Guidelines for Synthesis and Processing of Two-Dimensional Titanium Carbide (Ti₃C₂T_<i>x</i> MXene)

Alhabeb, Mohamed,Maleski, Kathleen,Anasori, Babak,Lelyukh, Pavel,Clark, Leah,Sin, Saleesha,Gogotsi, Yury American Chemical Society 2017 Chemistry of materials Vol.29 No.18

<P>Two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides (MXenes) were discovered in 2011. Since the original discovery, more than 20 different compositions have been synthesized by the selective etching of MAX phase and other precursors and many more theoretically predicted. They offer a variety of different properties, making the family promising candidates in a wide range of applications, such as energy storage, electromagnetic interference shielding, water purification, electrocatalysis, and medicine. These solution-processable materials have the potential to be highly scalable, deposited by spin, spray, or dip coating, painted or printed, or fabricated in a variety of ways. Due to this promise, the amount of research on MXenes has been increasing, and methods of synthesis and processing are expanding quickly. The fast evolution of the material can also be noticed in the wide range of synthesis and processing protocols that determine the yield of delamination, as well as the quality of the 2D flakes produced. Here we describe the experimental methods and best practices we use to synthesize the most studied MXene, titanium carbide (Ti<SUB>3</SUB>C<SUB>2</SUB>T<SUB><I>x</I></SUB>), using different etchants and delamination methods. We also explain effects of synthesis parameters on the size and quality of Ti<SUB>3</SUB>C<SUB>2</SUB>T<SUB><I>x</I></SUB> and suggest the optimal processes for the desired application.</P> [FIG OMISSION]</BR>

Electromagnetic interference shielding with 2D transition metal carbides (MXenes)

Shahzad, Faisal,Alhabeb, Mohamed,Hatter, Christine B.,Anasori, Babak,Man Hong, Soon,Koo, Chong Min,Gogotsi, Yury American Association for the Advancement of Scienc 2016 Science Vol.353 No.6304

<P>Materials with good flexibility and high conductivity that can provide electromagnetic interference (EMI) shielding with minimal thickness are highly desirable, especially if they can be easily processed into films. Two-dimensional metal carbides and nitrides, known as MXenes, combine metallic conductivity and hydrophilic surfaces. Here, we demonstrate the potential of several MXenes and their polymer composites for EMI shielding. A 45-micrometer-thick Ti3C2Tx film exhibited EMI shielding effectiveness of 92 decibels (>50 decibels for a 2.5-micrometer film), which is the highest among synthetic materials of comparable thickness produced to date. This performance originates from the excellent electrical conductivity of Ti3C2Tx films (4600 Siemens per centimeter) and multiple internal reflections from Ti3C2Tx flakes in free-standing films. The mechanical flexibility and easy coating capability offered by MXenes and their composites enable them to shield surfaces of any shape while providing high EMI shielding efficiency.</P>

2D Transition Metal Carbides (MXene) and their Polymer Composites for Electromagnetic Interference Shielding

Faisal Shahzad,Mohamed Alhabeb,Christine B. Hatter,Babak Anasori,홍순만,Yury Gogotsi,구종민 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.1

Lithium-ion capacitors with 2D Nb₂CT_x (MXene) – carbon nanotube electrodes

Byeon, Ayeong,Glushenkov, Alexey M.,Anasori, Babak,Urbankowski, Patrick,Li, Jingwen,Byles, Bryan W.,Blake, Brian,Van Aken, Katherine L.,Kota, Sankalp,Pomerantseva, Ekaterina,Lee, Jae W.,Chen, Ying,Gog Elsevier 2016 Journal of Power Sources Vol.326 No.-

<P><B>Abstract</B></P> <P>There is a growing interest to hybrid energy storage devices, such as lithium-ion capacitors, in which battery-type electrodes are combined with capacitor-type ones. It is anticipated that the energy density (either gravimetric or volumetric) of lithium-ion capacitors is improved if pseudocapacitive or fast insertion materials are used instead of conventional activated carbon (AC) in the capacitor-type electrode. MXenes, a new family of two-dimensional transition metal carbides, demonstrate metallic conductivity and fast charge-discharge behavior that make them suitable for this application. In this study, we move beyond single electrodes, half-cell studies and demonstrate three types of hybrid cells using Nb<SUB>2</SUB>CT<SUB>x</SUB>–carbon nanotube (CNT) films. It is shown that lithiated graphite/Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT, Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT/LiFePO<SUB>4</SUB> and lithiated Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT/Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT cells are all able to operate within 3 V voltage windows and deliver capacities of 43, 24 and 36 mAh/g (per total weight of two electrodes), respectively. Moreover, the polarity of the electrodes can be reversed in the symmetric Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT cells from providing a positive potential between 0 and 3 V to a negative one from −3 to 0 V. It is shown that the volumetric energy density (50–70 Wh/L) of our first-generation devices with MXene electrodes exceeds that of a lithium titanate/AC capacitor.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 3 types of lithium-ion capacitors using Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT as one electrode were tested. </LI> <LI> The highest volumetric energy density of 50–70 Wh/L was achieved. </LI> <LI> Energy density of symmetric cell exceeds that of lithium titanate/activated carbon. </LI> <LI> The lithiated graphite/Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT shows the highest gravimetric performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2D transition metal carbides (MXenes) in metal and ceramic matrix composites

Wyatt Brian C.,Nemani Srinivasa Kartik,Anasori Babak 나노기술연구협의회 2021 Nano Convergence Vol.8 No.16

Two-dimensional transition metal carbides, nitrides, and carbonitrides (known as MXenes) have evolved as competitive materials and fillers for developing composites and hybrids for applications ranging from catalysis, energy storage, selective ion filtration, electromagnetic wave attenuation, and electronic/piezoelectric behavior. MXenes’ incorporation into metal matrix and ceramic matrix composites is a growing field with significant potential due to their impressive mechanical, electrical, and chemical behavior. With about 50 synthesized MXene compositions, the degree of control over their composition and structure paired with their high-temperature stability is unique in the field of 2D materials. As a result, MXenes offer a new avenue for application driven design of functional and structural composites with tailorable mechanical, electrical, and thermochemical properties. In this article, we review recent developments for use of MXenes in metal and ceramic composites and provide an outlook for future research in this field.

Metallic Ti₃C₂T_<i>x</i> MXene Gas Sensors with Ultrahigh Signal-to-Noise Ratio

Kim, Seon Joon,Koh, Hyeong-Jun,Ren, Chang E.,Kwon, Ohmin,Maleski, Kathleen,Cho, Soo-Yeon,Anasori, Babak,Kim, Choong-Ki,Choi, Yang-Kyu,Kim, Jihan,Gogotsi, Yury,Jung, Hee-Tae American Chemical Society 2018 ACS NANO Vol.12 No.2

<P>Achieving high sensitivity in solid-state gas sensors can allow the precise detection of chemical agents. In particular, detection of volatile organic compounds (VOCs) at the parts per billion (ppb) level is critical for the early diagnosis of diseases. To obtain high sensitivity, two requirements need to be simultaneously satisfied: (i) low electrical noise and (ii) strong signal, which existing sensor materials cannot meet. Here, we demonstrate that 2D metal carbide MXenes, which possess high metallic conductivity for low noise and a fully functionalized surface for a strong signal, greatly outperform the sensitivity of conventional semiconductor channel materials. Ti<SUB>3</SUB>C<SUB>2</SUB>T<SUB><I>x</I></SUB> MXene gas sensors exhibited a very low limit of detection of 50–100 ppb for VOC gases at room temperature. Also, the extremely low noise led to a signal-to-noise ratio 2 orders of magnitude higher than that of other 2D materials, surpassing the best sensors known. Our results provide insight in utilizing highly functionalized metallic sensing channels for developing highly sensitive sensors.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2018/ancac3.2018.12.issue-2/acsnano.7b07460/production/images/medium/nn-2017-07460z_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn7b07460'>ACS Electronic Supporting Info</A></P>

Two-Dimensional Titanium Carbide MXene As a Cathode Material for Hybrid Magnesium/Lithium-Ion Batteries

Byeon, Ayeong,Zhao, Meng-Qiang,Ren, Chang E.,Halim, Joseph,Kota, Sankalp,Urbankowski, Patrick,Anasori, Babak,Barsoum, Michel W.,Gogotsi, Yury American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.5

<P>As an alternative to pure lithium-ion, Lit, systems, a hybrid magnesium, Mg2+, and Li+ battery can potentially combine the high capacity, high voltage, and fast Li+ intercalation of Li-ion battery cathodes and the high capacity, low cost, and dendrite-free Mg metal anodes. Herein, we report on the use of two-dimensional titanium carbide, Ti3C2Tx (MXene), as a cathode in hybrid Mg2+/Li+ batteries, coupled with a Mg metal anode. Free-standing and flexible Ti3C2Tx/carbon nanotube composite 'paper' delivered-,100 mAh at 0.1 C and similar to 50 mAh g(-1) at 10 C. At 1 C the capacity was maintained for >500 cycles at 80 mAh g(-1). The Mo2CTx MXene also demonstrated good performance as a cathode material in this hybrid battery. Considering the variety of available MXenes, this work opens the door for exploring a new large family of 2D materials with high electrical conductivity and large intercalation capacity as cathodes for hybrid Mg2+/Li+ batteries.</P>