Publications by authors named "Rasoul Khaledialidusti"

9 Publications

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High-Entropy 2D Carbide MXenes: TiVNbMoC and TiVCrMoC.

ACS Nano 2021 Jun 15. Epub 2021 Jun 15.

Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States.

Two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, are a fast-growing family of 2D materials. MXenes 2D flakes have + 1 ( = 1-4) atomic layers of transition metals interleaved by carbon/nitrogen layers, but to-date remain limited in composition to one or two transition metals. In this study, by implementing four transition metals, we report the synthesis of multi-principal-element high-entropy MCT MXenes. Specifically, we introduce two high-entropy MXenes, TiVNbMoCT and TiVCrMoCT, as well as their precursor TiVNbMoAlC and TiVCrMoAlC high-entropy MAX phases. We used a combination of real and reciprocal space characterization (X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, and scanning transmission electron microscopy) to establish the structure, phase purity, and equimolar distribution of the four transition metals in high-entropy MAX and MXene phases. We use first-principles calculations to compute the formation energies and explore synthesizability of these high-entropy MAX phases. We also show that when three transition metals are used instead of four, under similar synthesis conditions to those of the four-transition-metal MAX phase, two different MAX phases can be formed (.., no pure single-phase forms). This finding indicates the importance of configurational entropy in stabilizing the desired single-phase high-entropy MAX over multiphases of MAX, which is essential for the synthesis of phase-pure high-entropy MXenes. The synthesis of high-entropy MXenes significantly expands the compositional variety of the MXene family to further tune their properties, including electronic, magnetic, electrochemical, catalytic, high temperature stability, and mechanical behavior.
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http://dx.doi.org/10.1021/acsnano.1c02775DOI Listing
June 2021

High-throughput computational discovery of ternary-layered MAX phases and prediction of their exfoliation for formation of 2D MXenes.

Nanoscale 2021 Apr 12;13(15):7294-7307. Epub 2021 Apr 12.

Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.

The rush to synthesize novel two-dimensional (2D) materials has excited the research community studying ternary-layered carbide and nitride compounds, known as MAX phases, for the past two decades in the quest to develop new 2D material precursors. The objective of this study is to expand the family of MAX phases and to investigate their feasible exfoliation to generate 2D systems. To expand the family of MAX phases, we conduct systematic and fundamental research using elemental information and data from high-throughput density functional theory calculations performed on 1122 MAX candidates. Our results suggest that 466 MAX compounds can be synthesized, among which 136 MAX phases can be exfoliated to produce 26 MXenes. We investigate the transition metal or A elements that could be suitable for the formation of novel MAX phase carbides or nitrides and determine promising MAX phases that can be exfoliated to form 2D systems.
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http://dx.doi.org/10.1039/d0nr08791bDOI Listing
April 2021

Exploring structural, electronic, and mechanical properties of 2D hexagonal MBenes.

J Phys Condens Matter 2021 Mar 8;33(15):155503. Epub 2021 Mar 8.

Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.

A family of two-dimensional (2D) transition metal borides, referred to as MBenes, is recently emerging as novel materials with great potentials in electronic and energy harvesting applications to the field of materials science and technology. Transition metal borides can be synthesized from chemical exfoliation of ternary-layered transition metal borides, known as MAB phases. Previously it has been predicted that thin pristine 2D Sc-, Ti-, Zr-, Hf-, V-, Nb-, Ta-, Mo-, and W-based transition metal borides with hexagonal phase are more stable than their corresponding orthorhombic phase. Here, using a set of first-principles calculations (at absolute zero temperature), we have examined the geometric, dynamic stability, electronic structures, work function, bond strength, and mechanical properties of the hexagonal monolayer of transition metal borides (M = Sc, Ti, Zr, Hf, V, Nb, Ta, Mo, and W) chemically terminated with F, O, and OH. The results of the formation energies of terminated structures imply that the surface terminations could make a strong bond to the surface transition metals and provide the possibility of the development of transition metal borides with those surface terminations. Except for ScBO, which is an indirect bandgap semiconductor, the other transition metal borides are metallic or semimetal. Particularly, TiBF, ZrBF, and HfBF are metallic systems whose band dispersions close to the Fermi level indicate the coexistence of type-I and type-II nodal lines. Our calculated work functions indicate that 2D transition metal borides with OH (O) functionalization obtain the lowest (highest) work functions. The results of the mechanical properties of the considered structures imply that oxygen functionalized transition metal borides exhibit the stiffest mechanical strength with 248 < E (N m) < 348 while non-terminated transition metal borides are generally the weakest systems with 206 < E (N m) < 283.
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http://dx.doi.org/10.1088/1361-648X/abbb0eDOI Listing
March 2021

Comparison of Thermal Annealing Hydrothermal Treatment Effects on the Detection Performances of ZnO Nanowires.

ACS Appl Mater Interfaces 2021 Mar 18;13(8):10537-10552. Epub 2021 Feb 18.

PSL Université, Chimie ParisTech, Institut de Recherche de Chimie Paris-IRCP, CNRS UMR8247, Rue Pierre et Marie Curie 11, 75005 Paris, France.

A comparative investigation of the post-electroplating treatment influence on the gas detecting performances of single ZnO nanorod/nanowire (NR/NW), as grown by electrochemical deposition (ECD) and integrated into nanosensor devices, is presented. In this work, hydrothermal treatment (HT) in a HO steam and conventional thermal annealing (CTA) in a furnace at 150 °C in ambient were used as post-growth treatments to improve the material properties. Herein, the morphological, optical, chemical, structural, vibrational, and gas sensing performances of the as-electrodeposited and treated specimens are investigated and presented in detail. By varying the growth temperature and type of post-growth treatment, the morphology is maintained, whereas the optical and structural properties show increased sample crystallization. It is shown that HT in HO vapors affects the optical and vibrational properties of the material. After investigation of nanodevices based on single ZnO NR/NWs, it was observed that higher temperature during the synthesis results in a higher gas response to H gas within the investigated operating temperature range from 25 to 150 °C. CTA and HT or autoclave treatment showed the capability of a further increase in gas response of the prepared sensors by a factor of ∼8. Density functional theory calculations reveal structural and electronic band changes in ZnO surfaces as a result of strong interaction with H gas molecules. Our results demonstrate that high-performance devices can be obtained with high-crystallinity NWs/NRs after HT. The obtained devices could be the key element for flexible nanoelectronics and wearable electronics and have attracted great interest due to their unique specifications.
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http://dx.doi.org/10.1021/acsami.0c19170DOI Listing
March 2021

Pd-Functionalized ZnO:Eu Columnar Films for Room-Temperature Hydrogen Gas Sensing: A Combined Experimental and Computational Approach.

ACS Appl Mater Interfaces 2020 Jun 20;12(22):24951-24964. Epub 2020 May 20.

Functional Nanomaterials, Faculty of Engineering, Institute for Materials Science, Kiel University, Kaiserstr. 2, D-24143 Kiel, Germany.

Reducing the operating temperature to room temperature is a serious obstacle on long-life sensitivity with long-term stability performances of gas sensors based on semiconducting oxides, and this should be overcome by new nanotechnological approaches. In this work, we report the structural, morphological, chemical, optical, and gas detection characteristics of Eu-doped ZnO (ZnO:Eu) columnar films as a function of Eu content. The scanning electron microscopy (SEM) investigations showed that columnar films, grown via synthesis from a chemical solutions (SCS) approach, are composed of densely packed columnar type grains. The sample sets with contents of ∼0.05, 0.1, 0.15, and 0.2 at% Eu in ZnO:Eu columnar films were studied. Surface functionalization was achieved using PdCl aqueous solution with additional thermal annealing in air at 650 °C. The temperature-dependent gas-detection characteristics of Pd-functionalized ZnO:Eu columnar films were measured in detail, showing a good selectivity toward H gas at operating OPT temperatures of 200-300 °C among several test gases and volatile organic compound vapors, such as methane, ammonia, acetone, ethanol, -butanol, and 2-propanol. At an operating temperature OPT of 250 °C, a high gas response / of ∼115 for 100 ppm H was obtained. Experimental results indicate that Eu doping with an optimal content of about 0.05-0.1 at% along with Pd functionalization of ZnO columns leads to a reduction of the operating temperature of the H gas sensor. DFT-based computations provide mechanistic insights into the gas-sensing mechanism by investigating interactions between the Pd-functionalized ZnO:Eu surface and H gas molecules supporting the experimentally observed results. The proposed columnar materials and gas sensor structures would provide a special advantage in the fields of fundamental research, applied physics studies, and ecological and industrial applications.
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http://dx.doi.org/10.1021/acsami.0c02103DOI Listing
June 2020

Temperature-dependent mechanical properties of TiCO (n = 1, 2) MXene monolayers: a first-principles study.

Phys Chem Chem Phys 2020 Feb 27;22(6):3414-3424. Epub 2020 Jan 27.

Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.

Two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides (named as MXenes) have become of the fastest growing family of 2D materials in terms of compositions and their applications in different areas. One of the least explored properties of MXenes is their mechanical properties. While the basic elastic properties of MXenes have been studied by first-principles, the effects of temperature on the elastic properties have never been explored. In this study, we investigate temperature-dependent structural and mechanical properties of the titanium-containing MXenes (TiCO (n = 1, 2)) based on the first-principles calculations combined with quasi-harmonic approximation. The effective Young's modulus of a single layer of TiCO and TiCO is calculated to be 565 and 482 GPa, respectively, at 0 K. By increasing temperature to 1000 K, Young's moduli of TiCO and TiCO decrease to 469 GPa and 442 GPa, respectively, which indicates a larger reduction in stiffness in thinner MXenes at higher temperatures. Our calculations of the temperature-dependent bond strengths within MXenes showed that titanium and carbon atoms in TiCO form stronger bonds than TiCO and atomic bonds in TiCO lose their stiffness more than TiCO with increasing temperatures. The Debye temperature of these monolayers is also calculated to provide a comparison of the thermal conductivity between these monolayers, in which the results show that the TiCO has a higher thermal conductivity than TiCO. Our calculated electronic properties results of the monolayers are also shown that the electrical conductivity of the monolayers would not change with temperature. Our study extends MXenes applications to high-temperature applications, such as structural composite components and aerospace coatings.
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http://dx.doi.org/10.1039/c9cp06721cDOI Listing
February 2020

CO Adsorption and Activation on the (110) Chalcopyrite Surfaces: A Dispersion-Corrected DFT + Study.

ACS Omega 2019 Oct 20;4(14):15935-15946. Epub 2019 Sep 20.

Department of Mechanical and Industrial Engineering, NTNU, Trondheim 7491, Norway.

We have used the density functional theory within the plane-wave framework to understand the reconstruction of most stable (110) chalcopyrite surfaces. Reconstructions of the polar surfaces are proposed, and three different possible nonpolar terminations for the (110) surface, namely, I, II, and III, are investigated. A detailed discussion on stabilities of all three surface terminations is carried out. It is generally observed that the (110) chalcopyrite surfaces encounter significant reconstruction in which the metal Fe and Cu cations in the first atomic layer considerably move downward to the surface, while the surface S anions migrate slightly outward toward the surface. We also investigated the adsorption of the CO molecule on the three terminations for the (110) surface by exploring various adsorption sites and configurations using density functional theory calculations, in which long-range dispersion interactions are taken into consideration. We show that the CO molecule is adsorbed and activated, while spontaneous dissociation of the CO molecule is also observed on the (110) surfaces. Structural change from a neutral linear molecule to a negatively charged (CO ) slightly or considerably bent species with stretched C-O bond distances are highlighted for description of the activation of the CO molecule. The results address the potential catalytic activity of the (110) chalcopyrite toward the reduction and conversion of CO to the organic molecule, which is appropriate to the production of liquid fuels.
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http://dx.doi.org/10.1021/acsomega.9b01988DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6777085PMC
October 2019

Stabilization of 2D graphene, functionalized graphene, and TiCO (MXene) in super-critical CO: a molecular dynamics study.

Phys Chem Chem Phys 2019 Jun 5;21(24):12968-12976. Epub 2019 Jun 5.

Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.

The stabilization of nanoparticles is a main concern to produce an efficient nanofluid. Here, we carry out Molecular Dynamics (MD) modeling to evaluate the stabilization of 2D graphene, oxygen- and hydrogen-functionalized graphene, and TiCO MXene nano-sheets in carbon dioxide (CO) liquid under supercritical conditions. The rheological properties (i.e., viscosity and self-diffusion) of the nanofluids with the corresponding nano-sheets are also calculated. The results show that pristine graphene aggregates in the liquid and the adsorbed CO molecules on the graphene surfaces could not provide enough repulsive forces to avoid their aggregation. The stabilization of graphene is improved by surface functionalization of graphene with oxygen and hydrogen functional groups. This is because, first, the presence of the corresponding surface groups can alter the electrostatic forces of the graphene nano-sheets and, second, a larger number of CO molecules attracted by the functionalized nano-sheets can provide additional repulsive forces between the nano-sheets. The results demonstrate that TiCO MXene nano-sheets aggregate severely although they are covered by oxygen surface terminations and attract more CO molecules than the pristine graphene. This is attributed to the strong interlayer coupling between the MXene nano-sheets so that the electrostatic repulsion of the MXene surfaces could not overcome the interlayer coupling. Based on our results, the stabilization of the corresponding 2D nano-sheets in CO liquid is in the order: oxygen-functionalized graphene > hydrogen-functionalized graphene > pristine graphene > TiCO MXene. The calculation of the rheological properties of the nanofluids with different nano-sheets demonstrates that immersing the nano-sheets in the CO liquid affords a superior viscosity enhancement as much as possible to be dispersed in the liquid. This study expands the potential applications of these 2D materials in producing SC-CO based nanofluids.
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http://dx.doi.org/10.1039/c9cp02244aDOI Listing
June 2019

Rheological properties of super critical CO with CuO: Multi-scale computational modeling.

J Chem Phys 2018 Dec;149(22):224702

Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norway.

A multi-scale computational methodology based on the density functional theory and molecular dynamics has been used to investigate the rheological properties of super critical CO with CuO nano-particle (NP). Density functional theory which treats the electron density as the central variable has been used to explore the adsorption of CO molecules on the two most stable CuO surfaces [i.e., (111) and (011)] at absolute zero. The results of this theory would provide valuable information to make CuO NPs with the surface where the CO adsorption is maximum in order to have a stronger mono-layer of adsorbed CO molecules on the surface of the NP which is the most crucial factor in formation of a stable nanofluid. The results show that the CO molecule is adsorbed more strongly on the (011) surface with an adsorption energy of -99.06 kJ/mol compared to the (111) surface. A computational methodology based on molecular dynamics has been used to evaluate the enhancement of the rheological properties of the super-critical CO liquid based nanofluid at different temperatures and pressures. In this scale, first, the CO liquid has been modeled by employing the condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field potential and the fluid properties computed are in excellent agreement with the literature and experiment values. Second, the nanofluid has been modeled in order to study the enhancement of the fluid properties with the CuO NPs. The charged optimized many-body force field potential has been employed to consider the effect of the charge transferring between the NPs and liquid molecules and breaking of existing bonds and the formation of new bonds. The COMPASS force field potential is also employed for the interactions between CO molecules. The combination of these potentials is quite a new approach for the study of the super-critical (SC)-CO based nanofluid. The results show that the viscosity of the SC-CO is enhanced between 1.3 and 2.5 times under the temperature and pressure conditions studied.
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http://dx.doi.org/10.1063/1.5053571DOI Listing
December 2018
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