[2008.10.16]

Direct splitting of H2S into H2 and S on CdS-based photocatalyst under visible light irradiation
Guijun Ma, Hongjian Yan, Jingying Shi, Xu Zong, Zhibing Lei, Can Li*
Full paper.
http://dx.doi.org/10.1016/j.jcat.2008.09.017

AbstractThe conversion of H2S into H2 and S (H2S H2 + S) is beneficial for both environment and energy. Here we report that H2S can be splitted stoichiometrically into hydrogen and sulfur on CdS-based photocatalysts under visible light irradiation using ethanolamine as H2S solvent and reaction media at room temperature. Raman spectra show that the produced sulfur exists as S42- and S62- after photocatalytic reaction. The hydroxyls of the reaction media are found to be crucial for the hydrogen production and the rate determination step (RDS) of photocatalytic splitting H2S in diethanolamine is discussed. Electrochemical evaluation shows that the potential of H2S splitting in ethanolamine is greatly lowered and the photo-generated electrons could be fully used to reduce protons for hydrogen production. A free radical related one-electron electrochemical oxidation process on platinum electrode is suggested. This work demonstrates the possibility for the direct splitting H2S into S and H2 via photocatalysis.

KeywordsCadmium sulfide; Ethanolamine; Polysulfide; Hydrogen production; Hydrogen sulfide conversion; Photocatalysis; Electrochemistry