Modulating the D-π-A Interactions in Metal-Covalent Organic Frameworks for Efficient Electroreduction of CO2 into Formate.

Crystalline porous framework materials have attracted tremendous interest in electrocatalytic CO2 reduction owing to their ordered structures and high specific surface areas as well as rich designability, however, still suffer from a lack of accuracy in regulating the binding strength between the catalytic sites and intermediates, which is crucial for optimizing the electrocatalytic activity and expanding the product types. Herein, we report three new kinds of vinylene-linked metal-covalent organic frameworks (TMT-CH3-MCOF, TMP-CH3-MCOF and TMP-MCOF) with continuously tunable D-π-A interactions by adjusting the structure of the monomers at the molecular level for realizing efficient electroreduction of CO2 to formate for the first time. Interestingly, compared with TMT-CH3-MCOF and TMP-MCOF, the TMP-CH3-MCOF exhibited the highest HCOO- Faradaic efficiency (FEHCOO-) of 95.6% at -1.0 V vs RHE and displayed the FEHCOO- above 90% at the voltage range of -1.0 to -1.2 V vs. RHE, which is one of the highest among various kinds of reported electrocatalysts. Theoretical calculations further reveal that the catalytic sites in TMP-CH3-MCOF with unique moderate D-π-A interactions have suitable binding ability towards the reaction intermediate, which is beneficial for the formation of *HCOO and desorption of *HCOOH, thus effectively promoting the electroreduction of CO2 to formate.

Modulating luminescence through anion variation in lead-free Cs2NaInX6 (X = Cl, Br, and I) perovskites: a first-principles study.

The A2B+B'3+X6-type lead-free halide perovskite Cs2NaInCl6 has demonstrated limited luminescence performance attributed to parity-forbidden transitions in its intrinsic form. While extensive exploration has been dedicated to partial cation substitution in Cs2NaInCl6, there is a noticeable gap in understanding the impact of anion composition on this material. In this study, we investigated the influence of anion composition on the luminescence performance of Cs2NaInX6 using first-principles calculations. We first conducted calculations on Cs2NaInX6 in its intrinsic state and on Cs2NaInCl6 with cation substitution to establish the reliability of the transition dipole moment (TDM) as a luminescence descriptor in this system. Following this, we systematically assessed the formation energies, octahedral distortions, and luminescence properties of Cs2NaInX6 with diverse anion compositions. Despite sharing similar stability, closely aligned with the experimentally accessible Cs2NaInCl6, all mixed halide structures exhibited significant octahedral distortions. Additionally, most of these structures displayed considerably enhanced TDM compared to their single halide counterparts. Notably, the structures Cs2NaInX4X'2-b and Cs2NaInX3X'3-b demonstrated superior luminescence performance compared to other structures. The absorption spectra calculated for selected structures revealed the enhancement of their photo-absorbance in the presence of iodine, particularly in the low energy region. This observation provides additional evidence that light absorbance in different energy regions can be effectively regulated in this way. Finally, we also investigated other optical properties that impact luminescence performances, such as the energy loss spectrum L(ω), the reflectivity spectrum R(ω) and the refractivity index n(ω). The findings offer insights into optimizing the luminescence performance of lead-free halide perovskites through anion composition variation.

Lithium-Ion Charged Polymer Channels Flattening Lithium Metal Anode.

The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth. Resolving this issue will be key to achieving high-performance lithium metal batteries (LMBs). Herein, we construct a lithium nitrate (LiNO3)-implanted electroactive ß phase polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) crystalline polymorph layer (PHL). The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels. These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes, decreasing the growth of lithium dendrites. The stretched molecular channels can also accelerate the transport of Li ions. The combined effects enable a high Coulombic efficiency of 97.0% for 250 cycles in lithium (Li)||copper (Cu) cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm-2 with ultrahigh Li utilization of 50%. Furthermore, the full cell coupled with PHL-Cu@Li anode and LiFePO4 cathode exhibits long-term cycle stability with high-capacity retention of 95.9% after 900 cycles. Impressively, the full cell paired with LiNi0.87Co0.1Mn0.03O2 maintains a discharge capacity of 170.0 mAh g-1 with a capacity retention of 84.3% after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83. This facile strategy will widen the potential application of LiNO3 in ester-based electrolyte for practical high-voltage LMBs.

Unravelling abnormal in-plane stretchability of two-dimensional metal-organic frameworks by machine learning potential molecular dynamics.

Two-dimensional (2D) metal-organic frameworks (MOFs) hold immense potential for various applications due to their distinctive intrinsic properties compared to their 3D analogues. Herein, we designed a highly stable NiF2(pyrazine)2 2D MOF in silico with a two-dimensional periodic wine-rack architecture. Extensive first-principles calculations and molecular dynamics (MD) simulations based on a newly developed machine learning potential (MLP) revealed that this 2D MOF exhibits huge in-plane Poisson's ratio anisotropy. This results in anomalous negative in-plane stretchability, as evidenced by an uncommon decrease in its in-plane area upon the application of uniaxial tensile strain, which makes this 2D MOF particularly attractive for flexible wearable electronics and ultra-thin sensor applications. We further demonstrated the unique capability of MLP to accurately predict the finite-temperature properties of MOFs on a large scale, exemplified by MLP-MD simulations with a dimension of 28.2 × 28.2 nm2, relevant to the length scale experimentally attainable for the fabrication of MOF films.

Boosting the Cycle Performance of Iron Trifluoride Based Solid State Batteries at Elevated Temperatures by Engineering the Cathode Solid Electrolyte Interface.

Iron trifluoride (FeF3) is attracting tremendous interest due to its lower cost and the possibility to enable higher energy density in lithium-ion batteries. However, its cycle performance deteriorates rapidly in less than 50 cycles at elevated temperatures due to cracking of the unstable cathode solid electrolyte interface (CEI) followed by active materials dissolution in liquid electrolyte. Herein, by engineering the salt composition, the Fe3O4-type CEI with the doping of boron (B) atoms in a polymer electrolyte at 60 °C is successfully stabilized. The cycle life of the well-designed FeF3-based composite cathode exceeds an unprecedented 1000 cycles and utilizes up to 70% of its theoretical capacities. Advanced electron microscopy combined with density functional theory (DFT) calculations reveal that the B in lithium salt migrates into the cathode and promotes the formation of an elastic and mechanic robust boron-contained CEI (BOR-CEI) during cycling, by which the durability of the CEI to frequent cyclic large volume changes is significantly enhanced. To this end, the notorious active materials dissolution is largely prohibited, resulting in a superior cycle life. The results suggest that engineering the CEI such as tuning its composition is a viable approach to achieving FeF3 cathode-based batteries with enhanced performance.

Crystalline Dual-Porous Covalent Triazine Frameworks as a New Platform for Efficient Electrocatalysis.

Crystalline covalent triazine frameworks (CTFs) have gained considerable interest in energy and catalysis owing to their well-defined nitrogen-rich π-conjugated porosity and superior physicochemical properties, however, suffer from very limited molecular structures. Herein we report a novel solvent-free FeCl3 -catalyzed polymerization of 2, 6-pyridinedicarbonitrile (DCP) to achieve the first synthesis of crystalline, dual-porous, pyridine-based CTF (Fe-CTF). The FeCl3 could not only act as a highly active Lewis acid catalyst for promoting the two-dimensional ordered polymerization of DCP monomers, but also in situ coordinate with the tridentate chelators generated between pyridine and triazine groups to yield unique Fe-N3 single-atom active sites in Fe-CTF. Abundant few-layer crystalline nanosheets (Fe-CTF NSs) could be prepared through simple ball-milling exfoliation of the bulk layered Fe-CTF and exhibited remarkable electrocatalytic performance for oxygen reduction reaction (ORR) with a half-wave potential and onset potential up to 0.902 and 1.02 V respectively, and extraordinary Zn-air battery performance with an ultrahigh specific capacity and power density of 811 mAh g-1 and 230 mW cm-2 respectively. By combining operando X-ray absorption spectroscopy with density functional theory calculations, we revealed a dynamic and reversible evolution of Fe-N3 to Fe-N2 during the electrocatalytic process, which could further accelerate the electrocatalytic reaction.

Green and Scalable Synthesis of Atomic-Thin Crystalline Two-Dimensional Triazine Polymers with Ultrahigh Photocatalytic Properties.

Scalable and eco-friendly synthesis of crystalline two-dimensional (2D) polymers with proper band gap and single-layer thickness is highly desired for the fundamental research and practical applications of 2D polymers; however, it remains a considerable and unresolved challenge. Herein, we report a convenient and robust method to synthesize a series of crystalline covalent triazine framework nanosheets (CTF NSs) with a thickness of ∼80 nm via a new solvent-free salt-catalyzed nitrile cyclotrimerization process, which enables the cost-effective large-scale preparation of crystalline CTF NSs at the hundred-gram level. Theoretical calculations and detailed experiments revealed for the first time that the conventional salts such as KCl can not only act as physical templates as traditionally believed but also more importantly can efficiently catalyze the cyclotrimerization reaction of carbonitrile monomers as a new kind of green solid catalysts to achieve crystalline CTF NSs. Upon simple liquid-phase sonication, these CTF NSs can be easily further exfoliated into abundant single-layer crystalline 2D triazine polymers (2D-TPs) in high yields. The obtained atomically thin crystalline 2D-TPs with a band gap of 2.36 eV and rich triazine active groups exhibited a remarkable photocatalytic hydrogen evolution rate of 1321 µmol h-1 under visible light irradiation with an apparent quantum yield up to 29.5% at 420 nm and excellent photocatalytic overall water splitting activity with a solar-to-hydrogen efficiency up to 0.35%, which exceed all molecular framework materials and are among the best metal-free photocatalysts ever reported. Moreover, the processable 2D-TPs could be readily assembled on a support as a photocatalytic film device, which demonstrated superior photocatalytic performance (135.2 mmol h-1 m-2 for hydrogen evolution).

Nanoscale Iron-Based Metal-Organic Frameworks: Incorporation of Functionalized Drugs and Degradation in Biological Media.

Metal-organic frameworks (MOFs) attract growing interest in biomedical applications. Among thousands of MOF structures, the mesoporous iron(III) carboxylate MIL-100(Fe) (MIL stands for the Materials of Lavoisier Institute) is among the most studied MOF nanocarrier, owing to its high porosity, biodegradability, and lack of toxicity. Nanosized MIL-100(Fe) particles (nanoMOFs) readily coordinate with drugs leading to unprecedented payloads and controlled release. Here, we show how the functional groups of the challenging anticancer drug prednisolone influence their interactions with the nanoMOFs and their release in various media. Molecular modeling enabled predicting the strength of interactions between prednisolone-bearing or not phosphate or sulfate moieties (PP and PS, respectively) and the oxo-trimer of MIL-100(Fe) as well as understanding the pore filling of MIL-100(Fe). Noticeably, PP showed the strongest interactions (drug loading up to 30 wt %, encapsulation efficiency > 98%) and slowed down the nanoMOFs' degradation in simulated body fluid. This drug was shown to bind to the iron Lewis acid sites and was not displaced by other ions in the suspension media. On the contrary, PS was entrapped with lower efficiencies and was easily displaced by phosphates in the release media. Noticeably, the nanoMOFs maintained their size and faceted structures after drug loading and even after degradation in blood or serum after losing almost the totality of the constitutive trimesate ligands. Scanning electron microscopy with high annular dark field (STEM-HAADF) in conjunction with X-Ray energy-dispersive spectrometry (XEDS) was a powerful tool enabling the unraveling of the main elements to gain insights on the MOF structural evolution after drug loading and/or upon degradation.

Engineering Catalysis within a Saturated In(III)-Based MOF Possessing Dynamic Ligand-Metal Bonding.

Metal-organic frameworks have developed into a formidable heterogeneous catalysis platform in recent years. It is well established that thermolysis of coordinated solvents from MOF nodes can render highly reactive, coordinatively unsaturated metal complexes which are stabilized via site isolation and serve as active sites in catalysis. Such approaches are limited to frameworks featuring solvated transition-metal complexes and must be stable toward the formation of "permanent" open metal sites. Herein, we exploit the hemilability of metal-carboxylate bonds to generate transient open metal sites in an In(III) MOF, pertinent to In-centered catalysis. The transient open metal sites catalyze the Strecker reaction over multiple cycles without loss of activity or crystallinity. We employ computational and spectroscopic methods to confirm the formation of open metal sites via transient dissociation of In(III)-carboxylate bonds. Furthermore, the amount of transient open metal sites within the material and thus the catalytic performance can be temperature-modulated.

Switchable Metal Sites in Metal-Organic Framework MFM-300(Sc): Lewis Acid Catalysis Driven by Metal-Hemilabile Linker Bond Dynamics.

Uncommon reversible guest-induced metal-hemilabile linker bond dynamics in MOF MFM-300(Sc) was unraveled to switch on/switch off catalytic open metal sites. The catalytic activity of this MOF with non-permanent open metal sites was demonstrated using a model Strecker hydrocyanation reaction as a proof-of-concept. Conclusively, the catalytic activity was evidenced to be fully reversible, preserving the conversion performance and structure integrity of MFM-300(Sc) over multiple cycles. These experimental findings were corroborated by quantum-calculations that revealed a reaction mechanism driven by the Sc-open metal sites. This discovery paves the way towards the design of new effective and easily regenerable heterogeneous MOF catalysts integrating switchable metal sites.

Asymmetric pore windows in MOF membranes for natural gas valorization.

To use natural gas as a feedstock alternative to coal and oil, its main constituent, methane, needs to be isolated with high purity1. In particular, nitrogen dilutes the heating value of natural gas and is, therefore, of prime importance for removal2. However, the inertness of nitrogen and its similarities to methane in terms of kinetic size, polarizability and boiling point pose particular challenges for the development of energy-efficient nitrogen-removing processes3. Here we report a mixed-linker metal-organic framework (MOF) membrane based on fumarate (fum) and mesaconate (mes) linkers, Zr-fum67-mes33-fcu-MOF, with a pore aperture shape specific for effective nitrogen removal from natural gas. The deliberate introduction of asymmetry in the parent trefoil-shaped pore aperture induces a shape irregularity, blocking the transport of tetrahedral methane while allowing linear nitrogen to permeate. Zr-fum67-mes33-fcu-MOF membranes exhibit record-high nitrogen/methane selectivity and nitrogen permeance under practical pressures up to 50 bar, removing both carbon dioxide and nitrogen from natural gas. Techno-economic analysis shows that our membranes offer the potential to reduce methane purification costs by about 66% for nitrogen rejection and about 73% for simultaneous removal of carbon dioxide and nitrogen, relative to cryogenic distillation and amine-based carbon dioxide capture.

H2S Stability of Metal-Organic Frameworks: A Computational Assessment.

The H2S stability of a range of metal-organic frameworks (MOFs) was systematically assessed by first-principles calculations. The most likely degradation mechanism was first determined and we identified the rate constant of the degradation reaction as a reliable descriptor for characterizing the H2S stability of MOFs. A qualitative H2S stability ranking was thus established for the list of investigated materials. Structure-stability relationships were further envisaged considering several variables including the nature of the linkers and their grafted functional groups, the pore size, the nature of metal sites, and the presence/nature of coordinatively unsaturated sites. This knowledge enabled the anticipation of the H2S stability of one prototypical MOF, e.g., MIL-91(Ti), which has been previously proposed as a good candidate for CO2 capture. This computational strategy enables an accurate and easy handling assessment of the H2S stability of MOFs and offers a solid alternative to experimental characterizations that require the manipulation of a highly toxic and corrosive molecule.

Flexibilization of Biorefineries: Tuning Lignin Hydrogenation by Hydrogen Partial Pressure.

The present study describes an interesting and practical catalytic system that allows flexible conversion of lignin into aromatic or aliphatic hydrocarbons, depending on the hydrogen partial pressure. A combination of experiment and theory shows that the product distribution between aromatics and aliphatics can be simply tuned by controlling the availability of hydrogen on the catalyst surface. Noticeably, these pathways lead to almost complete oxygen removal from lignin biomass, yielding high-quality hydrocarbons. Thus, hydrogen-lignin co-refining by using this catalytic system provides high flexibility in hydrogen storage/consumption towards meeting different regional and temporal demands.

Design of MoS2/Graphene van der Waals Heterostructure as Highly Efficient and Stable Electrocatalyst for Hydrogen Evolution in Acidic and Alkaline Media.

The thermodynamically stable phase of molybdenum disulfide (MoS2) is evaluated as a promising and durable nonprecious-metal electrocatalyst toward the hydrogen evolution reaction (HER); however, its actual catalytic activity is restricted by an inert basal plane, low electronic conductivity, low density, and using efficiency of edged atoms. Moreover, 2D/2D van der Waals (vdws) heterostructures (HSs) with face-to-face contact can construct a highly coupled interface and are demonstrated to have immense potential for catalytic applications. In the present work, a 2D/2D hetero-layered architecture of an electrocatalyst, based on the alternate arrangement of ultrasmall monolayer MoS2 nanosheets (approximately 5-10 nm) and ultrathin graphene (G) sheets, is prepared by a facilely chemical process, which is named as MoS2/G HS. The unique structural characteristic of MoS2/G HS is in favor of accommodating more active sites as the centers of ad/desorption hydrogen and transferring and separating the charges at a coupled interface to improve the electronic conductivity and durability. The density functional theory calculation results further confirm that the alternately arranged G layers and MoS2 monolayers, as well as the expanded interplanar distance of 1.104 nm for MoS2/G HS, can exhibit a superior HER performance in both 0.5 M H2SO4 and 1.0 M KOH.

Real-time optical and electronic sensing with a ß-amino enone linked, triazine-containing 2D covalent organic framework.

Fully-aromatic, two-dimensional covalent organic frameworks (2D COFs) are hailed as candidates for electronic and optical devices, yet to-date few applications emerged that make genuine use of their rational, predictive design principles and permanent pore structure. Here, we present a 2D COF made up of chemoresistant ß-amino enone bridges and Lewis-basic triazine moieties that exhibits a dramatic real-time response in the visible spectrum and an increase in bulk conductivity by two orders of magnitude to a chemical trigger - corrosive HCl vapours. The optical and electronic response is fully reversible using a chemical switch (NH3 vapours) or physical triggers (temperature or vacuum). These findings demonstrate a useful application of fully-aromatic 2D COFs as real-time responsive chemosensors and switches.

Mössbauerite as Iron-Only Layered Oxyhydroxide Catalyst for WO3 Photoanodes.

Mössbauerite, a trivalent iron-only layered oxyhydroxide, has been recently identified as an electrocatalyst for water oxidation. We investigated the material as potential cocatalyst for photoelectrochemical water oxidation on semiconductor photoanodes. The band edge positions of mössbauerite were determined for the first time with a combination of Mott-Schottky analysis and UV-vis diffuse reflectance spectroscopy. The positive value of the Mott-Schottky slope and the flatband potential of 0.34 V vs reversible hydrogen electrode (RHE) identifies the material as an n-type semiconductor, but bare mössbauerite does not produce noticeable photocurrent during water oxidation. Type-II heterojunction formation by facile drop-casting with WO3 thin films yielded photoanodes with amended charge carrier separation and photocurrents up to 1.22 mA cm-2 at 1.23 V vs RHE. Mössbauerite is capable of increasing the charge carrier separation at lower potential and improving the photocurrent during photoelectrochemical water oxidation. The rise in photocurrent of the mössbauerite-functionalized WO3 photoanode thus originates from improved charge carrier separation and augmented hole collection efficiency. Our results highlight the potential of mössbauerite as a second-phase catalyst for semiconductor electrodes.

Bifunctional oxygen evolution and supercapacitor electrode with integrated architecture of NiFe-layered double hydroxides and hierarchical carbon framework.

Layered double hydroxide with exchangeable interlayer anions are considered promising electro-active materials for renewable energy technologies. However, the limited exposure of active sites and poor electrical conductivity of hydroxide powder restrict its application. Herein, bifunctional integrated electrode with a 3D hierarchical carbon framework decorated by nickel iron-layered double hydroxides (NiFe-LDH) is developed. A conductive carbon nanowire array is introduced not only to provide enough anchoring sites for the hydroxide, but also affords a continuous pathway for electron transport throughout the entire electrode. The 3D integrated architecture of NiFe-hydroxide and hierarchical carbon framework possesses several beneficial effects including large electrochemical active surfaces, fast electron/mass transport, and enhanced mechanical stability. The as-prepared electrode affords a current density of 10 mA cm-2 at a low overpotential of 269 mV for oxygen evolution reaction (OER) in 1 M of KOH. It also offers excellent stability with negligible current decline even after 2000 cycles. Besides, density functional theory calculations revealed that the (110) surface of NiFe-LDH is more active than the (003) surface for OER. Furthermore, the electrode possesses promising application prospects in alkaline battery-supercapacitor hybrid devices with a capacity of 178.8 mAh g-1 (capacitance of 1609.6 F g-1) at a current density of 0.2 A g-1. The viability of the as-prepared bifunctional electrode will provide a potential solution for wearable electronics in the near future.

Semiconducting Crystalline Two-Dimensional Polyimide Nanosheets with Superior Sodium Storage Properties.

The efficient synthesis of crystalline two-dimensional polymers (2DPs) with designed structures and properties is highly desired but remains a considerable challenge. Herein, we report the synthesis of two-dimensional polyimide (2DPI) nanosheets via hydrogen-bond-induced preorganization and subsequent imidization reaction. The formed intermolecular hydrogen bonds can significantly improve the internal order and in-plane periodicity of 2DPI. The crystalline few-layer 2DPI nanosheets are micrometer-size, solvent dispersible, and thermally stable. Interestingly, the 2DPI with π-conjugation shows a favorable bandgap of 2.2 eV and can function as a p-type semiconducting layer in field-effect transistor devices with an appreciable mobility of 4.3 × 10-3 cm2 V-1 s-1. Furthermore, when explored as a polymeric anode for sodium-ion batteries, the 2DPI exhibits ultrahigh capacity (312 mAh g-1 at 0.1 A g-1), impressive rate capability (137 mAh g-1 at 10.0 A g-1), and excellent cycling stability (95% capacity retention after 1100 cycles) due to its robust 2D conjugated porous structure, outperforming most organic/polymeric anodes ever reported. This work provides a versatile strategy for synthesizing 2DP nanosheets with promising electronics and energy-related applications.

Tuning the Porosity and Photocatalytic Performance of Triazine-Based Graphdiyne Polymers through Polymorphism.

Crystalline and amorphous organic materials are an emergent class of heterogeneous photocatalysts for the generation of hydrogen from water, but a direct correlation between their structures and the resulting properties has not been achieved so far. To make a meaningful comparison between structurally different, yet chemically similar porous polymers, two porous polymorphs of a triazine-based graphdiyne (TzG) framework are synthesized by a simple, one-pot homocoupling polymerization reaction using as catalysts CuI for TzGCu and PdII /CuI for TzGPd/Cu . The polymers form through irreversible coupling reactions and give rise to a crystalline (TzGCu ) and an amorphous (TzGPd/Cu ) polymorph. Notably, the crystalline and amorphous polymorphs are narrow-gap semiconductors with permanent surface areas of 660 m2 g-1 and 392 m2 g-1 , respectively. Hence, both polymers are ideal heterogeneous photocatalysts for water splitting with some of the highest hydrogen evolution rates reported to date (up to 972 µmol h-1 g-1 with and 276 µmol h-1 g-1 without Pt cocatalyst). Crystalline order is found to improve delocalization, whereas the amorphous polymorph requires a cocatalyst for efficient charge transfer. This will need to be considered in future rational design of polymer catalysts and organic electronics.

A Pseudolayered MoS2 as Li-Ion Intercalation Host with Enhanced Rate Capability and Durability.

As a popular strategy, interlayer expansion significantly improves the Li-ion diffusion kinetics in the MoS2 host, while the large interlayer spacing weakens the van der Waals force between MoS2 monolayers, thus harming its structural stability. Here, an oxygen-incorporated MoS2 (O-MoS2 )/graphene composite as a self-supported intercalation host of Li-ion is prepared. The composite delivers a specific capacity of 80 mAh g-1 in only 36 s at a mass loading of 1 mg cm-2 , and it can be cycled 3000 times (over 91% capacity retention) with a 5 mg cm-2 loading at 2 A g-1 . The O-MoS2 exhibits a dominant 1T phase with an expanded layer spacing of 10.15 Å, leading to better Li-ion intercalation kinetics compared with pristine MoS2 . Furthermore, ex situ X-ray diffraction tests indicate that O-MoS2 sustains a stable structure in cycling compared with the gradual collapse of pristine MoS2 , which suffers from excessive lattice breathing. Density functional theory calculations suggest that the MoOx (OH)y pillars in O-MoS2 interlayers not only expand the layer spacing, but also tense the MoS2 layers to avoid exfoliation in cycling. Therefore, the O-MoS2 shows a pseudolayered structure, leading to remarkable durability besides the outstanding rate capability as a Li-ion intercalation host.