Calix[4]arene-clicked clay through thiol-yne addition for the molecular recognition and removal of Cd(II) from wastewater

• Published in: Separation and purification technology 2020-11, Vol.251, p.117383, Article 117383
• Main Authors: Jlassi, Khouloud, Eid, Kamel, Sliem, Mostafa H., Abdullah, Aboubakr M., Chehimi, Mohamed M.
• Format: Article
• Language: English
• Subjects: Bentonite; Calixarene; Cd(II) removal; Heavy metals removal; Photo-induced Thiol-Yne Click chemistry; Wastewater treatment
• ISSN: 1383-5866
• DOI: 10.1016/j.seppur.2020.117383

[Display omitted] •Clay/Calix[4]arene were prepared through photo-induced radical-mediated thiol–yne addition.•Smart pathway for tailoring functional clays serving as adsorbent for environmental applications.•The maximum adsorption capacity was equal to 114 mg g−1 at pH 8 and room temperature. A novel type of hybrid Clay/Calix[4]arene (denoted as B-S-Calix), was prepared through fast photo-induced radical-mediated thiol–yne addition between a thiolated clay and an alkynylated calix[4]arene. The photo-induced radical-mediated thiol-yne reaction is a smart, low-cost, efficient, and fast pathway for tailoring low cost, reactive, and functional clay-based materials for potential wastewater treatment applications. The obtained materials were analyzed using X-ray photoelectron spectrometry (XPS), Fourier transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance spectroscopy (HNMR), which all displayed the successful formation of B-S-Calix. The as-synthesized B-S-Calix was used as an adsorbent for toxic Cd(II) metal from wastewater compared to mercaptosilanized bentonite (B-S) at room temperature. The adsorption of Cd(II) on B-S-Calix followed Langmuir isotherm models and pseudo-second-order kinetic, with a maximum removal efficiency of (92.8%) and adsorption capacity of 114 mg g−1 within only 1.5 min at pH 8 and room temperature. The presented B-S-Calix may serve as good candidates for emergent wastewater applications.