Towards a highly efficient simulated sunlight driven photocatalyst: a case of heterostructured ZnO/ZnS hybrid structure.

Large scale ZnO/ZnS heterostructured microflowers are fabricated through a rapid and facile strategy via microwave-assisted in situ surface sulfidation route. The as-obtained product possesses an average diameter of about 2 μm and is composed of many thin nanowires. Through a careful inspection under various growth conditions, the morphologies of the as-prepared hybrid structures could be controlled by tailoring the concentration of thioacetamide (TAA) solution during the microwave irradiation, and a possible growth mechanism was proposed. The photocatalytic experiment results for the photodegradation of eosin B under simulated sunlight irradiation revealed that the hybrid nanostructures possess significantly higher photocatalytic activity which is about triple that of the original ZnO precursors, indicating their potential applications in organically polluted water treatment. The optimal sulfidation concentration to realize the maximum photocatalytic activity in the ZnO/ZnS hybrid structures is also proposed and discussed. Meanwhile, this facile, rapid microwave-assisted strategy is scalable and can be extended to synthesize other oxide/sulfide (MOx/MSy) heterostructures.