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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Electrochemical Phase Engineering of γ′-V 2 O 5 Thin Films for Sodium-Ion Storage Electrodes

V 2 O 5 is a promising sodium-ion cathode material due to its high theoretical capacity (147 mAh/g) and working voltage (3.3 V vs Na/Na + ). Among its various crystal phases, γ′-V 2 O 5 has a large interlayer spacing, ensuring the reversible insertion–extraction of sodium ions. However, current synthesis methods for γ′-V2O5 require high temperatures (>600 °C) and toxic chemicals (NO 2 BF 4 ), which make the preparation demanding. Herein, we put forward an electrochemical phase engineering method combining thermal annealing and electrochemistry to easily prepare thin-film γ′-V 2 O 5 . Electrochemical characterization shows near-ideal performance as a thin-film cathode material for sodium-ion batteries. It shows a measured initial capacity of 152 mAh/g, a high working voltage (3.3 V vs Na + /Na), and an exceptional Coulombic efficiency of 98%, significantly surpassing previously reported values (∼50% CE). Cyclic voltammogram and galvanostatic capacity curves confirm the sodium insertion–deinsertion, which remains stable at 2 C. The γ′-V 2 O 5 thin film has electrochemical performance similar to γ′-V 2 O 5 powder, indicating another workable morphology of γ′-V 2 O 5 for sodium-ion batteries.

batteries↗
DOE OSTI2020

Direct Evidence of Photoinduced Charge Transport Mechanism in 2D Conductive Metal Organic Frameworks

Conductive metal organic frameworks (MOFs) represent a promising class of porous crystalline materials that have demon-strated potential in photo-electronics and photocatalytic applications. However, the lack of fundamental understanding on charge transport (CT) mechanism as well as the correlation of CT mechanism with their structure hampered their further development. Herein, we report the direct evidence of CT mechanism in 2D Cu-THQ MOFs and the correlation of temporal and spatial behaviors of charge carriers with their photoconductivity by combining three advanced spectroscopic methods including time resolved optical and X-ray absorption spectroscopy and terahertz spectroscopy. In addition to Cu-THQ, the CT in Cu/Zn-THQ after incorporating Zn2+ guest metal was also examined to uncover the contribution of through space pathway as the presence of the redox inactive 3d10 Zn2+ is expected to perturb the long range in-plane CT. We show that the hot carriers in Cu-THQ generated after photoexcitation are highly mobile and undergo fast localization to a lower energy state (cool carriers) with electrons occupying Cu center and holes in ligands. The cool carriers, which have super long lifetime (> 17 ns) are responsible for the long-term photoconductivity in Cu-THQ and transport through O-Cu-O motif with negligible contribution from interlayer ligand π-π stacking as incorporation of Zn2+ in Cu-THQ significantly reduced photoconductivi-ty. These unprecedent results not only demonstrate the capability to experimentally probe CT mechanism but also provide important insight in the rational design of 2D MOFs for photoelectronic and photocatalytic applications.

14 SOLAR ENERGY↗
DOE OSTI2021

Conjugation- and Aggregation-Directed Design of Covalent Organic Frameworks as White-Light-Emitting Diodes

2D covalent organic frameworks (COFs) have emerged as a promising class of organic luminescent materials due to their structural diversity, which allows the systematic tuning of organic building blocks to optimize emitting properties. However, a significant knowledge gap exists between the design strategy and the fundamental understanding of the key structural parameters that determine their photophysical properties. Here, in this work, we report two highly emissive sp 2 -C-COFs and the direct correlation of the structure (conjugation and aggregation) with their light absorption/emission, charge transfer (CT), and exciton dynamics, the key properties that determine their function as luminescent materials. We show that white light can be obtained by simply coating COFs on an LED strip or mixing the two COFs. Using the combination of time-resolved absorption and emission spectroscopy as well as computational prediction, we show that the planarity, conjugation, orientation of the dipole moment, and interlayer aggregation not only determine the light-harvesting ability of COFs but also control the exciton relaxation pathway and photoluminescent quantum yield.

14 SOLAR ENERGY↗
DOE OSTI2022

Conjugated Metal–Organic Macrocycles: Synthesis, Characterization, and Electrical Conductivity

The dimensional reduction of solids into smaller fragments provides a route to achieve new physical properties and gain deeper insight into the extended parent structures. Here, we report the synthesis of CuTOTP-OR (TOTP n – = 2,3,6,7-tetraoxidotriphenylene), a family of copper-based macrocycles that resemble truncated fragments of the conductive 2D metal–organic framework Cu 3 (HHTP) 2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene). The planar metal–organic macrocycles self-assemble into ordered nanotubes with internal diameters of ~2 nm and short interlayer distances of ~3.20 Å. Strong π–π stacking interactions between macrocycles facilitate out-of-plane charge transport, and pressed pellet conductivities as high as 2(1)×10 -3 S cm -1 are observed. Peripheral alkyl functionalization enhances solution processability and enables the fabrication of thin-film field-effect transistor devices. Ambipolar charge transport is observed, suggesting similar behavior may be operative in Cu 3 (HHTP) 2 . By coupling the attractive features of metal–organic frameworks with greater processability, these macrocycles enable facile device integration and a more nuanced understanding of out-of-plane charge transport in 2D conductive metal–organic frameworks.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Realizing Two-Electron Transfer in Ni(OH) 2 Nanosheets for Energy Storage

The theoretical capacity of a given electrode material is ultimately determined by the number of electrons transferred in each redox center. The design of multi-electron transfer processes could break through the limitation of one–electron transfer and multiply the total capacity, but is difficult to achieve because multiple electron transfer processes are generally thermodynamically and kinetically more complex. In this work, we report the discovery of two-electron transfer in monolayer Ni(OH) 2 nanosheets, which contrasts with the traditional one-electron transfer found in multilayer materials. The first-principles calculations predict that the first oxidation process from Ni 2+ →Ni 3+ occurs easily, whereas the second electron transfer from Ni 3+ →Ni 4+ is strongly hindered in multilayer materials by both the interlayer hydrogen bonds and the domain H structure induced by the Jahn-Teller distortion of the Ni 3+ (t 2g 6 e g 1 ) centered octahedra. In contrast, the second electron transfer can easily occur in monolayers because all H’s are fully exposed. Experimentally, the as-prepared monolayer is found to deliver an exceptional redox capacity of ~ 576 mAh/g, nearly two times the theoretical capacity of one-electron processes. In-situ experiments demonstrate that monolayer Ni(OH) 2 can transfer two electrons and mostly transform to Ni 4+ in the charging process, while bulk Ni(OH) 2 can be partially transformed . Our work reveals a new redox reaction mechanism in atomically thin Ni(OH) 2 nanosheets, and suggests a promising path towards tuning the electron transfer numbers to multiply the capacity of the relevant energy storage materials.

25 ENERGY STORAGE↗
DOE OSTI2022

Transuranium Sulfide via the Boron Chalcogen Mixture Method and Reversible Water Uptake in the NaCu T S 3 Family

The behavior of 5f electrons in soft ligand environments makes actinides, and especially transuranium chalcogenides, an intriguing class of materials for fundamental studies. Due to the affinity of actinides for oxygen, however, it is a challenge to synthesize actinide chalcogenides using non-metallic reagents. Using the Boron Chalcogen Mixture (BCM) method, we achieved the synthesis of the transuranium sulfide NaCuNpS 3 starting from the oxide reagent, NpO 2 . Via the same synthetic route, the isostructural composition of NaCuUS 3 was synthesized and the material contrasted with NaCuNpS 3 . Single crystals of the U-analog, NaCuUS 3 , were found to undergo an unexpected reversible hydration process to form NaCuUS 3 ·xH 2 O (x ≈ 1.5). Here, a large combination of techniques was used to fully characterize the structure, hydration process, and electronic structures, specifically a combination of single crystal, powder, high temperature powder X-ray diffraction, extended X-ray ab-sorption fine structure, infrared, and inductively coupled plasma spectroscopies, thermogravimetric analysis, and density functional theory calculations. The outcome of these analyses enabled us to determine the composition of NaCuUS 3 ·xH 2 O and obtain a structural model that demonstrated the retention of the local structure within the [CuUS 3 ] – layers throughout the hydration-dehydration process. Band structure, density of states, and Bader charge calculations for NaCuUS 3 , NaCu-US 3 ·xH 2 O, and NaCuNpS 3 along with X-ray absorption near edge structure, UV-vis-NIR and work function measurements on ACuUS 3 (A = Na, K, and Rb) and NaCuUS 3 ·xH 2 O samples were carried out to demonstrate that electronic properties arise from the [CuTS 3 ] – layers and show surprisingly little dependence on the interlayer distance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Scalable Synthesis and Characterization of Multilayer γ-Graphyne, New Carbon Crystals with a Small Direct Band Gap

γ-Graphyne is the most symmetric sp 2 /sp 1 allotrope of carbon, which can be viewed as graphene uniformly expanded through the insertion of two-carbon acetylenic units between all the aromatic rings. To date, synthesis of bulk γ-graphyne has remained a challenge. In this work, we report the synthesis of multilayer γ-graphyne through crystallization-assisted irreversible cross-coupling polymerization. A comprehensive characterization of this new carbon phase is described, including synchrotron powder X-ray diffraction, electron diffraction, lateral force microscopy, Raman spectroscopy, infrared spectroscopy, and cyclic voltammetry. Experiments indicate that γ-graphyne is a 0.48 eV band gap semiconductor, with a hexagonal a-axis spacing of 6.88 Å and an interlayer spacing of 3.48 Å, which is consistent with theoretical predictions. The observed crystal structure has an aperiodic sheet stacking. The material is thermally stable up to 240 °C but undergoes transformation at higher temperatures. While conventional 2D polymerization and reticular chemistry rely on error correction through reversibility, we demonstrate that a periodic covalent lattice can be synthesized under purely kinetic control. The reported methodology is scalable and inspires extension to other allotropes of the graphyne family.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Breaking New Ground: MB ene Route toward Selective Vinyl Double Bond Hydrogenation in Nitroarenes

Doping, or incremental substitution of one element for another, is an effective way to tailor a compound’s structure as well as its physical and chemical properties. Herein, we replaced up to 30% of Ni with Co in members of the family of layered LiNiB compounds, stabilizing the high-temperature polymorph of LiNiB while the room-temperature polymorph does not form. By studying this layered boride with in situ high-temperature powder diffraction, we obtained a distorted variant of LiNi 0.7 Co 0.3 B featuring a perfect interlayer placement of [Ni 0.7 Co 0.3 B] layers on top of each other–a structural motif not seen before in other borides. Because of the Co doping, LiNi 0.7 Co 0.3 B can undergo a nearly complete topochemical Li deintercalation under ambient conditions, resulting in a metastable boride with the formula Li 0.04 Ni 0.7 Co 0.3 B. Heating of Li 0.04 Ni 0.7 Co 0.3 B in anaerobic conditions led to yet another metastable boride, Li 0.01 Ni 0.7 Co 0.3 B, with a CoB-type crystal structure that cannot be obtained by simple annealing of Ni, Co, and B. No significant alterations of magnetic properties were detected upon Co-doping in the temperature-independent paramagnet LiNi 0.7 Co 0.3 B or its Li-deintercalated counterparts. Finally, Li 0.01 Ni 0.7 Co 0.3 B stands out as an exceptional catalyst for the selective hydrogenation of the vinyl C=C bond in 3-nitrostyrene, even in the presence of other competing functional groups. Finally, this research showcases an innovative approach to heterogeneous catalyst design by meticulously synthesizing metastable compounds.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Energizing Robust Sulfur/Lithium Electrochemistry via Nanoscale-Asymmetric-Size Synergism

Sluggish redox kinetics and dendrite growth perplex the fulfillment of efficient electrochemistry in lithium–sulfur (Li–S) batteries. The complicated sulfur phase transformation and sulfur/lithium diversity kinetics necessitate an all-inclusive approach in catalyst design. Herein, a compatible mediator with nanoscale-asymmetric-size configuration by integrating Co single atoms and defective CoTe 2–x (Co SA -CoTe 2–x @NHCF) is elaborately developed for regulating sulfur/lithium electrochemistry synchronously. Substantial electrochemistry and theoretical analyses reveal that CoTe 2–x exhibits higher catalytic activity in long-chain polysulfide transformation and Li 2 S decomposition, while monodispersed Co sites are more effective in boosting sulfur reduction kinetics to regulate Li 2 S deposition. Such cascade catalysis endows Co SA -CoTe 2–x @NHCF with the all-around service of “trapping-conversion-recuperation” for sulfur species during the whole redox reaction. Furthermore, it is demonstrated by in situ transmission electron microscopy that initially formed electronic-conductive Co and ionic-conductive Li 2 Te provide sufficient lithiophilic sites to regulate homogeneous Li plating and stripping with markedly suppressed dendrite growth. Consequently, by coupling the Co SA -CoTe 2–x @NHCF interlayer and Li@Co SA -CoTe 2–x @NHCF anode, the constructed Li–S full batteries deliver superior cycling stability and rate performance, and the flexible pouch cell exhibits stable cycling performance at 0.3 C. In conclusion, the gained insights into the synergistic effect of asymmetric-size structures pave the way for the integrated catalyst design in advanced Li–S systems.

36 MATERIALS SCIENCE↗
DOE OSTI2025

A Quasi-Ordered Mn-Rich Cathode with Highly Reversible Oxygen Anion Redox Chemistry

Anionic oxygen redox chemistry in Li-rich Mn-based layer oxide cathodes represents a transformative approach for boosting the energy density of next-generation lithium-ion batteries. However, conventional oxygen redox reactions often induce oxygen dimerization at high voltages, leading to irreversible lattice oxygen loss and a rapid voltage fade. Herein, we achieve highly reversible oxygen redox chemistry through a new quasi-ordered structural design that incorporates both intra- and interlayer cation disorder configurations. This unique structure significantly enhances lattice oxygen stability, effectively stabilizes oxidized oxygen, and inhibits the formation of peroxo- or superoxol-like species, thereby enabling anionic redox reactions to proceed reversibly even at deep delithiation states. The quasi-ordered design mitigates irreversible phase transitions and preserves the structural integrity throughout extended cycling. Consequently, the proposed cathode demonstrates exceptional cyclability with negligible capacity and voltage fade, retaining 99% capacity and 98% average voltage after long-term cycling. Finally this work provides fresh insights into addressing issues related to lattice oxygen instabilities and reforming strategies for developing long-life, high-energy-density anionic redox cathode materials for advanced batteries.

chemical structure↗
DOE OSTI2025

Planar Defect Layers Template a High-Pressure InBi Polymorph

The short- and long-range order of III–V materials under high pressure has long been the subject of debate, with advancements in structural characterization leading to significant revisions to the accepted structural models. Despite these revisions, previous high-pressure structural assignments in the In–Bi system include the site-disordered β-Sn structure type, a structure type demonstrated to be nonexistent in analogous III–V systems. While X-ray diffraction is consistent with site disordering in InBi at high pressure, cluster expansion calculations indicate that disordering requires temperatures above 3000 K. Here, we propose InBi as a model material for studying unique high-pressure planar defects due to its highly anisotropic stress-dependent properties and structure. Specifically, we identify two sets of planar defects that mimic the diffraction pattern of a site disordered β-Sn structure type and are compatible with the calculated disorder barrier. We derive these defects by symmetry relations over crystallographic transitions. Density functional theory calculations of the proposed defects suggest that these defects are stabilized by diminishing interlayer separations with pressure. Further, we find that one of the proposed defects closely resembles a bulk high-pressure phase of InBi, InBi-ϵ, and we assert that the proposed defects order upon heating, acting as a template for InBi-ϵ growth. The proposed defects and their electronic structure provide a basis for the trend of superconducting critical temperature with increasing pressure. These methods for identifying defects are generalizable to other materials with reports of site disorder at high pressure, prompting a broader search for related high-pressure defects.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Substitution-Mediated Calcination of Nickel-Based Cathodes: Decoupling Lithiation and Crystallization

Nickel-based layered cathodes such as LiNiO 2 offer high energy density for lithium-ion batteries, yet improvements in cycling performance and safety are required for practical use–often achieved through manganese and cobalt substitution as in LiNi 0.80 Mn 0.10 Co 0.10 O 2 (NMC811). However, how such substitution impacts calcination, the key process that governs lithiation, structural ordering, crystallization, and ultimately the resulting material properties, remains unclear. Here, in this study, we investigate substitution-mediated calcination dynamics in NMC811 compared to LiNiO 2 using multiscale-correlated in situ spectroscopy and atomistic-to-mesoscale modeling. While both systems progress through the same sequence of intermediates toward the thermodynamically favored layered phase, NMC811 exhibits an earlier onset of layering, concurrent with hydroxide decomposition followed by sluggish crystallization. Modeling reveals that Mn and Co lower the energy barrier for lithium incorporation and ordering but increase the penalty for interlayer gliding, thereby slowing crystal growth at elevated temperatures. This substitution-mediated decoupling of lithiation and crystallization explains the fine-grained microstructure observed in NMC811 versus coarsened particles in LiNiO 2 and establishes a mechanistic framework for predictive microstructure engineering of Ni-based cathodes.

Calcination↗
DOE OSTI2026

In Situ Insights into Enhanced Cooperative Ligand Exchange Kinetics via Solvent-Induced Restacking in a 2D Metal–Organic Framework

Understanding the reaction kinetics at catalytically active sites is crucial for integrating catalytic two-dimensional (2D) materials into industrial processes. This study focuses on in situ observation of ligand exchange kinetics and solvent-assisted structural restacking transition in the 2D paddle wheel-based MOF [Cu 2 (dttc) 2 ] n (DUT-134(Cu), dttc = dithieno[3,2-b:2′,3′- d]thiophene-2,6-dicarboxylate). The ligand exchange process, involving the replacement of dimethylformamide (DMF) with nitriles such as acetonitrile (ACN), pentanenitrile, and heptanenitrile, was investigated using advanced in situ characterization techniques with high temporal resolution, including powder X-ray diffraction and Raman spectroscopy. The larger analytes exhibited reduced exchange rates, consistent with enhanced steric hindrance and greater diffusion constraints. Interestingly, the study revealed that the exchange of DMF with ACN induces a structural transition to higher symmetry within few seconds, a transition from AB to AA stacking mode of the layers, and a widening of the interlayer distance. Crucially, this structural transition dramatically accelerates the solvent exchange process through cooperative effects, offering critical advantages for catalytic applications. Notably, the reverse exchange from ACN to DMF proceeds more slowly and does not reverse the structural changes, but a new phase is formed with preserved AA stacking. By isotope labeling of linker molecules in combination with two complementary theoretical vibrational simulation methods, the precise assignment of Raman bands and the vibrational modes associated with the ligand exchange process could be achieved. These pioneering insights into the dynamic behavior of 2D MOFs, coupled with ligand exchange, establish a highly promising and transformative approach to achieving enhanced tunability and responsiveness in future catalytic applications.

Layers↗
DOE OSTI2026

A Monolithic Artificial Leaf for Solar Methanol Production from CO 2 and H 2 O

Methanol, an important liquid fuel and chemical feedstock, has yet to be produced using solar energy, H 2 O, and CO 2 as sole inputs in a standalone device. Here, this study directly addresses this longstanding challenge through presenting the first demonstration of unbiased solar methanol production from CO 2 and H 2 O with a monolithic artificial leaf design, surpassing the previous best energy efficiency in solar alcohol production by at least 1 order of magnitude. We first develop a new generation of photocathodes based on Si micropillar arrays and a cobalt tetraaminophthalocyanine molecular catalyst. By integrating a C 60 interlayer that facilitates unidirectional electron transfer through the semiconductor/catalyst interface, we realize a photovoltage of 500 mV, one of the highest recorded for single-junction Si-based photoelectrodes in aqueous CO 2 reduction, as well as unprecedented methanol formation with a Faradaic efficiency of 30% and a partial current density of 6.3 mA cm –2 . We further integrate the photocathode with a multijunction perovskite photovoltaic minimodule to afford a standalone solar fuel system, which demonstrates a light-to-methanol conversion efficiency of 0.8%, 32 times higher than the present record in light-to-alcohol conversion with an artificial leaf.

alcohols↗
DOE OSTI2023

A Consistent Representation of Cloud Overlap and Cloud Subgrid Vertical Heterogeneity

Many global climate models underestimate the cloud cover and overestimate the cloud albedo, especially for low-level clouds. We determine how a correct representation of the vertical structure of clouds can fix part of this bias. We use the 1D McICA framework and focus on low-level clouds. Using Large Eddy Simulations results as reference, we propose a method based on exponential-random overlap that represents the cloud overlap between layers and the subgrid cloud properties over several vertical scales, with a single value of the overlap parameter. Starting from a coarse vertical grid, representative of atmospheric models, this algorithm is used to generate the vertical profile of the cloud fraction with a finer vertical resolution, or to generate it on the coarse grid but with subgrid heterogeneity and cloud overlap that ensures a correct cloud cover. Doing so we find decorrelation lengths are dependent on the vertical resolution, except if the vertical subgrid heterogeneity and interlayer overlap are taken into account coherently. We confirm that the frequently used maximum-random overlap leads to a significant error by underestimating the low-level cloud cover with a relative error of about 50%, that can lead to an error of SW cloud albedo as big as 70%. Not taking into account the subgrid vertical heterogeneity of clouds can cause a relative error of 20% in brightness, assuming the cloud cover is correct.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

A Dynamic Pore Network Model for Imbibition Simulation Considering Corner Film Flow

Wetting films can develop in the corners of angular pores under strong wetting conditions. Modeling the dynamics of corner film remains elusive using direct numerical simulations because of the significant scale difference between main meniscus and corner film flow. In this paper, the modified interacting capillary bundle model (ICB), developed in our previous work to describe accurately corner film dynamics in a single square tube, is incorporated into a single-pressure dynamic pore network model (DPNM) to simulate imbibition in strongly wetting porous media with corner film flow. The traditional pore network is decomposed into several layers of interacting subpore networks where the 0th layer of subpore network simulates the main meniscus flow and higher layers the corner film flow. The fluid flow between different layers is captured by interlayer throats. In addition, the snap-off mechanism caused by the thickening of wetting corner film is considered. The accuracy of the developed model is validated for four cases: spontaneous imbibition in a single square tube, wetting fluid redistribution through corner films under a capillary pressure difference, snap off in a narrow throat connecting two large pores, and imbibition dynamics in a real microfluidic porous geometry. The validated model is then used to simulate both spontaneous and controlled imbibition in a pore network with random pore size distribution. Finally, the interaction between corner film and main meniscus flow in porous media is analyzed from a pore-scale perspective.

58 GEOSCIENCES↗
DOE OSTI2026

Constraining the Hydration of Clay Minerals and Abundances of Amorphous Phases in Gale Crater, Mars

Both water and organic matter are required for the development and persistence of life. Phyllosilicates (clay minerals) have high surface areas that easily sorb water and organic matter. The Curiosity rover has investigated several hundred meters of stratigraphy in Gale crater, including where clays were detected from orbit. Previous results have suggested that subsurface hydration is greatest in units with the most abundant clays, suggesting that these minerals may be hydrated. Organics have also been found throughout Gale crater. Smectites are the most common and abundant phyllosilicates in Gale crater samples and can expand and sorb water and organics in interlayer sites. The most common organic sorption processes on Earth typically involve water or hydroxyl, so hydrated phyllosilicates are good candidates for organic preservation. Using newly derived subsurface hydration results with previously published mineralogy and geochemistry, we derived modeled constraints on the abundances of hydrated amorphous phases, “excess” water, and “excess” cations. These “excess” phases are not accounted for by published crystalline phase abundances or by amorphous phases constrained here. We found correlations between smectites and both “excess” water and “excess” cation abundances, indicating that smectites in Gale crater are hydrated and that cation bridging could be a mechanism for sorption of organics. Our results also show the persistence of amorphous sulfates, opal-A, and volcanic or impact glass, which indicate low water-rock interactions. Increased abundances of sulfates and glass in stratigraphically higher samples may indicate lower water availability and environmental aridification during the time these units were being deposited.

58 GEOSCIENCES↗
DOE OSTI2020

High permeability sub-nanometre sieve composite MoS 2 membranes

Two-dimensional membranes have gained enormous interest due to their potential to deliver precision filtration of species with performance that can challenge current desalination membrane platforms. Molybdenum disulfide (MoS 2 ) laminar membranes have recently demonstrated superior stability in aqueous environment to their extensively-studied analogs graphene-based membranes; however, challenges such as low ion rejection for high salinity water, low water flux, and low stability over time delay their potential adoption as a viable technology. Here, we report composite laminate multilayer MoS 2 membranes with stacked heterodimensional one- to two-layer-thick porous nanosheets and nanodisks. These membranes have a multimodal porous network structure with tunable surface charge, pore size, and interlayer spacing. In forward osmosis, our membranes reject more than 99% of salts at high salinities and, in reverse osmosis, small-molecule organic dyes and salts are efficiently filtered. Finally, our membranes stably operate for over a month, implying their potential for use in commercial water purification applications.

36 MATERIALS SCIENCE↗