Synthesis of hierarchical Polystyrene/Polyaniline@Au nanostructures of different surface states and studies of their catalytic properties

Review on polyaniline-based nanocomposite heterogeneous catalysts for catalytic reduction of hazardous water pollutants

Water contamination by highly toxic substances has generated serious ecological disturbances and health problems for humans. Hence, decontamination of toxic pollutants using advanced, inexpensive, and eco-friendly approaches is the current demand. Heterogeneous catalyst-based catalytic reduction processes have offered the opportunity to transform hazardous water pollutants into non-hazardous products via sustainable, eco-friendly, and efficient routes and might be a competitive substitute for existing traditional water purification techniques. However, the key challenges linked with pure heterogeneous catalysts include agglomeration and poor dispersion, stability, recovery, and reusability, which result in poor activity and efficiency. Thus, it is essential to produce multipurpose polymer-based composite catalysts using conducting polymers, which are exceptionally good supportive and matrix materials. The blending of metal-based nanomaterials with polyaniline conducting polymers produces highly stable and efficient heterogeneous nanocomposite catalysts with amazing catalytic activity against a wide range of water pollutants. The heterogeneous catalytic reductive degradation of immensely toxic pollutant water has gained substantial curiosity because of its excellent physicochemical and surface characteristics, porous structure, recoverability, and recyclability. Therefore, this review presents the latest efforts to generate various polyaniline-based nanocomposite catalysts using a polyaniline matrix and various nanofiller materials and their potential applications in heterogeneous catalytic reduction degradation of water pollutants.

Evaluation of physicochemical properties and catalytic activity of poly(PMDAH-co-ODA/PPDA) nanocomposites towards the removal of toxic pollutants

Synthesis of Polyimides (PIs) between pyromellitic dianhydride (PMDAH) and oxydianiline (ODA) or p-phenylenediamine (PPDA) in the presence and absence of V₂O₅ and Ag nanoparticles (NPs) were carried out under N₂ atmosphere at 160 °C for 5 h with vigorous stirring in N-methylpyrrolidone (NMP) solvent. The prepared PI and its nanocomposites were analyzed by FT-IR spectroscopy, ¹H NMR spectroscopy, FE-SEM, SEM, DSC and TGA like analytical instruments. The FE-SEM showed various surface morphologies for different PI nanocomposites. The particle size of the prepared nanoparticles was calculated as less than 60 nm for Ag and 15 nm for V₂O₅ nanoparticles by HR-TEM. The PI nanocomposites embedded with Ag nanoparticles (P2 and P5) showed a higher thermal stability than the pristine PIs (P1 and P4) and PI/V₂O₅ nanocomposites (P3 and P6). Further, the possible application of metal (Ag) and metal oxide (V₂O₅) NPs embedded PI nanocomposites was assessed on the catalytic reduction of highly toxic Cr(VI), Rhodamine 6G (R6G) dye and p-nitrophenol (NiP) pollutants with the help of a reducing agent (NaBH₄). The apparent rate constant (k_app) values were calculated to assess the catalytic efficiency of the prepared PI and its nanocomposites. The PI/Ag nanocomposite (P2) system showed an efficient catalytic reduction than the other systems.

From adsorbents to electrode materials: facile hydrothermal synthesis of montmorillonite/polyaniline/metal oxide (hydroxide) composites

Montmorillonite/polyaniline/metal oxide (hydroxide) composites are fabricated from the spent adsorbents of montmorillonite/polyaniline for the electrode materials of supercapacitors.

Interfacial synthesis of lollipop-like Au–polyaniline nanocomposites for catalytic applications

Lollipop-like Au–PANI nanocomposites show high catalytic activity for the reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) and plasmon-driven conversion of 4-aminothiophenol (4ATP) into 4,4′-dimercaptoazobenzene (DMAB).

Facile fabrication of well-defined polyaniline microtubes derived from natural kapok fibers for supercapacitors with long-term cycling stability

Well-defined polyaniline microtubes derived from natural kapok fibers exhibit long-term cycling stability as electrode materials of supercapacitors.

Silver nanoparticles on carboxyl-functionalized Fe3O4 with high catalytic activity for 4-nitrophenol reduction

Silver nanoparticles on carboxyl-functionalized Fe₃O₄ show a high catalytic activity toward 4-nitrophenol reduction.