| Abstract: | The Au/Porous silicon structure (Au/PS) was developed as hydrogen fuel cell. The use of a porous silicon filled with hydrochloric acid as a proton‐conducting membrane and thin gold film as a catalyst in Au/PS/Si fuel cell is demonstrated. The devices were fabricated by first creating 10–20 µm thick porous silicon layer by anodization etching in a standard silicon wafer and then depositing the gold catalyst film onto the porous silicon. Using sodium borohydride (NaBH4) solution as the fuel, generation of the open‐circuit voltage of 0.55 V and the fuel cell peak power density of 13 mW cm?2 at room temperature was achieved. Moreover production of hydrogen by evolution (out‐diffusion) of hydrogen from solid sodium borohydride during thermal annealing at 30–120°C was investigated. Data on the effective diffusion coefficient of the hydrogen in NaBH4 were determined from intensity changes of infrared vibration peaks of B–H bond (2280 and 3280 cm?1), as a result of thermal annealing of NaBH4 samples. The relatively high values of the diffusion coefficient of hydrogen, increasing from 1×10?6 cm2 s?1 to 2×10?4 cm2 s?1 suggest that a thermo‐stimulated evolution process can be used for producing hydrogen from NaBH4. Copyright © 2010 John Wiley & Sons, Ltd. |
