(Pyrenetetrasulfonate/ZnS) n Ordered Ultrathin Films with ZnAl Layered Double Hydroxide as Precursor and Ethanol‐Sensing Properties

Well‐ordered ultrathin films (UTFs) of {pyrenetetrasulfonate(PyTS)/ZnS} n were fabricated by alternating assembly of 1,3,6,8‐PyTS and exfoliated Zn 2 Al layered double hydroxide (LDH) nanosheets through layer‐by‐layer (LBL) electrostatic deposition, followed by an effective in situ gas/solid sulfurization reaction with H 2 S. The assembly process was monitored by UV/Vis spectroscopy, which showed regular stepwise growth of the (PyTS/LDH) n UTFs with consecutive deposition cycles. It is worth noting that the structure of the well‐ordered UTFs is retained after the in situ gas/solid sulfurization reaction. Although both (PyTS/LDH) n UTFs and the sulfurized (PyTS/ZnS) n UTFs respond to ethanol at a relatively low operating temperature (70 °C), the (PyTS/ZnS) n UTFs exhibit a much better response, a fact that can be attributed to synergistic interactions between inorganic ZnS and organic pyrene components. Moreover, the well‐ordered (PyTS/ZnS) 30 UTF exhibits a stronger sensor response to ethanol than to other gases, including NH 3 , H 2 , CO, C 2 H 2 , and CH 4 .