Interaction of Pyrene Ligands with Neat and Defective Two Dimensional ZnO: A First Principles Study

Many heterogeneous and flat two dimensional (2D) materials with finite band gap have been researched for its suitability in exotic applications. For instance, zinc oxide (ZnO) with honey comb structure has optimum band gap that makes it eligible for opto-electronic applications. Recently, our research group have found that pyrene based tetratopic ligands (PTL) are suitable for functionalizing ZnO nanorods. In this study, neat and defective 2D ZnO layer is functionalized with different pyrene based ligands with various functional groups. First principles calculations are done and the degree of affinity of pyrene ligands towards neat and defective ZnO sheets is compared. © 2017 Materials Research Society

Interaction of VOCs with pyrene tetratopic ligands layered on ZnO nanorods under visible light

In this work, the relationship between photosensitivity and chemical sensitivity of zinc oxide (ZnO) nanorods coated with pyrene based tetratopic ligands (PTL) is investigated under visible light. The electrical resistance of ZnO-PTL is affected by adsorption of different volatile organic compounds (VOCs) such as ethanol, n-hexane, trimethylamine, and triethylamine. The illumination strongly affects the response to the VOCs. To elucidate the interaction mechanism between PTL and VOCs, the experimental studies have been complemented by first principles calculations. Both experimental and computational results have shown that the amines are bound to PTL with higher affinity followed by ethanol (alcohol) and n-hexane (alkane). Our results have proved that the COOH functional group at the peripheral site of PTL is not only used for anchoring the molecule onto the ZnO, but it is also the main adsorption site for the VOCs, in particular for amines. In practice, the photo-optical properties of pyrene molecules are complemented by the high affinity of COOH group for amines in order to achieve a photo-activated sensor. The complementary use of optical dyes and chemical ligands can provide an innovative methodology for chemical sensors design. (C) 2016 Elsevier B.V. All rights reserved