Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials: Rational Design and Synthesis of Nanostructures
Program Organizers: Haitao Zhang, University of North Carolina at Charlotte; Gurpreet Singh, Kansas State University; Kathy Lu, Virginia Tech; Edward Gorzkowski, Naval Research Laboratory ; Jian Shi, Rensselaer Polytechnic Institute; Kejie Zhao, Purdue University ; Michael Naguib, Tulane University

Tuesday 2:00 PM
October 1, 2019
Room: D134
Location: Oregon Convention Center

Session Chair: Haitao Zhang, University of North Carolina at Charlotte; Gurpreet Singh, Kansas State University

2:00 PM  Keynote
Crafting Uniform Hairy Nanocrystals for Energy Conversion and Storage : Lin Zhiqun1; 1Georgia Institute of Technology
    In this talk, I will elaborate several general and robust strategies for crafting a rich variety of functional 0D, 1D and shish-kebab nanocrystals with precisely controlled dimensions (e.g., plain, core/shell and hollow nanoparticles; plain and core/shell nanorods; nanotubes; etc.) by capitalizing on a set of rationally designed unimolecular star-like, bottlebrush-like, and worm-like block copolymers, respectively, as nanoreactors. These strategies are effective and able to produce oil-soluble and water-soluble monodisperse nanocrystals, including metallic, ferroelectric, magnetic, luminescent, semiconductor, perovskite, and their core/shell structures, which represent a few examples of the kind of nanocrystals that can be produced using these techniques. The applications of these functional nanocrystals in energy conversion and storage (e.g., dye-sensitized solar cells, perovskite solar cells, photocatalysis, LEDS, thermoelectrics, ferroelectrics, and batteries) will be discussed

2:40 PM  Invited
The Core-shell Engineering on Energy Product of Magnetic Nanometals: Shenqiang Ren1; 1University at Buffalo, The State University of New York
    The rational design and growth of magnetic nanocomposites comprised of two or more materials has been considered a promising strategy for energy product challenges. In this context, magnetic core-shell nanocomposites by coupling magnetically hard and soft phases can simultaneously achieve high magnetocrystalline anisotropy and saturation magnetization. These core-shell architectures can efficiently tune magnetic properties (such as the thermal stability of magnetization and coercivity) via control of the core-shell parameters. There is an immediate need for a simple, scalable and reliable synthesis method for manufacturing high-performance metallic core-shell nanocomposites with the coupling interactions between the core and the shell interfaces. We have demonstrated a solution-based growth of magnetically hard and soft (core-shell) nanoparticles with the controllable exchange coupling interaction. The results imply that the core-shell engineering has the potential to enhance the energy product of next-generation nanomagnets.

3:10 PM  
Epitaxial Growth of Soft Perovskites and the Hidden Carrier Dynamics: Jie Jiang1; Yiping Wang1; Jing Feng2; Jian Shi1; 1Rensselaer Polytechnic Institute; 2Kunming University of Science and Technology
    High-temperature vapor phase epitaxy (VPE) has been proved ubiquitously powerful in enabling high-performance electro-optic devices in III–V semiconductor field. A typical example is the successful growth of p-type GaN by VPE for blue light-emitting diodes. VPE excels as it controls film defects such as point/interface defects and grain boundary, thanks to its high-temperature processing condition and controllable deposition rate. In this talk, we will present single-crystalline high-temperature VPE soft halide perovskite thin film as a unique platform on unveiling previously uncovered carrier dynamics in inorganic halide perovskites. Hot photoluminescence and nanosecond photo-Dember effect are revealed in inorganic halide perovskite. These two phenomena suggest that inorganic halide perovskite could be as compelling as its organic–inorganic counterpart regarding optoelectronic properties and help explain the long carrier lifetime in halide perovskite. The findings suggest a new avenue on developing high-quality large-scale single-crystalline halide perovskite films requiring precise control of defects and morphology.

3:30 PM  Invited
Synthesis, Processing and Additive Manufacturing of Architected Materials with Designed Structural and Multi-functional Responses: Xiaoyu Zheng1; 1Virginia Polytechnic Institute and State University
    Materials with multi-functionalities present the challenge for manufacturing with trade-off in processability and responsiveness. In this talk I will discuss the synthesis, processing and additive manufacturing of a suite of multi-functional material feedstock. Attention is focused on achieving precise control of three-dimensional features and simultaneously optimizing responsiveness. Next, we examine the vast new property space unleashed from the new degrees of freedom brought by manufacturing and design, including rapid recreation of materials with designed-in structural and multi-functional behaviors. In the last part of the talk I will discuss applications including assembly free energy transduction and storage devices to smart material composites for sensing and actuation.

4:00 PM  
Self Supported Cu Doped TiO2 Nano-fibrous Blankets for Visible Light Photo Catalysis: Fateh Mikaeili1; Perena Gouma1; 1Ohio State University
    It has been reported that the transition metal dopant such as Cu2+, Fe3+, Mn3+, and Ni2+ adjusts not only the band gap but also the behavior of electron-hole separation in TiO2. For the first time, 3D- nanostructured and fibrous photocatalytic blankets based on the Cu-TiO2 system were produced by our in-house designed High Throughput electrospinning from sol-gel precursors. The results indicate uniform doping of Cu along the TiO2 fibers with ultra high aspect ratio without any impurities. The self-supported Cu-TiO2 nanomats constitute a novel design concept for functional 3D nano-architectures to be used as self-supported photocatalytic blankets. Photocatalysis results along with in-depth studies of the behavior of photo generated carriers as a function of dopant and morphology was carried out in order to clarify the mechanism behind the increase in photo catalytic activities.

4:20 PM  
Controlled Synthesis of Lamellar-like Electrospun Ceramic Nanofibers for Energy Application: Oren Elishav1; Gennady Shter1; Gideon Grader1; 1Technion
    Ceramic nanofibers can offer useful chemical and physical properties beneficial for energy harvesting and storage applications. Electrospinning is a simple and robust method to produce nanofibers with controlled morphology and diverse compositions. Unique lamellar-like porous nanofibers were synthesized and designated as a selective catalysts for carbon dioxide hydrogenation to liquid fuels. The structure is obtained by reordering of an initially uniform fibers consisting of two metals coordination complexes (Al/Fe(acac)3) and a polymer. A general mechanism for the morphology formation is suggested, where the final structure depends on deformation processes during thermal treatment. The mechanism is realized in other material systems providing the same structure but different functionality. For example, in a system of nickel-based fibers for lithium ion anodes. The relation between morphology and fibers' performance will be discussed. The presented process can yield nanofibers with designed properties that are highly promising for various applications.

4:40 PM  
Nickel-SiOC Magnetoceramics from Water Assisted Pyrolysis of Polymers: Kathy Lu1; Ni Yang1; 1Virginia Polytechnic Institute
    In this study, novel ferromagnetic Ni-containing silicon oxycarbide (SiOC-Ni) was successfully fabricated from a base polysiloxane (PSO) with addition of nickel 2,4-pentanedionate. The resultant SiOC-Ni composite consists of in-situ formed Ni crystallites with a small amount of NiO uniformly dispersed in the amorphous SiOC matrix. The formation of nickel silicides (NixSiy) is successfully suppressed. The Ni crystallite size increases with the pyrolysis temperature. The fundamental phase evolution process and mechanism are explained. In an argon atmosphere, the SiOC-Ni materials pyrolyzed at 900 C are stable with less than 6 wt% weight loss up to 1000 C; they also exhibit desirable electrical conductivity up to ~900 C; the highest electrical conductivity is ~247 S/m. This series of SiOC-Ni materials demonstrates exciting ferromagnetic behaviors. The new semi-conducting behavior with soft ferromagnetism presents promising application potentials for magnetic sensors, transformers, actuators, etc.