides as catalysts for the I-/I3- redox couple. Results showed yttrium oxide, molybdenum oxide and cadmium sulfide had promising efficiencies and cost efficiencies compared to platinum. Future work will involve testing other early transition metal catalyst-nanostructure combinations and redox couples to improve efficiencies while minimizing costs.

1. THE IMPACT OF EARLY TRANSITION METAL-BASED
CATALYSTS ON THE PERFORMANCE OF I-/I3– REDOX
COUPLES IN DYE-SENSITIZED SOLAR CELLS.
Kavirath Jain
Christopher Zhen
Maxwell Tucker
North Carolina School of Science and Mathematics

2. Introduction | Experiment | Results | Analysis | Conclusions
DYE SENSITIZED SOLAR CELLS (DSSCS)

3. Introduction | Experiment | Results | Analysis | Conclusions
THE CATALYST PROBLEM
• Platinum
• Very Expensive and Rare
• Directly Responsible for Efficiency
• Not suitable for new organic and even some inorganic couples
• Undermines idea behind the cost effective DSSC

4. Introduction | Experiment | Results | Analysis | Conclusions
EARLY TRANSITION METALS – THE NEW FRONTIER
• Early Transition Metals (ETM) Properties
• Covalent Character
• Ionic Character
• Electrically/Thermally Conductive
• Pt-like Catalytic Activity
• Cost Effective
• Current Research
• Early Transition Metal Carbides, Nitrides, Oxides, Sulfides (CNOS)
• Our Proposition
• Test some more novel ETM CNOS
• Test insoluble hydroxide
• Focus on Cost-Effectiveness

5. Introduction | Experiment | Results | Analysis | Conclusions
EXPERIMENTAL SETUP

6. Introduction | Experiment | Results | Analysis | Conclusions
THE CATALYSTS AND SYNTHESIS OF MOLYBDENUM OXIDE

7. Introduction | Experiment | Results | Analysis | Conclusions
DATA COLLECTION
Voltage (mV)
Potentiometer
DSSC
Current (μA)

8. Introduction | Experiment | Results | Analysis | Conclusions
I-V CURVES AND GAUSSIAN CURVE FITS

9. Introduction | Experiment | Results | Analysis | Conclusions
MAXIMUM POWER INTERPOLATION

10. Introduction | Experiment | Results | Analysis | Conclusions
EFFICIENCY DATA
3.5
3
2.5 Carbon
Palladium
Efficiency (%)
2
Manganese
Yttrium
1.5
Molybdenum
1 Palladium
Cadmium
0.5
0
Catalyst

11. Introduction | Experiment | Results | Analysis | Conclusions
COST EFFICIENCY RESULTS
Catalyst Cost ($/5g) Efficiency (%) Efficiency (%/cost)
Platinum 122.00 7.5000 0.0615
Manganese Oxide 56.40 1.6460 0.0292
Yttrium Oxide 14.35 1.6430 0.1145
Molybdenum Oxide 52.40 1.1610 0.0222
Ammonium Molybdate tetrahydrate 6.43 1.1610 0.1806
Palladium Hydroxide 75.00 2.1610 0.0288
Cadmium Sulfide 1.82 0.1130 0.0621

12. Introduction | Experiment | Results | Analysis | Conclusions
CONCLUSIONS
• More effort is needed to improve efficiencies
• Yttrium (III) Oxide minimizes cell degradation
• High potential for cost effective replacements for Platinum
• Yttrium (III) Oxide
• Molybdenum (VI) Oxide
• Cadmium Sulfide

13. Introduction | Experiment | Results | Analysis | Conclusions
FUTURE WORK
• Other ETM CNOS catalysts
• Other redox couples
• More trials for current catalysts
• Investigate Cell Degradation
• Synergistic Approach
• Mesoporous Carbon
• Combinations of ETM CNOS

14. Acknowledgments and References
WORKS CITED
• Emery, K. a., & Osterwald, C. R. (1986). Solar cell efficiency measurements. Solar Cells, 17(2-3), 253–274.
doi:10.1016/0379-6787(86)90016-5
• Kim, J.-Y., Lee, J.-K., Han, S.-B., Lee, Y.-W., & Park, K.-W. (2010). Improved Tri-iodide Reduction Reaction of Co-
TMPP/C as a Non-Pt Counter Electrode in Dye-Sensitized Solar Cells. Journal of Electrochemical Science and
Technology, 1(2), 75–80. doi:10.5229/jecst.2010.1.2.075
• Law, M., Greene, L. E., Johnson, J. C., Saykally, R., & Yang, P. (2005). Nanowire dye-sensitized solar cells. Nature
materials, 4(6), 455–9. doi:10.1038/nmat1387
• Study on the Kinetics of the Thermal Decomposition of Ammonium Molybdates.pdf. (n.d.).
• Wang, L., Diau, E. W.-G., Wu, M., Lu, H.-P., & Ma, T. (2012). Highly efficient catalysts for Co(II/III) redox couples in
dye-sensitized solar cells. Chemical communications (Cambridge, England), 48(20), 2600–2.
doi:10.1039/c2cc17389a
• Wang, M., Anghel, A. M., Ha, N. C., & Pootrakulchote, N. (2009). CoS Supersedes Pt as Efficient Electrocatalyst for
Triiodide Reduction in Dye-Sensitized Solar Cells, 15976–15977.
• Wu, M., Lin, X., Hagfeldt, A., & Ma, T. (2011). A novel catalyst of WO2 nanorod for the counter electrode of dye-
sensitized solar cells. Chemical communications (Cambridge, England), 47(15), 4535–7. doi:10.1039/c1cc10638d
• Wu, M., Lin, X., Wang, Y., Wang, L., Guo, W., Qi, D., Peng, X., et al. (2012). Economical Pt-free catalysts for counter
electrodes of dye-sensitized solar cells. Journal of the American Chemical Society, 134(7), 3419–28.
doi:10.1021/ja209657v
• Wu, M., Wang, Y., Lin, X., Yu, N., Wang, L., Wang, L., Hagfeldt, A., et al. (2011). Economical and effective sulfide
catalysts for dye-sensitized solar cells as counter electrodes. Physical chemistry chemical physics PCCP, 13(43),
:
19298–301. doi:10.1039/c1cp22819f
•

15. Acknowledgments and References
SPECIAL THANKS
• Dr. Myra Halpin
• NCSSM Research in Chemistry Program
• Research done by Nguyen, Pan, Rathod
• NCSSM Physics Department

16. Questions?