Occlusion of Diblock Copolymer-Modified Gold Nanoparticles Generates Diabolo-Shaped Au@ZnO Nanocomposite Crystals with Enhanced Photocatalytic Properties

Double-hydrophilic diblock copolymers have been extensively used as additives to tune the growth of inorganic crystals in aqueous media. However, there have been no reports of how double-hydrophilic diblock copolymer-decorated nanoparticles influence the morphology, structure, and properties of such crystals. Herein, a well-defined poly(ammonium 2-sulfatoethyl methacrylate)-poly(glycerol monomethacrylate) diblock copolymer is prepared by reversible addition-fragmentation chain transfer polymerization and then adsorbed onto the surface of gold nanoparticles via its dithiobenzoate end-group to form sterically stabilized nanoparticles. The growth of zinc oxide (ZnO) crystals in the presence of such nanoparticles leads to their occlusion, producing Au@ZnO nanocomposite crystals with a remarkable diabolo morphology. Furthermore, such Au@ZnO crystals enable the rapid photocatalytic degradation of a model organic dye (rhodamine B) when subjected to visible light irradiation. This study opens up a new avenue for the design of diblock copolymer-stabilized nanoparticles to enable the construction of organic–inorganic nanocomposite crystals that exhibit emergent properties.