Highly Regenerable Mussel-Inspired Fe₃O₄@Polydopamine-Ag Core–Shell Microspheres as Catalyst and Adsorbent for Methylene Blue Removal

Abstract

We report a facile method to synthesize Fe3O4@polydopamine (PDA)-Ag core-shell microspheres. Ag nanoparticles (NPs) are deposited on PDA surfaces via in situ reduction by mussel-inspired PDA layers. High catalytic activity and fast adsorption of a model dye methylene blue (MB) at different pH values are achieved mainly due to the presence of monodisperse Ag NPs and electrostatic interactions between PDA and MB. The as-prepared Fe3O4@PDA-Ag microspheres also show high cyclic stability (>27 cycles), good acid stability, and fast regeneration ability, which can be achieved efficiently within several minutes by using NaBH4 as the desorption agent, showing great potentials in a wide range of applications.

Nanocomposites of graphene oxide, Ag nanoparticles, and magnetic ferrite nanoparticles for elemental mercury (Hg0) removal

“…Efficient adsorbents typically require large specic surface area which ensures sufficient contact between adsorbents and mercury, and high degree of surface reactivity for a suitable mercury adsorption capacity. Therefore, porous materials [13][14][15][16][17] such as activated carbons, zeolite, and mesoporous silica have been extensively explored as scaffolds to impregnate active chemicals including chlorine, sulfur, bromide, iodine and noble metals, and are employed as adsorbents. 13,18,19 However, most of these sorbents are difficult to regenerate due to the strong chemical interactions involved in mercury adsorption, thereby incurring high operating costs.…”

Mussel inspired green synthesis of silver nanoparticles-decorated halloysite nanotube using dopamine: characterization and evaluation of its catalytic activity

“…To investigate the diversity of as-prepared Ag/HNTs nanocatalyst, the catalytic reduction of methylene blue (MB) was also studied as model pseudo-first-order reaction due to its rapid and easy analysis (Xie et al 2014). MB shows two characteristic UV-vis peaks at 668 and 608 nm due to the existing equilibrium between MB and its dimer (as shown in Fig.…”

Biomimetic polymer-based Ag nanocomposites as a antimicrobial platform

“…The characterization of these materials surfaces has highlighted their potential application in various fields, including biosensors [7,25] and tissue engineering [26][27][28]. Recently, PDA-functionalized hybrid nanomaterials have been developed, which showed great potential in catalysis [29], medical metallic implants [30], and anti-fouling applications [16]. The present study introduces a simple method for preparing dopamine-functionalized hybrid silver nanoparticle substrates, and examines their efficacy towards microorganism inhibition, their anti-biofouling properties, and their biocompatibility.…”