Patrick Urbankowski

MoS2‐on‐MXene Heterostructures as Highly Reversible Anode Materials for Lithium‐Ion Batteries

Two-dimensional (2D) heterostructured materials, combining the collective advantages of individual building blocks and synergistic properties, have spurred great interest as a new paradigm in materials science. The family of 2D transition-metal carbides and nitrides, MXenes, has emerged as an attractive platform to construct functional materials with enhanced performance for diverse applications. Here, we synthesized 2D MoS2 -on-MXene heterostructures through in situ sulfidation of Mo2 TiC2 Tx MXene. The computational results show that MoS2 -on-MXene heterostructures have metallic properties. Moreover, the presence of MXene leads to enhanced Li and Li2 S adsorption during the intercalation and conversion reactions. These characteristics render the as-prepared MoS2 -on-MXene heterostructures stable Li-ion storage performance. This work paves the way to use MXene to construct 2D heterostructures for energy storage applications.

Effect of glycine functionalization of 2D titanium carbide (MXene) on charge storage

Restacking of two-dimensional (2D) flakes reduces the accessibility of electrolyte ions and is a problem in energy storage and other applications. Organic molecules can be used to prevent restacking and keep the interlayer space open. Here, we report on a combined theoretical and experimental investigation of the interaction between 2D titanium carbide (MXene), Ti3C2Tx, and glycine. From first principle calculations, we presented the functionalization of glycine on the Ti3C2O2 surface, evidenced by the shared electrons between Ti and N atoms. To experimentally validate our predictions, we synthesized flexible freestanding films of Ti3C2Tx/glycine hybrids. X-ray diffraction and X-ray photoelectron spectroscopy confirmed the increased interlayer spacing and possible Ti–N bonding, respectively, which agree with our theoretical predictions. The Ti3C2Tx/glycine hybrid films exhibited an improved rate and cycling performances compared to pristine Ti3C2Tx, possibly due to better charge percolation within expanded Ti3C2Tx.

Effect of Synthesis on Performance of MXene/Iron Oxide Anode Material for Lithium-Ion Batteries

Two-dimensional heterostructures, such as Fe2O3/MXene nanoparticles, can be attractive anode materials for lithium-ion batteries (LIBs) due to the synergy between high lithium-storage capacity of Fe2O3 and stable cyclability and high conductivity provided by MXene. Here, we improved the storage performance of Ti3C2T x (MXene)/Fe2O3 nanocomposite by confining Fe2O3 nanoparticles into Ti3C2T x nanosheets with different mixing ratios using a facile and scalable dry ball-milling process. Composites of Ti3C2T x-25 wt % Fe2O3 and Ti3C2T x-50 wt % Fe2O3 synthesized by ball-milling resulted in uniform distribution of Fe2O3 nanoparticles on Ti3C2T x nanosheets with minimum oxidation of MXene as compared to composites prepared by hydrothermal or wet sonication. Moreover, the composites demonstrated minimum restacking of the nanosheets and higher specific surface area. Among all studied composites, the Ti3C2T x-50 wt % Fe2O3 showed the highest reversible specific capacity of ∼270 mAh g-1 at 1C (∼203 mAh g-1 based on the composite) and rate performance of 100 mAh g-1 at 10C. This can open the door for synthesizing stable and high-performance MXene/transition metal oxide composites with significantly enhanced electrochemical performance for LIB applications.