Surface aspects of hydrogen photogeneration on titanium oxides
Abstract
The effects of surface platinization on photoactivity are discussed and evidence for a thermal reaction between Pd and TiO2 surfaces is given. No Auger detectable changes in surfaces composition correlate with the higher rates of hydrogen photogeneration on metal-free SrTiO3 observed in highly concentrated aqueous alkaline electrolyte. Platinized crystals and photoelectrochemical cells show similar enhancement of photoactivity at high hydroxide concentrations. Although no hydrogen photogeneration is seen from water vapor at pressures up to 20 Torr on crystals near room temperatures, hydrogen photogeneration does occur on prereduced crystals at temperatures where oxygen diffusion into the bulk is rapid. Kinetics of hole transfer or hydroxylation may determine the overall reaction rate at zero applied potential.
- Publication:
-
Presented at the ACS Symp. on Photoeffects at Semiconductor-Electrolyte Interfaces
- Pub Date:
- July 1980
- Bibcode:
- 1980acs..meetS....W
- Keywords:
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- Hydrogen Production;
- Surface Properties;
- Titanium Oxides;
- Electrolysis;
- Photochemical Reactions;
- Photoelectrochemical Devices;
- Reaction Kinetics;
- Solid-State Physics