Abstract
TiO 2 and WO 3 heterojunction electrodes are studied for their bi-functionality on harvesting light and storing energy. Both semiconductors are fabricated either 'single' (mixed) electrodes or two different electrodes galvanically coupled in a mixed electrolyte of 0.1M sodium formate and 0.1M sodium chloride. Irradiation of AM 1.5-light shifts the open circuit potentials (OCPs) of the mixed and coupled electrodes from around -0.1V SCE (dark OCPs) to a potential range between -0.8 and -0.5V SCE, which slowly return to their respective dark OCPs over a period of around 14h. Such discharging periods are significantly influenced by the irradiation (photocharging) time and weight or area ratios of TiO 2 and WO 3. When the TiO 2 and WO 3 mixed electrodes are galvanically coupled to stainless steel electrodes for application to anticorrosion, the mixed potentials of the couple are maintained at ca. -0.4V SCE over 10h even after light off. The measured galvanic currents verify that the photogenerated electrons of TiO 2 flow to WO 3 (charging) and even overflow to the steel (cathodic protection) during the irradiation, while the stored electrons at WO 3 flow to the galvanically coupled steel electrodes directly or through the TiO 2 upon light off.
Original language | English |
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Pages (from-to) | 74-80 |
Number of pages | 7 |
Journal | Applied Catalysis B: Environmental |
Volume | 115-116 |
DOIs | |
State | Published - 5 Apr 2012 |
Keywords
- Anticorrosion
- Artificial photosynthesis
- Battery
- Discharging
- Galvanic
- Solar