The surging demand for electronics is causing detrimental environmental consequences through massive electronic waste production. Urgently shifting toward renewable and eco-friendly materials is crucial for fostering a green circular economy. Herein, we develop a multifunctional bionanocomposite using an algae-derived carbohydrate biopolymer (alginate) and boron nitride nanosheet (BNNS) that can be readily employed as a multifunctional dielectric material.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2024
In the realm of carbon fiber research, a variety of structural configurations is noted, comprising crystalline, noncrystalline, and semicrystalline forms. Recent investigations into this domain have revealed an array of intriguing phases of carbon, among which amorphous graphite is the most notable for its unique mechanical, thermal, and electrical properties that arise from its inherent topological disorders. In this study, we utilized the ReaxFF molecular dynamics (MD) simulations to investigate the carbonization and graphitization processes involved in the production of amorphous graphite from benzothiophene, a sulfur-containing polar aromatic precursor.
View Article and Find Full Text PDFHydrogen is a fuel of the future that has the potential to replace conventional fossil fuels in several applications. The quickest and most effective method of producing pure hydrogen with no carbon emissions is water electrolysis. Developing highly active electrocatalysts is crucial due to the slow kinetics of oxygen and hydrogen evolution, which limit the usage of precious metals in water splitting.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2023
We leverage first-principles density functional theory (DFT) calculations to understand the electrocatalytic processes in Mg-CO batteries, considering ruthenium oxide (RuO) as an archetypical cathode catalyst. Our goal is to establish a mechanistic framework for understanding the charging and discharging reaction pathways and their influence on overpotentials. On the RuO (211) surface, we found reaction initiation through thermodynamically favorable adsorption of Mg followed by interactions with CO.
View Article and Find Full Text PDFExploring highly active and earth-abundant electrocatalysts for the oxygen evolution reaction (OER) is considered one of the prime prerequisites for generating green hydrogen. Herein, a competent microwave-assisted decoration of Ru nanoparticles (NPs) over the bimetallic layered double hydroxide (LDH) material is proposed. The same has been used as an OER catalyst in a 1 M KOH solution.
View Article and Find Full Text PDFReactive force fields for molecular dynamics have enabled a wide range of studies in numerous material classes. These force fields are computationally inexpensive compared with electronic structure calculations and allow for simulations of millions of atoms. However, the accuracy of traditional force fields is limited by their functional forms, preventing continual refinement and improvement.
View Article and Find Full Text PDFBackground Plantar fasciitis is the most common cause of foot pain. Patients with plantar fasciitis typically present with 'first step pain,' which tends to decrease with activity and worse with heavy use. This study determines the effect of ultrasound-guided, single-dose, platelet-rich plasma (PRP) injection in patients with chronic plantar fasciitis.
View Article and Find Full Text PDFThe enhanced safety, superior energy, and power density of rechargeable metal-air batteries make them ideal energy storage systems for application in energy grids and electric vehicles. However, the absence of a cost-effective and stable bifunctional catalyst that can replace expensive platinum (Pt)-based catalyst to promote oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air cathode hinders their broader adaptation. Here, it is demonstrated that Tin (Sn) doped β-gallium oxide (β-Ga O ) in the bulk form can efficiently catalyze ORR and OER and, hence, be applied as the cathode in Zn-air batteries.
View Article and Find Full Text PDFThe dissolution of intermediate lithium polysulfides (LiPS) into an electrolyte and their shuttling between the electrodes have been the primary bottlenecks for the commercialization of high-energy density lithium-sulfur (Li-S) batteries. While several two-dimensional (2D) materials have been deployed in recent years to mitigate these issues, their activity is strictly restricted to their edge-plane-based active sites. Herein, for the first time, we have explored a phase transformation phenomenon in a 2D material to enhance the number of active sites and electrocatalytic activity toward LiPS redox reactions.
View Article and Find Full Text PDFMultiple unfavorable features, such as poor electronic conductivity of sulfur cathodes, the dissolution and shuttling of sodium polysulfides (NaS) in electrolytes, and the slower kinetics for the decomposition of solid NaS, make sodium-sulfur batteries (NaSBs) impractical. To overcome these obstacles, novel double-transition metal (DTM) MXenes, MoTiCT, (T = O and S) are studied as an anchoring material (AM) to immobilize higher-order polysulfides and to expedite the otherwise slower kinetics of insoluble short-chain polysulfides. Density functional theory (DFT) calculations are carried out to justify and compare the effectiveness of MoTiCS and MoTiCO as AMs by analyzing their interactions with S/NaS ( = 1, 2, 4, 6, and 8).
View Article and Find Full Text PDFWe characterize the atomic processes that underlie forming, reset, and set in HfO-based resistive random access memory (RRAM) cells through molecular dynamics (MD) simulations, using an extended charge equilibration method to describe external electric fields. By tracking the migration of oxygen ions and the change in coordination of Hf atoms in the dielectric, we characterize the formation and dissolution of conductive filaments (CFs) during the operation of the device with atomic detail. Simulations of the forming process show that the CFs form through an oxygen exchange mechanism, induced by a cascade of oxygen displacements from the oxide to the active electrode, as opposed to aggregation of pre-existing oxygen vacancies.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2021
Room temperature sodium-sulfur (Na-S) batteries, because of their high theoretical energy density and low cost, are considered as a promising candidate for next-generation energy storage devices. However, the practical utilization of the Na-S batteries is greatly hindered by various deleterious factors such as dissolution of sodium polysulfides (NaS) into the electrolyte commonly termed as "shuttle effect," sluggish decomposition of solid NaS, and poor electronic conductivity of sulfur. To overcome the challenges, we introduced single-layer vanadium disulfide (VS) as an anchoring material (AM) to immobilize higher-order polysulfides from the dissolution and also to accelerate the otherwise sluggish kinetics of insoluble short-chain polysulfides.
View Article and Find Full Text PDFReactive force fields provide an affordable model for simulating chemical reactions at a fraction of the cost of quantum mechanical approaches. However, classically accounting for chemical reactivity often comes at the expense of accuracy and transferability, while computational cost is still large relative to nonreactive force fields. In this Perspective, we summarize recent efforts for improving the performance of reactive force fields in these three areas with a focus on the ReaxFF theoretical model.
View Article and Find Full Text PDFWe use classical non-equilibrium molecular dynamics (NEMD) simulations to investigate the phonon thermal conductivity (PTC) of hexagonal boron nitride (hBN) supported stanene. At first, we examine the length dependent PTCs of bare stanene and hBN, and the stanene/hBN heterostructure and realize the dominance of the hBN layer to dictate the PTC in the heterostructure system. Afterward, we assess the length-independent bulk PTCs of these materials.
View Article and Find Full Text PDFNi-based super alloy Inconel-718 is ubiquitous in metal 3D printing where a high cooling rate and thermal gradient are present. These manufacturing conditions are conducive to high initial dislocation density and porosity or voids in the material. This work proposes a molecular dynamics (MD) analysis method that can examine the role of dislocations, cooling rates, voids, and their interactions governing the material properties and failure mechanisms in Inconel-718 using the Embedded Atom Method (EAM) potential.
View Article and Find Full Text PDFMonolayer antimonene has drawn the attention of research communities due to its promising physical properties. However, the mechanical properties of antimonene have remained largely unexplored. In this work, we investigate the mechanical properties and fracture mechanisms of two stable phases of monolayer antimonene - β-antimonene (puckered structure) and α-antimonene (buckled structure) - through molecular dynamics (MD) simulations.
View Article and Find Full Text PDFBismuthene has opened up a new avenue in the field of nanotechnology because of its spectacular electronic and thermoelectric features. The strong spin-orbit-coupling enables its operation as the largest nontrivial bandgap topological insulator and quantum spin hall material at room temperature, which is unlikely for any other 2D material. It is also known to be the most promising thermoelectric material due to its remarkable thermoelectric properties, including a substantially high power factor.
View Article and Find Full Text PDFThe response of high-energy-density materials to thermal or mechanical insults involves coupled thermal, mechanical, and chemical processes with disparate temporal and spatial scales that no single model can capture. Therefore, we developed a multiscale model for 1,3,5-trinitro-1,3,5-triazinane, RDX, where a continuum description is informed by reactive and nonreactive molecular dynamics (MD) simulations to describe chemical reactions and thermal transport. Reactive MD simulations under homogeneous isothermal and adiabatic conditions are used to develop a reduced-order chemical kinetics model.
View Article and Find Full Text PDFThe practical applications of lithium selenium (Li-Se) batteries are impeded primarily due to the dissolution and migration of higher-order polyselenides (LiSe) into the electrolyte (known as the shuttle effect) and inactive deposition of lower-order polyselenides. The high electrical conductivity and mechanical strength of MXenes make them a suitable candidate to provide adequate anchoring to prevent polyselenide dissolution and improved electrochemical performance. Herein, we used density functional theory (DFT) calculations to understand the binding mechanism of LiSe on graphene and surface-functionalized TiC MXenes.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2018
Electric double layer (EDL) dynamics in graphene field-effect transistors (FETs) gated with polyethylene oxide (PEO)-based electrolytes are studied by molecular dynamics (MD) simulations from picoseconds to nanoseconds and experimentally from microseconds to milliseconds. Under an applied field of approximately mV/nm, EDL formation on graphene FETs gated with PEO:CsClO occurs on the timescale of microseconds at room temperature and strengthens within 1 ms to a sheet carrier density of n ≈ 10 cm. Stronger EDLs (i.
View Article and Find Full Text PDFSilicene has become a topic of interest nowadays due to its potential application in various electro-mechanical nanodevices. In our previous work on silicene, fracture stresses of single crystal and polycrystalline silicene have been investigated. Existence of defects in the form of cracks reduces the fracture strength of silicene nanosheets to a great extent.
View Article and Find Full Text PDFTo avoid unexpected environmental mechanical failure, there is a strong need to fully understand the details of the oxidation process and intrinsic mechanical properties of reactive metallic iron (Fe) nanowires (NWs) under various aqueous reactive environmental conditions. Herein, we employed ReaxFF reactive molecular dynamics (MD) simulations to elucidate the oxidation of Fe NWs exposed to molecular water (H2O) and hydrogen peroxide (H2O2) environment, and the influence of the oxide shell layer on the tensile mechanical deformation properties of Fe NWs. Our structural analysis shows that oxidation of Fe NWs occurs with the formation of different iron oxide and hydroxide phases in the aqueous molecular H2O and H2O2 oxidizing environments.
View Article and Find Full Text PDFHighly reactive metallic nickel (Ni) is readily oxidized by oxygen (O) molecules even at low temperatures. The presence of the naturally resulting pre-oxide shell layer on metallic Ni nano materials such as Ni nanowires (NW) is responsible for degrading the deformation mechanisms and related mechanical properties. However, the role of the pre-oxide shell layer on the metallic Ni NW coupled with the complicated mechanical deformation mechanism and related properties have not yet been fully and independently understood.
View Article and Find Full Text PDFSilicene, a 2D analogue of graphene, has spurred a tremendous research interest in the scientific community for its unique properties essential for next-generation electronic devices. In this work, for the first time, we present a molecular dynamics (MD) investigation to determine the fracture strength and toughness of nanocrystalline silicene (nc-silicene) sheet of varying grain sizes and pre-existing cracks at room temperature. Our results suggest a transition from an inverse pseudo Hall-Petch to a pseudo Hall-Petch behaviour in nc-silicene at a critical grain size of 17.
View Article and Find Full Text PDFWe present a computational tool, eReaxFF, for simulating explicit electrons within the framework of the standard ReaxFF reactive force field method. We treat electrons explicitly in a pseudoclassical manner that enables simulation several orders of magnitude faster than quantum chemistry (QC) methods, while retaining the ReaxFF transferability. We delineate here the fundamental concepts of the eReaxFF method and the integration of the Atom-condensed Kohn-Sham DFT approximated to second order (ACKS2) charge calculation scheme into the eReaxFF.
View Article and Find Full Text PDF