Modeling Transfer of Electrons between Energy States of an Electrolyte and CdS Thin Films using Gerischer Model

Authors

  • Cliff Orori Mosiori Technical University of Mombasa
  • John Maera Maasai Mara University
  • W. Kamande Njoroge Kenyatta University
  • T. Reuben Shikambe Kenyatta University
  • Matthew Munji
  • Robert Magare Maasai Mara University

DOI:

https://doi.org/10.18034/ei.v3i1.197

Keywords:

Fe 3/Fe 2 Oxidant-Reductant electrolyte, cadmium sulfide, Gerischer model, Indium tin oxide, ITO, ITO/CdS interface, Marcus

Abstract

A number of models have been developed to describe electron transfer between electrolytes and group II–VI binary semiconductors. In this report, a study was conducted to describe and model electron transfer between an inorganic semiconductor, (i.e. CdS) and a ferric oxidizing/reducing agent [i.e. K3Fe(CN)6/K4Fe(CN)6]. We describe the interfacial electron transfer using the semi-classical theory approaches as described by Marcus and later developed by Gerischer and therefore called Gerischer model as it is applied to heterogeneous electron transfer in a semiconductor - electrolyte interface. CdS thin films were grown by electro-deposition method on the indium tin oxide (ITO) substrates and were used as electrodes. The data collected was used to determine the kinetic constant rates and re-orientation energies as measured in the solutions with different concentration of redox system, Fe+3/ Fe+2. Experiments showed that when concentration of oxidized species increased and causing an increase in  activity, the kinetic constant rates decreases inversely. Equally light induced current at 0.0V/Ag was higher when the ratio of the oxidant-reductant (i.e. 2/0.02 and 0.2/0.02) was high. EIS studies revealed that for the two ratios of. 2/0.02 and 0.2/0.02, the difference of current density was comparable to the transfer of the charge carriers for the oxidant-reductant electrolyte at 2/0.02 with respect to 0.2/0.02.

Downloads

Download data is not yet available.

Author Biographies

  • Cliff Orori Mosiori, Technical University of Mombasa

    Department of Mathematics & Physical Sciences, Technical University of Mombasa, Box 90420 – 80100 Mombasa, KENYA

  • John Maera, Maasai Mara University

    Department of Mathematics & Physical Sciences, Maasai Mara University, Box 861 - 20500, Narok , KENYA

  • W. Kamande Njoroge, Kenyatta University

    Department of Physics, Kenyatta University, Box 43844 - 00100, Nairobi, KENYA

  • T. Reuben Shikambe, Kenyatta University

    Department of Physics, Kenyatta University, Box 43844 - 00100, Nairobi, KENYA

  • Matthew Munji

    Department of Physics, Kenyatta University, Box 43844 - 00100, Nairobi, KENYA

  • Robert Magare, Maasai Mara University

    Department of Mathematics & Physical Sciences, Maasai Mara University, Box 861 - 20500, Narok , KENYA

References

Appleby, A. J. (1974). Electrocatalysis. In Modern aspects of electrochemistry (pp. 369-478). Springer US.
Boddy, P. J., Kahng, D., & Chen, Y. S. (1968). Oxygen evolution on potassium tantalate anodes. Electrochimica Acta, 13(6), 1311-1328.
Chiba, Y., Islam, A., Watanabe, Y., Komiya, R., Koide, N., & Han, L. (2006). Dye-sensitized solar cells with conversion efficiency of 11.1%. Japanese Journal of Applied Physics, 45(7L), L638.
Cottrell, F. G. (1902). Application of the Cottrell equation to chronoamperometry. Z Physik Chem, 42, 385.
Di Quarto, F., Di Paola, A., & Sunseri, C. (1981). Semiconducting properties of anodic WO 3 amorphous films. Electrochimica Acta, 26(8), 1177-1184.
Dogonadze, R. R., & Kuznetsov, A. M. (1975). Theory of charge transfer kinetics at solid-polar liquid interfaces. Progress in Surface Science, 6(1), 1-41.
Dogonadze, R. R., & Kuznetsov, A. M. (1975). Theory of charge transfer kinetics at solid-polar liquid interfaces. Progress in Surface Science, 6(1), 1-41.
Dogonadze, R. R., Kuznetsov, A. M., & Levich, V. G. (1968). Theory of hydrogen-ion discharge on metals: Case of high over-voltages. Electrochimica Acta, 13(5), 1025-1044.
Einstein, A., B. Podolsky, and N. Rosen, 1935, “Can quantum-mechanical description of physical reality be considered complete?”, Phys. Rev. 47, 777-780
Gerischer, H. (1990). The impact of semiconductors on the concepts of electrochemistry. Electrochimica Acta, 35(11), 1677-1699.
Heusler, K. E., & Schulze, M. (1975). Electron-transfer reactions at semiconducting anodic niobium oxide films. Electrochimica Acta, 20(3), 237-244.
Jia, H., Hu, Y., Tang, Y., & Zhang, L. (2006). Synthesis and photoelectrochemical behavior of nanocrystalline CdS film electrodes. Electrochemistry communications, 8(8), 1381-1385.
Memming, R. (1984). Electron transfer processs with excited molecules at semiconductor electrodes. Progress in surface science, 17(1), 7-73.
Nazeeruddin, M. K., Pechy, P., Renouard, T., Zakeeruddin, S. M., Humphry-Baker, R., Comte, P., ... & Spiccia, L. (2001). Engineering of efficient panchromatic sensitizers for nanocrystalline TiO2-based solar cells. Journal of the American Chemical Society, 123(8), 1613-1624.
Stimming, U., & Schultze, J. W. (1979). A semiconductor model of the passive layer on iron electrodes and its application to electrochemical reactions. Electrochimica Acta, 24(8), 859-869.
Vanmaekelbergh, D. (1997). Direct and surface state mediated electron transfer at semiconductor/electrolyte junctions—I. A comparison of steady-state results. Electrochimica acta, 42(7), 1121-1134.
Vanmaekelbergh, D. (1997). Direct and surface state mediated electron transfer at semiconductor/electrolyte junctions—I. A comparison of steady-state results. Electrochimica acta, 42(7), 1121-1134.
Wang, M., Chamberland, N., Breau, L., Moser, J. E., Humphry-Baker, R., Marsan, B., ... & Grätzel, M. (2010). An organic redox electrolyte to rival triiodide/iodide in dye-sensitized solar cells. Nature Chemistry, 2(5), 385-389.
Wang, M., Chamberland, N., Breau, L., Moser, J. E., Humphry-Baker, R., Marsan, B., ... & Grätzel, M. (2010). An organic redox electrolyte to rival triiodide/iodide in dye-sensitized solar cells. Nature Chemistry, 2(5), 385-389.
Wolcott, A., Smith, W. A., Kuykendall, T. R., Zhao, Y., & Zhang, J. Z. (2009). Photoelectrochemical water splitting using dense and aligned TiO2 nanorod arrays. Small, 5(1), 104-111.
--0--

Published

2015-06-18

Issue

Section

Peer Reviewed Articles

How to Cite

Mosiori, C. O., Maera, J., Njoroge, W. K., Shikambe, T. R., Munji, M., & Magare, R. (2015). Modeling Transfer of Electrons between Energy States of an Electrolyte and CdS Thin Films using Gerischer Model. Engineering International, 3(1), 35-44. https://doi.org/10.18034/ei.v3i1.197

Similar Articles

1-10 of 57

You may also start an advanced similarity search for this article.