Generalized Gradient Approximation Made Simple

Improving 5-halouracils SERS detection driven by Watson & Crick pairing recognition. A spectroscopic & DFT study

The halogenated C5-substituted uracil derivatives (5-fluor-, 5-chloro, and 5-bromouracil) have drawn attention recently due to their pharmacological uses, properties, and importance as biomarkers and water pollutants. From an analytical point of view, these species are expected to be at very low levels in biological and environmental samples, and the development of methodologies for their determination is a central goal in research. The Raman technique and one of its special effects, Surface-Enhanced Raman Scattering (SERS), is a very suitable approach for detecting and quantifying these compounds. In practice, enhancing Raman scattering requires a nanostructured noble metal surface with the species of interest attached to it. Still, to maximize the effect, a deeper comprehension of the nature of the analyte-metal surface interaction is desirable. The structural information SERS spectra provide can be complemented by theoretical approaches, such as the Density Functional Theory (DFT) calculations. This work studied three 5-halouracils attached to silver nanoparticles (AgNPs) from experimental and theoretical perspectives. The observed patterns in the spectroscopic behavior showed a trend related to the electronegativity at the halogenated moieties, suggesting their direct influence in enhancing CC and CO stretching modes. Then, the formation of base pairs with adenine through hydrogen bonding was studied as a strategy to improve the detectability through SERS, supported by the well-known high affinity of adenine towards metal nanoparticles. We show that adenine favors the orientation of the 5-halouracils, reaching an additional signal enhancement that is very useful for analytical purposes, as demonstrated for 5-FU, reaching a limit of detection (LOD) of 2.36 nmol L-1. Wavenumber shifts and intensification of NH modes observed in the SERS spectra, along with DFT calculations, strongly suggest that forming hydrogen bonding (NH----N) upon the interaction of the base pairs with an Ag20 cluster is key for improving the halouracils LOD through SERS.

CO2 capture performance of ZrO2-doped Na2CO3/γ-Al2O3 adsorbent

Sodium-based adsorbents (Na2CO3/γ-Al2O3) exhibit significant potential for commercial utilization in CO2 capture. Nevertheless, the requirement for high desorption temperatures poses challenges in terms of the high-quality heat needed for desorption. This study integrated ZrO2 doping into a sodium-based adsorbent to enhance its CO2 capture performance and lower its desorption temperature. The research investigated the CO2 adsorption capacity, reaction rate, and desorption characteristics of the ZrO2-doped Na2CO3/γ-Al2O3 adsorbents in detail. Additionally, the catalytic mechanism of ZrO2 was elucidated through Density Functional Theory calculations. The results showed that ZrO2 doping increased the adsorption rate and capacity of the adsorbent and reduced the desorption energy consumption. Desorption reaction activation energy reduced to 44.8 kJ/mol. The adsorbent doped with 3 wt.% ZrO2 demonstrated the highest adsorption capacity and rate under optimal conditions, with a reaction temperature of 45 ℃, an adsorption capacity of 1.66 mmol/g, and a carbon conversion rate of 80.2 %. ZrO2 acted as a catalyst, enhancing CO2 and H2O adsorption, and facilitated CO2 desorption in the sodium-based adsorbent by forming [ZrO(OH)]+ and OH- through H2O adsorption activation. The lower energy barrier (0.17 eV) for the dissociative adsorption pathway of H2O molecules on the ZrO2 surface further supported the role of ZrO2 in enhancing the overall adsorption performance of the adsorbent in the carbon capture process. Ultimately, the ZrO2-doped Na2CO3/γ-Al2O3 adsorbent was identified as having low desorption energy consumption, high adsorption capacity, and rate, offering potential cost reductions in CO2 capture and representing a promising adsorbent for this application.

Nickel atoms of nickel foam simultaneously mediated charge redistribution and firm immobilization of zinc oxide for safe and efficient photocatalytic nitrogen oxide removal

Photocatalytic technology has emerged as a promising solution for air purification of ppb-level nitrogen oxides (NOx), but potential risk of secondary pollution should not be overlooked, which could be triggered by the production of toxic intermediate and the potential release of airborne catalyst particles during reaction processes. Herein, nickel foam (NF) has been introduced as not only carrier material but also performance promoter for zinc oxide (ZnO). The NF supported ZnO sample (Ni-ZnO/NF) demonstrates multifunctional superiority: 66.4 % nitric oxide (NO) removal efficiency, <1.7 % nitrogen dioxide (NO2) byproduct generation, and ultralow photocatalyst loss (<1.2 % mass). Mechanistic investigations combining experimental characterization and theoretical simulations reveal atomic substitution processes where NF-derived Ni atoms replace Zn sites in the ZnO lattice, forming stable Ni-O interfacial bonds, which contributes to enhance interaction between ZnO and NF for firm immobilization and form electron localization zones around Ni-O bond for reactants activation and reactive oxygen species formation. The optimized reaction pathway (NO + e- → NO-, NO- + 1O2 → NO3-) ensures complete oxidation while suppressing hazardous intermediates. This work blueprints next-generation supported photocatalysts through atomic-level interface engineering, advancing practical application of photocatalytic technology for sustainable air purification.

Structure modification of P2-Na0.67Ni0.15Fe0.2Mn0.65O2 cathode by incorporation of cerium for high-performance sodium-ion batteries

The P2-type transition metal oxides hold promise for the cathode of sodium-ion batteries (SIBs). However, the prevailing irreversible phase transition and Jahn-Teller effects of this kind of metal oxides lead to low capacity and poor cycling stability of SIBs. To address these challenges, in this study, the rare-earth metal element cerium (Ce) is successfully introduced into P2-Na0.67Ni0.15Fe0.2Mn0.65O2 (NFM), achieving a synergistic bulk doping and surface modification for NFM. Upon incorporating larger Ce3+ into the lattice, the interlayer spacing of P2- NFM is increased, facilitating the diffusion of Na+. The substitution of Ce for Mn sites suppresses the Jahn-Teller effect caused by Mn3+ in P2-NFM. The concurrently formed CeO2 on the surface effectively inhibits the corrosion and degradation of P2-NFM by the electrolyte. Benefitting from the dual-modification, P2-Na0.67Ni0.15Fe0.2Mn0.61Ce0.04O2 (NFMC-0.04) exhibits an increased discharge capacity of 171.6 mAh g-1 at 0.1C as compared to that of NFM (142.9 mAh g-1), and a higher capacity retention of 57.40 % after 200 cycles than that of NFM (37.97 %). Impressively, it can deliver a capacity retention of 58.41 % after 250 cycles at 1C, while the discharge capacity of un-modified NFM is close to zero. In-situ XRD analysis reveals that the successful doping of Ce into the bulk phase of NFM suppresses the structural distortion of NFM from P2 to OP4 phase. Density Functional Theory calculations disclose that the substitution of Mn sites by Ce elements is energetically most favorable in NFM. Ce doping not only improves the electronic conductivity of NFM by enhancing the degree of electron localization, but also suppresses the Jahn-Teller effect by modulating the electronic structure of Mn. This study provides a new approach for engineering of layered transition metal oxides toward the high-performance cathode of SIBs.

Synergistic optimization of charge carrier separation and transfer in ZnO through crystal facet engineering and piezoelectric effect

Rational regulation of photogenerated charge carrier separation and transfer is a key strategy for optimizing photocatalytic activity. Leveraging the synergistic effects of crystal facet engineering and the piezoelectric effect, a series of hexagonal Zinc oxide (ZnO) photocatalysts with varying exposure ratios of the {002} and {210} facets were successfully synthesized and employed under simultaneous excitation by simulated sunlight and ultrasound. As expected, compared to amorphous ZnO, the hexagonal ZnO samples demonstrated a significant enhancement in piezo-photocatalytic tetracycline hydrochloride degradation and polyethylene terephthalate reforming processes. In-depth investigations confirm that the pronounced piezo-photocatalytic performance of the hexagonal ZnO samples is attributed to the synergistic effect of the built-in electric field formed at the facet junctions and the polarization electric field generated by the piezoelectric effect, both of which significantly influence charge separation and carrier mobility. These findings offer new strategies for improving catalytic efficiency and advancing sustainable technologies through photocatalysis.

Engineering multifunctional high-entropy oxide nanozymes for robust marine antifouling

High-performance interfacial antifouling coatings are crucial for sustainable marine resource utilization. This work reports a novel high-entropy oxide (HEO) nanozyme, CrMnFeNiCuOX nanoparticles, where the synergistic interplay of polymetallic cations and defect engineering yield remarkable multi-enzyme mimetic activity combined with a photothermal conversion efficiency of 40.06%. Under simulated solar irradiation, the HEO nanozyme exhibited complete (100%) bactericidal activity against both Escherichia coli and Staphylococcus aureus, and effectively suppresses biofilm formation in a simulated marine environment. Mechanistic investigations demonstrated that the HEO nanozyme exhibits a tailored electronic structure and adsorption properties, enabling disruption of bacterial membrane integrity, perturbation of intracellular redox homeostasis, and suppression of quorum sensing signaling. This multifaceted approach offers a promising strategy for developing durable and environmentally friendly antifouling coatings for diverse marine applications.

Cation vacancy modified bismuth selenide nanosheets toward durable and ultrafast sodium-ion batteries

High-performance metal chalcogenide anodes based on conversion and alloy reaction are promising for the next generation of sodium-ion batteries (SIBs) due to their high theoretical capacity. However, the intrinsic limitations of metal chalcogenides, including inadequate electrical conductivity and suboptimal ion diffusion kinetics, impede high-rate performance and large-scale applicability. Herein, a two-dimensional ultrathin Cu heteroatom-doped Bi2Se3 nanosheet with cation vacancies (denoted as DBS) has been developed as an anode for SIBs, exhibiting high capacity and superior rate performance. The electrical conductivity of DBS is enhanced by the contribution of surface topological states and the regulation of electronic structure due to structural defects. Furthermore, the modified crystal structure demonstrates improved ion transport capabilities, elevated Na+ adsorption energy, and a greater number of adsorption sites, as substantiated by density functional theory (DFT) calculations. Consequently, the DBS electrode exhibits reduced polarization potential, fast capacitive charge storage and a more comprehensive conversion-alloy reaction, thereby achieving a high specific capacity (528 mA h g-1 at 0.2 A g-1), large rate performance (383 mA h g-1 at 10 A g-1), and long cycling stability. This superior performance enhances the appealing electrochemical properties of both coin and pouch-type DBS//Na3V2(PO4)3@C full cells.

Nanoscale palladium-Mo6S8/carbon nanowires toward efficient electrochemical hydrogen evolution and hydrogen peroxide detection

Chevrel phase (CP) molybdenum sulfides (Mo6S8) have attracted extensive research attention in the field of energy conversion and storage due to their unique electronic structures and rich open channels. However, comprehensive understanding of intrinsic kinetic mechanisms governing the electrocatalytic bi-functional hydrogen evolution reaction (HER) and hydrogen peroxide (H2O2) sensing on CP-based composites is still lacking. Herein, nanosized palladium (Pd) and Mo6S8 particles were assembled in carbon nanowires (C NWs) via electrospinning followed by pyrolysis. The as-obtained novel Pd-Mo6S8/C NWs exhibited excellent performance in terms of a low overpotential of -194 mV at η10 for HER, and an ultrahigh sensitivity of 2231 μA mM-1 cm-2 with a limit of detection of 25 nM for H2O2 sensing. The experimental and theoretical findings demonstrated that Pd and Mo6S8 nanoparticles (NPs) exhibited exceptional catalytic activity and strong electronic interactions. The synergistic effects of these two components could effectively modulate the binding strength of reactants and intermediates on the catalyst surface, ultimately leading to improved electrochemical catalytic performance toward reduction of small molecules. Moreover, verification of the stable tolerance in various environments and good selectivity of the electrocatalyst promoted the further use of Pd-Mo6S8/C NWs-based electrochemical sensing system for sensing additional H2O2 in milk samples, proving the widespread potential of this material for practical applications. This study significantly advances the understanding of nanoscale and bi-functional CP-based composites.

Construction of an SnS-based heterostructure catalyst for electrochemical CO2 reduction to formate over a wide potential window

SnS has emerged as an attractive catalyst for the electrochemical CO2 reduction reaction (CO2RR) to formate, while its long-term operational stability is hindered by the self-reduction of Sn2+ and sulfur dissolution. Thus, maintaining high current efficiency across a wide negative potential range to achieve high production rates of formate remains a significant challenge. In this study, we present a heterostructure constructed with SnS and CuS for efficient CO2RR to formate. The SnS-CuS (30) exhibits a remarkable formate Faradaic efficiency (FEf) of 93.94 % at -1 V vs. reversible hydrogen electrode (RHE) and demonstrates long-term stability for 7.5 h, maintaining high activity (with an average FEf of 85.6 %) across a wide negative potential range (from -0.8 to -1.2 V (vs. RHE)). The results reveal that the heterogeneous interface between SnS and CuS mitigates the self-reduction issue of SnS by sacrificing Cu²⁺, highlighting that the true active species is SnS, which effectively resists structural changes during the electrolysis process under the protection of CuS. The synergistic interaction within the CuS and SnS heterostructure, combined with the tendency for electron self-conduction, enables the catalyst to maintain high formate activity and selectivity across a wide potential range. Furthermore, theoretical results further indicate that the incorporation of CuS enhances CO2 adsorption and lowers the energy barrier for the formation of formate intermediates. This study inspires the concept of applying protective layers to active species, promoting high selectivity in Sn-based electrocatalysts.

Enhancement of carbon monoxide catalytic oxidation performance by co-doping silver and cerium in three-dimensionally ordered macroporous Co-based catalyst

Carbon monoxide (CO) catalytic oxidation offers an effective solution for environmental pollutant; however, its progress is limited by sluggish kinetics, and efficient catalysts remain scarce. Herein, we prepared Ag-Ce co-doped three-dimensionally ordered macroporous (3DOM) Co-based catalysts through the synergistic approach of co-doping and morphology control, systematically investigating their CO catalytic oxidation mechanisms. The appropriate amount of Ag-Ce co-doping maintained the original 3DOM structure, promote the mass transfer and diffusion of CO, promoted the redox capacity by increasing the ratio of Co3+ to surface reactive oxygen species (O-/ O2-), achieving low temperature conversion of CO. Specifically, concentration of Co3+ is promoted via Co2+ + Ag+ → Ag0 + Co3+ and then combining the generated the active oxygen specie reduce the CO conversion temperature (Co3+ + O-/ O2- + CO → CO2 + Co2+). Among them 3D-5 %AgCo16Ce1 exhibited a lower activation energy (Ea) and T50, which were only 48.79 KJ mol-1 and 76.8 °C, respectively. Theoretical calculation indicated that the synergistic of co-doped system can lower down the O2 dissociation energy barrier by 0.242 eV compared with 3D-Co16Ce1, thus facilizing the generation of active oxygen species and improving the oxidation kinetic of CO. This work innovated the preparation method of 3DOM co-doped system and provided opportunities to design high-performance heterogeneous catalysts.

Metal effect boosts the photoelectric properties of two-dimentional Dion-Jacobson (3AMPY)(MA)3M4I13 perovskites

Two-Dimentional (2D) Dion-Jacobson (DJ) perovskites are emerging photovoltaic materials due to their excellent rigid structures and improved environmental stability compared to 2D Ruddlesden-Popper (RP) perovskites. Herein, we adopt 3-(aminomethyl)pyridine (3AMPY) as the divalent interlayer spacer to alleviate the toxicity of lead and explore more highly potential DJ alternatives, the optoelectronic and photovoltaic performance of lead-free DJ (3AMPY)(MA)3M4I13 perovskites are investigated by first-principles calculations, where the central metals are considered as Ba, Cd, Cu, Ge, Mg, Mn, Ni, Sn and Zn to replace Pb. Our findings reveal that introducing Mn, Cd, Ni, and Ge can effectively tune the bandgap within the optimal range of 0.90-1.60 eV for solar cell application. Notably, (3AMPY)(MA)3Ni4I13 exhibits the most favorable optical response capacity, with the light-harvesting efficiency maintaining 80 % in the UV-Vis range. (3AMPY)(MA)3Ge4I13 displays the most excellent carrier transport with electron mobility as high as 555.43 cm2 V-1 s-1, exhibiting a great advantage over 2D perovskites. The predicted photovoltaic performance shows that (3AMPY)(MA)3Mg4I13 possesses the largest open circuit voltage (VOC) (2.12 V), (3AMPY)(MA)3Ge4I13 has the highest short circuit current density (Jsc) (38.90 mA/cm2), and (3AMPY)(MA)3Mn4I13 is with the highest power conversion efficiency (PCE) of 22.55 %. The metal substitutions with Cd, Ni, and Ge show promoted photovoltaic potential over (3AMPY)(MA)3Pb4I13. These results form a basis for broadening the potential candidates of this 2D DJ series in photovoltaic perovskite solar cells (PSCs).

Multifunctional role of gallium-doping in O3-type layered-oxide cathodes for sodium-ion batteries: Enhancing bulk-to-surface stability

Charging O3-type layered-oxide cathodes to a high cutoff voltage of 4.3 V (vs. Na+/Na) can enhance the energy density of sodium-ion batteries (SIBs). However, the irreversible oxygen redox reaction at high voltages often leads accelerated capacity degradation. Herein, a series of Ga3+-doped O3-type Na0.9Zn0.07Ni0.38-0.5xGaxMn0.45-0.5xTi0.1O2 cathode materials are prepared, and the impact of Ga3+ doping on their bulk/interface properties and electrochemical performance is systematically examined. Ga3+ incorporation enhances the structural ordering of the layered framework and widens Na+ transport pathways, thereby reducing Na+ transport barrier. The Ga3+-doped material demonstrates superior structural reversibility and mechanical stability compared to the pristine counterpart during cycling. As evidenced by the density functional theory calculations, Ga3+ doping modulates the O 2p state near the Fermi level, mitigating the charge compensation mechanism of lattice oxygen, oxygen vacancy formation, and electrolyte decomposition at high voltages. Consequently, within the voltage range of 2.2-4.3 V, Na0.9Zn0.07Ni0.35Ga0.06Mn0.42Ti0.1O2 exhibits a higher capacity retention after 100 cycles at 100 mA g-1 (86.4 % vs. 68.1 %) and better rate capability at 2000 mA g-1 (94.1 mAh g-1 vs. 80.0 mAh g-1) than Na0.9Zn0.07Ni0.38Mn0.45Ti0.1O2. This work provides valuable insights into the role of Ga3+ in high-voltage O3-type layered oxides and offers guidance for the design of high-entropy cathode materials for SIBs.

Phase-engineered CoP-Co2P/coal-based carbon fibers composite as self-supporting electrocatalyst for efficient overall water splitting

The development of highly efficient electrocatalysts is critical to advancing overall water splitting (OWS). Herein, a self-supporting composite electrocatalyst based on CoP-Co2P/coal-based carbon fibers (CoP-Co2P/C-CFs) is successfully fabricated through phase-engineering. The formation mechanism of precursors is investigated, enabling precise modification of CoP and Co2P composite phases. This phase-engineering minimizes the Gibbs free energy of hydrogen adsorption, thereby enhancing OWS performance. In addition, the specific active sites involved in the OWS reaction are examined to confirm the effectiveness of phase modulation on CoP and Co2P. Furthermore, C-CFs derived from coal exhibit self-supporting properties as well as good acid and alkaline resistances, making them a promising potential candidate for OWS. A two-electrode cell assembled using CoP-Co2P/C-CFs exhibits a low voltage of 1.60 V at 10 mA cm-2 for OWS, superior to 1.64 V obtained using Pt/C//RuO2. This study not only presents a reliable strategy for obtaining phase-engineered cobalt phosphide catalysts but also outlines a novel approach for coal into high-value-added CFs. Consequently, it offers a new perspective for the development of self-supporting electrocatalysts for OWS.

Interface control in TiO2/BaTiO3 ferroelectric heterostructures: A bidirectional catalytic pathway toward high-performance Li-S batteries

Li-S batteries (LSBs), noted for their high energy density and low cost, face challenges due to sluggish lithium polysulfide (LiPS) redox kinetics and complex phase transformations during charge/discharge cycles. Herein, we introduce a novel hollow nanocomposite, a titanium oxide/barium titanate (TiO2/BaTiO3) heterostructure with an ultrathin carbon coating, designed to act as a bidirectional electrocatalyst, enhancing the sequential conversion of sulfur (S8) to Li2S4 and then to lithium sulfide (Li2S). The ferroelectric nature of BaTiO3 enhances LiPS adsorption, reducing the shuttling effect and improving battery performance. The interface-induced electric field directs LiPS migration to TiO2, facilitating the redox process. An applied electric field polarizes the heterostructure, optimizing the dipole moment of BaTiO3 and further enhancing performance. Electrochemical measurements and theoretical calculations confirm the superior electrocatalytic activity of TiO2/BaTiO3@C for LiPS redox kinetics. The composite electrode achieves a high initial capacity of 836 mAh g-1 at 1C, retaining 64 % of its capacity after 400 cycles with a low fading rate of 0.075 % per cycle. Under practical operation conditions (sulfur areal loading: 6.02 mg cm-2; electrolyte/sulfur (E/S) ratio: 6.5 μL mg-1), the as-fabricated LSBs still demonstrate good areal capacities of 5.18, 4.09, 3.84, 3.64, and 3.15 mAh cm-2, respectively, at current densities from 0.05 to 0.5C. This study elucidates the critical synergy between self-induced electric fields and heterostructure engineering in polysulfide conversion, providing fundamental guidance for designing advanced catalysts in high-energy LSBs and related electrochemical energy systems.

Self-activated oxophilic surface of porous molybdenum carbide nanosheets promotes hydrogen evolution activity in alkaline environment

Molybdenum carbides are promising alternatives to Pt-based catalysts for the hydrogen evolution reaction (HER) due to their similar d-band electronic configuration. Notably, MoxC exhibits superior HER kinetics in alkaline media compared to acidic conditions, contrasting with Pt-based catalysts. Herein, we present 3D porous β-Mo2C nanosheets, achieving an overpotential of 111 mV at 10 mA cm-2 in 1 M KOH, significantly lower than in acidic environments. Simulations on pristine Mo2C surface reveal that water dissociation poses a higher energy barrier in alkaline media, suggesting that crystal structure alone does not dictate kinetics. Operando attenuated total reflection surface-enhanced infrared absorption spectroscopy shows that Mo2C activates interfacial water, generating liquid-like and free water, and facilitates hydroxyl species adsorption, reducing activation energy to below 38.43 ± 0.19 kJ/mol. Our findings on the self-activation effect offer insights into the HER mechanism of Mo-based electrocatalysts and guide the design of highly active HER catalysts.

An insight into in silico strategies used for exploration of medicinal utility and toxicology of nanomaterials

Nanomaterials (NMs) and the exploration of their comprehensive uses is an emerging research area of interest. They have improved physicochemical and biological properties and diverse functionality owing to their unique shape and size and therefore they are being explored for their enormous uses, particularly as medicinal and therapeutic agents. Nanoparticles (NPs) including metal and metal oxide-based NPs have received substantial consideration because of their biological applications. Computer-aided drug design (CADD) involving different strategies like homology modelling, molecular docking, virtual screening (VS), quantitative structure-activity relationship (QSAR) etc. and virtual screening hold significant importance in CADD used for lead identification and target identification. Despite holding importance, there are very few computational studies undertaken so far to explore their binding to the target proteins and macromolecules. Although the structural properties of nanomaterials are well documented, it is worthwhile to know how they interact with the target proteins making it a pragmatic issue for comprehension. This review discusses some important computational strategies like molecular docking and simulation, Nano-QSAR, quantum chemical calculations based on Density functional Theory (DFT) and computational nanotoxicology. Nano-QSAR modelling, based on semiempirical calculations and computational simulation can be useful for biomedical applications, whereas the DFT calculations make it possible to know about the behaviour of the material by calculations based on quantum mechanics, without the requirement of higher-order material properties. Other than the beneficial interactions, it is also important to know the hazardous consequences of engineered nanostructures and NPs can penetrate more deeply into the human body, and computational nanotoxicology has emerged as a potential strategy to predict the delirious effects of NMs. Although computational tools are helpful, yet more studies like in vitro assays are still required to get the complete picture, which is essential in the development of potent and safe drug entities.

Oxygen vacancies in NaTi2(PO4)3 nanoribbons to enhance low-temperature performance for Na storage

Sodium superionic conductor NaTi2(PO4)3 has attracted significant interest as an anode material for sodium-ion batteries (SIBs). However, its practical application is hindered by its low inherent electrical conductivity, particularly at low temperatures. In this study, oxygen vacancies (VO) were introduced into NaTi2(PO4)3 nanoribbons to enhance sodium storage performance at low temperatures. X-ray diffraction with Rietveld refinement, electron paramagnetic resonance, and X-ray photoelectron spectroscopy confirm that NaTi2(PO4)3-2 nanoribbons (NTP-2) exhibit the richest VO concentration. These VO, which bridge TiO6 octahedra and PO4 tetrahedra, significantly enhance the antibonding interactions of Ti1-O2 and P1-O1 bonds, while stabilizing the bonding in NaTi2(PO4)3. The energy barrier for Na+ migration is reduced to 0.40 eV involving the VO. The optimized NTP-2 anode demonstrates superior low-temperature performance, maintaining a capacity of 106.1 mAh g-1 (about 96.1 % of its initial capacity) at -20 °C after 300 cycles. Additionally, the NTP-2 anode exhibits a moderate Na+ diffusion coefficient of 1.47 × 10-11 cm2 s-1 at -20 °C. Furthermore, the Na3V2(PO4)3//NTP-2 full cell retains a capacity of 64 mAh g-1 at -20 °C after 250 cycles, highlighting its potential for low-temperature applications. By integrating oxygen vacancies and nanoengineering, both electronic and ionic conductivities are significantly enhanced in NaTi2(PO4)3, positioning promising applications for SIBs in low-temperature environments.

Fluid-induced piezoelectric field enhanced photocatalytic antibiotic removal over nitrogen-doped carbon quantum dots/Bi2WO6@polyvinylidene fluoride-co-hexafluoropropylene membrane in aqueous environments

Enhancing the charge separation efficiency of photocatalysts is crucial to their catalytic activity, which is still challenging. Herein, nitrogen-doped carbon quantum dots (N-CQDs) were combined with Bi2WO6 to construct an N-CQDs/Bi2WO6 heterocomposite, which was loaded onto the surface of polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) membrane to design a flexible, porous and hydrophilic N-CQDs/Bi2WO6@PVDF-HFP photocatalytic membrane. Piezo-response force microscopy (PFM) and the maximum effective piezoelectric coefficient (d33) measurements demonstrate that the PVDF-HFP membrane has favorable piezoelectric properties. Besides, fluid-induced mechanical energy can generate a piezoelectric field within the PVDF-HFP membrane. Theoretical calculations indicate that the difference in work function at the N-CQDs/Bi2WO6 heterocomposite interface creates an inherent electric field. Therefore, the synergistic effect of the two electric fields improves the separation and migration efficiency of photogenerated carriers in N-CQDs/Bi2WO6 heterocomposite. The membrane effectively removed 85.3 % of oxytetracycline (OTC) under the synergistic driving of water flow (900 r/min) and visible light, surpassing the results of only water flow (34.4 %) and visible light (63.1 %). Furthermore, the degradation performance of the membrane towards OTC remains almost unchanged after multiple recycles, highlighting its favorable reusability. This work addresses the issue of powdery catalysts in recovering for practical applications and underlines the potential of integrating with natural low-frequency water flows to purify organic-contaminated wastewater.

Single yttrium atom coordinated by nitrogen and oxygen with an asymmetric 4d orbit as efficient oxygen reduction electrocatalyst

Developing transition metal-nitrogen-carbon (MNC) with the inert metal-atom center for the Fenton reaction is crucial to achieving precious metal-free electrocatalysis of oxygen reduction reaction (ORR). Herein, we report a new structure of YNC nanosheets for efficient ORR, which was synthesized by pyrolyzing the Y ion-containing self-polymerized compound of 2, 4, 6-triaminopyrimidine (TAP) as a new precursor. Results demonstrate that the precursor of TAP with high N content is capable of forming atomically dispersed specific YN4O moieties anchoring in N-rich carbon nanosheets, exhibiting excellent ORR performance with a higher half-wave potential of 0.88 V and 0.78 V in 0.1 M KOH and 0.5 M H2SO4 than FeNC synthesized by the same strategy. Meanwhile, the zinc-air battery and proton exchange membrane fuel cell tests also verify its feasibility for practical application with a maximum power output density of 151 mW cm-2 and 496 mW cm-2 respectively. Theoretical calculations further reveal that the axial O coordination in YN4 moiety causes an symmetry breaking of the d-orbital electrons of yttrium and weakens the spin polarization, which can shift the rate-limiting step from the *OH step to the *OOH step with a lower ORR overpotential than the classic FeNC. This work proves that YNC with single yttrium atom holds a great promise as a substitute for the conventional FeNC with active Fenton effect as a none-precious metal ORR electrocatalyst.

Synergistic effect of RuNi alloy supported by carbon nanohorns for boosted hydrogen evolution from ammonia borane hydrolysis

The present study addresses the critical challenges associated with hydrogen production from ammonia borane (AB) hydrolysis, focusing on the development of cost-effective, high efficient, and stable catalysts. A promising strategy to achieve superior catalytic performance in AB hydrolysis involves alloying noble and non-precious metals. Herein, RuNi bimetallic nanoparticles were successfully deposited onto carbon nanohorns (CNHs) through a facial hydrothermal-reduction processes. The optimized Ru0.6Ni0.4-CNHs catalyst demonstrates a remarkably high turnover frequency (TOF) of 144  [Formula: see text]  molRu-1 min-1, approximately twice that of Ru-CNHs. The synergistic effect between CNHs and the RuNi alloy enhances the anchoring and dispersion of metal particles, leading to reduced particle size and a narrow distribution, along with exceptional stability. Experimental results reveal that the incorporation of the RuNi alloy enables precise regulation of the electron distribution in Ru. Furthermore, density functional theory (DFT) calculations demonstrate that the RuNi alloy significantly reduces the activation and dissociation energies of AB and H2O on the Ru site of Ru0.6Ni0.4 compared to those on a monometallic Ru site. This work provides valuable insights for designing efficient and economical bimetallic nanocatalysts for AB hydrolysis.

NaCl-Assisted electrospinning of bifunctional carbon fibers for High-Performance flexible zinc-air batteries

With the increasing demand for flexible, rechargeable zinc-air batteries (ZABs), developing efficient oxygen electrocatalysts is challenging. A large specific surface area and porous structure are critical for electrochemical performance but can compromise mechanical strength and flexibility. Herein, a novel strategy with NaCl-assisted electrospinning and pyrolysis has been proposed to fabricate self-supported carbon fibers with a solid core and mesoporous shell as bifunctional oxygen electrocatalysts for flexible ZABs. The fibers incorporate NaCl and ZnCo-ZIFs via coaxial electrospinning. NaCl enhances both the electrospinning process and ZIF carbonization, creating a porous surface on robust carbon fibers that balances surface exposure with structural stability. Experimental data and density functional theory calculations confirm that cobalt atoms anchored on the carbon surface are the primary active sites, boosting electrocatalytic performance. Zinc facilitates the formation of structural defects and porosity during volatilization at high temperatures, promoting NaCl molten salt infiltration, ZIF decomposition, and large pore formation. The resulting cross-linked porous structure increases active site exposure, enhancing catalytic efficiency. The synthesized ZN3-CNFs-900 exhibit remarkable catalytic activity, achieving an oxygen reduction reaction half-wave potential of 0.834 V and an oxygen evolution reaction overpotential of 1.695 V at 10 mA cm-2. ZABs assembled with these carbon fibers demonstrate an open-circuit voltage of 1.43 V, a peak power density of 111 mW cm-2, and cycling stability beyond 400 h. The carbon fiber-based solid-state ZABs show a high open circuit voltage of 1.39 V, a power density of 81.7 mW cm-2 and a cycle life of 33 h.

Defect and doping synergistic optimization for efficient and durable alkaline seawater hydrogen production

Seawater electrolysis offers a dual benefit of alleviating freshwater scarcity and advancing hydrogen energy technologies. However, its practical implementation is hindered by the complex chemical composition of seawater, particularly the corrosive chloride ions that induce electrode degradation and parasitic chlorine evolution, posing critical challenges to long-term electrolytic stability. To address this issue, we designed an efficient electrocatalyst by introducing vanadium (V) doping and oxygen vacancies (Ov) into nanoflower-structured Co3O4 (V-Co3O4(Ov)-250) through hydrothermal synthesis and controlled annealing. The Ov configuration modulates electronic structures and facilitates charge transfer, whereas V doping enhances corrosion resistance, increases lattice defects, and generates active sites. This dual modification synergistically improves surface reactivity and conductivity, boosting catalytic performance. V-Co3O4(Ov)-250 achieves low overpotentials of 69 mV for the hydrogen evolution reaction (HER) and 158 mV for the oxygen evolution reaction (OER) in alkaline freshwater, and 133 mV (HER) and 228 mV (OER) in alkaline seawater at a current density of 10 mA cm-2. When assembled into an electrolytic cell, the catalyst requires a low voltage of 1.68 V to drive a current density of 100 mA cm-2 in an alkaline seawater electrolyzer, while maintaining outstanding stability over 100 h of continuous operation. This performance surpasses that of most non-precious metal-based electrocatalysts for seawater electrolysis. Theoretical analysis elucidates that V doping promotes preferential adsorption of OH- at the active site and optimizes intermediates' adsorption-desorption equilibrium through its synergy with Ov, consequently lowering the reaction energy barrier and enhancing intrinsic catalytic activity.

Quenching induced Cu and F co-doping multi-dimensional Co3O4 with modulated electronic structures and rich oxygen vacancy as excellent oxygen evolution reaction electrocatalyst

The development of highly efficient non-precious electrocatalysts for the oxygen evolution reaction (OER) remains a significant challenge. In this work, we introduce a highly effective OER electrocatalyst, Cu-F-Co3O4, synthesized by doping copper (Cu) and fluorine (F) into Co3O4 using a quenching method. Both experimental and theoretical calculations reveal that Cu and F incorporation significantly shifts the d-band center closer to the Fermi level, creates abundant oxygen vacancies, and facilitates the reconstruction of the catalyst to form the CuCo2O4-yFy/CuO heterojunction. This structural modification enhances the OER performance of the catalyst. Additionally, the multi-dimensional architecture exposes more active sites and accelerates mass and charge transfer kinetics. The optimal catalyst, Cu-F-Co3O4-0.7, demonstrates a low overpotential of 290 mV at 10 mA·cm-2, along with remarkable stability exceeding 100 h, significantly outperforming both pristine Co3O4 and benchmark RuO2 electrocatalysts. These findings offer new insights into activating surface reconstruction in spinel oxides by engineering both anion and cation defects for water oxidation.

Ameliorating water splitting by entropy regulation and electronic structure engineering on pristine Prussian blue analog

Electrochemical water splitting is the most promising green method for hydrogen production. In this work, the traditional Prussian blue analogs were endowed with the new concept of high entropy to bring a breakthrough in electrocatalytic performance. A classic two-step synthetic strategy was employed to fabricate the high-entropy FeCoNiCr6P nanoparticle via phosphating the FeCoNiCr6, which was prefabricated using a facile coprecipitation method. The phosphides can trap protons by acting as bases to promote the discharge step faster. FeCoNiCr6P requires a lower overpotential of only 268.3 mV at a current density of 100 mA cm-2 for OER. The FeCoNiCr6P//FeCoNiCr6P electrochemical water splitting couple can realize a low voltage of 1.58 V to at 10 mA cm-2 current density. Furthermore, the electronic states and coordination environment of catalyst active sites were investigated to get deeper insight into material design.

Bimetallic sulfide Fe5Ni4S8 nanoparticles modified N/S co-doped carbon nanofibers as anode materials for high-performance sodium-ion batteries

Transition metal sulfides (TMSs) have garnered significant attention owing to high theoretical capacities, favorable environmental compatibility, abundant natural resources, and suitable discharge/charge voltage platform in the field of anode materials for sodium-ion batteries (SIBs). However, the sluggish reaction rates and significant volume alteration during the process of sodiation/desodiation restrict the practical application of TMSs for SIBs. Herein, a novel bimetallic sulfide Fe5Ni4S8 nanoparticles modified nitrogen/sulfur co-doped carbon nanofibers (NSCFs) composite is successfully synthesized using a straightforward electrostatic spinning and sulfurization treatment. As an anode material for SIBs, Fe5Ni4S8/NSCFs exhibits a high reversible specific capacity of 686.34 mAh g-1 at 0.1 A/g and a capacity of 607.26 mAh g-1 after 120 cycles at 1.0 A/g with a capacity retention rate of 96.9 %. Even at 10.0 A/g, it still maintains a capacity of 481.14 mAh g-1 after 800 cycles, indicating an excellent electrochemical energy storage performance. Density functional theory calculations demonstrate that the Fe5Ni4S8 exhibits enhanced binding with NSCFs, promoted electron transfers, improved Na+ adsorption ability, and decreased Na+ diffusion barrier energy compared to those of monometallic sulfide FeS. Additionally, the three-dimensional network skeleton of NSCFs can effectively enhance the electrical conductivity and relieve the volume change during the discharge and charge process. The innovative multicomponent design and nanostructural configuration provide a promising strategy to develop high-performance anode materials based on bimetallic sulfide for SIBs.

Tunable interfacial charge transfer in a nickel sulfide/red phosphorus composite for efficient benzyl alcohol selective oxidation: Effect of nickel sulfide crystal phase

Red phosphorus (RP) has recently attracted considerable attention in the field of photocatalysis owing to its remarkable optical properties. However, the rapid recombination of photogenerated carriers presents a substantial challenge for the application of RP in the selective photocatalytic oxidation of benzyl alcohol. Herein, a series of nickel sulfide (NiS) materials with different crystal phase, including α-NiS, β-NiS and α-β-NiS, were employed to modulate the interfacial charge transfer in RP for photocatalytic oxidation of benzyl alcohol (BA) coupled with H2 evolution. A comprehensive array of experimental and theoretical analyses has demonstrated that the Ohmic junction formed between β-NiS and RP is more conducive to enhancing the separation and migration of carriers in comparison to the Schottky junction formed between α-NiS and RP. As expected, the β-NiS/RP exhibited superior photocatalytic performance, achieving higher yields of benzaldehyde (6.79 μmol g-1 h-1) and H2 (7.16 μmol g-1 h-1) compared to α-NiS/RP, α-β-NiS(glo)/RP and α-β-NiS(fla)/RP. The observed enhancement in photocatalytic activity can primarily be attributed to the distinct carrier separation mechanisms, specifically the Ohmic contact in the β-NiS/RP system and the Schottky junction in the α-NiS/RP system. This study introduces an effective strategy for optimizing carrier migration mechanisms in composite catalysts via crystal phase modulation, thereby providing valuable insights into the design of highly efficient photocatalysts for energy and environmental applications.

Interaction, inhibition and disruption of lysozyme fibrillar aggregates by the plant alkaloid berberine

This study investigated the interaction and impact of berberine, a pharmacologically important natural alkaloid, on lysozyme amyloidosis with the aim to develop effective anti-amyloidogenic agents. Interaction between berberine and lysozyme was analyzed using both theoretical and experimental tools to unleash its anti-amyloidogenic potency. The intrinsic fluorescence of lysozyme was quenched by berberine through static mechanism, indicating the presence of single binding site predominantly involving TRP residues. Complexation with berberine caused microenvironmental and conformational changes in lysozyme as shown by synchronous and 3D fluorescence spectroscopic analysis. Molecular docking and dynamic simulation study revealed the probable binding site and pharmacokinetics involved in lysozyme-berberine complexation. Berberine significantly inhibited lysozyme fibrillation which was confirmed by Thioflavin T, Congo red, Nile red and ANS assays. FTIR and circular dichroism studies revealed that berberine reduced β-sheet content of lysozyme fibrillar samples, indicating inhibition of fibril formation. Additionally, berberine can degrade pathogenic mature fibril as well. Amyloid inhibition and defibrillation was visualised by atomic force microscopy.

Probing ultraviolet-induced dissociation of hydrogen bond networks in tyrosine by terahertz spectroscopy

Tyrosine (Tyr) has gained significant attention as one of the most sensitive amino acids. Its oxidation is accompanied by changes in hydrogen bonds, so the oxidation process of Tyr is monitored and the dissociation sequence of different hydrogen bond network is elucidated based on the sensitivity of terahertz (THz) waves to intermolecular interactions. We find that the peak height of Tyr at 0.97 THz and 2.08 THz decreases with time, but the change behavior of the two is different. Combined with density functional theory (DFT), this phenomenon is attributed to the difference of factors that dominate THz vibration. The weakening of the peak height of Tyr at 0.97 THz is due to the ordered dissociation of hydrogen bonds with different intensities, while the peak at 2.08 THz mainly involves the lattice itself. This means that the peak at 0.97 THz is a more accurate parameter for characterizing the oxidation process. Our study reveals the hydrogen bond changes of Tyr when its structure is destroyed, and provides a spectral technique for monitoring and preventing harmful oxidation reactions using hydrogen bond network evolution.

Cationic conjugated microporous polymers for efficient quinolone antibiotics extraction: Experimental and DFT study

The development of exquisitely sensitive analytical methods for the surveillance of quinolone antibiotics (QAs) holds pivotal significance in safeguarding both ecosystems and human well-being. In this work, a cationic conjugated microporous polymer (iCMP) was constructed through a facile post-synthetic approach. Capitalizing on its unique dual-porosity architecture, cationic framework, and π-conjugated backbone, iCMP exhibited exceptional adsorption capabilities and remarkable repeatability. Integrating with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a solid-phase extraction (SPE) method founded on iCMP was meticulously developed for the sensitive and accurate detection of QAs within complex matrices. This proposed analytical method exhibited remarkably low limits of detection, specifically 0.0200-0.128 ng·L-1 for water samples and 0.0250-0.105 ng·g-1 for meat samples, along with good accuracy in the range of 70.9 %-115 %. The underlying adsorption mechanism was comprehensively investigated using a synergistic approach that combined systematic adsorption experiments, density functional theory (DFT) calculations, and in-depth material characterizations. Overall, this study presents viable strategies for the precise trace-level analysis of QAs in complex environmental and food samples.

Metallic TiN-mediated interface to boost charge transfer of bismuth vanadate toward enhanced photoelectrochemical water oxidation

Surface modification of cocatalysts is one of the most efficient strategies to improve the surface charge transfer of bismuth vanadate (BVO) photoanodes. However, the interfacial recombination between BVO semiconductors and cocatalysts is seriously undervalued. Herein, metallic titanium nitride (TiN) nanoparticles are decorated on the surface of BVO to tune the carrier dynamics at BVO/cocatalysts interface. The enlarged band bending at the near-surface of the BVO semiconductor enables significantly promoted interfacial charge transfer and separation, resulting in a much higher charge separation efficiency (83.7 %) than that of the untreated BVO photoanode (67.8 %). Subsequently, the deposition of CoFe-based oxygen evolution catalyst (CoFe-OEC) raises the charge injection efficiency of TiN/BVO from 38 % to 81 % by accelerating water oxidation reaction kinetics. Stemming from the fast charge transfer and separation at semiconductor/cocatalyst/electrolyte interface, a prominent photo-current density of 5.0 mA cm-2 along with outstanding PEC stability can be achieved by the hybrid CoFe-OEC/TiN/BVO photoanode. This work will pave a new design avenue to enhance the carrier dynamics in semiconductor/cocatalyst system for efficient PEC water oxidation.

Single atom catalysts adsorbed on reduced monolayers for enhanced kinetics in Al-S batteries

Rechargeable aluminum-sulfur (Al-S) batteries have attracted significant attention as potential next-generation energy storage devices due to their safety, the natural abundance of the elemental components, and high theoretical energy density. However, their utilization is hindered by sluggish reaction kinetics and poor reversibility. Introducing single-atom catalysts (SACs) can promote redox processes at the cathode and help in mitigating the shuttle effect of Al polysulfides (Al2Sx). While the electrochemical, thermodynamic, and thermal stabilities of SACs (Co, Fe, Ir, Ni, Pt, and Rh) have been explored in previous studies, this work focuses on their potential role in enhancing reaction kinetics in Al-S batteries. Our calculations indicate that SACs-based substrates exhibit more robust binding energies for capturing Al2Sx than the bare surfaces. Additionally, SACs lower the free energies associated with the rate-determining step during discharging and exhibit lower decomposition barriers during charging. Moreover, the interaction of soluble Al2Sx with the electrolyte reveals that SAC supported polysulfides are less likely to dissolve in the electrolyte than their pristine counterparts. The analysis of the underlying mechanisms of the interaction of molecules and the Co@ substrate reveals the ability of this substrate to accommodate large volume changes and support a sulfur loading up to 53.37 wt% during the charging and discharging cycles, without causing fractures. The mechanism driving this enhanced performance is extensively investigated through charge transfer, bond strength, and d-band center analyses. Our findings present an effective strategy for designing SACs substrates to improve the electrochemical performance of Al-S cathodes.

One-pot synthesis of transition-metal-sulfides decorated CdS by low-temperature KSCN flux: An effective route to strengthen the interface for enhanced photocatalytic H2 evolution

The performance of decorated photocatalysts is highly dependent on the interfacial contact between the cocatalyst and the substrate photocatalyst, which is essentially determined by their fabrication routes. Herein, a simple one-pot preparation method based on low-temperature KSCN flux was developed for the synthesis of sulfide photocatalysts with MS/CdS (MS = CoS2, NiS2, Cu1.8S, SnS2, MoS2, and WS2) as prototypes. The results indicate that a sulfidation of Cd2+ and the cocatalyst precursors can be achieved successively in the reaction system, which facilitates the formation of a welded interface as the cocatalysts can grow epitaxially on the formed CdS surface. The KSCN flux serves not only as a reaction medium but also as S2- precursor. Most of the MS (except for WS2) could be successfully fabricated and deposited in situ on CdS. However, only the transition-metal-sulfides (TMSs, MoS2, CoS2, and NiS2) decorated samples showed enhanced photocatalytic H2 evolution reaction (HER) performance and the activities decreased in the order of MoS2 > CoS2 > NiS2. The sample loaded with 1 %MoS2 demonstrated the highest activity, which was 25 times higher than that of the pristine CdS. The superior HER performance could be ascribed to the loading of the active MoS2 sites for HER and the intimate tandem type I (between CdS and 2H-MoS2) and Schottky (between 2H- and 1T-MoS2) junctions for separation of photoinduced charge carriers. Compared to the conventional preparation methods, the developed one-pot flux route demonstrates remarkable advantages in fabricating highly efficient MoS2/CdS photocatalyst besides its convenience, versatility, and scalability. We believe that, in addition to CdS, the developed route can also be applied to synthesize other sulfide-based photocatalysts.

ZnIn2S4 enwrapping CoP with phosphorus vacancies hollow microspheres for efficient photocatalytic hydrogen production

To address the pressing challenges of energy shortages and environmental sustainability, photocatalytic water splitting for hydrogen production has emerged as a promising strategy for solar energy conversion. While semiconductor catalysts exhibit significant potential in photocatalysis, their practical applications are hindered by limitations such as inefficient charge separation and insufficient active sites. Designing and preparing efficient, non-precious co-catalysts is therefore essential. In this work, we synthesized cobalt phosphide with phosphorus vacancy defects (vp-CoP) hollow microsphere co-catalysts and loaded them with indium zinc sulfide (ZnIn2S4) nanosheets to construct vp-CoP@ZnIn2S4 (vp-CoP@ZIS) heterojunction photocatalysts. Under visible light irradiation, the vp-CoP@ZIS photocatalyst achieved a hydrogen production rate of 7.4 mmol g-1 h-1, which was 7.6 times higher than that of pristine ZnIn2S4. This remarkable enhancement arises from the synergistic effects between vp-CoP and ZnIn2S4. Specifically, the introduction of single-atom phosphorus vacancies significantly improved electron transfer efficiency and promoted charge separation within the heterojunction. This innovative design and synthesis strategy underscores the potential of vp-CoP@ZIS as a robust photocatalyst for solar-driven hydrogen production, providing a sustainable pathway for efficient solar energy utilization.

Optimized microwave absorption and thermal properties for TiB2@BN/PDMS composites via TiB2@BN heterogeneous interface engineering

The single electromagnetic (EM) wave loss mechanism leads to suboptimal microwave absorption in dielectric materials, whereas, introducing different materials and constructing distinctive microstructures can significantly improve microwave absorption. In this study, TiB2 and TiB2@BN powders were synthesized using boron thermal reduction and chemical solution methods. Their microwave absorption and thermal properties were systematically analyzed. Compared to TiB2/PDMS, TiB2@BN/PDMS composites achieve enhanced microwave absorption across the 2-18 GHz. The minimum reflection loss (RLmin) reaches -31.2 dB at 17.92 GHz with 60 wt% TiB2@BN and a thickness of 1.55 mm. RL below -10 dB covers the frequency range of 12.88-18 GHz with 65 wt% TiB2@BN and a thickness of 1.75 mm. Radar cross-section (RCS) simulations show notable stealth capabilities, making it suitable for practical applications. Establishing the TiB2@BN heterointerface can optimize impedance matching and EM wave attenuation, thereby enhancing microwave absorption. Charge transfer from B and N atoms to Ti atoms at the heterointerface, combined with lattice defects, generates strong interface and dipole polarization loss under an external EM field. Additionally, TiB2@BN/PDMS composites possess excellent thermal conductivity. These results highlight the potential of TiB2@BN/PDMS composites in advanced microwave absorption and thermal management applications.

Gas-pressure-assisted strategy for precise control of palladium-based nanoparticle sizes: Unveiling size effects on methanol oxidation activity

Understanding the relationship between catalyst particle size and activity is crucial for developing efficient catalytic systems. However, the size-dependent behavior of Pd-based alloy catalysts remains poorly understood, requiring a comprehensive investigation. This study presents a straightforward and effective gas-pressure-assisted heat-treatment method that allows precise control over the particle sizes of various Pd-based catalysts, including Pd, Pd3Fe, Pd3Co, Pd3Ni, and Pd3Cu. Our findings demonstrate that high pressure significantly inhibits nanoparticle sintering by increasing energy barriers for both metal atomic diffusion and nanocluster migration. A linear relationship has been established between average particle size and applied gas pressure. Specifically, this method was employed to synthesize Pd3Fe nanoparticles (NPs) with an average particle size ranging from 2.8 to 6.9 nm. Furthermore, we explored the size effect of Pd3Fe/C in the methanol oxidation reaction (MOR). The mass activity (MA) of the catalyst exhibited a volcano-shaped trend as particle size decreased. Notably, the Pd3Fe/C-7 MPa catalyst with a particle size of 3.9 nm demonstrated superior MA compared to other samples within this range of sizes tested in this study. This work offers a valuable approach for systematically studying the size effect on catalytic performance, which aids researchers in designing high-performance catalytic materials.

Nitrogen imported in nickel clusters promotes carbon dioxide electrochemical reduction to carbon monoxide

The Ni-N coordination structure has been shown to be conducive to the electrochemical CO2 reduction reaction (CO2RR) to CO, and this process has been extensively validated. However, the impact of Ni-N coordination structures within Ni-based clusters on CO2RR has received relatively limited research attention to date. In this study, catalysts containing Ni single atoms and Nin clusters (Ni-N/Nin) were synthesised, and subsequently, Nin clusters were transformed into NinNx clusters (Ni-N/NinNx) through secondary nitridation. The experimental results, as illustrated by X-ray photoelectron spectra and X-ray absorption fine structure spectra, demonstrate that the Ni-N bond in Ni-N/NinNx increased and Ni-N-Ni bonds within atomic clusters were generated, thereby confirming the transformation from Nin clusters to NinNx clusters. Density functional theory calculations show that the NinNx clusters have a lower energy barrier for the *CO2- + H+ → *COOH step compared to Nin clusters, and promote the entire reaction. Furthermore, in-situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) calculations collectively indicate that abundant Ni-N coordination structures in clusters effectively reduce the energy barrier of CO2 + e- → *CO2- and facilitate the activation of CO2 to *CO2- across a broader potential window. Ni-N/NinNx demonstrates high Faraday efficiency of CO (FECOmax = 98.6 % at -0.4 V vs. RHE), a wider potential window (-0.3 to -0.8 V vs. RHE, FECO > 90 %) and high CO partial current density (jCO > 100 mA cm-2). In comparison with Ni-N/Nin, the maximum CO partial current density of Ni-N/NinNx is enhanced by approximately 4.6 times. These findings offer valuable insights into the structure-activity relationship of Ni-based cluster catalysts and facilitate the development of more advanced atomically cluster catalysts.

Transition metal doped pyrazine-graphyne for high-performance CO2 reduction reaction to C1 products

The pressing necessity to mitigate climate change and transition to a sustainable energy economy underscores the importance of developing highly efficient and selective catalysts for electrocatalytic CO2 reduction (CO2RR). This study explores nitrogen-doped graphyne (N-GY) as a promising substrate for anchoring 3d and 4d transition metal atoms (TMs), facilitating the creation of high-performance electrocatalysts. Through comprehensive computational analysis based on density functional theory (DFT), we provide a detailed understanding of the mechanisms involved in CO2 capture by these catalysts. Our results reveal a "donation-backdonation" mechanism during CO2 adsorption, characterized by significant charge transfer and orbital overlap, which enhance CO2 adsorption and activation. We identify ten catalysts exhibiting exceptional activity and selectivity, with V-S2@N-GY standing out for its ultra-low limiting potential of -0.279 V, which is particularly beneficial for carbon monoxide generation. The mechanistic analysis further underscores the critical role of the *COOH intermediate adsorption strength in dictating CO2RR activity. This study provides valuable theoretical insights for the design and optimization of efficient CO2RR catalysts.

Fabricating stable protective layer on orthorhombic tungsten oxide anode for long-lifespan pseudocapacitors by trace of aluminum ion electrolyte additives

Orthorhombic tungsten oxide (WO3·H2O) has been considered as a promising anode material due to its layered crystal structure and high capacity. However, the instability of its crystal structure usually results in poor cyclic stability of the battery/capacitor. Herein, a novel strategy of introducing aluminum ion (Al3+) additives for designing hybrid electrolyte is demonstrated to enhance the cycling stability of WO3·H2O. Aluminum ions may participate in the redox reaction and contribute extra capacitance. More importantly, the Al3+ ions can facilitate fast phase transformation of metastable orthorhombic tungsten oxides to stable monoclinic phase, but also participate in the construction of stable protective layer during the long-term cycling, forming a protective layer at the surface of tungsten oxide for alleviating the dissolution and structural damage. The WO3·H2O is electrodeposited on the exfoliated graphite foil (Ex-GF) and shows a specific capacitance of 395 mF cm-2 at 2 mA cm-2 in the LiCl + AlCl3 hybrid electrolyte (pH = 2.93), and the capacitance remains 91.8 % after 10,000 charge/discharge cycles, indicating that the WO3·H2O/Ex-GF electrode material exhibits excellent stability in supercapacitors. The density functional theory (DFT) calculations further demonstrate whether the adsorption energy or intercalation energy of Li+ at the monoclinic WO3 is lower than the orthorhombic WO3·H2O. This result suggests that the electrochemical performance of WO3·H2O, which operates on a pseudocapacitive reaction mechanism, can be enhanced through the phase transformation from the orthorhombic phase to the monoclinic phase during the cycling. Hence, this ion additive approach can adjust the interface composition and protect internal active material, and can be extended to the stability improvement of other metal oxide electrodes.

Noncovalent guest-host interactions unlock the potential of MOFs for anesthetic xenon recovery: GCMC and DFT insights into real anesthetic conditions

Innovative designs offering cost-effective and highly efficient methods for xenon (Xe) recovery are becoming important for developing sustainable applications. Recently, the use of metal-organic frameworks (MOFs) has shown promise as candidates for separating Xe from anesthetic gas mixtures, however, there are limited studies available. We conducted combined Grand Canonical Monte Carlo (GCMC) and Density Functional Theory (DFT) simulations to determine the Xe recovery capacities of 19 MOFs from the exhaled anesthetic gas mixture, Xe/CO2/O2/N2. COCMUE, GUHMIH, MAHCOQ, and PADKOK have demonstrated overall larger volumetric and gravimetric Xe uptake, demonstrating how ligand types can enhance selective Xe adsorption in MOFs. At low pressures, Xe atoms mainly adsorbed in close vicinity to the ligands, with tetrazole, phenyl, pyridyl, carboxamide, dicarboxylic acid, phenoxazine, and triazole ligands in the MOF structures acting as Xe trapping locations. Electronic structure analyses reveal that Xe-host interactions are primarily driven by charge-induced dipole and aerogen-π interactions. Our combined GCMC and DFT study shows that a relatively high amount of anesthetic Xe can be captured from real anesthetic exhale gas mixtures using MOFs with the proper chemical and geometrical characteristics. These characteristics maximize noncovalent Xe-host interactions and ultimately enable the utilization of Xe as an anesthetic gas in clinical applications.

Modulation of the electronic structure of nitrogen-carbon sites by sp3-hybridized carbon coupled to chloride ions improves electrochemical carbon dioxide reduction performance

The challenges remain to develop cost-effective carbon-based catalysts with high activity and selectivity. Here, we synergistically modulate carbon-based electrocatalysts through Cl doping with intrinsic defects in sp3-hybridized carbon and apply them to the electrochemical CO2 reduction reaction (CO2RR). The designed electrocatalyst achieved high selectivity over a wide potential range (-0.7 to -1.0 V), with a faraday efficiency of 96.3 % at -0.8 V for CO. In situ Fourier transform infrared spectroscopy, and analytical studies show pyrrole N to be the active site of CO2RR, and doping Cl increases the content of sp3-hybridized carbon in the carbon substrate, which synergistically accelerates the supply of hydrolysis dissociated protons and facilitates the protonation process of the intermediate products from *CO2 to *COOH. Density functional theory calculations show that Cl coupled sp3-hybridized carbon inhibits the adsorption of H* in the pyrrole N site and facilitates the desorption of *CO, thus promoting the whole process of CO2RR.

Unveiling the adsorption mechanism of perfluorooctane sulfonate onto polypropylene nanoplastics: A combined theoretical and experimental investigation

Polypropylene (PP) is a key component of nanoplastics detected globally in water, which can carry pollutants through co-transport. In this regard, the co-transport of perfluoroalkyl substances (PFAS) by nanoplastics (NPs) raises significant concern, as NPs can act as vectors that enhance PFAS uptake and bioaccumulation in organisms during co-exposure. In this context, research has shown interactions between NPs and PFAS, but the adsorption mechanism remains still unclear. In this work, a powerful synergic approach combining several computational and experimental techniques has been used to unveil the adsorption mechanism of perfluorooctanesulfonate (PFOS), which is one of the most widespread contaminants of emerging concerns (CECs) on PP nanoparticles. According to our DFT results, PFOS adsorbs onto the outer and inner surface of the nanoparticle, with a maximum adsorption energy of ≈ 18 kcal/mol and an adsorption mechanism mainly governed by dispersion forces between the two fragments. Batch experiments have confirmed that PFOS rapidly adsorbs on PP nanoparticle, showing that pH can reduce the adsorption capacity thus affecting the co-transport. Moreover, the dipole moment of the PFOS-nanoparticle complex has been found to be significantly larger as compared to the bare nanoparticle, resulting in a more pronounced transport in aqueous environment and making the PFOS-PP nanoparticle complex much more dangerous than the bare PP nanoparticle. Altogether, our results allowed us to disentangle the adsorption mechanism of PFAS on PP nanoparticles, which is a fundamental step to understand the co-occurrence of such dangerous pollutants in environmental matrices, as well as to obtain new information for toxicity and risk-models development.

Superior performance lithium-ion battery anode based on Co9S8 nanoparticles layered in-situ growth with capacitive synergy

Identifying new anode materials that possess high energy density, outstanding cycling stability, and superior rate capability has emerged as a pivotal research focus in the development of lithium-ion batteries (LIBs). Herein, we successfully synthesized a novel Co9S8-MoB MBene heterostructure. This innovative material was developed through a space-confined growth process, wherein Co9S8 nanoparticles were incorporated within the interstitial layers of MoB MBene, thereby creating a unique composite with enhanced electrochemical properties. The Co9S8-MoB MBene electrode showed excellent performance, retaining 756.34 mAh/g capacity after 200 cycles at 100 mA/g (initial capacity 828.67 mAh/g), with an impressive retention rate of 91.27 %. Even at a high current density (800 mA/g), the specific capacity of 632.1 mAh/g was maintained with a retention rate of 79.83 % after 700 cycles, and the Coulombic efficiency was consistently around 99 %. The excellent cycling stability and rate performance are attributed to the two-dimensional layered structure of conductive MoB MBene. Density functional theory (DFT) calculations reveal that MoB MBene's low lithium diffusion barrier significantly decreases the Co9S8's lithium binding energy, through rapid kinetic charge transfer, improving the efficiency of lithium-ion insertion and extraction. The incorporation of MoB MBene restricts the volume expansion of Co9S8 during lithiation and delithiation, and facilitates the formation of surface capacitance and the development of diffusion-controlled pseudocapacitors. The excellent electrochemical performance suggests that the Co9S8-MoB MBene materials designed in this work can be a rational approach to be applied for high-performance LIBs anodes.

Mechanistic impact of organics on electro-induced transformation of iron oxides and simultaneous uranium immobilization in wastewater

The incorporation of uranium into the magnetite generated through via electrochemical methods represents a sustainable strategy for remediation of uranium-contaminated organic wastewater. Nevertheless, the influence mechanisms of organics on this treatment process remain insufficiently understood. This study used an electrochemical system featuring iron and graphite electrodes along with sodium chloride as the electrolyte to investigate the impact of various organics on uranium removal. The results showed that disodium ethylenediaminetetraacetate addition delayed magnetite formation, resulting in a final product with a mixture of various iron oxides. However, this alteration did not significantly affect the mechanism and efficiency of uranium removal. In contrast, the introduction of oxalate reduced the particle size of magnetite, thereby shifting the primary mechanism of uranium removal towards adsorption, which results in a slight decrease in removal efficiency. Notably, due to the chelation properties of citrate, which nearly eliminate Fe(II) in the solution, magnetite formation was inhibited, thereby substantially reducing the final uranium removal. A 200-day leaching experiment demonstrated that the structural integrity of the synthesized mineral is predominantly maintained. This study elucidates the impact of common organics on the electrochemical mineralization system for uranium removal and offers theoretical guidance for the treatment of uranium-contaminated organic wastewater.

Boosting selective CO2 reduction via strong spin-spin coupling on dual-atom spin-catalysts

Achieving high selectivity in electrochemical conversion of carbon dioxide (CO2) into valuable products remains a significant challenge. This study investigates the influence of spin states on dual-atom catalysts within two-dimensional metal-organic frameworks (2D-MOFs) and zero-dimensional molecular metal complexes (0D-MMCs), emphasizing their role in the selective electrocatalytic reduction of CO2. Utilizing first-principles calculations, we systematically evaluate dual-atom spin-catalysts (DASCs) TM2S4(NH)2(C6H4)2 0D-MMC and TM2S4(NH)2C4 2D-MOF for CO2 reduction reactions (CO2RR) across various spin states: antiferromagnetic (AFM), ferromagnetic (FM), and non-magnetic (NM). Our analysis confirms that, beyond successfully designing and screening highly active catalysts, the selectivity for various C1 products in CO2 reduction can be readily adjusted by DASCs via spin-spin coupling. Specifically, Mn2 and Fe2 2D-MOF DASCs with an AFM ground state are more inclined to produce formic acid, while their FM counterparts favor the formation of methane, surpassing formic acid among others. Additionally, we demonstrate that 0D-MMCs, as molecular units of 2D-MOFs, achieve comparable catalytic performance. Combining theoretical insights with machine learning highlights the crucial role of electronic and geometric descriptors in the catalytic performance. Our work establishes the correlation between spin-spin coupling and highly selective CO2 reduction in DASCs, offering an effective strategy for designing tunable and efficient electrocatalysts.

Two-dimensional unilamellar cation-deficient metal oxide nanosheet incorporated composite polymer electrolytes for all-solid-state lithium metal batteries

Composite polymer electrolytes (CPEs) are considered among the leading contenders for next-generation all-solid-state lithium-metal batteries. However, CPEs simultaneously face multiple significant challenges, including reduced ion transference number, insufficient ionic conductivity, and poor cycling stability, which severely limit their practical applicability. Herein, we have designed a multifunctional unilamellar inorganic nanosheets (Ti0.87O2) additive for CPEs with cationic defects which is capable of simultaneously addressing all aforementioned challenges. The atomic Ti vacancies facilitate the direct passage of lithium ions through the nanosheets, and the monolayer structure accelerates the diffusion of lithium ions through the nanosheets. In addition, the atomic Ti vacancies can promote lithium salt dissociation while hindering anion transport. These two features of Ti0.87O2 nanosheet additives collectively enhance the ionic conductivity and lithium transference number. Furthermore, benefiting from the large specific surface area and defects, the Ti0.87O2 nanosheets can accommodate a high density of lithium ions, thereby releasing them to mitigate the polarization and elongating the Sand's time, which ultimately improves the battery's cycling stability. Finally, the ionic conductivity of CPE incorporated with this additive has improved by 42 times. Furthermore, the Li||Li symmetric cell demonstrates stable cycling for over 700 h at 0.1 mA cm-2. This work provides a new avenue for designing novel additives to develop solid-state electrolytes that offer excellent ionic conductivity and stability.

Functionalized membrane assembled by iron-based two-dimensional Fenton-like catalyst for ultra-efficient water decontamination: Mechanism and application insights

The design of functionalized membrane-coupled Fenton-like catalysis processes is pivotal for wastewater treatment, providing a promising strategy to enhance peroxide activation and degrade organic contaminants. Herein, a functionalized membrane based on Fe3O4 nanosheets (Fe3O4 NS) was designed, featuring a densely stacked structure with highly exposed reactive sites, creating an optimal environment for efficient Fenton-like catalysis. The Fe3O4 NS membrane achieved nearly complete degradation of target contaminants at a flux of 289.97 L·m-2·h-1, with a pseudo-first-order rate constant of 0.021 ms-1 for Fenton-like catalysis, surpassing previously reported Fenton-like catalytic membrane systems by 6-17 times. Detailed mechanistic experiments and theoretical calculations elucidated the efficient activation of hydrogen peroxide (H2O2) by the Fe3O4 NS membrane from both thermodynamic and kinetic perspectives. Notably, the Fe3O4 NS membrane/H2O2 system significantly reduced the toxicity of target contaminants and their degradation intermediates toward activated sludge, thereby alleviating the subsequent biochemical treatment burden. Moreover, it demonstrated potential for treating actual secondary effluent. The findings of this study advance the design of sustainable and efficient water purification strategies, offering a viable approach to overcoming the technical limitations of traditional Fenton-like catalysis.

Enhanced immobilization of Cd(II) by successive isomorphic substitution with Ca(II) and Mg(II) from ternary layered double hydroxides

The challenge with calcium-containing layered double hydroxides (LDHs) for stabilizing Cd(II) lies in the poor release of Ca(II) into solution, which is crucial for isomorphic substitution with Cd(II). To overcome this, we developed a ternary CaMgAl-LDH (OLDH) that enhances cation release and creates more vacant sites for Cd(II). Our findings reveal that OLDH has a significantly higher Cd(II) immobilizing capacity of 5.38 mmol/g compared to CaAl-LDH (4.54 mmol/g) and MgAl-LDH (0.78 mmol/g) at an initial pH of 5.0. This is attributed to its enhanced isomorphic substitution efficiency of 84.6 % and surface complexation of 15.4 %. The solubility product constant (Ksp) of the resulting Cd-containing LDH was 25 orders of magnitude smaller than that of OLDH, indicating a more stable crystalline product due to the presence of Ca(II). Additionally, 100 % of Ca(II) and 35 % of Mg(II) in OLDH were sequentially released to engage in stepwise isomorphic substitution. The inclusion of Mg(II) in OLDH tends to expose under-coordinated divalent metal centers, which was confirmed by experimental observations and density functional theory (DFT) calculations. This research provides a deeper understanding of the mechanism for Cd(II) immobilization by ternary LDHs and offers practical guidance for the preparation of immobilizers with respect to efficient isomorphic substitution.

Unveiling co-acting effects of potassium and hydroxide ions on carbon dioxide reduction reaction selectivity

The interfacial microenvironment plays a crucial role in influencing the absorption of important reaction intermediates and the resulting selectivity for carbon dioxide reduction reaction (CO2RR) (Xu et al., 2022) [1]. In this paper, the influence effects of potassium and hydroxide ions on CO2RR of Cu-based catalysts are comprehensively investigated using in-situ Raman spectroscopy and theoretical calculation. The results showed that potassium ions improved the binding strength of CO adsorbates (COad) intermediates on active sites, which is conducive to C-C coupling or further reaction. The presence of hydroxyl adsorbates (OHad) changes the charge distribution on the catalyst surface and reduces the energy barrier of C-C coupling. However, the excessive OHad adsorption can occupy a large number of active sites, leading to a decrease in COad coverage. We unveiled that the combined co-acting effect of potassium ions and hydroxide ions co-regulated the COad adsorption energy and COad coverage on Cu-based catalysts, leading to the modulation of the products selectivity. This work provides new insights for understanding the effect of interfacial microenvironment on the catalytic performance of CO2RR catalytic systems.

Boosted chlorate hydrogenation reduction via continuous atomic hydrogen

Chlorate (ClO3-) is a common toxic oxyanion pollutant from various industrial processes, and hydrogenation reduction of ClO3- by atomic hydrogen (H*) is a promising and effective method. Therefore, more efforts are needed to rationalize the design of catalytic active sites for H2 activation to boost ClO3- hydrogenation reduction. In this work, superior H2 activating capabilities were achieved for efficient ClO3- reduction on a porous graphene-based bimetallic catalyst (RuPd/PG). Edge sites and porosity structures on porous graphene promote the anchoring and confinement of Ru and Pd NPs (Nanoparticles), forming abundant Pd-Ru bonding interfaces and highly dispersed NPs. Based on DFT analysis, the ample Pd-Ru interfaces and highly dispersed Ru NPs are the main active sites, simultaneously boosting H* generation and reactant activation for rapid ClO3- reduction. The defective layer of Ru NPs on the Pd surface provides intermediates with accessibility to the inner Pd NPs, thereby avoiding ClO3- regeneration on Ru. Therefore, ClO3- hydrogenation reduction was significantly enhanced on RuPd/PG with an initial turnover frequency (TOF0) of 27.2 min-1, possessing superior robustness in recycling tests and actual water samples. Undoubtedly, this work provides new insights into H* generation and reactant activation to optimize ClO3- hydrogenation reduction applicable for water treatment.

Enoxacin-embedded EuMOF-based ratio fluorescent sensing platform integrated with paper-based sensor and skin-attachable hydrogel for glyphosate detection in foods

To address the urgent requirement for food safety and ecological environmental protection, there is a need for a sensitive and user-friendly method for detecting glyphosate (GLY). Herein, we developed a novel enoxacin-embedded Eu(III) metal-organic frameworks (ENX@EuMOF) sensing platform for fluorescent and visual dual-modes GLY detection in food samples. The ENX@EuMOF exhibited dual fluorescent signal responses to GLY at 613 nm (decrease) and 520 nm (increase) wavelengths, attributed to alterations in energy transfer efficiency and the ligand-to-metal charge transfer effects. The ratiometric fluorescent platform illustrated excellent sensitivity, achieving a low limitation of detection (LOD) of 0.35 mg/L and 10 mg/ L for fluorescent and visual detection, respectively. The linear response fell into the concentration range of 5 mg/L to 100 mg/L. Furthermore, it was also successfully applied to GLY-contaminated food, including corn, sunflower seed, soybean, eggplant, citrus, and tea. Meanwhile, the paper- and polyacrylamide hydrogel-based sensors were developed for rapid and real-time GLY detection on-site. These microsensors facilitated real-time, convenient, and sensitive GLY analysis, offering an efficient and practical solution for agricultural monitoring, which suggests a promising prospect for application.