A WS2/sepiolite composite with highly dispersed WS2 nanosheets for photocatalytic wastewater treatment

Two-dimensional tungsten disulfide (WS 2 ) nanosheets with large specific surface energies usually suffer from serious aggregation, hindering their catalytic activity and potential applications. In this work, highly dispersed WS 2 nanosheets were synthesized in a cost-effective way by employing sepiolite (Sep) nanofibers as the carrier via a hydrothermal treatment followed by calcination under H 2 /N 2 atmosphere, and the mass fraction of the raw materials including ammonium metatungstate, thioacetamide, oxalate acid and sepiolite were determined as 29.3 wt%, 35.7 wt%, 25.0 wt% and 10.0 wt%, respectively. The dispersed WS 2 nanosheets were uniformly grown on the Sep, as observed by an electron microscope . First principle calculations further revealed that the favorable bonding between the tungsten of WS 2 [W(WS 2 )] and the oxygen of Sep [O(Sep)] at the WS 2 /sepiolite interface enables Sep a unique support, superior to other minerals for growing such a highly-dispersed ultrathin WS 2 architecture. Compared with pure WS 2 , the as-prepared WS 2 /sepiolite composite exhibits about 7 times the specific surface area and 7.4 times the photocatalytic efficiency toward rhodamine B (RhB) degradation due to the better dispersion of WS 2 nanosheets and synergetic effects of sepiolite. Besides, the radical trapping experiment indicates that photo-generated hole (h + ) plays the leading role, while hydroxyl radical (·OH) and superoxide radical (·O 2 − ) act as the assistants during photocatalysis . This work provides a novel strategy for the low-cost preparation of high-quality two-dimensional materials via assembly on mineral materials.