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1.
Adv Mater ; : e1906905, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32003086

RESUMO

Excavating and developing highly efficient and cost-effective nonnoble metal single-atom catalysts for electrocatalytic reactions is of paramount significance but still in its infancy. Herein, reported is a general NaCl template-assisted strategy for rationally designing and preparing a series of isolated transition metal single atoms (Fe/Co/Ni) anchored on honeycomb-like nitrogen-doped carbon matrix (M1 -HNC-T1 -T2 , M = Fe/Co/Ni, T1 = 500 °C, T2 = 850 °C). The resulting M1 -HNC-500-850 with M-N4 active sites exhibits superior capability for oxygen reduction reaction (ORR) with the half-wave potential order of Fe1 -HNC-500-850 > Co1 -HNC-500-850 > Ni1 -HNC-500-850, in which Fe1 -HNC-500-850 shows better performance than commercial Pt/C. Density functional theory calculations reveal a choice strategy that the strong p-d-coupled spatial charge separation results the Fe-N4 effectively merges active electrons for elevating d-band activity in a van-Hove singularity like character. This essentially generalizes an optimal electronic exchange-and-transfer (ExT) capability for boosting sluggish alkaline ORR activity. This work not only presents a universal strategy for preparing single-atom electrocatalyst to accelerate the kinetics of cathodic ORR but also provides an insight into the relationship between the electronic structure and the electrocatalytical activity.

2.
Adv Mater ; : e1906722, 2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31957092

RESUMO

The development of Li-S batteries is largely impeded by the growth of Li dendrites and polysulfide shuttling. To solve these two problems simultaneously, herein the study reports a "single atom array mimic" on ultrathin metal organic framework (MOF) nanosheet-based bifunctional separator for achieving the highly safe and long life Li-S batteries. In the designed separator, the periodically arranged cobalt atoms coordinated with oxygen atoms (CoO4 moieties) exposed on the surface of ultrathin MOF nanosheets, "single atom array mimic", can greatly homogenize Li ion flux through the strong Li ion adsorption with O atoms at the interface between anode and separator, leading to stable Li striping/plating. Meantime, at the cathode side, the Co single atom array mimic serves as "traps" to suppress polysulfide shuttling by Lewis acid-base interaction. As a result, the Li-S coin cells with the bifunctional separator exhibit a long cycle life with an ultralow capacity decay of 0.07% per cycle over 600 cycles. Even with a high sulfur loading of 7.8 mg cm-2 , an areal capacity of 5.0 mAh cm-2 can be remained after 200 cycles. Moreover, the assembled Li-S pouch cell displays stable cycling performance under various bending angles, demonstrating the potential for practical applications.

3.
Adv Healthc Mater ; 9(2): e1901528, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31820854

RESUMO

Bimetallic nanoparticles have received considerable attention owing to synergistic effect and their multifunctionality. Herein, new multifunctional Pd@Au bimetallic nanoplates decorated hollow mesoporous MnO2 nanoplates (H-MnO2 ) are demonstrated for achieving not only nucleus-targeted NIR-II photothermal therapy (PTT), but also tumor microenvironment (TME) hypoxia relief enhanced photodynamic therapy (PDT). The Pd@Au nanoplates present a photothermal conversion efficiency (PTCE) as high as 56.9%, superior to those PTAs activated in the NIR-II region such as Cu9 S5 nanoparticles (37%), Cu3 BiS3 nanorods (40.7%), and Au/Cu2- x S nanocrystals (43.2%). They further functionalize with transactivator of transcription (TAT) moiety for cell nuclear-targeting and biodegradable hollow mesoporous MnO2 (≈100 nm) loaded with photosensitizer Ce6 (TAT-Pd@Au/Ce6/PAH/H-MnO2 ) to construct a hierarchical targeting nanoplatform. The as-made TAT-Pd@Au/Ce6/PAH/H-MnO2 demonstrates good premature renal clearance escape ability and increased tumor tissue accumulation. It can be degraded in acidic TME and generate O2 by reacting to endogenous H2 O2 to relieve the hypoxia for enhanced PDT, while the released small TAT-Pd@Au nanoplates can effectively enter into the nucleus to mediate PTT. As a result, a remarkable therapeutic effect is achieved owing to the synergistic PTT/PDT therapy. This hierarchical targeting, TME-responsive, cytoplasm hypoxia relief PDT, and nuclear NIR-II PTT synergistic therapy can pave a new avenue for nanomaterials-based cancer therapy.

4.
Angew Chem Int Ed Engl ; 59(1): 232-236, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31609053

RESUMO

Traditional methods for analyzing organophosphorus pesticide chlorpyrifos, usually require the tedious sample pretreatment and sophisticated bio-interfaces, leading to the difficulty for real-time analysis. Herein, we use palladium single-atom (PdSA)/TiO2 as a photocatalytic sensing platform to directly detect chlorpyrifos with high sensitivity and selectivity. PdSA/TiO2 , prepared by an in situ photocatalytic reduction of PdCl4 2- on the TiO2 , shows much higher photocatalytic activity (10 mol g-1 h-1 ) for hydrogen evolution reaction than Pd nanoparticles (1.95 mol g-1 h-1 ), and excellent stability. In the presence of chlorpyrifos, the photocatalytic activity of PdSA/TiO2 decreases. Through this inhibition effect the platform can realize a detection limit for chlorpyrifos of 0.01 ng mL-1 , much lower than the maximum residue limit (10 ppb) permitted by the U.S. Environmental Protection Agency.

5.
Adv Mater ; 32(7): e1904249, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31880031

RESUMO

The development of highly efficient photocatalytic systems with rapid photogenerated charge separation and high surface catalytic activity is highly desirable for the storage and conversion of solar energy, yet remains a grand challenge. Herein, a conceptionally new form of atomically dispersed Co-P3 species on CdS nanorods (CoPSA-CdS) is designed and synthesized for achieving unprecedented photocatalytic activity for the dehydrogenation of formic acid (FA) to hydrogen. X-ray absorption near edge structure, X-ray photoelectron spectroscopy, and time-resolved photoluminescence results confirm that the Co-P3 species have a unique electron-rich feature, greatly improving the efficiency of photogenerated charge separation through an interface charge effect. The in situ attenuated total reflection infrared spectra reveal that the Co-P3 species can achieve much better dissociation adsorption of FA and activation of CH bonds than traditional sulfur-coordinated Co single atom-loaded CdS nanorods (CoSSA-CdS). These two new features make CoPSA-CdS exhibit the unprecedented 50-fold higher activity in the photocatalytic dehydrogenation of FA than CoSSA-CdS, and also much better activity than the Ru-, Rh-, Pd-, or Pt-loaded CdS. Besides, CoPSA-CdS also shows the highest mass activity (34309 mmol gCo -1 h-1 ) of Co reported to date. First-principles simulation reveals that the Co-P3 species herein can form an active PHCOO intermediate for enhancing the rate-determining dissociation adsorption of FA.

6.
Adv Mater ; 32(6): e1905661, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31851401

RESUMO

Defects, inevitably produced within bulk and at perovskite-transport layer interfaces (PTLIs), are detrimental to power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). It is demonstrated that a crosslinkable organic small molecule thioctic acid (TA), which can simultaneously be chemically anchored to the surface of TiO2 and methylammonium lead iodide (MAPbI3 ) through coordination effects and then in situ crosslinked to form a robust continuous polymer (Poly(TA)) network after thermal treatment, can be introduced into PSCs as a new bifacial passivation agent for greatly passivating the defects. It is also discovered that Poly(TA) can additionally enhance the charge extraction efficiency and the water-resisting and light-resisting abilities of perovskite film. These newly discovered features of Poly(TA) make PSCs herein achieve among the best PCE of 20.4% ever reported for MAPbI3 with negligible hysteresis, along with much enhanced ultraviolet, air, and operational stabilities. Density functional theory calculations reveal that the passivation of MAPbI3 bulk and PTLIs by Poly(TA) occurs through the interaction of functional groups (COOH, CS) in Poly(TA) with under-coordinated Pb2+ in MAPbI3 and Ti4+ in TiO2 , which is supported by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.

7.
Dalton Trans ; 49(2): 267-273, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31840720

RESUMO

Electrocatalysis plays a crucial role in the transformation between electrical and chemical energy. Particularly, the search for high-performance electrocatalysts lies at the heart of numerous renewable energy conversion and storage technologies, such as water electrolysers and fuel cells, which potentially enable an energy-sustainable society. This Frontier article briefly describes the pathway from debates on "animal electricity" to the current understanding of electrocatalysis, and how knowledge can be harnessed to guide the discovery of well-defined electrocatalysts based on precious metal nanocrystals. We summarize basic design principles and key parameters associated with a good electrocatalyst and highlight the adoption of wet-chemical approaches for constructing nanocatalysts with desired structural properties. We close this article with personal perspectives on current challenges and future research directions in this field.

8.
Chemistry ; 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31769895

RESUMO

Searching for new anti-poisoning Pt-based catalysts with enhanced activity for alcohol oxidation is the key in direct alcohol fuel cells (DAFCs). However, in the traditional strategy for designing bimetallic or multimetallic alloy is still difficult to achieve a satisfactory heterogeneous electrocatalyst because the activity often depends on only the surface atoms. Herein, we fabricate the multicomponent active sites by creating a sulfide structure on 1D PtNiCo trimetallic nanowires (NWs), to give a PtNiCo/NiCoS interface NWs (IFNWs). Owing to the presence of sulfide interfaces, the PtNiCo/NiCoS IFNWs enable an impressive methanol/ethanol oxidation reaction (MOR/EOR) performance and excellent anti-CO poisoning tolerance. They have the MOR and EOR mass activities of 2.25 Amg-1 Pt and 1.62 Amg-1 Pt , around 1.26, 3.21 and 1.46, 2.96 times higher than those of PtNiCo NWs and commercial Pt/C, respectively. CO-stripping and XPS measurements further demonstrate that the new interfacial structure and optimal bonding of Pt-CO can result in accelerating the removal of surface adsorbed carbonaceous intermediates. Moreover, such a unique structure has also demonstrated a much-improved ability for the electrochemical detection of some important molecules (H2 O2 and NH2 NH2 ).

9.
Nat Commun ; 10(1): 5231, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745074

RESUMO

The grand challenge in the development of atomically dispersed metallic catalysts is their low metal-atom loading density, uncontrollable localization and ambiguous interactions with supports, posing difficulty in maximizing their catalytic performance. Here, we achieve an interface catalyst consisting of atomic cobalt array covalently bound to distorted 1T MoS2 nanosheets (SA Co-D 1T MoS2). The phase of MoS2 transforming from 2H to D-1T, induced by strain from lattice mismatch and formation of Co-S covalent bond between Co and MoS2 during the assembly, is found to be essential to form the highly active single-atom array catalyst. SA Co-D 1T MoS2 achieves Pt-like activity toward HER and high long-term stability. Active-site blocking experiment together with density functional theory (DFT) calculations reveal that the superior catalytic behaviour is associated with an ensemble effect via the synergy of Co adatom and S of the D-1T MoS2 support by tuning hydrogen binding mode at the interface.

10.
iScience ; 20: 195-204, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31581068

RESUMO

As one of the most promising semiconductor oxide materials, titanium dioxide (TiO2) absorbs UV light but not visible light. To address this limitation, the introduction of Ti3+ defects represents a common strategy to render TiO2 visible-light responsive. Unfortunately, current hurdles in Ti3+ generation technologies impeded the widespread application of Ti3+ modified materials. Herein, we demonstrate a simple and mechanistically distinct approach to generating abundant surface-Ti3+ sites without leaving behind oxygen vacancy and sacrificing one-off electron donors. In particular, upon adsorption of organodiboron reagents onto TiO2 nanoparticles, spontaneous electron injection from the diboron-bound O2- site to adjacent Ti4+ site leads to an extremely stable blue surface Ti3+‒O-· complex. Notably, this defect generation protocol is also applicable to other semiconductor oxides including ZnO, SnO2, Nb2O5, and In2O3. Furthermore, the as-prepared photoelectronic device using this strategy affords 103-fold higher visible light response and the fabricated perovskite solar cell shows an enhanced performance.

11.
Nature ; 574(7776): 81-85, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31554968

RESUMO

The efficient interconversion of chemicals and electricity through electrocatalytic processes is central to many renewable-energy initiatives. The sluggish kinetics of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER)1-4 has long posed one of the biggest challenges in this field, and electrocatalysts based on expensive platinum-group metals are often required to improve the activity and durability of these reactions. The use of alloying5-7, surface strain8-11 and optimized coordination environments12 has resulted in platinum-based nanocrystals that enable very high ORR activities in acidic media; however, improving the activity of this reaction in alkaline environments remains challenging because of the difficulty in achieving optimized oxygen binding strength on platinum-group metals in the presence of hydroxide. Here we show that PdMo bimetallene-a palladium-molybdenum alloy in the form of a highly curved and sub-nanometre-thick metal nanosheet-is an efficient and stable electrocatalyst for the ORR and the OER in alkaline electrolytes, and shows promising performance as a cathode in Zn-air and Li-air batteries. The thin-sheet structure of PdMo bimetallene enables a large electrochemically active surface area (138.7 square metres per gram of palladium) as well as high atomic utilization, resulting in a mass activity towards the ORR of 16.37 amperes per milligram of palladium at 0.9 volts versus the reversible hydrogen electrode in alkaline electrolytes. This mass activity is 78 times and 327 times higher than those of commercial Pt/C and Pd/C catalysts, respectively, and shows little decay after 30,000 potential cycles. Density functional theory calculations reveal that the alloying effect, the strain effect due to the curved geometry, and the quantum size effect due to the thinness of the sheets tune the electronic structure of the system for optimized oxygen binding. Given the properties and the structure-activity relationships of PdMo metallene, we suggest that other metallene materials could show great promise in energy electrocatalysis.

12.
Langmuir ; 35(44): 14173-14179, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31411486

RESUMO

ZnO semiconductor oxides are versatile functional materials that are used in photoelectronics, catalysis, sensing, etc. The Zn+-O- surface electronic states of semiconductor oxides were formed on the ZnO surface by Zn 4s and O 2p orbital coupling with the diboron compound's B 2p orbitals. The formation of spin-coupled surface states was based on the spin-orbit interaction on the interface, which has not been reported before. This shows that the semiconductor oxide's spin surface states can be modulated by regulating surface orbital energy. The Zn+-O- surface electronic states were confirmed by electron spin resonance results, which may help in expanding the fundamental research on spintronics modulation and quantum transport.

13.
Angew Chem Int Ed Engl ; 58(40): 14184-14188, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31365167

RESUMO

Noble metal single atoms coordinated with highly electronegative atoms, especially N and O, often suffer from an electron-deficient state or poor stability, greatly limiting their wide application in the field of catalysis. Herein we demonstrate a new PH3 -promoted strategy for the effective transformation of noble metal nanoparticles (MNPs, M=Ru, Rh, Pd) at a low temperature (400 °C) into a class of thermally stabilized phosphorus-coordinated metal single atoms (MPSAs) on g-C3 N4 nanosheets via the strong Lewis acid-base interaction between PH3 and the noble metal. Experimental work along with theoretical simulations confirm that the obtained Pd single atoms supported on g-C3 N4 nanosheets exist in the form of PdP2 with a novel electron-rich feature, conceptionally different from the well-known single atoms with an electron-deficient state. As a result of this new electronic property, PdP2 -loaded g-C3 N4 nanosheets exhibit 4 times higher photocatalytic H2 production activity than the state-of-art N-coordinated PdSAs supported on g-C3 N4 nanosheets. This enhanced photocatalytic activity of phosphorus-coordinated metal single atoms with an electron-rich state was quite general, and also observed for other active noble metal single atom catalysts, such as Ru and Rh.

14.
Angew Chem Int Ed Engl ; 58(39): 13840-13844, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31359586

RESUMO

Structure and defect control are widely accepted effective strategies to manipulate the activity and stability of catalysts. On a freestanding hierarchically porous carbon microstructure, the tuning of oxygen vacancy in the embedded hollow cobaltosic oxide (Co3 O4 ) nanoparticles is demonstrated through the regulation of nanoscale Kirkendall effect. Starting with the embedded cobalt nanoparticles, the concentration of oxygen-vacancy defect can vary with the degree of Kirkendall oxidation, thus regulating the number of active sites and the catalytic performances. The optimized freestanding catalyst shows among the smallest reversible oxygen overpotential of 0.74 V for catalyzing oxygen reduction/evolution reactions in 0.1 m KOH. Moreover, the catalyst shows promise for substitution of noble metals to boost cathodic oxygen reactions in portable zinc-air batteries. This work provides a strategy to explore catalysts with controllable vacancy defects and desired nano-/microstructures.

15.
Chem Sci ; 10(23): 5898-5905, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31360394

RESUMO

Sub-nanometer noble metal catalysts, especially single atom (SA), are a new class of catalytic materials for boosting catalysis and possess unique catalytic properties and high atomic utilization efficiency. Exploring the interaction between two neighboring atom monomers has great potential to further improve the performance of SA catalysts and deepen the understanding on the catalytic mechanism of heterogeneous catalysis at the atomic level. Herein, we demonstrate that the synergetic effect between neighboring Pt and Ru monomers supported on N vacancy-rich g-C3N4 promotes the catalytic CO oxidation. The experimental observation and theoretical simulation reveal that the N vacancy in the g-C3N4 structure builds an optimized triangular sub-nanometer cavity for stabilizing the neighboring Pt-Ru monomers by forming Pt-C and Ru-N bonds. The mechanistic studies based on the in situ IR spectrum and theoretical simulation confirm that the neighboring Pt-Ru monomers possess a higher performance for optimizing O2 activation than Ru-Ru/Pt-Pt monomers or isolated Ru/Pt atoms by balancing the energy evolution of reaction steps in the catalytic CO oxidation. The discovery of the synergetic effect between neighboring monomers may create a new path for manipulating the catalytic properties of SA catalysts.

16.
Chem Soc Rev ; 48(12): 3265-3278, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31089609

RESUMO

The strain effect, along with the ligand effect and synergistic effect, contributes primarily to the optimization of electrocatalytic activity and stability. The strain effect leads to a shift in the d-band center and alters binding energies toward adsorbates. Under electrocatalytic circumstances, the strain effect and ligand effect by and large function in combination; however, the decay and vanishing of the ligand effect precede the strain effect as the thickness of the shell in the core/shell structure or metallic overlayers on substrates increases. The strain effect on electrocatalytic activity can be well engineered by tuning the thickness of shells or atomic composition. Microstrain, or localized lattice strain, is another type of strain associated with structural defects such as grain boundaries and multi-twinning. In this review, we discuss the origin of the strain effect and how it affects electrocatalytic activity based on the d-band model. We present the structural characterization and quantitative determination of strain. Metal-based nanocrystals are basically grouped into two types of structures to which the strain engineering applies, i.e. lattice strain-associated structures (which include the general core/shell structure and solid solution alloy) and multiple defects-induced structures. Then analysis is performed on the correlation of strain and ligand effects and on the tuning strategies of the strain effect for electrocatalysis. After that, we use representative examples to demonstrate how strain engineering assists in typical electrocatalytic reactions on anodes and cathodes. Finally, we summarize and propose potential research areas in terms of enhancing electrocatalytic activities by strain engineering in the future.

17.
Nano Lett ; 19(5): 2758-2764, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-30958673

RESUMO

Metallic 1T-phase transition metal dichalcogenides (TMDs) are of considerable interest in enhancing catalytic applications due to their abundant active sites and good conductivity. However, the unstable nature of 1T-phase TMDs greatly impedes their practical applications. Herein, we developed a new approach for the synthesis of highly stable 1T-phase Au/Pd-MoS2 nanosheets (NSs) through a metal assembly induced ultrastable phase transition for achieving a very high electrocatalytic activity in the hydrogen evolution reaction. The phase transition was evoked by a novel mechanism of lattice-mismatch-induced strain based on density functional theory (DFT) calculations. Raman spectroscopy and transmission electron microscopy (TEM) were used to confirm the phase transition on experimental grounds. A novel heterostructured 1T MoS2-Au/Pd catalyst was designed and synthesized using this mechanism, and the catalyst exhibited a 0 mV onset potential in the hydrogen evolution reaction under light illumination. Therefore, this method can potentially be used to fabricate 1T-phase TMDs with remarkably enhanced activities for different applications.

18.
Adv Mater ; 31(16): e1808267, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30803063

RESUMO

Metal single-atom materials with their high atom utilization efficiency and unique electronic structures usually show remarkable catalytic performances in many crucial chemical reactions. Herein, a facile and easily scalable "impregnation-carbonization-acidification" strategy for fabricating a class of single-atom-anchored (including cobalt and nickel single atoms) monolith as superior binder-free electrocatalysts for developing high-performance wearable Zn-air batteries is reported. The as-prepared single atoms, supported by N-doped carbon flake arrays grown on carbon nanofibers assembly (M SA@NCF/CNF), demonstrate the dual characteristics of excellent catalytic activity (reversible oxygen overpotential of 0.75 V) and high stability, owing to the greatly improved active sites' accessibility and optimized single-sites/pore-structures correlations. Furthermore, wearable Zn-air battery based on Co SA@NCF/CNF air electrode displays superior stability under deformation, satisfactory energy storage capacity, and good practicality to be utilized as an integrated battery system. Theoretical calculations reveal a mechanism for the promotion of the catalytic performances on single atomic sites by lowering the overall oxygen reduction/evolution reaction barriers comparing to metal cluster co-existing configuration. These findings provide a facile strategy for constructing free-standing single-atom materials as well as the engineering of high-performance binder-free catalytic electrodes.

19.
Adv Mater ; 31(15): e1805833, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30803065

RESUMO

The development of new electrocatalysts with high activity and durability for alcohol oxidation is an emerging need of direct alcohol fuel cells. However, the commonly used Pt-based catalysts still exhibit drawbacks including limited catalytic activity, high overpotential, and severe CO poisoning. Here a general approach is reported for preparing ultrathin PtNiM (M = Rh, Os, and Ir) nanowires (NWs) with excellent anti-CO-poisoning ability and high activity. Owing to their superior nanostructure and optimal electronic interaction, the ultrathin PtNiM NWs show enhanced electrocatalytic performance for both methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). The optimal PtNiRh NWs show mass activity of 1.72 A mg-1 and specific activity of 2.49 mA cm-2 for MOR, which are 3.17 and 2.79 times higher than those of Pt/C. In particular, the onset potentials of PtNiRh NWs for MOR and EOR shift down by about 65 and 85 mV compared with those of Pt/C. Density functional theory calculations further verify their high antipoison properties for MOR and EOR from both an electronic and energetic perspective. Facilitated by the introduction of Rh and Ni, the stable pinning of the Pt 5d band associated with electron-rich and depletion centers solves the dilemma between reactivity and anti-CO poisoning.

20.
ACS Nano ; 13(2): 2167-2175, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30689350

RESUMO

Despite its very high capacity (4200 mAh g-1), the widespread application of the silicon anode is still hampered by severe volume changes (up to 300%) during cycling, which results in electrical contact loss and thus dramatic capacity fading with poor cycle life. To address this challenge, 3D advanced Mxene/Si-based superstructures including MXene matrix, silicon, SiO x layer, and nitrogen-doped carbon (MXene/Si@SiO x@C) in a layer-by-layer manner were rationally designed and fabricated for boosting lithium-ion batteries (LIBs). The MXene/Si@SiO x@C anode takes the advantages of high Li+ ion capacity offered by Si, mechanical stability by the synergistic effect of SiO x, MXene, and N-doped carbon coating, and excellent structural stability by forming a strong Ti-N bond among the layers. Such an interesting superstructure boosts the lithium storage performance (390 mAh g-1 with 99.9% Coulombic efficiency and 76.4% capacity retention after 1000 cycles at 10 C) and effectively suppresses electrode swelling only to 12% with no noticeable fracture or pulverization after long-term cycling. Furthermore, a soft package full LIB with MXene/Si@SiO x@C anode and Li[Ni0.6Co0.2Mn0.2]O2 (NCM622) cathode was demonstrated, which delivers a stable capacity of 171 mAh g-1 at 0.2 C, a promising energy density of 485 Wh kg-1 based on positive active material, as well as good cycling stability for 200 cycles even after bending. The present MXene/Si@SiO x@C becomes among the best Si-based anode materials for LIBs.

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