@phdthesis{Pan2023,
  author    = {Pan, Xuefeng},
  title     = {Soft-template directed functional composite nanomaterials},
  doi       = {10.25932/publishup-61270},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-612709},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VI, 185},
  year      = {2023},
  abstract  = {Soft-template strategy enables the fabrication of composite nanomaterials with desired functionalities and structures. In this thesis, soft templates, including poly(ionic liquid) nanovesicles (PIL NVs), self-assembled polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) particles, and glycopeptide (GP) biomolecules have been applied for the synthesis of versatile composite particles of PILs/Cu, molybdenum disulfide/carbon (MoS2/C), and GP-carbon nanotubes-metal (GP-CNTs-metal) composites, respectively. Subsequently, their possible applications as efficient catalysts in two representative reactions, i.e. CO2 electroreduction (CO2ER) and reduction of 4-nitrophenol (4-NP), have been studied, respectively. In the first work, PIL NVs with a tunable particle size of 50 to 120 nm and a shell thickness of 15 to 60 nm have been prepared via one-step free radical polymerization. By increasing monomer concentration for polymerization, their nanoscopic morphology can evolve from hollow NVs to dense spheres, and finally to directional worms, in which a multi-lamellar packing of PIL chains occurred in all samples. The obtained PIL NVs with varied shell thickness have been in situ functionalized with ultra-small Cu nanoparticles (Cu NPs, 1-3 nm) and subsequently employed as the electrocatalysts for CO2ER. The hollow PILs/Cu composite catalysts exhibit a 2.5-fold enhancement in selectivity towards C1 products compared to the pristine Cu NPs. This enhancement is primarily attributed to the strong electronic interactions between the Cu NPs and the surface functionalities of PIL NVs. This study casts new aspects on using nanostructured PILs as novel electrocatalyst supports in efficient CO2 conversion. In the second work, a novel approach towards fast degradation of 4-NP has been developed using porous MoS2/C particles as catalysts, which integrate the intrinsically catalytic property of MoS2 with its photothermal conversion capability. Various MoS2/C composite particles have been prepared using assembled PS-b-P2VP block copolymer particles as sacrificed soft templates. Intriguingly, the MoS2/C particles exhibit tailored morphologies including pomegranate-like, hollow, and open porous structures. Subsequently, the photothermal conversion performance of these featured particles has been compared under near infrared (NIR) light irradiation. When employing the open porous MoS2/C particles as the catalyst for the reduction of 4-NP, the reaction rate constant has increased by 1.5-fold under light illumination. This catalytic enhancement mainly results from the open porous architecture and photothermal conversion performance of the MoS2 particles. This proposed strategy offers new opportunities for efficient photothermal-assisted catalysis. In the third work, a facile and green approach towards the fabrication of GP-CNTs-metal composites has been proposed, which utilizes a versatile GP biomolecule both as a stabilizer for CNTs in water and as a reducing agent for noble metal ions. The abundant hydrogen bonds in GP molecules bestow the formed GP-CNTs with excellent plasticity, enabling the availability of polymorphic CNTs species ranging from dispersion to viscous paste, gel, and even dough by increasing their concentration. The GP molecules can reduce metal precursors at room temperature without additional reducing agents, enabling the in situ immobilization of metal NPs (e.g. Au, Ag, and Pd) on the CNTs surface. The combination of excellent catalytic property of Pd NPs with photothermal conversion capability of CNTs makes the GP-CNTs-Pd composite a promising catalyst for the efficient degradation of 4-NP. The obtained composite displays a 1.6-fold increase in conversion under NIR light illumination in the reduction of 4-NP, mainly owing to the strong light-to-heat conversion effect of CNTs. Overall, the proposed method opens a new avenue for the synthesis of CNTs composite as a sustainable and versatile catalyst platform. The results presented in the current thesis demonstrate the significance of using soft templates for the synthesis of versatile composites with tailored nanostructure and functionalities. The investigation of these composite nanomaterials in the catalytic reactions reveals their potential in the development of desired catalysts for emerging catalytic processes, e.g. photothermal-assisted catalysis and electrocatalysis.},
  language  = {en}
}
@article{DaniTauberZhangetal.2017,
  author    = {Dani, Alessandro and Tauber, Karoline and Zhang, Weiyi and Schlaad, Helmut and Yuan, Jiayin},
  title     = {Stable Covalently Photo-Crosslinked Poly(Ionic Liquid) Membrane with Gradient Pore Size},
  series = {Macromolecular rapid communications},
  volume    = {38},
  journal   = {Macromolecular rapid communications},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201700167},
  pages     = {4},
  year      = {2017},
  abstract  = {Porous polyelectrolyte membranes stable in a highly ionic environment are obtained by covalent crosslinking of an imidazolium-based poly(ionic liquid). The crosslinking reaction involves the UV light-induced thiol-ene (click) chemistry, and the phase separation, occurring during the crosslinking step, generates a fully interconnected porous structure in the membrane. The porosity is on the order of the micrometer scale and the membrane shows a gradient of pore size across the membrane cross-section. The membrane can separate polystyrene latex particles of different size and undergoes actuation in contact with acetone due to the asymmetric porous structure.},
  language  = {en}
}