Transition Metal Chelated Biopolymer Coated Mesoporous Silica Nanoparticles as Highly Efficient, Stable, and Recyclable Nanocatalysts for Catalytic Bleaching

Abstract

The role of catalysts in the development of improved bleaching methods is of paramount scientific and industrial importance in the bleaching of raw cotton and laundry stains. Despite tremendous efforts, developing novel earth abundant metal nanocatalysts with high activity and stability remains a great challenge. Here, we demonstrate the successful formation of earth abundant transition metal‐chelated layer‐by‐layer hyaluronic acid/chitosan polyelectrolyte‐coated mesoporous silica nanoparticles (Metal@PEM‐MSNPs) as novel bleaching nanocatalysts. Metal@PEM‐MSNPs have been tested for both the oxidative degradation of a natural plant dye in solution and tea‐ and beetroot‐ stains on cotton fabrics. While manganese and iron‐chelated PEM‐MSNPs (Mn2+@PEM‐MSNPs and Fe2+@PEM‐MSNPs) have little catalytic activity, cobalt‐chelated PEM‐MSNPs (Co2+@PEM‐MSNPs) display an unexpected, surprisingly high activity in the oxidation reaction under the same experimental conditions. The results suggest that Co2+@PEM‐MSNPs are excellent nanocatalytic systems for the low temperature bleaching (<30 0C) and the design strategy used in Metal@PEM‐MSNP nanocatalysts can further be extended to prepare a wide range of highly active self‐assembled bio‐inspired nanocatalysts for catalytic bleaching and other organic transformations.

Photochemically Synthesized Ruthenium Nanoparticle-Decorated Carbon-Dot Nanochains: An Efficient Catalyst for Synergistic Redox Reactions

“…In comparison, the rate constants of morin achieved with Ru/C-dots are much higher than those obtained with other metal NPs-based catalysts, which signify the superior catalytic performance of Ru/C-dots toward morin. − Meijboom et al reported the catalytic evaluation in the oxidation of morin with individual Au, Pd, and Pt NPs encapsulated by dendrimer. They have found rate constants of 0.0009, 0.0038, 0.0015, and 0.0003 s –1 for Au-DENs, Pd-DENs, Pt-DENs, and PdAu-DENs-OH, respectively. − Recently, Xiao et al and Yu et al have reported the catalytic oxidation of morin by biocompatible dendrimer-encapsulated Pd NPs and bovine serum albumin-stabilized Pt NPs, respectively. , Similarly, mesoporous structured nanocatalysts including Co/Sn oxide- and transition-metal (Mn 2+ , Fe 2+ , and Co 2+ )-chelated biopolymer-coated silica nanoparticles were applied to the oxidation of morin. , …”

“…42 45,46 Similarly, mesoporous structured nanocatalysts including Co/ Sn oxide-and transition-metal (Mn 2+ , Fe 2+ , and Co 2+ )-chelated biopolymer-coated silica nanoparticles were applied to the oxidation of morin. 47,48 The mechanism was proposed for the catalytic oxidation of morin, as shown in Scheme 2. The absorption peaks observed at 267 and 394 nm corresponding to the π−π* transitions are assigned to the conjugated system of rings A and B in connection with ring C, respectively.…”

Catalytic investigation of hyaluronic acid-stabilized Ag nanoparticles as non-toxic nanocatalysts in the oxidation of morin

“…Recently, different metal nanoparticles have been used as active catalysts in catalytic oxidation since they possess several unique properties, like easy synthesis, high surface area, distinctive optical behaviors, easy removal from the reaction environment, considerable dispersion in the solutions, etc. 4,[10][11][12][13][14][15] Among other transition metal nanoparticles, silver nanoparticles (AgNPs) are particularly useful in oxidation processes because of their exceptional properties, such as high catalytic activity, long-term stability, small sizes, and special optical features. 14,[16][17][18][19][20] The first report on the catalytic evaluation of AgNPs as oxidation nanocatalysts in the presence of H 2 O 2 was published by Meijboom et al 21 In their manuscript, they presented the preparation and characterization of poly-(amidoamine) (PAMAM)-stabilized AgNPs and their catalytic activity in the degradation of morin.…”

Assembling of Reprocessable Polybutadiene-Based Vitrimers with High Strength and Shape Memory via Catalyst-Free Imine-Coordinated Boroxine

“…Until now, the reversible effects arising from dynamic covalent bonds (transesterification reaction, − disulfide bond, − Diels–Alder reactions, − etc.) and noncovalent supramolecular interactions (hydrogen bonding, , metal coordination, − host–guest interactions, ,, and π–π stacking interactions) have been achieved. Dichtel et al fabricated an acid-degradable polycarbonate material with recyclability based on trans-carbonation exchange chemistry, having a high tensile strength (36 MPa) and Young’s modulus (∼1 GPa).…”