Layer by layer growth of nano porous lead(ii) coordination polymer on natural silk fibers and its application in removal and recovery of iodide

Abstract

The growth of a three-dimensional (3D) porous coordination polymer, [Pb(4-bpdh)(NO₃)(H₂O)] (HMTI-1) on silk fibers were achieved by stepwise layer-by-layer growth technique in alternating bath of lead(II) nitrate and 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh) solutions. The silk fibers containing HMTI-1 metal–organic framework similar to nano powders of HMTI-1 synthesized by microwave have superior adsorption capacity and recovery of I₂ under ambient condition. In order to investigate the role of sonicating and microwave-irradiation on the morphology of products, one of the reactions was performed with ultrasound irradiation and repeated under microwave-irradiation. The stepwise deposition on the surface was monitored by powder X-ray diffraction (PXRD), IR spectroscopy, EDX, WDX and scanning electron microscopy (SEM) and UV-vis spectroscopy.