Abstract: Photocatalytic cleavage of hydrogen sulfide into hydrogen and sulfur in aqueous alkaline solution with CdS semiconductor photocatalyst has been studied. It has been examined that sodium lauryl sulfate (SDS) anion surfactant effects on catalyst surface property and catalytic activity in above system. The change of the flatband potential of CdS single crystal electrode is measured with electrochemical method when SDS is added into above system at concentration below the CMC. Thus, It is concluded that the flatband potential of CdS single crystal is shifted toward positive direction in the presence of SDS. The present consequence accords with the decrease of hydrogen quantities evoluted from hydrogen sulfide of photocatalytic cleavage in above system. It is approached that the flatband potential of CdS single crystal electrode is shifted toward positive direction, which is due to competitive adsorption of anion of surfactant and S^2- of the system on the surface of CdS single crystal electrode.

Key words: anion surfactant, semiconductor, hydrogen sulfide, photocatalytic cleavage, cadmium sulfide, sodiumlaurylsulfate