Technical Data Sheet

Transcription

1 Technical Data Sheet Product Description: A photoelectrochemical (PEC) device capable of splitting water into storable hydrogen fuel directly using solar energy is becoming a very attractive technology since it is clean and sustainable. A PEC cell device has to comply with several requirements for lab applications: I. Should allow different photoelectrodes configuration see example setup II. III. below; To maximize the light penetration through the cell to reach the photoelectrodes; The cell should be resistant to corrosive electrolytes; IV. Providing a continuously electrolyte feeding; V. The need of a membrane to maintain the evolved gases separated. Bearing in mind all these requirements a new PEC cell was developed as depicted in Figure : Lopes, T., et al., An innovative photoelectrochemical lab device for solar water splitting. Solar Energy Materials and Solar Cells, (0): p

2 Figure. Photoelectrochemical cell for Solar H 2 production. The developed PEC cell consists of a reservoir that holds the electrolyte solution wherein the two electrodes are immersed: the anode and the cathode, where one or both electrodes must be photoactive. This electrolyte container have a transparent window allowing the light to reach the photoactive electrode triggering the correspondent electrochemical reactions responsible for water splitting into hydrogen and oxygen. The proposed cell can be easily connected to an external bias source whenever the energetic requirements of the photoelectrode(s) alone are not enough to promote the water splitting reaction (or other electrochemical reaction). Moreover, this PEC cell reactor allows a continuous electrolyte feeding, a separate evolution of hydrogen and oxygen, besides having a great flexibility for hosting the electrodes. The new PEC cell depicted in Fejl! Henvisningskilde ikke fundet. is prepared to host photoelectrodes up to 0 0 cm 2. Photoelectrochemical Cell components The photoelectrochemical reactor comprised the following items: Qty Description Picture Transparent acrylic (Perspex ) cap (gas collection chamber) and 2 screws (HASTELLOY )

3 Transparent acrylic (Perspex ) cap (electrodes contacts - Titanium) Acrylic (Perspex ) diaphragm holder 2 Black acrylic (Perspex ) for light blocking with 2 screws (HASTELLOY ) 6 Transparent window made of polycarbonate 2 Metal frames to hold the transparent window with 2 screws - HASTELLOY Transparent PEC cell body (made of acrylic Perspex )

4 Figure 2. Schematic representation of a 0 0 cm 2 photoelectrochemical cell components: Transparent acrylic cap (gas collection chamber); 2 Teflon membrane; 3- Transparent acrylic cap (electrodes contacts); 4 Photoelectrode; 5 Diaphragm to separate both electrodes; 6 - Metal-counter electrode; 7 Black acrylic for light blocking; 8 Transparent window; 9 Transparent PEC cell body. Example Setup Photosplitting of water for Hydrogen and Oxygen production The experimental setup shown in Figure 3 comprises: a PEC cell (Figure 3 a) wherein two electrodes, a photoelectrode of WO 3 (not included) and a commercial platinized Ti-mesh (not included), are immersed in a M NaOH electrolyte solution Figure 3 - b. The cell contacts can be made through the use of an alligator clip Figure 3 - c. The upper Teflon membrane Figure 3 - d (commercial Teflon tape not included) prevents the electrolyte leakage to the gas collection chamber Figure 2 - but allows the gas to cross it through pressure difference. The diaphragm Figure 3 e prevents the evolved gases mix (H 2 and O 2) before being collected in the chamber (Figure 2). The electrolyte feeding is preformed according to Figure 3 f.

5 Figure 3. Setup for conducting water splitting experiments for solar H 2 production. Technical specifications PEC cell size: 22 cm x 8 cm Active Area: up to 0 x 0 cm 2 Cell Weight: ~ 4 kg Operation ph range: 4 Temperature operating range: 5 C to 80 C Power radiation: < 3 sun Other devices PORTOCell for small photoelectrodes with an active area up to 5 x 5 cm 2.