Browsing by Author "Luong, Duy Xuan"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Alkali-metal anode with alloy coating applied by friction
    (2024-05-14) Tour, James M.; Salvatierra, Rodrigo Villegas; Luong, Duy Xuan; Rice University; United States Patent and Trademark Office
    An electrochemical cell with a lithium-metal anode that suppresses dendrite formation and can be fabricated using a simple, inexpensive, and solvent-free process. The anode is coated with a layer of disordered nanomaterial, saturated with lithium ions, that suppresses dendrite formation during charging. The dendrite-suppression coating can be applied simply using a dry, abrasive technique in which the lithium-metal anode is alternately abraded to roughen the surface and polished using a polishing powder of a material that alloys with the lithium.
  • Thumbnail Image
    Item
    High-surface-area corundum nanoparticles by resistive hotspot-induced phase transformation
    (Springer Nature, 2022) Deng, Bing; Advincula, Paul A.; Luong, Duy Xuan; Zhou, Jingan; Zhang, Boyu; Wang, Zhe; McHugh, Emily A.; Chen, Jinhang; Carter, Robert A.; Kittrell, Carter; Lou, Jun; Zhao, Yuji; Yakobson, Boris I.; Zhao, Yufeng; Tour, James M.; Smalley-Curl Institute; NanoCarbon Center; Welch Institute for Advanced Materials
    High-surface-area α-Al2O3 nanoparticles are used in high-strength ceramics and stable catalyst supports. The production of α-Al2O3 by phase transformation from γ-Al2O3 is hampered by a high activation energy barrier, which usually requires extended high-temperature annealing (~1500 K, > 10 h) and suffers from aggregation. Here, we report the synthesis of dehydrated α-Al2O3 nanoparticles (phase purity ~100%, particle size ~23 nm, surface area ~65 m2 g−1) by a pulsed direct current Joule heating of γ-Al2O3. The phase transformation is completed at a reduced bulk temperature and duration (~573 K, < 1 s) via an intermediate δʹ-Al2O3 phase. Numerical simulations reveal the resistive hotspot-induced local heating in the pulsed current process enables the rapid transformation. Theoretical calculations show the topotactic transition (from γ- to δʹ- to α-Al2O3) is driven by their surface energy differences. The α-Al2O3 nanoparticles are sintered to nanograined ceramics with hardness superior to commercial alumina and approaching that of sapphire.
  • Thumbnail Image
    Item
    High-temperature electrothermal remediation of multi-pollutants in soil
    (Springer Nature, 2023) Deng, Bing; Carter, Robert A.; Cheng, Yi; Liu, Yuan; Eddy, Lucas; Wyss, Kevin M.; Ucak-Astarlioglu, Mine G.; Luong, Duy Xuan; Gao, Xiaodong; JeBailey, Khalil; Kittrell, Carter; Xu, Shichen; Jana, Debadrita; Torres, Mark Albert; Braam, Janet; Tour, James M.; NanoCarbon Center and the Rice Advanced Materials Institute; Smalley-Curl Institute
    Soil contamination is an environmental issue due to increasing anthropogenic activities. Existing processes for soil remediation suffer from long treatment time and lack generality because of different sources, occurrences, and properties of pollutants. Here, we report a high-temperature electrothermal process for rapid, water-free remediation of multiple pollutants in soil. The temperature of contaminated soil with carbon additives ramps up to 1000 to 3000 °C as needed within seconds via pulsed direct current input, enabling the vaporization of heavy metals like Cd, Hg, Pb, Co, Ni, and Cu, and graphitization of persistent organic pollutants like polycyclic aromatic hydrocarbons. The rapid treatment retains soil mineral constituents while increases infiltration rate and exchangeable nutrient supply, leading to soil fertilization and improved germination rates. We propose strategies for upscaling and field applications. Techno-economic analysis indicates the process holds the potential for being more energy-efficient and cost-effective compared to soil washing or thermal desorption.
  • Thumbnail Image
    Item
    Laser Induced Graphene Nanomaterials and Applications
    (2017-10-16) Luong, Duy Xuan; Tour, James M
    Laser-induced graphene (LIG) was recently discovered by one step laser induction of CO2 laser (10.6 µm wavelength) under ambient atmosphere. Because of the porous structure with lots of defect sites, LIG were studied as mircrosupercapacitors, electrochemical catalyst, heat transfer and number of applications are being researched. In this thesis, in the first chapter, I will begin my work with tuning the laser parameters to understand the formation of the LIG structure that was found to be a fluid dynamic that interestingly, is similar to a sneeze. A new LIG structure, another product of this laser induction process which named Laser Induced Graphene Scrolls (LIGS) was also discovered as scrolled version of LIG that can be fabricated to millimeter scale vertical aligned forest. The second chapter will be the laminated object manufacturing technique for the 3D printing of both LIG and LIGS and their potential applications in energy storage and high strength graphene base composite. Lastly, in the third chapter, I will discuss how control environment alter the morphology and doping of LIG that eventually leading to the change from superhydrophobic to superhydrophilics.
  • Thumbnail Image
    Item
    Nondestructive flash cathode recycling
    (Springer Nature, 2024) Chen, Weiyin; Cheng, Yi; Chen, Jinhang; Bets, Ksenia V.; Salvatierra, Rodrigo V.; Ge, Chang; Li, John Tianci; Luong, Duy Xuan; Kittrell, Carter; Wang, Zicheng; McHugh, Emily A.; Gao, Guanhui; Deng, Bing; Han, Yimo; Yakobson, Boris I.; Tour, James M.; Applied Physics Program;Smalley-Curl Institute;NanoCarbon Center;Rice Advanced Materials Institute
    Effective recycling of end-of-life Li-ion batteries (LIBs) is essential due to continuous accumulation of battery waste and gradual depletion of battery metal resources. The present closed-loop solutions include destructive conversion to metal compounds, by destroying the entire three-dimensional morphology of the cathode through continuous thermal treatment or harsh wet extraction methods, and direct regeneration by lithium replenishment. Here, we report a solvent- and water-free flash Joule heating (FJH) method combined with magnetic separation to restore fresh cathodes from waste cathodes, followed by solid-state relithiation. The entire process is called flash recycling. This FJH method exhibits the merits of milliseconds of duration and high battery metal recovery yields of ~98%. After FJH, the cathodes reveal intact core structures with hierarchical features, implying the feasibility of their reconstituting into new cathodes. Relithiated cathodes are further used in LIBs, and show good electrochemical performance, comparable to new commercial counterparts. Life-cycle-analysis highlights that flash recycling has higher environmental and economic benefits over traditional destructive recycling processes.
  • Thumbnail Image
    Item
    Phase controlled synthesis of transition metal carbide nanocrystals by ultrafast flash Joule heating
    (Springer Nature, 2022) Deng, Bing; Wang, Zhe; Chen, Weiyin; Li, John Tianci; Luong, Duy Xuan; Carter, Robert A.; Gao, Guanhui; Yakobson, Boris I.; Zhao, Yufeng; Tour, James M.; Smalley-Curl Institute; NanoCarbon Center and the Welch Institute for Advanced Materials
    Nanoscale carbides enhance ultra-strong ceramics and show activity as high-performance catalysts. Traditional lengthy carburization methods for carbide syntheses usually result in coked surface, large particle size, and uncontrolled phase. Here, a flash Joule heating process is developed for ultrafast synthesis of carbide nanocrystals within 1 s. Various interstitial transition metal carbides (TiC, ZrC, HfC, VC, NbC, TaC, Cr2C3, MoC, and W2C) and covalent carbides (B4C and SiC) are produced using low-cost precursors. By controlling pulse voltages, phase-pure molybdenum carbides including β-Mo2C and metastable α-MoC1-x and η-MoC1-x are selectively synthesized, demonstrating the excellent phase engineering ability of the flash Joule heating by broadly tunable energy input that can exceed 3000 K coupled with kinetically controlled ultrafast cooling (>104 K s−1). Theoretical calculation reveals carbon vacancies as the driving factor for topotactic transition of carbide phases. The phase-dependent hydrogen evolution capability of molybdenum carbides is investigated with β-Mo2C showing the best performance.
  • Thumbnail Image
    Item
    Urban mining by flash Joule heating
    (Springer Nature, 2021) Deng, Bing; Luong, Duy Xuan; Wang, Zhe; Kittrell, Carter; McHugh, Emily A.; Tour, James M.; Smalley-Curl Institute; NanoCarbon Center; Welch Institute for Advanced Materials
    Precious metal recovery from electronic waste, termed urban mining, is important for a circular economy. Present methods for urban mining, mainly smelting and leaching, suffer from lengthy purification processes and negative environmental impacts. Here, a solvent-free and sustainable process by flash Joule heating is disclosed to recover precious metals and remove hazardous heavy metals in electronic waste within one second. The sample temperature ramps to ~3400 K in milliseconds by the ultrafast electrical thermal process. Such a high temperature enables the evaporative separation of precious metals from the supporting matrices, with the recovery yields >80% for Rh, Pd, Ag, and >60% for Au. The heavy metals in electronic waste, some of which are highly toxic including Cr, As, Cd, Hg, and Pb, are also removed, leaving a final waste with minimal metal content, acceptable even for agriculture soil levels. Urban mining by flash Joule heating would be 80× to 500× less energy consumptive than using traditional smelting furnaces for metal-component recovery and more environmentally friendly.