LAUSR

Abstract Zinc sulfide (ZnS) sphere-decorated titanium dioxide (TiO 2 ) flowers at various ZnS hydrothermal synthesis durations were synthesized using a two-step facile hydrothermal methodology. The ZnS hydrothermal synthesis duration affected the content and distribution of ZnS spheres decorated on the surfaces of TiO 2 petals. Thus, the separate and random distribution of these spheres, without considerable aggregation, could be obtained by adequately controlling the ZnS hydrothermal synthesis duration. A structural analysis demonstrated that the as-synthesized ZnS spheres and TiO 2 flowers were in crystalline cubic zinc blend and rutile phases, respectively. Moreover, the gas-sensing response of the TiO 2 flowers to ethanol vapor markedly enhanced after the decoration of the ZnS spheres. An optimal ZnS hydrothermal synthesis duration of 2 h for the TiO 2 –ZnS composites was determined to result in the highest gas-sensing response at the given gas-sensing test condition. The strongly favorable ion–species interactions in the gas sensing of ZnS spheres and the formation of TiO 2 /ZnS heterojunctions in the TiO 2 –ZnS composites accounted for the enhanced gas-sensing responses of TiO 2 flowers decorated with ZnS spheres in this study.