Mechanochemical synthesis of ultrafine ZnS/Zn-Al layered double hydroxide heterojunction and their photocatalytic activities in dye degradation

ZnS/Zn-Al layered double hydroxide (LDH) heterostructures were synthesized by a mechanochemical method and characterized by a set of analytical methods: X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and scanning electron microscopy. The photocatalytic degradation activity for Rhodamine B (RHB) under ultraviolet light irradiation exhibited a large enhancement with the increasing ZnS content, with 94% RHB degraded in 180 min by using 2ZnS/Zn-Al LDH heterostructured composite, but only 75% by the LDH sample without ZnS. A detailed discussion was performed to understand the reason for the enhanced photocatalytic activity based on the efficient separation of photoinduced electrons and holes. This work provides an effective way to fabricate a series of LDH-based and transition metal sulfide-containing heterostructured photocatalysts.