MoS 2 /CdS p-n heterojunction films with high photoelectrochemical activity for H 2 evolution under visible light were successfully prepared by electrodeposition followed by chemical bath deposition. The films were characterized by X-ray diffraction, scanning electron microscopy, UV−visible absorption, X-ray photoemission spectroscopy, photoluminescence, and photoelectrochemical response. The MoS 2 /CdS heterostructure shows much higher visible-light photoelectrocatalytic activity and higher stability toward the water splitting than pure CdS film. The MoS 2 /CdS film with an optimal ratio of 0.14% exhibits the highest photocurrent of 28 mA/cm 2 and the highest IPCE of ca. 28% at 420 nm at 0 V vs Ag/ AgCl. The critical role of MoS 2 in the MoS 2 /CdS film was investigated. The improved photoelectrochemical performance of the MoS 2 /CdS heterojunction film was attributed to the visible light absorption enhanced by MoS 2 and the formation of a p-n junction between CdS and MoS 2 , which accelerates the effective separation of photogenerated carriers by the internal electrostatic field in the junction region.

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A novel type of titanium precursor, ammonium-exchanged titanate nanowires, is used to hydrothermally synthesize nanosized TiO 2 single crystals with well-defined facets. With additives of appropriate shape-capping reagents, octahedral, truncated octahedral, and spindle-like TiO 2 nanocrystals have been obtained. We proposed that the transformation mechanism from ammonium-exchanged titanate nanowires to TiO 2 may be a "dissolution-nucleation" process. Furthermore, the photocatalytic activities of anatase TiO 2 nanocrystals with different facets exposed have been investigated.

concentrations in the permeate solution. Single gas permeation experiments were performed at 200 C in a cross-flow gas permeation setup [3a]. Pervaporation experiments were performed with water/ 1,4-dioxane and water/glycol binary liquids at 75±80 C in a dead-end pervaporation unit [4a,5]. The permeate composition was analyzed by Karl Fischer titration.