Molecular Oxygen for Photooxidation Process

The presence of dissolved molecular oxygen favors recombination of photogenerated charge carriers in Ti02 particles [40]. In agreement with this, a typical current-potential characteristic of Ti02 thin layers (particle size about 10 nm) is shown in Fig. 5.13. 

The photocurrent was generated via UV illumination from a Xe lamp (150 W) in argon purged (dashed line) and in oxygen saturated (full line) electrolyte. The dark current remained the same in both atmosphere. 

In an oxygen saturated electrolyte, the photocurrent (e. g., at 0.3 V/SHE), generated via Xe lamp (150 W), is ca. 28% less than the photocurrent generated in an argon 

As indicated by Fig. 5.14(b) and (c), both surfaces are able to photooxidize HCOOH to C02 in the presence of oxygen. However, the consumption of this latter at n-Ti02/RuxSey is more effective with the concomitant enhancement of the C02 signal. Further, the applied bias of 0.3 V/SHE (see arrow (3)) does not enhance the efficiency of the modified surface, but the non-modified one. This indicates that under UV-illumination 

I would like to thank my students and coworkers. The author specially acknowledges Dr. P. Bogdanoff (Hahn-Meitner-Institut-Berlin) for his help in DEMS measurements. 

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