Adsorption of heavy metal ions by thiophene containing mesoporous polymers: An experimental and theoretical study

Abstract

Two novel mesoporous polymers poly [(1E,4E)-1,5-Di-2-thienylpenta-1,4-dien-3-one] (PTCA) and poly[(1E,4E)-2,4-dimethyl-1,5-di(thiophen-2-yl)penta-1,4-dien-3-one] (PTCM) having electron-rich heteroatoms (O and S) have been designed and synthesized by oxidative coupling polymerization promoted by FeCl3. Paid to their excellent physiochemical properties such as porous nature, thermal stability, chemical stability, tunable functionality, presence of electron-rich heteroatoms, etc., they are determined as a prominent candidate for heavy metal ion adsorption irrespective of their low surface area. Hence the synthesized polymers were tested for the adsorption of heavy metal ions from aqueous solutions and found to be promising in the effective removal of Zn2+ and Pb2+ ions. The maximum adsorption capacity of the polymer PTCA for Zn2+ and Pb2+ was calculated as 729.4 ​mg/g and 569.1 ​mg/g respectively, and the maximum adsorption capacity of the polymer PTCM for Zn2+ and Pb2+ was calculated as 652.7 ​mg/g and 545.1 ​mg/g respectively. The desorption study reveals that for PTCA the maximum percentage recovery of Zn2+ and Pb2+ ions was 76.9% and 79.9% respectively, and for PTCM the maximum percentage recovery of Zn2+ and Pb2+ ions was 68.5%, and 73.7% respectively. The theoretical study was conducted to support the experimental results. Also, our materials generate a breakthrough in the field of simple, economic, and template-free development of the same type of novel polymers having different functionalities.