Conductive Polymers and Their Nanocomposites as Adsorbents in Environmental Applications

Abstract

Proper treatment and disposal of industrial pollutants of all kinds are a global issue that presents significant techno-economical challenges. The presence of pollutants such as heavy metal ions (HMIs) and organic dyes (ODs) in wastewater is considered a significant problem owing to their carcinogenic and toxic nature. Additionally, industrial gaseous pollutants (GPs) are considered to be harmful to human health and may cause various environmental issues such as global warming, acid rain, smog and air pollution, etc. Conductive polymer-based nanomaterials have gained significant interest in recent years, compared with ceramics and metal-based nanomaterials. The objective of this review is to provide detailed insights into different conductive polymers (CPs) and their nanocomposites that are used as adsorbents for environmental remediation applications. The dominant types of CPs that are being used as adsorbent materials include polyaniline (PANI), polypyrrole (Ppy), and polythiophene (PTh). The various adsorption mechanisms proposed for the removal of ODs, HMIs, and other GPs by the different CPs are presented, together with their maximum adsorption capacities, experimental conditions, adsorption, and kinetic models reported.

Selective Adsorption Behavior of Sulfuric Acid Oxidized and Doped Conjugated Microporous Poly(aniline)s toward Lead Ions in an Aqueous Environment

“…However, producing polymers integrated with nitrogen and sulfate sites is challenging due to low yields and limited adsorption site density. Numerous studies have also utilized the acid doping and dedoping features of conductive polymers to incorporate various acid anions, achieving specific modifications and enhanced adsorption. − Yet, most conductive polymers have minimal specific surface areas, constraining the amount of introduced specific sites. , Emerging structures like metal–organic frameworks (MOFs) and covalent–organic frameworks (COFs) have expansive surface areas suitable for adding numerous sites. But MOFs exhibit stability concerns, while synthesizing COFs presents formidable challenges. − Our objective is to harness materials with extensive specific surface areas for site introduction, which also maintain stability and exhibit a simple synthesis process.…”

Synthesis, characterization, and application of a zinc oxide–pyrrole–thiophene nanocomposite as an efficient adsorbent for the removal of tetracycline

“…4,[11][12][13] Among numerous adsorbent materials, nanocomposites based on conducting polymers, including their co-polymers, have been utilized as adsorbents and have proven to be efficient for wastewater remediation, due to their peculiar and significant characteristics, including very cheap starting material with high electrical conductivity, conjugated porous structure, easy synthesis, nontoxicity, and feasible molecular tuning. 11,[14][15][16] Despite these characteristics, the pristine polymer shows low adsorption capacity due to its crystalline behavior in the polymeric chain. Previous studies have shown that the synergistic interaction of these polymers with different metal oxides (i.e., doping), including TiO 2 , ZnO, Fe 2 O 3 , Fe 3 O 4 , and MnO 2 , leads to an enhancement of the adsorption capacity through the higher exposed specific surface area and additional adsorption sites for the adsorption of antibiotics from polluted water.…”

Functional impacts of polyaniline in composite matrix of photocatalysts: an instrumental overview

“…Thus, to address these issues, the conducting polymer polyaniline (PANI) has been incorporated in the blend. 8,9 Some other examples of conjugated conducting polymers are polyacetylene, polypyrrole, poly(thiophene), poly(paraphenylene vinylene) and poly(carbazole). [10][11][12] Among them, the recent emphasis on PANI is based on its incredible morphological, reactive and functional impacts upon its incorporation in the fabrication of photocatalyst composites, enhancing their spontaneous degradative activities in the photocatalysis of recalcitrant dyes, which are present in large quantities in effluents.…”

“…13 The impacts of PANI in the blend have the potential of tackling challenges of agglomeration and electron-hole recombination, which are major setbacks in photocatalysis. 9,12 Furthermore, the PANI functionally is superior to other conducting polymers due to its unique charge transport dynamics, which accounts for its high photon-sensitizing impacts, while equally enhancing the sorption activity on fabricated composites. 14,15 However, accessing the functional impacts of PANI during the fabrication of composites requires intensive microscopic and spectroscopic elucidation.…”