Ultrafine Nanoparticles Research Articles

Ultrafine CoFe Alloy Nanoparticles Confined in Highly Ordered Mesoporous Carbon Films as Catalysts for the Oxygen Evolution Reaction

Ultrafine CoFe Alloy Nanoparticles Confined in Highly Ordered Mesoporous Carbon Films as Catalysts for the Oxygen Evolution Reaction

Ultrafast complete dechlorination enabled by ferrous oxide/graphene oxide catalytic membranes via nanoconfinement advanced reduction

Chlorinated organic pollutants widely exist in aquatic environments and threaten human health. Catalytic approaches are proposed for their elimination, but sluggish degradation, incomplete dechlorination, and catalyst recovery remain extremely challenging. Here we show efficient dechlorination using ferrous oxide/graphene oxide catalytic membranes with strong nanoconfinement effects. Catalytic membranes are constructed by graphene oxide nanosheets with integrated ultrafine and monodisperse sub-5 nm nanoparticles through simple in-situ growth and filtration assembly. Density function theory simulation reveals that nanoconfinement effects remarkably reduce energy barriers of rate-limiting steps for iron (III)-sulfite complex dissociation to sulfite radicals and dichloroacetic acid degradation to monochloroacetic acid. Combining with nanoconfinement effects of enhancing reactants accessibility to catalysts and increasing catalyst-to-reactant ratios, the membrane achieves ultrafast and complete dechlorination of 180 µg L−1 dichloroacetic acid to chloride, with nearly 100% reduction efficiency within a record-breaking 3.9 ms, accompanied by six to seven orders of magnitude greater first-order rate constant of 51,000 min−1 than current catalysis. Meanwhile, the membranes exhibit quadrupled permeance of 48.6 L m−2 h−1 bar−1 as GO ones, because nanoparticles adjust membrane structure, chemical composition, and interlayer space. Moreover, the membranes show excellent stability over 20 cycles and universality for chlorinated organic pollutants at environmental concentrations.

Unique features of plasmonic absorption in ultrafine metal nanoparticles: unity and rivalry of volumetric compression and spill-out effect

Abstract We present a solution to a longstanding challenge in nanoplasmonics and colloid chemistry: the anomalous optical absorption of noble metal nanoparticles in the ultrafine size range of 2.5–10 nm, characterized by a rapid long-wavelength shift in plasmon resonance as the particle size increases. Our investigation delves into the impact of alterations in electron density along the radial direction of nanoparticles and the resulting variations in dielectric constants on the spectral positioning of the plasmon resonance. We explore the interplay of the spill-out effect, volumetric compression, and their combined impact in different experimental conditions on electron density variation within the particle volume and its blurring at the particle boundary. The latter effectively forms a surface layer with altered dielectric constants and a size-independent extent. As particle size decreases, the influence of the surface layer becomes more pronounced, especially when its extent is comparable to the particle radius. These findings are specific to ultrafine plasmonic nanoparticles and highlight their unique properties.

Asymmetric supercapacitors assembled by hollow N, s co-doped carbon spheres decorated FeOOH and Co3S4 nanoparticles

Exploiting advanced anode and cathode materials with distinctive architectures and multi-component participation is of great significance to boosting the energy density of asymmetric supercapacitors. Herein, ultra-fine FeOOH nanoparticles are in situ grown on the hollow N, S co-doped carbon (HNSC) spheres using a facile solvothermal strategy and subsequent calcination process. Benefiting from the attractive hollow architecture and the synergistic effect between FeOOH and HNSC, the FeOOH/HNSC composite as anode for supercapacitors delivers an optimal capacity of 588.2C g−1 (1 A g−1) and remains 88.3 % of its initial value after 10,000 cycles at 15 A g−1 in 6 M KOH. Furthermore, the HNSC-supported Co3S4 nanoparticles are also prepared through a one-step solvothermal strategy. The obtained Co3S4/HNSC composite as cathode achieves a capacity of 420C g−1 (1 A g−1) and maintains a high retention of 95.3 % after 10,000 cycles at 15 A g−1. The constructed asymmetric supercapacitor using FeOOH/HNSC and Co3S4/HNSC as anode and cathode appears to possess a superior energy density of 82.3 Wh kg−1 at 821.6 W kg−1 with retention of 84.9 % after 10,000 cycles at 10 A g−1. These attainments demonstrate that constructing multi-component electrode materials with unique structures is an effective method to optimize the electrochemical characteristics of asymmetric supercapacitors.

Facile synthesis of ultrafine Co3O4/Al2O3 catalysts for superior peroxymonosulfate activation in rhodamine B degradation

Advanced oxidation processes based on persulfate (PS-AOPs) have emerged as effective strategies for environmental remediation, with cobalt-based oxides serving as prominent catalysts for peroxymonosulfate (PMS) activation. In this study, we developed a highly active Co3O4/Al2O3 catalyst (Co/AA) featuring ultrafine nanoparticles, synthesized via a facile approach using tannic acid (TA) as a coordinating agent and activated alumina as a robust support. Co/AA-0.1, as the representative catalyst, was characterized and exhibited outstanding performance in degrading rhodamine B (RB) via PMS activation. Our findings highlight TA's critical role in reducing Co3O4 nanoparticle size, thereby increasing the availability of active sites. The degradation mechanism was elucidated through reactive oxygen species (ROS) quenching experiments and electron paramagnetic resonance (EPR) analysis, revealing that sulfate radicals (SO4•−) are the dominant ROS. The high activity of Co/AA-0.1 is confirmed by analyzing X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area and O2-temperature programmed desorption data of the samples. We also investigate the effects of various factors, such as anions, reaction temperatures, and PMS dosage, on RB degradation. Higher temperatures for treating the catalyst are found to reduce activity but improve stability. Notably, the catalyst synthesized through EDTA-assisted synthesis showed balanced activity and stability. Furthermore, the versatility of our synthesis method was demonstrated by successfully applying it to other supports, such as SiO2 and TiO2, offering the development of more efficient and stable catalysts for environmental applications.

Mesoporous silica-confined ultrafine ruthenium nanoparticles supported by graphene: Robust catalysts for biphasic oxidation at the oil-water interface

Graphene-supported ultrafine ruthenium nanoparticles covered by mesoporous silica (mSiO2) were synthesized as interfacially active catalysts for biphasic oxidation at the oil-water interface. These mesoporous SiO2 layers serve to confine metal nanoparticles of specific sizes, preventing their sintering even under harsh conditions, which is attributed to the confinement effects within porous materials. Furthermore, Pickering emulsion systems formulated with these amphiphilic catalysts exhibit significantly higher catalytic efficiency compared to conventional organic-aqueous biphasic systems with Ru/rGO and commercial Ru/C catalysts. The catalytic performance is directly influenced by surface wettability, and the catalytic efficiency reveals a parabolic distribution with respect to the content of mSiO2, indicative of the optimal activity over Ru/rGO@mSiO2-100 with a conversion of up to > 92 % and a selectivity to benzaldehyde of up to > 99 % under base-free conditions after 2 h. Moreover, rGO–silica hybrids demonstrate the excellent reusability for over five cycles which benefits from the protective effect of mSiO2.

Laccase‐Copper Nanohybrids as Highly Active Catalysts for Bio‐degradation

AbstractPhenolic contamination is one of the crucial concerns for the safety of drinking water. Enzymatic degradation is a green and efficient manner for phenolic compounds removal from water. However, enzymatic degradation of phenolic pollutants in water is limited as a result of the low activity, stability and reusability of the enzyme. Herein, we propose a novel strategy to degrade phenolic pollutants in water by using an enzyme‐metal hybrid catalyst constructed by in situ formation of ultrafine Cu nanoparticles on the cross‐linked Laccase aggregates. The designed Cu/Lac CLEAs showed excellent performance on phenolic pollutants removal due to the cooperative catalysis between Lac CLEA and Cu NPs and the enrichment of phenolic pollutants in hybrid catalyst. The degradation efficiency of 2,4,6‐trichlorophenol catalyzed by Cu/Lac CLEAs was improved by 33 % compared to the Lac CLEAs, while Cu NPs barely catalyzed the degradation process of phenolic pollutants. The Cu/Lac CLEAs hybrid catalyst exhibit high catalytic activity at room temperature in a wide pH range of 5–8, making the degradation of phenolic pollutants more practically operational. In other words, this study develops a novel hybrid catalyst for the efficient removal of pollutants from water.

Effect of Electric Field on Carbon Encapsulation and Catalytic Activity of Pd for Efficient Formic Acid Decomposition

Utilizing carbon coated ferroelectric materials to introduce polarization‐induced electric field (PIEF) stimulates research of electric field‐assisted catalysts for various reactions. However, effect of PIEF on carbon coating mechanism has not been studied. Herein, tourmaline nanoparticles (TNPs) with spontaneous dipole moments were applied as the PIEF supplier and sucrose was utilized as the carbon precursor to synthesize carbon coated TNPs (TNP@SC) to uncover the influence of PIEF on the carbon coating and catalytic activity of Pd toward formic acid decomposition (FAD). PIEF enhanced the adsorption capacity of TNPs for the caramelized intermediate species and increased H+ concentration by facilitating water ionization. Polymerization of adsorbed caramelized intermediate species on TNPs was accelerated. Uniformly coated carbon layer with more defects, larger specific surface area, and higher porosity was coated on TNP. Such surface properties of the carbon layer were beneficial for strongly anchoring ultrafine Pd nanoparticles. Owing to the specific properties of carbon layer and existence of PIEF, Pd/TNP@SC exhibited higher FAD activity than the catalysts absent of PIEF. Stronger PIEF leaded to higher initial turnover frequency. This study provides guidance to supply electric field for catalysis.

Metal-organic framework-derived in situ-grown Cu2Sb@NC octahedra for high-performance stable lithium/sodium storage

Intermetallic compounds are considered a special class of alloy-type anode materials that show great potential for use in lithium/sodium-ion batteries due to their inherent advantages, such as high specific capacity and enhanced safety features. However, their practical application is often impeded by the substantial volume changes that occur during the insertion and extraction of Li+/Na+ ions, leading to capacity decay and reduced service life. To address this challenge, we developed a novel composite material comprising Cu2Sb nanoparticles encapsulated within a N-doped octahedral carbon matrix (Cu2Sb@N-C). This composite structure features a heteroatom-doped conductive network, a three-dimensional carbon framework, and finely dispersed Cu2Sb nanoparticles. Benefiting from the heteroatom-doped conductive network, three-dimensional carbon framework and ultrafine Cu2Sb nanoparticles, they not only provide a penetrating network for the fast transfer of charge carriers and improve the accessibility of ions, but also alleviate the agglomeration and volume expansion of Cu2Sb during cycling. For LIBs, the material exhibited a reversible capacity of 1001.0 mAh/g after 330 cycles at 0.2 A/g, while maintaining a substantial capacity of 565.5 mAh/g after 1000 cycles at 1.0 A/g. In the case of SIBs, the material exhibited a capacity of 375.6 mAh/g after 100 cycles at 0.2 A/g. Post-cycling electrode analyses revealed that the Cu2Sb@N-C anode material retained its structural integrity, demonstrating its ability to withstand the continuous insertion and extraction of Li+/Na+ ions. This research contributes insights into the effective design of innovative high-capacity alloy-based anode materials for advanced secondary batteries.

Oxygen Vacancy-Mediated Synthesis of Inter-Atomically Ordered Ultrafine Pt-Alloy Nanoparticles for Enhanced Fuel Cell Performance.

Pt-based intermetallics are expected to be the highly active catalysts for oxygen reduction reaction (ORR) in proton-exchange membrane fuel cells but still face great challenges in controllable synthesis of interatomically ordered and ultrafine intermetallic nanoparticles. Here, we propose an oxygen vacancy-mediated atomic diffusion strategy by mechanical alloying to reduce the energy barrier of the transition from interatomic disordering to ordering, and to resist interparticulate sintering via strong M-O-C bonding. This synthesis results in a nanosized core/shell structure featuring an interatomically ordered PtM core and a Pt shell of two to three atomic layers in thickness and can be extended to the multicomponent PtM (M = Co, FeCo, FeCoNi, FeCoNiGa) systems. The electron enrichment in the Pt outer shell induced by the compressive strain leads to the enhanced antibonding orbital occupation below the Fermi level and accelerated OH* desorption kinetics. The optimized PtCo-O/C-6 catalyst presents excellent ORR activity (mass activity = 1.28 A mgPt-1 at 0.9 ViR-free, peak power densities = 2.38/1.25 W cm-2 in H2-O2/-air) and durability (∼1% activity loss in over 50 h in air condition) in fuel cells at a total Pt loading of 0.1 mgPt cm-2. Furthermore, we establish a systematic correlation to elucidate the formation mechanisms of highly ordered intermetallic catalysts underlying oxygen vacancies. This study provides a general approach for the large-scale production of highly ordered and nanosized Pt-dispersed intermetallic catalysts.

Immobilization of Metal Nanoparticles to an Ultrathin Two-Dimensional Conjugated Metal-Organic Framework for Synergistic Electrocatalysis.

Metal-organic frameworks (MOFs) have been considered as promising hosts for immobilizing ultrafine metal nanoparticles (MNPs) due to their high surface area and porosity. However, electrochemical applications of such emerging composites are severely limited by the poor electrical conductivity and large size of the MOFs. Herein, we report the general synthesis of incorporating various MNPs into a conjugated MOF ultrathin nanosheet (Cu-TCPP UNS) matrix, which not only prevents agglomeration and restricts the growth of MNPs but also benefits the exposure of active sites and the transport of electrons. Specifically, the obtained PtCu@Cu-TCPP UNSs exhibited nearly two times higher mass activity for the methanol oxidation reaction (MOR) than the commercial Pt/C catalyst. Mechanistic studies reveal that the strong interaction between MNPs and Cu-TCPP promotes the oxidation of the CO intermediate. Moreover, the PtCu@Cu-TCPP UNSs can be employed as bifunctional electrocatalysts to couple MOR with the hydrogen evolution reaction for highly efficient hydrogen production.

Perspective on using non-human primates in Exposome research

The physiological and pathological changes in the human body caused by environmental pressures are collectively referred to as the Exposome. Human society is facing escalating environmental pollution, leading to a rising prevalence of associated diseases, including respiratory diseases, cardiovascular diseases, neurological disorders, reproductive development disorders, among others. Vulnerable populations to the pathogenic effects of environmental pollution include those in the prenatal, infancy, and elderly stages of life. Conducting Exposome mechanistic research and proposing effective health interventions are urgent in addressing the current severe environmental pollution. In this review, we address the core issues and bottlenecks faced by current Exposome research, specifically focusing on the most toxic ultrafine nanoparticles. We summarize multiple research models being used in Exposome research. Especially, we discuss the limitations of rodent animal models in mimicking human physiopathological phenotypes, and prospect advantages and necessity of non-human primates in Exposome research based on their evolutionary relatedness, anatomical and physiological similarities to human. Finally, we declare the initiation of NHPE (Non-Human Primate Exposome) project for conducting Exposome research using non-human primates and provide insights into its feasibility and key areas of focus. SynopsisNon-human primate models hold unique advantages in human Exposome research.

Boosting selectivity for multi-carbon products in electrochemical CO2 reduction via enhanced hydroxide adsorption in ultrafine CuOx/CeOx nanoparticles

The electricity-driven reduction of CO2 presents a unique prospect of mitigating atmospheric CO2 levels and converting renewable energy into chemical fuels. However, the lack of an efficient catalyst that can transform CO2 into desired products with appreciable selectivity at commercially relevant current densities (ID) impedes the practical implications of this technology. This work describes a scalable approach for producing ultrafine nanoparticles of CuOx-CeOx (CuCe) composites via rapid coprecipitation under oxygen-deprived conditions. In this process, Ce(OH)3 acts as a reducing agent converting Cu(OH)2 into ultrafine Cu2O nanoparticles. Thus, the Ce: Cu ratio in composite effectively controls the particle size and bulk structural fixture of the CuCe composites. Despite having lower ECSA, The CuCe composites exhibit superior catalytic performance compared to CuO, with significantly higher selectivity for ethanol production and lower selectivity for CO and H2. The Cu1.5Ce prepared using a Cu: Ce ratio of 1.5:1, demonstrated remarkable catalytic activity with Faradaic efficiencies (F. E.) of 34.2 % for ethanol, 44.1 % for ethylene, and 81.08 % for multi-carbon (C2+) products. Moreover, while operating at the ID of 500 mA cm−2, Cu1.5Ce achieves a single pass CO2 conversion (SPCC) of 19.9 %, and a half-cell energy efficiency (E. E. half-cell) of 31.5 % for the C2+ products. It produces the C2+ products at the partial current density (pID) of 405.4 mA cm−2. The superior performance of Cu1.5Ce can be attributed to the improved hydroxide adsorption and partial retention of oxidized copper species under cathodic bias.

Tailoring of Ultrasmall NiMnO3 Nanoparticles: Optimizing Synthesis Conditions and Solvent Effects

Nickel manganese oxide (NiMnO3) combines magnetic and dielectric properties, making it a promising material for sensor and supercapacitor applications, as well as for catalytic water splitting. The efficiency of its utilization is notably influenced by particle size. In this study, we investigate the influence of thermal treatment parameters on the phase composition of products from alkali co-precipitation of nickel and manganese (II) ions and identify optimal conditions for synthesizing phase-pure nickel manganese oxide. Ultrafine nanoparticles of NiMnO3 (with sizes as small as 2 nm) are obtained via liquid-phase ultrasonic dispersion, exhibiting a narrow size distribution. A systematic exploration of the solvent nature (water, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide) on the efficiency of ultrasonic dispersion of NiMnO3 nanoparticles is provided. It is demonstrated that particle size is influenced not only by absorbed acoustic power, dependent on the physical properties of the used solvent (boiling temperature, gas solubility, viscosity, density) but also by the chemical stability of the solvent under prolonged ultrasonic treatment. Our findings provide insights for designing ultrasonic treatment protocols for nanoparticle dispersions with tailored particle sizes.

Boost Electrocatalytic Activity of La0.6Sr0.4Co0.2Fe0.8O3-δ Air Electrode Prepared by High-Temperature Shock for Solid Oxide Electrochemical Cells.

High-temperature shock (HTS) is an emerging material synthesis technology with advantages, such as rapid processing, low energy consumption, and high controllability. This technology can prepare ultrafine nanoparticles with uniform particle size distribution and introduce additional oxygen vacancies, offering significant potential for the preparation of key materials for solid oxide electrochemical cells (SOCs). In this study, the La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) air electrode was successfully prepared using HTS technology. Compared to the conventional muffle furnace calcination, the HTS-prepared LSCF exhibits a larger specific surface area and a higher oxygen vacancy concentration, and it demonstrates significant improvements in performance. The oxygen ion conducting SOC (O-SOC) with the HTS-LSCF air electrode achieved a peak power density (PPD) of 960 mW cm-2 and a current density of 0.38 A cm-2 (at 1.3 V) at 700 °C. Meanwhile, the proton conducting SOC (P-SOC) with HTS-LSCF air electrode reached a PPD value of 1.34 W cm-2 and a current density of 3.43 A cm-2 (at 1.3 V) at 700 °C. Additionally, the P-SOC with HTS-LSCF air electrode showed no significant degradation during over 200 h of long-term testing, reflecting the excellent stability of HTS-LSCF. This work provides a fast, efficient, and economical approach for synthesizing high-performance, high-stability SOC air electrode materials.

Ultrafine Pd nanoparticles confined in naphthalene-based covalent triazine frameworks for efficient and stable hydrogen production from formic acid

Formic acid (FA) is considered as a kind of promising hydrogen storage materials due to its economic feasibility, safety, stability and high hydrogen density. Nevertheless, it is a challenge to design a high-performance catalyst with high activity, selectivity and stability for the dehydrogenation of FA to generate hydrogen (H2). Herein, a range of covalent triazine frameworks (CTFs including 1,8-CTF, 1,5-CTF and 2,3-CTF) with abundant nitrogen atoms are developed to support palladium nanoparticles for efficiently catalyzing FA dehydrogenation. Ultrasmall palladium nanoparticles with a size of 1.2 ± 0.3 nm showed near 100 % H2 selectivity and high catalytic activity in FA dehydrogenation supported by 1,8-CTF. The activation energy of FA dehydrogenation catalyzed by Pd/1,8-CTF reaches 26.17 kJ·mol−1. In addition, Pd/1,8-CTF exhibits high stability and easy recyclability, and the catalytic activity is maintained even after 6 cycles. This work gives a feasible strategy to develop high-efficiency and selective nanocatalysts for H2 production from FA dehydrogenation.

Dual optimization strategy assisted m-phenylenediamine-based hypercrosslinked polymer loaded ultrafine bimetallic nanoparticles for efficient formic acid dehydrogenation

Heterogeneous catalysts based on Pd play a vital role in enabling efficient formic acid decomposition (FAD). Nevertheless, the performance of Pd-based catalysts is constrained by inherent challenges, such as Pd particles’ tendency to aggregate and possess localized electronic structures. Therefore, there is an urgent need to develop an effective strategy to simultaneously overcome these challenges. In response to this, we synthesized knitting hypercrosslinked polymers (HCPs) using m-phenylenediamine (MPD) as the aromatic monomer. A dual-optimization approach was proposed, aiming to mitigate the adverse effects of excessive coordination and maximize the involvement of residual Fe3+ in the bimetallic synergistic effect. Experimental findings, DFT calculations, and ab initio molecular dynamics simulations (AIMDs) collectively suggest that reducing the coordination effect leads to enhanced nitrogen exposure in the HCPs, consequently reducing the size of Pd species. Furthermore, the incorporation of residual Fe3+ into Pd forms Pd-Fe bimetallic species, which then adjusts the catalytic reaction barrier and enhances catalytic activity. Notably, the optimized Pd@MHCP-2 catalyst exhibited exceptional performance in the FAD reaction at 323 K, achieving a remarkable turnover frequency (TOF) value of 1486 h−1. This research introduces a novel perspective for the design and development of next-generation Pd-based catalysts.

Ultrafine Fe-Mn bimetallic nanoparticles anchored in nitrogen-doped carbon nanofiber electro-Fenton membrane with strong metal-support interactions for sustainable water decontamination in wide pH ranges

Designing a membrane electrode with high activity and anti-scaling ability in a wide pH range is crucial to the development of flow-through electro-Fenton system. Herein, we reported a novel porous membrane composed of ultrafine FeMn bimetallic nanoparticles anchored in nitrogen-doped carbon nanofibers (FeMn/N-CNF) obtained through a facile electrospinning-carbonization process. The strong metal-support interaction (SMSI) phenomena including carbon encapsulation structure and electron transfer from metal to N-CNF, beneficial to the intrinsic activities, were successfully induced by the enhanced interfacial metal-nitrogen bonding in FeMn/N-CNF. Microstructural characterizations and leaching test revealed that the SMSI encapsulation structure could promote the formation of ultrafine FeMn nanoparticles in N-CNF during the high-temperature carbonization process and prevent leaching of active Fe/Mn metals into solution across a wide pH range. The constructed gravity-driven flow-through electro-Fenton system based on a FeMn/N-CNF cathode membrane exhibited superior performance to generate H2O2 (36.23 mmol L−1 h−1) and subsequent activate H2O2 decomposition to hydroxyl radicals (0.1024 min−1), achieving remarkable degradation efficiencies of 96.8%, 92.3%, and 90.3% within 60 min for Rhodamine B, Tetracycline, and Methyl Orange, respectively. Furthermore, the FeMn/N-CNF membrane filter demonstrated good pH adaptability, excellent cycle stability and anti-scaling ability during the degradation process. This work offers a viable avenue to enhance degradation performance and environmental robustness for practical water decontamination via achieving SMSI effect in carbon-supported electro-Fenton membranes.

Interface engineering-induced enhancements in sodium-ion batteries: A nexus of ZnS nanoparticles and reduced graphene oxide for augmented storage and conductivity

Due to the inherent sluggish kinetics and the pronounced volumetric expansion of zinc sulfide (ZnS), it has become a prevalent modification strategy to regulate its morphology and composite with graphene for using ZnS as anodes in sodium-ion batteries (SIBs). Nevertheless, the elucidation of mechanisms underpinning the electrochemical performance facilitated by graphene incorporation remains scant. To further describe the synergistic mechanism, the ultrafine ZnS nanoparticles anchored on reduced graphene oxide (rGO) were synthesized through a simple solvothermal method. Research shows that the ZSG (ZnS nanoparticles-reduced graphene oxide composite) electrode suggests superior rate capability, maintaining a reversible specific capacity of 228.6 mAh·g−1 upon returning from a high current density of 5 A·g−1. Furthermore, the nanoscale integration of ZnS particles with rGO synergistically mitigates the structural expansion of the ZSG electrode encountered during cycling, thereby decelerating the degradation of cyclic performance. Insights gleaned from first-principles calculations and comprehensive electrochemical evaluations reveal that the built-in electric field, engendered within the composite architecture, substantially augments charge transfer ability and mitigates the energy barriers impeding sodium ion (Na+) diffusion accordingly. Consequently, the methodology adopted for synthesis and the synergistic modification mechanism can proffer a reference for the design of advanced anode materials in SIBs.

Architecturing ultra-stable multi-dimensional MXene/MAX self-supporting electrode anchored with Low-Pt for efficient hydrogen evolution reaction in harsh environments

The design of self-supporting structure is particularly important to improve the stability and electrochemical performance of hydrogen evolution reaction electrode. Here, a facile strategy for building novel ultra-stable 0D-2D-3D integrated self-supporting electrode with high conductivity, sufficient diffusion channels and large reactive surface area was proposed. In the heterostructure, 2D Ti3C2Tx flakes in-situ synthesized on 3D network porous Ti3AlC2 surface which provides the multiple reactive surface areas and aggregation resistance to facilitating 0D ultrafine Pt nanoparticles uniform anchorage. Combined with structural characterization and first-principles calculations revealed that, the highly dispersed ultrafine Pt synergistically coupling strong metal-support interactions creates a unique multifunctional catalytic interface with high stability and atomic utilization efficiency of Pt to promote the HER in acidic and seawater. The resultant self-supporting electrode (support 0.48 wt% Pt) exhibits much superior activity to 10 % commercial Pt/C (loaded on foam nickel) in 0.5 M H2SO4 (55 mV@10 mA cm−2) and simulate seawater (196 mV@10 mA cm−2) while reducing the Pt usage by 15 times. Meanwhile, the electrode also illustrates outstanding stability under high current densities (100 h@100 mA cm−2). This study provides a new design idea for developing integrated self-supporting catalytic electrodes to meet the durability of hydrogen evolution reaction applications in harsh environments.