Christopher Shuck

Drexel University | DU · A.J. Drexel Nanotechnology Institute (DNI)

The diverse and tunable surface and bulk chemistry of MXenes affords valuable and distinctive properties, which can be useful across many components of energy storage devices. MXenes offer diverse functions in batteries and supercapacitors, including double-layer and redox-type ion storage, ion transfer regulation, steric hindrance, ion redistribut...

MXenes are an emergent class of two-dimensional materials with a very wide spectrum of promising applications. The synthesis of multiple MXenes, specifically solid-solution MXenes, allows fine tuning of their properties, expands their range of applications, and leads to enhanced performance. The functionality of solid-solution MXenes is closely rel...

Achieving pseudocapacitive intercalation in MXenes with neutral aqueous electrolytes and driving reversible redox reactions is scientifically appealing and practically useful. Here, we report that the partial oxidation of MXene intensifies pseudocapacitive Li+ intercalation into Ti3C2Tx MXene from neutral water-in-salt electrolytes. An in situ X-ra...

The development of high capacitance materials with high packing density and low viscosity in suspension electrodes is critical for progressing towards high-efficiency, low-footprint electrochemical flow capacitors (EFCs). Here, we report on the first electrochemical and rheological characterization of MXene-based suspension electrodes, using multil...

Slow methanol oxidation reaction kinetics with current electrocatalysts is the major limitation to widespread application and development in direct-methanol fuel cells (DMFCs). The present work demonstrates a highly efficient electrocatalyst for methanol electrooxidation reaction (MEOR) using polyaniline/palladium/Ti3C2Tx (PANI/Pd/MXene) nanocompos...

MXenes are promising pseudocapacitive materials with ultrahigh specific capacitance. Currently, more than 30 stoichiometric MXene compositions and about 20 solid solutions have been experimentally synthesized. However, most studies focus on Ti3C2Tx or a few other single-M MXenes, and little is known about the electrochemical properties of solid-sol...

MXenes have shown record-breaking redox capacitance in aqueous electrolytes, but in a limited voltage window due to oxidation under anodic potential and hydrogen evolution under high cathodic potential. Coupling Ti3C2Tx MXene negative electrode with RuO2 or carbon-based positive electrodes expanded the voltage window in sulfuric acid electrolyte to...

Low and selective infrared emission materials are necessary for next generation thermal technologies, including passive heating, infrared identification, and photothermal conversion. Here, we report on the intrinsic infrared radiation properties of three MXenes: Ti3C2Tx, Ti3CNTx, and V4C3Tx. The infrared emissivity of 200 nm thick Ti3C2Tx coating i...

One of the primary factors limiting further research and commercial use of the two-dimensional (2D) titanium carbide MXene Ti3C2, as well as MXenes in general, is the rate at which freshly made samples oxidize and degrade when stored as aqueous suspensions. Here, we show that including excess aluminum during synthesis of the Ti3AlC2 MAX phase precu...

Two-dimensional transition metal carbides/carbonitrides known as MXenes are rapidly growing as multimodal nanoplatforms in biomedicine. Here, taking SARS-CoV-2 as a model, we explored the antiviral properties and immune-profile of a large panel of four highly stable and well-characterized MXenes - Ti3C2Tx, Ta4C3T x , Mo2Ti2C3T x and Nb4C3T x . T...

Transition metal carbides and nitrides (MXenes) are a relatively new class of 2D materials, which include metallic and semiconducting examples. The chemical compositions of the vast MXene family span a broad range of the periodic table, yet the optical spectra of only a handful of MXene compositions have been reported, and in only one example are t...

MXenes, a large family of two-dimensional materials, have attracted tremendous attention due to their unique physical and chemical properties. Reversible ion intercalation between MXene layers allows modification of the optical, thermal, magnetic, and chemical properties. The electrochemical charge/ discharge of MXenes in aqueous electrolytes was r...

Abstract Simultaneously hard and tough nitride ceramics open new venues for a variety of advanced applications. To produce such materials, attention is focused on the development of high-entropy ceramics, containing four or more metallic components distributed homogeneously in the metallic sublattice. While the fabrication of bulk high-entropy carb...

The MXene field continues to grow and expand as more research groups begin to study this fascinating and very large class of 2D materials. While synthesis and applications of MXenes have been widely discussed in literature, characterization is often overlooked. Due to the large variety of MXene structures and compositions, it is often necessary to...

Alloying is a long-established strategy to tailor properties of metals for specific applications, thus retaining or enhancing the principal elemental characteristics while offering additional functionality from the added elements. We propose a similar approach to the control of properties of two-dimensional transition metal carbides known as MXenes...

Bilayered vanadium oxides (BVOs) are a high-capacity intercalation host with affinity for various ions in energy storage systems. However, the electrochemical stability of BVOs upon extended galvanostatic cycling, especially at high rates, is lackluster. In this study, we demonstrate a transformative synthesis of chemically preintercalated BVOs wit...

The COVID-19 pandemic has become a major worldwide crisis. Although respiratory symptoms are a key feature of the disease, many people who are hospitalized with COVID-19 also suffer acute kidney injury, a condition that exacerbates patient mortality and may have to be treated through renal replacement therapy. Much of the focus on hospital capacity...

Flow electrode CDI systems (FE-CDI) have recently garnered attention because of their ability to prevent cross contamination, and operate in uninterrupted cycles ad infinitum. Typically, FE-CDI electrodes suffer from low conductivity, which reduces deionization performance. Higher mass loading to combat low conductivity leads to poor rheological pr...

Often described as “wonder materials,” two-dimensional (2D) materials have been touted as the next generation solution to many of the world’s problems, from energy storage to environmental remediation. However, despite the expectations and effort that the scientific community has placed on them, there are few examples of 2D materials moving from th...

MXenes have demonstrated high efficiency as negative electrodes in supercapacitors with aqueous electrolytes owning to their high redox capacitance. However, oxidation limits their use under positive potential, requiring design of asymmetric devices with positive electrodes made of other materials, usually less capacitive compared to MXenes and lim...

New ultrathin and multifunctional electromagnetic interference (EMI) shielding materials are required for protecting electronics against electromagnetic pollution in the fifth-generation networks and Internet of Things era. Micrometer-thin Ti3C2T x MXene films have shown the best EMI shielding performance among synthetic materials so far. Yet, the...

Ti3C2T x MXene has exhibited great potential for use in wearable devices, especially as pressure sensors, due to its lamellar structure, which changes its resistance as a function of interlayer distance. Despite the good performance of the reported pure MXene pressure sensors, their practical applications are limited by moderate flexibility, excess...

The discovery of liquid crystalline (LC) phases in dispersions of two-dimensional (2D) materials has enabled the development of macroscopically aligned three-dimensional (3D) macrostructures. Here, we report the first experimental observation of self-assembled LC phases in aqueous Ti3C2T x MXene inks without using LC additives, binders, or stabili...

Scaling the production of synthetic 2D materials to industrial quantities has faced significant challenges due to synthesis bottlenecks whereby few have been produced in large volumes. These challenges typically stem from bottom‐up approaches limiting the production to the substrate size or precursor availability for chemical synthesis and/or exfol...

MXenes are a family of two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides with a general formula of Mn+1XnTx, in which two, three, or four atomic layers of a transition metal (M: Ti, Nb, V, Cr, Mo, Ta, etc.) are interleaved with layers of C and/or N (shown as X), and Tx represents surface termination groups such as -OH, =O...

Scaling the production of synthetic two-dimensional (2D) materials to industrial quantities has faced significant challenges due to synthesis bottlenecks whereby only a few (graphene, BN, MoS2) have been produced in large volumes for industrial use. These challenges typically stem from bottom-up approaches limiting the production to the substrate s...

2D materials, like MXenes [1], provide very attractive building blocks for a very large variety of applications in electrical engineering, composites, energy and other fields [2-4]. However, availability and cost are the key factors limiting applications of advanced nanomaterials in industry. There are currently many insulating and semiconducting 2...

Sodium-sulfur batteries using abundant elements offer an attractive alternative to currently used batteries, but they need better sulfur host materials to compete with lithium-ion batteries in capacity and cyclability. We report an in situ sulfur-doping strategy to functionalize MXene nanosheets by introducing heteroatomic sulfur into the MXene str...

The relatively low operating voltage window of aqueous energy storage devices is a key parameter that limits their energy density. Electrode materials with high electrochemical activities and a wide stable working potential range are crucially needed. Herein, we reported a strategy to control the working potential range of the negative electrode by...

Ti3C2Tx MXene is an attractive two-dimensional (2D) material for a wide variety of applications, however measured properties vary widely from study to study. A potential factor to the property differences relates to variability in the MAX phase precursors. To illustrate this, Ti3AlC2, the precursor for Ti3C2Tx MXene, was synthesized using three car...

An emerging class of two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides, known as MXenes have garnered significant interest in the scientific community due to their unique electrical, optical, and chemical properties [1]. Studies have reported high electrical conductivity and response, surface hydrophilicity, compositional...

MXenes, a large family of 2D transition metal carbides and nitrides, have shown potential in energy storage and optoelectronic applications. Here, the optoelectronic and pseudocapacitive properties of titanium carbide (Ti3C2Tx) are combined to create a MXene electrochromic device, with a visible absorption peak shift from 770 to 670 nm and a 12% re...

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) have attracted significant attention due to their electronic, electrochemical, chemical, and optical properties. However, understanding of their thermal stability is still lacking. To date, MXenes are synthesized via top-down wet chemical etching, which intrinsically results in su...

Using in-situ techniques, which couple energy dispersive spectroscopy mapping with a heated transmission electron microscope stage, solid-state diffusion of Ni-Al is studied in the temperature range 623–723 K with characteristic diffusion lengths of 1–100 nm. When the concentration profiles are analyzed using the Sauer-Freise method, and evaluated...

MXenes, a class of two-dimensional (2D) transition metal carbides and nitrides, have a wide range of potential applications due to their unique electronic, optical, plasmonic, and other properties. Herein, we explore the use of Ti3C2 MXene in organic-inorganic lead halide perovskite solar cells (PSCs) due to its metallic conductivity. SnO2-Ti3C2 MX...

A high-speed electrothermography approach is applied to investigate the mechanism and kinetics for nanostructured Al/Ni foils. Application of the Kolmogorov-Johnson-Mehl-Avrami and adiabatic thermal explosion models reveal that the activation energy for nucleation appears to be much higher than that for reaction. It is shown that formation of inter...

Recently, a large family of 2D materials called MXenes have attracted much attention in the field of supercapacitors, thanks to the excellent performance demonstrated by Ti3C2 MXene-based electrodes. However, research on MXenes for supercapacitor applications has been primarily focused on Ti3C2, even though there are more than 20 other members of t...

In Situ TEM Study of Diffusion Kinetics in Al/Ni Nanomaterials - Volume 24 Supplement - Christopher E. Shuck, Joshua M. Pauls, Sergei Rouvimov, Alexander S. Mukasyan, Arda Genc

In this paper, the authors overview previous publications and present novel results related to self-sustained solid-state reactions: the solid flame. Due to recent advances in the fabrication of nano-structured reactive media, this phenomenon, which is first reported fifty years ago, has found a new perspective for a wide variety of exothermic syst...

Reactive Ni/Al composite particles with different internal microstructures were fabricated by ball milling. The propagation of gasless combustion waves through the compacted composite particle media was investigated using high-speed microscope video recording, with resolution of 10 μm/pixel and 21.25 μs/frame. The microstructural combustion-wave ch...

Here, we report a simple and scalable synthesis strategy of metal (Ni or Cu) nanoparticles uniformly distributed inside a mesoporous silica matrix. This method involves incorporation of metal nitrates and citric acid in a stable silica gel through controlled hydrolysis of tetraethyl orthosilicate. Combustion of dried gels with ammonium nitrate in a...

The current state of chemical kinetics for self-propagating high-temperature non-catalytic reactions has been reviewed for results over the past 50 years. Five different characterization techniques are primarily considered: differential thermal analysis (DTA), electrothermal explosion (ETE), electrothermography (ET), combustion velocity/temperature...

We present co-designed experimental, theoretical, and numerical investigations aiming at estimating the value of the Young’s modulus for cold compacted powder materials. The concept of image-based modeling is used to reconstruct the morphology of the powder structure with high fidelity. Analyses on aluminum powder pellets provide significant unders...

Stochastically structured Ni/Al reactive nanocomposites (RNCs) were prepared using short term high-energy ball milling. Differing milling times were utilized to prepared RNCs with differing internal nanostructures. These internal structures were quantitatively and statistically analyzed by use of serial focused ion beam sectioning coupled with 3D r...

Reactive nanocomposites (RNCs), which are comprised of stochastically layered metals, were fabricated using short term high-energy ball milling of nickel and aluminum powders. By varying the milling conditions, the internal nanostructure of the RNCs can be controlled. Utilizing the slice & view methodology by use of a dual beam scanning electron/io...

Knowing the relationship between three-dimensional structure and properties is paramount for complete understanding of material behavior. In this work, the internal nanostructure of micrometer-size (∼10 µm) composite Ni/Al particles was analyzed using two different approaches. The first technique, synchrotron-based X-ray nanotomography, is a nondes...

The synthesis of amorphous Ni (a-Ni) using a liquid-phase chemical reduction approach is reported. Detailed structural analysis indicates that this method allows for efficient fabrication of high surface area (210 m2/g) amorphous Ni nanopowder with low impurity content. We investigated the self-propagating exothermic waves associated with crystalli...

The tantalum-carbon reactive system possesses a high energy of reaction with an adiabatic combustion temperature of 2743 K, which is significantly below the melting points of the reactants, as well as any intermediate phases and final products. It was suggested that a combustion wave could propagate in Ta+C mixtures solely owing to a solid-solid re...

div class="title">TEM Analysis of Structural Transformation in Al/Ni Nanomaterials under High Energy Ion Irradiation - Volume 21 Issue S3 - Khachatur Manukyan, Sergei Rouvimov, Christopher E. Shuck, Alexander S. Mukasyan

We studied the reduction kinetics of bulk NiO crystals by hydrogen and the corresponding structural transformations in the temperature range of 543−1593 K. A new experimental approach allows us to arrest and quench the reaction at different stages with millisecond time resolution. Two distinctive temperature intervals are found where the reaction k...

We have investigated the effect of accelerated ion beam irradiation on the structure and reactivity of multilayer sputter deposited Al/Ni nanomaterials. Carbon and aluminum ion beams with different charge states and intensities were used to irradiate the multilayer materials. The conditions for the irradiation-assisted self-ignition of the reactive...

High-Energy Ball Milling (HEBM) is a ball milling process where a powder mixture placed in the ball mill is subjected to high-energy collisions from the balls. Among other applications, it is a versatile technique that allows for effective preparation of gasless reactive nanostructured materials with high energy density per volume (Ni+Al, Ta+C, Ti+...