Mark Anayee

Drexel University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Yury Gogotsi

Drexel University

Mikhail Shekhirev

Drexel University

Christopher E. Shuck

Drexel University

Ruocun Wang

Drexel University

Robert W. Lord

Drexel University

Kateryna Shevchuk

Drexel University

Asia Sarycheva

Lawrence Berkeley National Laboratory

Kanit Hantanasirisakul

Drexel University

Oleksiy Gogotsi

Drexel University

Ariana Levitt

Drexel University

Cooperative Institutions

Drexel University

Philadelphia University

University of Pennsylvania

Clemson University

Materials Science & Engineering

Korea Advanced Institute of Science and Technology

Łukasiewicz Research Network

Government of the Republic of Korea

California University of Pennsylvania

Georgia Institute of Technology

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Effect of oxygen substitution and oxycarbide formation on oxidation of Ti₃AlC₂ MAX phase

Journal of the American Ceramic Society (2024)

Mark Anayee Mikhail Shekhirev Ruocun Wang Yury Gogotsi

Abstract MAX phases, ternary transition metal carbides and nitrides, represent one of the largest families of layered materials. They also serve as precursors to MXenes, two‐dimensional (2D) carbides and nitrides. The possibility of oxygen substitution in the carbon sublattice, forming oxycarbide MAX phases and MXenes, was recently reported using secondary ion mass spectrometry. However, while the effect of oxygen substitution on the properties of MXenes was investigated, little is known about its effect on the properties of MAX phases. Here, we explore the influence of process parameters (e.g., particle size, synthesis temperature, annealing time, etc.) and oxygen presence in the lattice on the oxidation resistance of Ti 3 AlC 2 MAX phase powders. We show that X‐ray diffraction measurements can identify oxygen substitution and assist in selecting MAX precursors to synthesize stable and highly conductive MXenes. Eliminating the substitutional oxygen from the MAX phase lattice increases the onset of oxidation by 400°C, from approximately 490 to 890°C. Finally, we discuss the impact of oxygen substitution in the MAX phases on the synthesis of MXenes and their resulting properties.

Substitution (logic)

10.1111/jace.19861

Cite

Citations (0)

(Invited) Energy Storage in Ti₃C₂T _x MXene in a Wide Temperature Range

Meeting abstracts/Meeting abstracts (Electrochemical Society. CD-ROM) (2024)

Ruocun Wang Mark Anayee Muhammad Nihal Naseer Teng Zhang Yuan Zhang

Pseudocapacitors have the potential to achieve high energy and high power density simultaneously, a holy grail for electrochemical energy storage. MXene-based pseudocapacitors have made major progress in the last decade, achieving better energy and power density than carbon supercapacitors using the double-layer charge storage mechanism. However, one obstacle facing pseudocapacitors is their shorter lifetime. In MXene-based pseudocapacitors, which showed up to 500,000 cycles lifetime in aqueous electrolyte at room temperature, this concern is pronounced particularly at high temperatures due to the limited stability of the active material in aqueous solutions. This work shows that Ti 3 C 2 T x MXene electrodes in 5 M H 2 SO 4 possess excellent rate capabilities from -50 °C to 100 °C but also a sufficient lifetime at 70 °C when using a float test holding at -0.9 V vs. Hg/Hg 2 SO 4 . Post-mortem characterization using X-ray photoelectron spectroscopy and Raman spectroscopy showed negligible signs of oxidation in the bulk of the film. This work suggests sufficient stability of Ti 3 C 2 T x MXene as a negative electrode in protic aqueous electrolytes across a wide temperature range rooted in thermodynamics, making it promising for pseudocapacitor energy storage.

Atmospheric temperature range

10.1149/ma2024-017817mtgabs

Cite

Citations (0)

Evaluation of substituted ebselen derivatives as potential trypanocidal agents

Bioorganic & Medicinal Chemistry Letters (2016)

Heeren M. Gordhan Stephen L. Patrick Maria I. Swasy Amber L. Hackler Mark Anayee

Ebselen

Trypanocidal agent

Lead compound

10.1016/j.bmcl.2016.12.021

Cite

Citations (22)

Surface Modification of a MXene by an Aminosilane Coupling Agent

Advanced Materials Interfaces (2020)

Hossein Riazi Mark Anayee Kanit Hantanasirisakul Ahmad Arabi Shamsabadi Babak Anasori

Abstract MXenes, two‐dimensional (2D) transition metal carbides and/or nitrides, possess surface termination groups such as hydroxyl, oxygen, and fluorine, which are available for surface functionalization. Their surface chemistry is critical in many applications. This article reports amine functionalization of Ti 3 C 2 T x MXene surface with [3‐(2‐aminoethylamino)‐propyl]trimethoxysilane (AEAPTMS). Characterization techniques such as X‐ray photoelectron spectroscopy verify the success of the surface functionalization and confirm that the silane coupling agent bonds to Ti 3 C 2 T x surface both physically and chemically. The functionalization changes the MXene surface charge from −35 to +25 mV at neutral pH, which allows for in situ preparation of self‐assembled films. Further, surface charge measurements of the functionalized MXene at different pH values show that the functionalized MXene has an isoelectric point at a pH around 10.7, and the highest reported positive surface charge of +62 mV at a pH of 2.58. Furthermore, the existence of a mixture of different orientations of AEAPTMS and the simultaneous presence of protonated and free amine groups on the surface of Ti 3 C 2 T x are demonstrated. The availability of free amine groups on the surface potentially permits the fabrication of crosslinked electrically conductive MXene/epoxy composites, dye adsorbents, high‐performance membranes, and drug carriers. Surface modifications of this type are applicable to many other MXenes.

Surface Modification

MXenes

Surface charge

10.1002/admi.201902008

Cite

Citations (197)

Computationally Guided Synthesis of MXenes by Dry Selective Extraction

Advanced Materials (2023)

Ervin Rems Mark Anayee Eiara Fajardo Robert L. Lord David Bugallo

MXenes are a rapidly growing family of 2D transition metal carbides and nitrides that are promising for various applications, including energy storage and conversion, electronics, and healthcare. Hydrofluoric-acid-based etchants are typically used for large-scale and high-throughput synthesis of MXenes, which also leads to a mixture of surface terminations that impede MXene properties. Herein, a computational thermodynamic model with experimental validation is presented to explore the feasibility of fluorine-free synthesis of MXenes with uniform surface terminations by dry selective extraction (DSE) from precursor MAX phases using iodine vapors. A range of MXenes and respective precursor compositions are systematically screened using first-principles calculations to find candidates with high phase stability and low etching energy. A thermodynamic model based on the "CALculation of PHAse Diagrams" (CALPHAD) approach is further demonstrated, using Ti3 C2 I2 as an example, to assess the Gibbs free energy of the DSE reaction and the state of the byproducts as a function of temperature and pressure. Based on the assessment, the optimal synthesis temperature and vapor pressure are predicted and further verified by experiments. This work opens an avenue for scalable, fluorine-free dry synthesis of MXenes with compositions and surface chemistries that are not accessible using wet chemical etching.

MXenes

10.1002/adma.202305200

Cite

Citations (19)

Multi-year Study of Environmental Stability of Ti$_3$C$_2$T$_x$ MXene Films

arXiv (Cornell University) (2023)

Asaph Lee Mikhail Shekhirev Mark Anayee Yury Gogotsi

MXenes are a family of two-dimensional (2D) carbides and nitrides that display extraordinary electrical, optical, chemical, and electrochemical properties. There is a perception that MXenes are unstable and degrade quickly, limiting potential applications and requiring specific storage conditions to last for a long time. This was true for delaminated MXenes flakes in dilute dispersions prepared from defective precursors when MXene research was in its infancy. Since then, significant developments in MXene synthesis, processing, and understanding of its chemistry led to dramatic increases in environmental stability. Herein, we analyze Ti$_3$C$_2$T$_x$ free-standing films aged from 4 to 9 years through structural and morphological characterization along with electrical conductivity measurements to reveal the effect, or lack thereof, of prolonged storage under ambient conditions. Further, we show that the decrease in electronic conductivity over time is largely caused by the uptake of water by the hydrophilic surface chemistry of MXenes, which can be easily removed and its effect reversed by vacuum annealing.

MXenes

Limiting

Chemical Stability

10.48550/arxiv.2312.11679

Cite

Citations (2)

Cover Feature: Interconnected Two‐dimensional Arrays of Niobium Nitride Nanocrystals as Stable Lithium Host (Batteries & Supercaps 1/2021)

Batteries & Supercaps (2020)

Xu Xiao Wei Yao Jun Tang Chuanfang Liu Ruqian Lian

The Cover Feature illustrates 2D arrays of NbN nanocrystals, which are used as stable Li host. Coupled with lithium nickel–manganese–cobalt oxide, a long-term cycling full Li-metal battery is realized under practical condition. More information can be found in the Communication by Y. Gogotsi and co-workers.

Niobium oxide

10.1002/batt.202000305

Cite

Citations (0)

Modified MAX Phase Synthesis for Environmentally Stable and Highly Conductive Ti3C2 MXene

Tyler S. Mathis Kathleen Maleski Adam Goad Asia Sarycheva Mark Anayee

One of the primary factors limiting further research and the commercial use of the two-dimensional (2D) MXene titanium carbide (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 precursor leads to the creation of Ti3AlC2 grains with improved stoichiometry and crystallinity. Ti3C2 nanosheets produced from the improved Ti3AlC2 are of higher quality, as evidenced by their increased resistance to oxidation and an increase in their electrical conductivity to 20,000 S/cm. Our results indicate that defects created during the synthesis of Ti3C2 (and by inference, other MXenes) lead to the previously observed instability. We show that by eliminating those defects results in Ti3C2 that is highly stable in aqueous solutions and in air. Aqueous suspensions of single- to few-layer Ti3C2 flakes produced from the modified Ti3AlC2 have a shelf life of over ten months, compared to one to two weeks for Ti3C2 produced from conventional Ti3AlC2, even when stored in ambient conditions. Freestanding films made from Ti3C2 suspensions stored for ten months show minimal decreases in electrical conductivity and negligible oxidation. Oxidation of the improved Ti3C2 in air initiates at temperatures that are 100-150°C higher than conventional Ti3C2. The observed improvements in both the shelf life and properties of Ti3C2 will facilitate the widespread use of this material.

MXenes

MAX phases

Titanium carbide

Stoichiometry

10.26434/chemrxiv.12805280.v1

Cite

Citations (17)

Modified MAX Phase Synthesis for Environmentally Stable and Highly Conductive Ti3C2 MXene

Tyler S. Mathis Kathleen Maleski Adam Goad Asia Sarycheva Mark Anayee

MXenes

MAX phases

Titanium carbide