| Abstract: | One of the applications of solar energy is the photo-thermochemical production of fuel, particularly hydrogen. In this regard photo-oxidations/reductions are important processes and may provide a route to harnessing solar energy. Liquid sulphur absorbs in the visible region (400–500 nm). The absorption of light in this region will produce excited sulphur and hence can take part in the photo-oxidation/reduction process. The photo-oxidation of liquid sulphur by Fe(III) salt (anhydrous ferric chloride) at 150 ± 5°C was studied in both the presence and absence of visible light. It was found that liquid sulphur was photo-oxidized by Fe3+ which itself was reduced to Fe2+. The overall rate constants for photo-thermochemical and pure thermochemical reactions were found to be 5–3 × 10?6 M?1 s?1 and 2–8 × 10?6 M?1 s?1, respectively. A mechanism for the photo-thermochemical reaction is proposed. |
