Efficient adsorption and facile photocatalytic degradation of organic dyes over H-bonded proton-transfer complex: An experimental and theoretical approach

In this work, a proton-transfer complex namely, 5-hydroxy-isophthalic acid (IPA) with 3-((4-(3isocyanobenzyl) piperazine-1-yl) methyl) benzonitrile (PBN) (1) was synthesized and employed to study the adsorption and photocatalytic properties. Interestingly, it exhibited selective adsorption of cationic dyes such as Methyl Red (MR) and Methylene Blue (MB). Subsequently, the photocatalytic potential of complex 1 was also explored towards facile degradation of MR and MB dyes under UV-light illumination. The dye adsorption activity of complex 1 could be attributed to charge transfer and the existence of an intricate array of non-covalent interactions between them, whereas efficient charge separation between HOMO-LUMO is pivotal for photo degradation of dyes under UV-light illumination. Moreover, the kinetic studies reveal both adsorptions as well as photocatalytic degradation of dyes, followed the pseudo-first order mechanism. The density functional theory (DFT) calculations were used to validate the dye adsorption mechanism. However, the alterations in the electronic property were noticed by comparing the theoretical results before and after the adsorption, showing that adsorption is a physical process. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, a proton-transfer complex was synthesized and found to exhibit selective adsorption of dyes and efficient photocatalytic degradation. The adsorption activity was attributed to charge transfer and non-covalent interactions, while efficient charge separation was crucial for photo degradation.