| 초록 |
The MWCNT-modified Fe2O3 electrode was well made through spray coating of MWCNT and e-beam evaporation of iron particles on FTO coated glass. The growth and light absorption characteristics of Fe2O3 were not affected by the modification of MWCNT. The electrode had layered structure of FTO, MWCNT, and Fe2O3. The photocurrent increases by 66 % in the MWCNT-modified Fe2O3 electrode than in the unmodified electrode at 0.23 V vs. Ag/AgCl which is potential necessary for water oxidation at pH 13.8. In potentiostatic EIS, we could observe the dramatically increased capacitance at the Fe2O3 | FTO and the decreased resistances over the MWCNT-modified Fe2O3 electrode. It explains the role of the MWCNT layer as an expressway for electrons which helps not only charge transfer in the Fe2O3 layer but also charge separation over the entire electrode. In Mott-Schottky analysis, flat band potential of the Fe2O3 electrode was shifted to more positive potentials in the MWCNT-modified case and it confirmed charge migration from the Fe2O3 layer to the MWCNT layer. It also showed good agreement with the result about onset potential of photocurrent. |
