Solar photocatalytic hydrogen production from water using a dual bed photosystem. Task 2 report; Annual report
This work is an investigation into the use of photocatalytic particles in a dual bed configuration, so as to effect the solar-driven decomposition of water to its constituent elements, particularly hydrogen. The system envisioned would consist of two modules, each consisting of a shallow, flat, sealed container, in which micron-sized photocatalytic particles are immobilized. An aqueous solution containing a redox mediator is pumped between the two chambers. Different photoparticles and catalysts are chosen for their respective modules so as to effect oxidative water-splitting in one vessel to evolve oxygen gas, and reductive water-splitting in the other to evolve hydrogen. This is a direct photoconversion scheme that breaks down the energetic requirement for water decomposition into a 2-photon process, and enables separate production of hydrogen and oxygen. Titanium dioxide, TiO{sub 2}, and indium phosphide, InP, were employed as photoparticles in the O{sub 2}- and H{sub 2}-evolving beds, respectively. Platinum catalysts were evaluated to prompt H{sub 2}-evolution. Calculations on the energy band structure of free and immobilized particles provided guidance as to how the microstructure of the particles should be configured. A series of redox mediators, spanning a range of redox potentials, were tested. While many electron donors facilitated H{sub 2}-evolution, only the most oxidizing ones enabled O{sub 2}-evolution. A single redox couple, capable of charge exchange in both modules, is desirable to avoid system design complexity.
- Research Organization:
- Florida Solar Energy Center, Cocoa, FL (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
- DOE Contract Number:
- FG04-94AL85802
- OSTI ID:
- 564090
- Report Number(s):
- DOE/AL/85802-T2-Pt.2; FSEC-CR-857-95-Pt.2; ON: DE98002550; TRN: AHC29804%%55
- Resource Relation:
- Other Information: PBD: Dec 1995
- Country of Publication:
- United States
- Language:
- English
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Solar photocatalytic H{sub 2} production from water using a dual bed photosystem
Solar photocatalytic H{sub 2} production from water using a dual bed photosystem