Direct Z-scheme 1D/2D WO2.72/ZnIn2S4 hybrid photocatalysts with highly-efficient visible-light-driven photodegradation towards tetracycline hydrochloride removal

There are increasing environmental concerns of serious pollution from emission of antibiotic wastewater. Herein, a series of direct Z-scheme WO2.72/ZnIn2S4 (WOZIS) hybrid photocatalysts composed of one-dimensional (1D) WO2.72 (WO) nanorods and two-dimensional (2D) ZnIn2S4 (ZIS) nanosheets have been designed and constructed for tetracycline hydrochloride (TCH) degradation without presence of solid-state electron mediators. The crystalline phase, chemical composition, morphology, optical properties and photocatalytic activity of the as-prepared samples were characterized by the XRD, XPS, SEM, HRTEM, BET, UV-vis DRS, and PL. Obviously, all the WOZIS hybrid photocatalysts exhibited significantly enhanced photocatalytic activity towards TCH degradation. Meanwhile, WOZIS-1 sample with WO/ZIS molar ratio of 1:1 showed the highest photocatalytic activity. The significantly enhanced photoactivity of WOZIS hybrid photocatalyst was due to Z-scheme charge separation mechanism based on the build of tight interfacial contacts between WO nanorods and ZIS nanosheets, thereby driving efficient charge separation. Moreover, the high photocatalytic stability of as-prepared WOZIS-1 hybrid sample was revealed through seven successive cycling reactions.