Spatially Controlled Occlusion of Polymer‐Stabilized Gold Nanoparticles within ZnO

Abstract

In principle, incorporating nanoparticles into growing crystals offers an attractive and highly convenient route for the production of a wide range of novel nanocomposites. Herein we describe an efficient aqueous route that enables the spatially-controlled occlusion of gold nanoparticles (AuNPs)within ZnO crystals at up to 20 % by mass. Depending on the precise synthesis protocol, these AuNPs can be (i) solely located within a central region, (ii) uniformly distributed throughout the ZnO host crystal or (iii) confined to a surface layer. Remarkably, such efficient occlusion is mediated by a nonionic water-soluble polymer, poly(glycerol monomethacrylate)70 (G70), which is chemically grafted to the AuNPs; pendent cis-diol side-groups on this steric stabilizer bind Zn 2+ cations, which promotes nanoparticle interaction with the growing ZnO crystals. Finally, uniform occlusion of G70-AuNPs within this inorganic host leads to faster UV-induced photodegradation of a model dye. Biominerals provide many wonderful examples of the incorporation of water-solublebiomacromolecules within various inorganic crystals, such as bones, teeth and seashells. [1] However, incorporating nanoparticles into inorganic crystals is much more challenging. [2] This is because crystallization normally favors impurity expulsion, rather than occlusion. [3] Nevertheless, various inorganic nanoparticles (e.g. Pt, Au, Fe3O4, quantum dots, etc) have been encapsulated into zeolites, [4] metal organic frameworks (MOFs), [5] and ionic crystals, [6] albeit typically at relatively low loadings. In related work, inorganic nanoparticles can also be incorporated into CaCO3 (calcite) [7] or Cu2O [8] respectively using a gel-trapping or confinement-based strategy.

Role of Polymer Structures in Catalysis by Transition Metal and Metal Oxide Nanoparticle Composites

“…A pioneering work has been recently published by the Armes group, where an ionic water-soluble polymer, poly(glycerol monomethacrylate) 70 (G 70 ), was grafted on the surface of Au NPs. 80 The pendent diol groups of G 70 bound Zn 2+ cations allow for Au NP interactions with growing ZnO crystals and result in occlusion of the former within the crystal. Depending on the synthetic method, Au NPs could be differently distributed within the ZnO crystal, leading to different catalytic performance.…”

Efficient photocatalytic hydrogen evolution of g-C3N4/Vs-SnS2/CdS through a sulfur vacancy-rich SnS2 induced charge storage effect

“…S7, † a peak at 531.1 eV is attributed to the metal-oxygen bond, further verifying the formation of Cd-OH, and the other peak at 532.0 eV can be attributed to the chemical oxygen adsorbed on the surface of g-C 3 N 4 /Vs-SnS 2 /CdS. 28,29 It indicates that the heterojunction would enhance the water adsorption (H 2 O adsorption isotherm curves and contact angles which have been measured evidence the enhanced H 2 O adsorption and will be introduced below).…”

Ptychographic X-ray tomography reveals additive zoning in nanocomposite single crystals

“…The occlusion of additives ranging from small molecules, 7,32,53,54 to polymers, 34,55,56 to organic and inorganic nanoparticles, 4,5,8,18,22,24,26,28 in single crystals provides a unique strategy for creating new materials with tailor-made properties. However, to fully prot from this approach, it is necessary to control the composition and structure of these nanocomposites.…”

“…This approach has been demonstrated for the occlusion of nanoparticles including magnetite (Fe 3 O 4 ), gold and organic nano-objects in calcite and ZnO. [24][25][26][27][28] Nanoparticle aggregation is less signicant in organic solvents, such that successful occlusion has been achieved of Pt nanoparticles in MOFs 29 and PbS particles in methylammonium lead iodide perovskites. 4,30 In all of these cases, the properties of these single crystal nanocomposites are dependent not only on their compositions, but also on their 3D structures.…”