2D metal carbides and nitrides (MXenes) for sensors and biosensors

1981 ◽

Vol 39 ◽

pp. 312-313

Author(s):

R. Padmanabhan ◽

W. E. Wood

Keyword(s):

Heat Treatment ◽

Metal Carbides ◽

Austenite Grain Size ◽

300M Steel ◽

Heat Treated ◽

Strain Fracture ◽

Prior Austenite Grain Size ◽

Short Time ◽

Final Tempering ◽

Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

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Tuning Transition Metal Carbides Activity by Surface Metal Alloying: Case Study on CO2 Capture and Activation

10.26434/chemrxiv.6377330.v1 ◽

2018 ◽

Author(s):

Marti Lopez ◽

Luke Broderick ◽

John J Carey ◽

Francesc Vines ◽

Michael Nolan ◽

...

Keyword(s):

Transition Metal ◽

Co2 Capture ◽

Density Functional ◽

Deep Understanding ◽

Metal Carbides ◽

Transition Metal Carbides ◽

Adsorption Sites ◽

Surface Metal ◽

A Minor

<div>CO2 is one of the main actors in the greenhouse effect and its removal from the atmosphere is becoming an urgent need. Thus, CO2 capture and storage (CCS) and CO2 capture and usage (CCU) technologies are intensively investigated as technologies to decrease the concentration</div><div>of atmospheric CO2. Both CCS and CCU require appropriate materials to adsorb/release and adsorb/activate CO2, respectively. Recently, it has been theoretically and experimentally shown that transition metal carbides (TMC) are able to capture, store, and activate CO2. To further improve the adsorption capacity of these materials, a deep understanding of the atomic level processes involved is essential. In the present work, we theoretically investigate the possible effects of surface metal doping of these TMCs by taking TiC as a textbook case and Cr, Hf, Mo, Nb, Ta, V, W, and Zr as dopants. Using periodic slab models with large</div><div>supercells and state-of-the-art density functional theory based calculations we show that CO2 adsorption is enhanced by doping with metals down a group but worsened along the d series. Adsorption sites, dispersion and coverage appear to play a minor, secondary constant effect. The dopant-induced adsorption enhancement is highly biased by the charge rearrangement at the surface. In all cases, CO2 activation is found but doping can shift the desorption temperature by up to 135 K.</div>

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Graphene Supported Tungsten Carbide as Catalyst for Electrochemical Reduction of CO2

10.26434/chemrxiv.8280986 ◽

2019 ◽

Author(s):

Sahithi Ananthaneni ◽

Rees Rankin

Keyword(s):

Tungsten Carbide ◽

Electrochemical Reduction ◽

Low Cost ◽

Co2 Reduction ◽

Platinum Group Metal ◽

Reduction Reaction ◽

Metal Carbides ◽

Depth Study ◽

Reduction Of Co2 ◽

Co2 Reduction Reaction

<div>Electrochemical reduction of CO2 to useful chemical and fuels in an energy efficient way is currently an expensive and inefficient process. Recently, low-cost transition metal-carbides (TMCs) are proven to exhibit similar electronic structure similarities to Platinum-Group-Metal (PGM) catalysts and hence can be good substitutes for some important reduction reactions. In this work, we test graphenesupported WC (Tungsten Carbide) nanocluster as an electrocatalyst for the CO2 reduction reaction. Specifically, we perform DFT studies to understand various possible reaction mechanisms and determine the lowest thermodynamic energy landscape of CO2 reduction to various products such as CO, HCOOH, CH3OH, and CH4. This in-depth study of reaction energetics could lead to improvements and develop more efficient electrocatalysts for CO2 reduction.<br></div>

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Predicting the Effect of Dopants on CO2 Adsorption in Transition Metal Carbides: Case Study on TiC (001)

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.0c03893 ◽

2020 ◽

Vol 124 (29) ◽

pp. 15969-15976 ◽

Cited By ~ 1

Author(s):

Martí López ◽

Francesc Viñes ◽

Michael Nolan ◽

Francesc Illas

Keyword(s):

Transition Metal ◽

Co2 Adsorption ◽

Metal Carbides ◽

Transition Metal Carbides

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Oxidation behavior of non-stoichiometric (Zr,Hf,Ti)Cx carbide solid solution powders in air

Journal of Advanced Ceramics ◽

10.1007/s40145-021-0469-y ◽

2021 ◽

Author(s):

Huilin Lun ◽

Yi Zeng ◽

Xiang Xiong ◽

Ziming Ye ◽

Zhongwei Zhang ◽

...

Keyword(s):

Solid Solution ◽

Oxidation Resistance ◽

Oxidation Behavior ◽

Group Iv ◽

Hypersonic Vehicles ◽

Metal Carbides ◽

Initial Oxidation ◽

Plasma Sintering ◽

Spark Plasma ◽

Kinetics Of

AbstractMulti-component solid solutions with non-stoichiometric compositions are characteristics of ultra-high temperature carbides as promising materials for hypersonic vehicles. However, for group IV transition-metal carbides, the oxidation behavior of multi-component non-stoichiometric (Zr,Hf,Ti)Cx carbide solid solution has not been clarified yet. The present work fabricated four kinds of (Zr,Hf,Ti)Cx carbide solid solution powders by free-pressureless spark plasma sintering to investigate the oxidation behavior of (Zr,Hf,Ti)Cx in air. The effects of metallic atom composition on oxidation resistance were examined. The results indicate that the oxidation kinetics of (Zr,Hf,Ti)Cx are composition dependent. A high Hf content in (Zr,Hf,Ti)Cx was beneficial to form an amorphous Zr-Hf-Ti-C-O oxycarbide layer as an oxygen barrier to enhance the initial oxidation resistance. Meanwhile, an equiatomic ratio of metallic atoms reduced the growth rate of (Zr,Hf,Ti)O2 oxide, increasing its phase stability at high temperatures, which improved the oxidation activation energy of (Zr, Hf, Ti)Cx.

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Advances in MXene Films: Synthesis, Assembly, and Applications

Transactions of Tianjin University ◽

10.1007/s12209-021-00282-y ◽

2021 ◽

Author(s):

Xiaohua Li ◽

Feitian Ran ◽

Fan Yang ◽

Jun Long ◽

Lu Shao

Keyword(s):

Spin Coating ◽

Reaction Mechanisms ◽

Membrane Separation ◽

Synthesis Methods ◽

Metal Carbides ◽

Max Phases ◽

Practical Applications ◽

Coating Methods ◽

And Performance ◽

Important Form

AbstractA growing family of two-dimensional (2D) transition metal carbides or nitrides, known as MXenes, have received increasing attention because of their unique properties, such as metallic conductivity and good hydrophilicity. The studies on MXenes have been widely pursued, given the composition diversity of the parent MAX phases. This review focuses on MXene films, an important form of MXene-based materials for practical applications. We summarized the synthesis methods of MXenes, focusing on emerging synthesis strategies and reaction mechanisms. The advanced assembly technologies of MXene films, including vacuum-assisted filtration, spin-coating methods, and several other approaches, were then highlighted. Finally, recent progress in the applications of MXene films in electrochemical energy storage, membrane separation, electromagnetic shielding fields, and burgeoning areas, as well as the correlation between compositions, architecture, and performance, was discussed.

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Two-dimensional metal carbides and nitrides (MXenes): preparation, property, and applications in cancer therapy

Nanophotonics ◽

10.1515/nanoph-2019-0550 ◽

2020 ◽

Vol 9 (8) ◽

pp. 2125-2145 ◽

Cited By ~ 1

Author(s):

Lu Ming Dong ◽

Cui Ye ◽

Lin Lin Zheng ◽

Zhong Feng Gao ◽

Fan Xia

Keyword(s):

Cancer Therapy ◽

Scientific Community ◽

Critical Role ◽

High Specific Surface Area ◽

Future Perspective ◽

Two Dimensional ◽

Metal Carbides ◽

Practical Applications ◽

Two Dimensional Materials ◽

Size And Morphology

AbstractTransition metal carbides and nitrides (MXenes), which comprise a rapidly growing family of two-dimensional materials, have attracted extensive attention of the scientific community, owing to its unique characteristics of high specific surface area, remarkable biocompatibility, and versatile applications. Exploring different methods to tune the size and morphology of MXenes plays a critical role in their practical applications. In recent years, MXenes have been demonstrated as promising nanomaterials for cancer therapy with substantial performances, which not only are helpful to clarify the mechanism between properties and morphologies but also bridge the gap between MXene nanotechnology and forward-looking applications. In this review, recent progress on the preparation and properties of MXenes are summarized. Further applications in cancer therapy are also discussed. Finally, the current opportunities and future perspective of MXenes are described.

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