1. Solar Hydrogen Update: 10 th November 2009

2. Probes: pH, pO 2 Hamilton® process sensors http://www.hamiltoncompany.co m/downloads/690127R04klein.pdf H 2 (with Fessehaye) Temperature: Thermocouple In-line heater Hydor® ETH heater http://www.hydor.it/prodotti/sho w/famprod/9/list/3 Omega Engineering® http://www.omega.com/pptst/AH P_SERIES.html Agitation: Peristaltic, re-circulation (diaphragm) pumps Aqua Medic®, Hydor®... KNF Neuberger® http://www.knf.co.uk/ Watson-Marlow® http://www.watson-marlow.com/ MIMS: Membrane Mass Spectrometer Mesh and seal (with Chris) Improvements: Even out agitation Simplify drain and cleaning Water displacement (with Paul) OD measurement (with Steve D) Control: National Instruments® circuit board PC with LabVIEW® (with Chin) http://www.ni.com/ Other: HPLC RI detector (with Steve B) http://www.hplc4sale.co.uk/ Filtration systems (with Prof Holdrich) http://www.aquatechnologies.de/en/

3. Light Intensity - Measurements: PBR1 – Low intensity LED arrayPBR2 – High intensity LED array Sartorius reactor – Cool white fluorescent lightsCulture reactor – Cool white fluorescent lights Distance from LED array (cm) Light Intensity (±0.5 W/m2) No reactorPBR1 408.14.1 308.55.4 2010.16.9 Distance from LED array (cm) Light Intensity (±0.5 W/m2) No reactorPBR2 4056.340.0 3070.448.8 2088.263.5 Distance from light (cm)Light Intensity (±0.5 W/m2) 1031.2 Sartorius light (%) @ 5cm separation Light Intensity (±0.5 W/m2) DownUpAverage 10090.086.688.3 9086.481.684.0 8076.572.774.6 7064.861.163.0 6053.149.851.5 5040.338.639.5 4027.526.427.0 3014.614.114.4 203.6

4. Light Intensity - Spectra: PBR1 – Low intensity LED arrayPBR2 – High intensity LED array Sartorius reactor – Cool white fluorescent lightsCulture reactor – Cool white fluorescent lights

5. Photo-electrochemical Reactor General Picture H2OH2O H2H2 O2O2 + Semiconductorhνhν+Semiconductor (e -, h + ) 2H + H2H2 +2e - +2h + H2OH2O½ O 2 +2H + Considerations - Ease of maintenance - Photo-anode performance - Electrode stability - Orientation / configuration of reactor - Pressure drop across the reactor - Type of electrolyte (steam system) - Source of water - Overall efficiency

6. Photo-electrochemical Reactor General Picture H 2 O (l)Reactor hνhν H 2 (g)O 2 (g) Un-reacted H 2 O (l) Strengths: - Simplicity in reactor - Easy to maintain Problems/Challenges: - H2 and O2 separation - Bubble formation Current reactor ++ Status: - Un-tested - preparation of electrodes in progress

7. Photo-electrochemical Reactor Reactor Idea H 2 O (g)Reactor hνhν Un-reacted H 2 O (g) H 2 (g) O 2 (g) +

8. Photo-electrochemical Reactor H 2 O (g) hνhν Considerations - Modification from current reactor - Pressure drop - Electrolyte - Gap between electrodes H 2 (g) O 2 (g) Un-reacted H 2 O (g) + Reactor Idea Nafion Photo-anode mesh

9. Reactors Out There -Founding from Midwest opto-electric - Using a bi-polar tandem cell configuration (Si-SiGe) - Substrate is coated with indium tin oxide - Claimed to have 5% solar to hydrogen efficiency - Deposition of photo-anode: Sputter system

10. Reactors Out There

11. GaAs Stability

12. Fe 2 O 3 deposition progress Ryan & Jason (4 th Year Project) + Chin Kin Spray pyrolysis Plasma deposition: atmospheric pressure system

13. Fe 2 O 3 : plasma deposition Awaiting access to system: –Requirements: compressed air (cylinder) aqueous reagents (Fe(III)/Fe(II) salts) –Plan: deposit onto unheated substrates

14. Fe 2 O 3 : spray pyrolysis Initial spraying tests (air brush): –Undoped and doped (Sn) films –Good quality films (visual) –Thin (compared to HS) Testing –Electrochemical evaluation: starts Thursday