High Stability Research Articles

Investigation on mechanism of mechanical activation and chemical reactions in CMP of diamond assisted by hydroxyl free radicals

Chemical mechanical polishing (CMP) is a crucial manufacturing process for diamond substrate applications. However, due to the extremely high hardness and chemical stability of diamond, its CMP efficiency is extremely low. This study aims to achieve microscopic simulation of atomic oxidation removal at the three-phase interface between diamond abrasive particle, diamond substrate, and hydroxyl free radicals (∙OH) aqueous solution. The mechanical activation behavior, microscopic mechanism, and feasibility of elementary reactions in the ∙OH aqueous solution environment was studied using various perspectives of radial distribution function, central atomic coordination state, atomic bonding and removal forms, energy, electron orbitals, and density functional theory (DFT). The simulation results indicate that during the process of diamond atomic oxidation removal, the atomic density at the first adjacent position centered on one atom decreases, and the stable covalent bond structure is disrupted, resulting in an amorphous phase transition. The chemical adsorption reaction generates C-O and C–H bonds. The C atoms mainly separate from the diamond substrate by the forming products such as carbon monoxide (CO), carbon dioxide (CO2), and carbon chains. The mechanical activation behavior indirectly reduces the activation energy of chemical reactions, while increasing the absolute value of adsorption energy and improving the ability of chemical adsorption solution atoms H and O, as well as ∙OH groups. Based on DFT, it has been verified that the intrusion process of ∙OH groups in the elementary reactions involving the typical product C*O2 is an exothermic reaction that can occur spontaneously, and the energy barrier needs to be overcome by the mechanical action of abrasive particles. At the same time, the energetics of the oxidation of diamond C atoms to generate C*O2 have successfully confirmed that the combined action of ∙OH and diamond abrasive particles is expected to achieve efficient oxidation removal and finishing polishing of diamond atoms.

Enhanced performance of low-dielectric siloxane-polyimide copolymers: Synthesis and properties

Low-dielectric polyimides (PI) films with outstanding overall performance are attractive for next generation microelectronic applications. Herein, a series of two different FPIs and BPIs derived from 4,4′-diaminodiphenyl ether (ODA) and two different functional dianhydrides, 4,4'-(hexafluoroisopropylidene) biphthalic anhydride (6FDA) and 4,4′-(4,4′-isopropyldiphenoxy) biphthalic anhydride (BPADA), respectively, were synthesized by a conventional two-step methodology that included thermoimidatization. Additionally, employing aminopropyl-terminated polydimethylsiloxane PDMS (molecular weight = 1000) as the source of siloxane-oxygen bonds, a series of polyimide siloxane (SiFPIs and SiBPIs) copolymers were synthesized by varying the siloxane content (ranging from 0 to 5 wt%) within the copolymer structure. The effects of siloxane bond on the thermal, solubility, water resistance, dielectric and mechanical properties of polyimide were investigated systematically. The integration of siloxane significantly enhanced the solubility of these copolymers in polar aprotic solvents (DMAC, DMF, NMP), expanding their applicability in diverse processing environments. Crucially, these copolymers exhibited remarkably low dielectric constants—2.90 for SiFPI at 3% PDMS and 2.92 for SiBPI at 4% PDMS—coupled with low loss values, positioning them as prime candidates for advanced microelectronic applications. All the composite films have high thermal stability near pure PI. The introduction of PMDS into PI can improve the elongation at break and at the same time, the composite films still remained with higher modulus and tensile strength. Extensive hydrophobicity assessments through contact angle and water absorption studies underscored the copolymers’ superior moisture resistance, a critical parameter for their potential deployment in high-performance, environmentally sensitive electronic components.

Enhanced Electrochemiluminescence of Luminol and-Dissolved Oxygen by Nanochannel-Confined Au Nanomaterials for Sensitive Immunoassay of Carcinoembryonic Antigen.

Simple development of an electrochemiluminescence (ECL) immunosensor for convenient detection of tumor biomarker is of great significance for early cancer diagnosis, treatment evaluation, and improving patient survival rates and quality of life. In this work, an immunosensor is demonstrated based on an enhanced ECL signal boosted by nanochannel-confined Au nanomaterial, which enables sensitive detection of the tumor biomarker-carcinoembryonic antigen (CEA). Vertically-ordered mesoporous silica film (VMSF) with a nanochannel array and amine groups was rapidly grown on a simple and low-cost indium tin oxide (ITO) electrode using the electrochemically assisted self-assembly (EASA) method. Au nanomaterials were confined in situ on the VMSF through electrodeposition, which catalyzed both the conversion of dissolved oxygen (O2) to reactive oxygen species (ROS) and the oxidation of a luminol emitter and improved the electrode active surface. The ECL signal was enhanced fivefold after Au nanomaterial deposition. The recognitive interface was fabricated by covalent immobilization of the CEA antibody on the outer surface of the VMSF, followed with the blocking of non-specific binding sites. In the presence of CEA, the formed immunocomplex reduced the diffusion of the luminol emitter, resulting in the reduction of the ECL signal. Based on this mechanism, the constructed immunosensor was able to provide sensitive detection of CEA ranging from 1 pg·mL-1 to 100 ng·mL-1 with a low limit of detection (LOD, 0.37 pg·mL-1, S/N = 3). The developed immunosensor exhibited high selectivity and good stability. ECL determination of CEA in fetal bovine serum was achieved.

Biomass derived 3D N, P co-doped porous carbon incorporated with Ni-Cu bimetallic phosphide: Synergistic effect of Ni-Cu boosting Na+ storage performance

Transition metal phosphides (TMPs) as promising anode materials for sodium-ion batteries (SIBs) due to their amazing properties such as high theoretical specific capacity, various bond types and good electrical conductivity. However, TMPs are still facing poor cycling stability and unsatisfactory specific capacity, which restrict their practical application. Herein, NixCu3-xP incorporated in biomass derived 3D N, P co-doped porous carbon (NixCu3-xP-NPC) is constructed as SIB anode and the electrochemical behaviors with various Ni/Cu ratios are explored. The synergistic effect of Ni-Cu in NixCu3-xP is approved by the resulting investigation, and density functional theory (DFT) calculation further confirmed its important influence in enhancing electronic conductivity and boosting Na+ storage. Evidently, the optimum synergistic effect was observed when Ni0.15Cu2.85P/NPC is utilized for SIB anode. It exhibits a reversible specific capacity of 663 mAh g−1 after 200 cycles at 0.2 A g−1, long cycling stability (467 mAh g−1 after 1000 cycles at 1.0 A g−1), and excellent rate capability (432 mAh g−1 at 2.0 A g−1). The ex-situ X-ray diffraction and ex-situ X-ray photoelectron spectroscopy verify the combined conversion mechanism of Ni and Cu during sodiation/desodiation processes, which is greatly favorable for high specific capacity and cycling stability.

Molecular dynamics simulations of uranyl and plutonyl cations in a task-specific ionic liquid.

Ionic liquids (ILs) are a unique class of solvents with potential applications in advanced separation technologies relevant to the nuclear industry. ILs are salts with low melting points and a wide range of tunable physical properties, such as viscosity, hydrophobiciy, conductivity, and liquidus range. ILs have negligible vapor pressure, are often non-flammable, and can have high thermal stability and a wide electrochemical window, making them attractive for use in separations processes relevant to the nuclear industry. Metal salts generally have a low solubility in ILs; however, by incorporating new functional groups into the IL cation or anion that promote complexation with the metal, the solubility can be greatly increased. One such task-specific ionic liquid (TSIL) is 1-carboxy-N, N, N-trimethylglycine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) [Nockemann et al., J. Phys. Chem. B 110, 20978-20992 (2006)]. Water, which is detrimental for electrochemical separations, is a common impurity in ILs and can coordinate with actinyl cations, particularly in ILs containing only weakly coordinating components. Understanding the behavior of actinides in TSIL/water mixtures on a molecular level is vital for designing improved separations processes. Classical molecular dynamics simulations of uranyl(VI) and plutonyl(VI) in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf2N]) with deprotonated Hbet (betaine) and water have been performed to understand the coordination and dynamics of the actinyl cations. We find that betaine is a much stronger ligand than water and prefers to coordinate the metal in a bidentate manner. Potential of mean force simulations yield a relative free energy for betaine coordination of approximately -120 to -90 kJ/mol in mixtures with water. As the amount of betaine coordinated to the actinide increases, the diffusion coefficient of the actinyl cation decreases. Moreover, the betaine ligand is able to bridge between two metal centers, resulting in dimeric complexes with actinide-actinide distances of ∼5Å. Potential of mean force simulations show that these structures are stable, with relative free energies of up to -40 kJ/mol. The crystal structure for [(UO2)2(bet)6(H2O)2][Tf2N]4 shows that the betaine bridges between two uranium atoms to form dimeric complexes similar to those found in our simulations [Nockemann et al. Inorg. Chem. 49, 3351-33601 (2010)].

CuO and spinel CuCo2O4 supported on mesoporous nanocubes with dual redox-active centers for electrocatalytic H2O2 reduction and sensing

The copper hexacyanoferrate (CuHCF) nanocube and its cobalt-substituted analogue (CoCuHCF) possess numerous micropores; however, they demonstrate limited electrocatalytic performance for H2O2 reduction. Heat treatment of CuHCF in air (CuHCF-ht) results in the formation of CuO and Fe3O4 with noticeable aggregation. In contrast, the heat treatment of CoCuHCF in air (CoCuHCF-ht) preserves its nanocube structure while also forming a spinel CuCo2O4 phase. The partial substitution of cobalt ions for copper ions in CuHCF enhances both thermal and structural stability, leading to the transformation of micropores into mesopores during heat treatment. This transformation improves electrolyte accessibility and structural integrity. The CoCuHCF-ht electrode features dual redox-active centers (Cu+/Cu2+ couple) derived from the CuO and CuCo2O4 phases, serving as catalytic redox mediators for H2O2 reduction. This dual redox activity results in superior performance for H2O2 reduction compared to CuHCF-ht, which only exhibits a single pair of Cu+/Cu2+ couple from CuO as an active mediator. This enhanced performance is evidenced by a lower Tafel slope, a higher catalytic rate constant, and improved mass transfer of analytes. The CoCuHCF-ht catalyst, characterized by dual redox-active centers in mesoporous nanocubes, demonstrates a high sensitivity of 234.03 μA mM−1 cm−2 and a low limit of detection (0.26 μM), along with high selectivity, stability, repeatability, and reproducibility.

Fluorine-lodged high-valent high-entropy layered double hydroxide for efficient, long-lasting zinc-air batteries.

Efficient and stable bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts are urgently needed to unlock the full potential of zinc-air batteries (ZABs). High-valence oxides (HVOs) and high entropy oxides (HEOs) are suitable candidates for their optimal electronic structures and stability but suffer from demanding synthesis. Here, a low-cost fluorine-lodged high-valent high-entropy layered double hydroxide (HV-HE-LDH) (FeCoNi2F4(OH)4) is conveniently prepared through multi-ions co-precipitation, where F- are firmly embedded into the individual hydroxide layers. Spectroscopic detections and theoretical simulations reveal high valent metal cations are obtained in FeCoNi2F4(OH)4, which enlarge the energy band overlap between metal 3d and O 2p, enhancing the electronic conductivity and charge transfer, thus affording high intrinsic OER catalytic activity. More importantly, the strengthened metal-oxygen (M-O) bonds and stable octahedral geometry (M-O(F)6) in FeCoNi2F4(OH)4 prevent structural reorganization, rendering long-term catalytic stability. Furthermore, an efficient three-phase reaction interface with fast oxygen transportation was constructed, significantly improving the ORR activity. ZABs assembled with FeCoNi2F4(OH)4@HCC (hydrophobic carbon cloth) cathodes deliver a top performance with high round-trip energy efficiency (60.6% at 10 mA cm-2) and long-term stability (efficiency remains at 58.8% after 1050 charge-discharge cycles).

9-(9-Alkylcarbazol-3-yl)-3-(methoxypyridin-3-yl)carbazoles as host materials for very efficient OLEDs

Four derivatives of 9-(9-alkylcarbazol-3-yl)-3-(methoxypyridin-3-yl)carbazoles (HM1-HM4) have been synthesized from key starting compounds: 9-alkyl-3-iodocarbazoles and corresponding 3-(methoxypyridin-3-yl)-9H-carbazoles by using Ullmann coupling reactions. The objective materials have very high thermal stabilities (temperatures of 5 % weight loss 371–387 °C) and can form amorphous layers, also having rather high glass transition temperatures in the region of 89–97 °C. Triplet energy gaps of the four compounds were about 2.7–2.8 eV, making them appropriate for use as host materials in green phosphorescent OLEDs with Ir(ppy)3 guest. Additionally, a composite host system incorporating a synthesized compound of HM series and bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine was developed. The devices with HM2 or HM4 demonstrated the best characteristics whether the emitting layer was a single host or a co-host system, indicating that both compounds could facilitate ideal energy transfer and achieve carrier balance in the device architectures. Notably, the device using 9-(9-butylcarbazol-3-yl)-3-(2-methoxypyridin-3-yl)carbazole (HM2) host outperformed the other devices, achieving peak efficiencies of 16.9 % (58.3 cd/A and 65.0 lm/W) with maximum luminance exceeding 241100 cd/m2.

A family of 2D APt2B3 (A = K, Rb, Cs; B = S, Se) with high-performance for photocatalytic water splitting

Photocatalytic water splitting (PWS) is a promising approach for sustainable hydrogen production, which can potentially address the growing energy demands and environmental concerns. In this paper, we designed a family of 18 two-dimensional materials, AX2B3 (A = K, Rb, Cs; X = Ni, Pd, Pt; BS, Se), and further investigated their stability, electronic structures and PWS performance. We illustrated that all the materials possess high stability, and exhibit semiconducting characteristics with band-gaps from 0.78 to 2.07 eV. Interestingly, there are 6 Pt-containing materials, KPt2S3, KPt2Se3, RbPt2S3, RbPt2Se3, CsPt2S3 and CsPt2Se3, with suitable band-edges to drive hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the process of PWS. Besides, these 6 candidates can release high PWS activity due to their high electron mobility of ∼103 cm2/Vs, which is significantly higher than that of hole. Moreover, they have strong optical absorption coefficient (∼105 cm−1) covering visible to ultraviolet light, and deliver amazing solar-to-hydrogen efficiencies from 24.57% to 26.72%, which are higher than those of common PWS materials. Ultimately, two-dimensional APt2B3 (A = K, Rb, Cs; BS, Se) are suitable candidates for PWS application under sun light.

Association between uric acid and the risk of depressive symptoms in US adults: results from NHANES 2005–2018

BackgroundThis study explores the relationship between serum uric acid(UA) levels and depression. UA is the final product of purine metabolism in the human body, possessing certain physiological functions such as blood pressure regulation, antioxidation, DNA protection, and anti-aging, thereby drawing attention for its potential role in preventing and treating depression.MethodsThis cross-sectional study includes 32,424 participants aged ≥ 20 years from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2018, generating a nationally representative database. Depressive symptoms were assessed using the Patient Health Questionnaire-9. Serum uric acid concentration was measured using the uricase-peroxidase coupled method, and participants were divided into quartiles of serum uric acid concentration. Weighted data were calculated according to analysis guidelines. The association between serum uric acid and depressive symptoms was analyzed using weighted multivariable logistic regression models and restricted cubic spline regression analyses. Subgroup analyses were also performed.ResultsAmong 32,424 participants, 3,421 were defined as having depressive symptoms. The crude prevalence of depressive symptoms was 10.5% (weighted prevalence: 9.086% [95% confidence interval: 9.032–9.139%]). Compared with the first quartile, individuals with higher UA levels had a decreased risk of depressive symptoms by 9% (OR: 0.910, 95% CI: 0.797–10.40), 14.6% (OR: 0.854, 95% CI: 0.741–0.983), and 20.5% (OR: 7795, 95% CI: 0.680–0.930), respectively. Further restricted cubic spline regression analysis revealed a nonlinear association between UA and depressive symptoms, with an inflection point of 319.72 µmol/L. Subgroup multivariable weighted logistic regression analysis found that the association between UA and the risk of depressive symptoms remained consistent across all subgroups, demonstrating high stability and reliability.ConclusionThis study emphasizes a significant nonlinear negative correlation between serum uric acid and depressive symptoms. This suggests that proper control of serum uric acid levels may play a role in preventing and treating depression.

Kinetics of EBV antibody-based NPC risk scores in Taiwan NPC multiplex families.

Nasopharyngeal carcinoma (NPC) risk prediction models based on Epstein-Barr virus (EBV)-antibody testing have shown potential for screening of NPC; however, the long-term stability is unclear. Here, we investigated the kinetics of two EBV-antibody NPC risk scores within the Taiwan NPC Multiplex Family Study. Among 545 participants with multiple blood samples, we evaluated the stability of a 2-marker enzyme-linked immunosorbent assay score and 13-marker multiplex serology score using the intra-class correlation coefficient (ICC) by fitting a linear mixed model that accounted for the clustering effect of multiple measurements per subject and age. We also estimated the clustering of positive tests using Fleiss's kappa statistic. Over an average 20-year follow-up, the 2-marker score showed high stability over time, whereas the 13-marker score was more variable (p < .05). Case-control status is associated with the kinetics of the antibody response, with higher ICCs among cases. Positive tests were more likely to cluster within the same individual for the 2-marker score than the 13-marker score (p < .05). The 2-marker score had an increase in specificity from ~90% for single measurement to ~96% with repeat testing. The 13-marker score had a specificity of ~73% for a single measurement that increased to ~92% with repeat testing. Among individuals who developed NPC, none experienced score reversion. Our findings suggest that repeated testing could improve the specificity of NPC screening in high-risk NPC multiplex families. Further studies are required to determine the impact on sensitivity, establish optimal screening intervals, and generalize these findings to general population settings in high-risk regions.

Exploring Transgressive Segregation for Enhanced Yield in F2 Segregants of Sesame (Sesamum indicum L.)

The experiment involved F2 generation of three superior crosses of sesame: Thilak X Ayali 1, Thilathara X Ayali 2 and Thilak X Ayali 5, grown in a Compact Family Block Design. A total of 200 plants were grown with a spacing of 30 x 25 cm, and observations were recorded on yield related characters. Significant variation was found among most traits, except for capsule length, capsule width, number of seeds per capsule and the number of primary branches. The cross Thilathara X Ayali 2 exhibited a high frequency of transgressive segregants for multiple traits, particularly for seed yield per plant, making it highly promising for further breeding efforts. Plant height had the highest mean and range, showing considerable potential for selection. CV analysis revealed high variability for traits like the number of capsules per plant and seed yield per plant. In contrast, low variability and high stability was observed for traits like capsule length, number of seeds per capsule and days to maturity. Higher PCV and GCV were recorded for traits like days to first flowering, number of capsules per plant, and seed yield per plant, showing substantial genetic and environmental influences. Moderate PCV and GCV were found for plant height and days to maturity, while traits like capsule length, number of seeds per capsule, and capsule width had the lowest PCV and GCV, indicating limited genetic variation. Days to first flowering and days to maturity showed high heritability combined with high genetic advance, suggesting the preponderance of additive gene action and are ideal for simple selection. Traits like capsule length, capsule width, and number of seeds per capsule showed low heritability and genetic advance, making them less ideal for selection. The cross, Thilathara X Ayali 2 should be prioritized in future generations to recover desirable segregants, especially for economically important traits like seed yield.

Discovery of Novel PTP1B Inhibitors by High-throughput Virtual Screening.

To Discover novel PTP1B inhibitors by high-throughput virtual screening Background: Type 2 Diabetes is a significant global health concern. According to projections, the estimated number of individuals affected by the condition will reach 578 million by the year 2030 and is expected to further increase to 700 million deaths by 2045. Protein Tyrosine Phosphatase 1B is an enzymatic protein that has a negative regulatory effect on the pathways involved in insulin signaling. This regulatory action ultimately results in the development of insulin resistance and the subsequent elevation of glucose levels in the bloodstream. The proper functioning of insulin signaling is essential for maintaining glucose homeostasis, whereas the disruption of insulin signaling can result in the development of type 2 diabetes. Consequently, we sought to utilize PTP1B as a drug target in this investigation. The purpose of our study was to identify novel PTP1B inhibitors as a potential treatment for managing type 2 diabetes. To discover potent PTP1B inhibitors, we have screened the Maybridge HitDiscover database by SBVS. Top hits have been passed based on various drug-likeness rules, toxicity predictions, ADME assessment, Consensus Molecular docking, DFT, and 300 ns MD Simulations. Two compounds have been identified with strong binding affinity at the active site of PTP1B along with drug-like properties, efficient ADME, low toxicity, and high stability. The identified molecules could potentially manage T2DM effectively by inhibiting PTP1B, providing a promising avenue for therapeutic strategies.

Supersaturated Antisolvent-Assisted Crystallization for Highly Efficient Inorganic Perovskite Light-Emitting Diodes.

We introduced a strategy to form nanocrystalline CsPbBr3 perovskite films with high luminescence and stability, inhibiting crystal growth using a CsBr supersaturated antisolvent during the antisolvent-assisted crystallization process. We devised this strategy because the supersaturated antisolvent has a higher CsBr concentration over its solubility limit in the saturated antisolvent and consequently will form the smaller perovskite nanocrystalline grains due to the quick precipitation of the CsBr. Here, the CsBr is chosen as a model inorganic antisolvent additive for a crystal growth inhibitor and a passivator. Consequently, we have achieved a nanocrystalline CsPbBr3 film with an average grain size of ∼39 nm by the CsBr supersaturated antisolvent-assisted crystallization process, which is about 41% smaller than the average grain size of the control sample. Hence, the perovskite thin film exhibited a much higher photoluminescence quantum yield than the control film. The maximum current efficiency (CEmax) and the maximum external quantum efficiency (EQEmax) of the corresponding CsPbBr3 perovskite light-emitting diodes (PeLEDs) were approximately twice higher (CEmax of 94.64 cd A-1 and EQEmax of 22.93%) than those of the control device. Simultaneously, the inclusion of CsBr additives played a multifunctional role in diminishing the leakage current of PeLEDs and enhancing their operational lifetime.

Alicyclic Polyimide With Multiple Breakdown Self-Healing Based on Gas-Condensation Phase Validation for High Temperature Capacitive Energy Storage.

Polymer dielectrics with combined thermal stability and self-healing properties are specifically desired for high-temperature film capacitors. The high thermal stability of conventional polymers benefits from the abundance of aromatic rings in the molecule backbone, but the high carbon content sacrifices their self-healing properties. Here, analicyclic polyimide with a high glass transition temperature (256°C) and wide energy bandgap (4.58eV) is designed, which exhibits electric conductivity more than an order of magnitude lower than that of classical polyimide at high electric fields and high temperatures. As a result, alicyclic polyimide achieves a discharged energy density of 4.54 Jcm-3 and a charge-discharge efficiency of above 90% at 200°C, which is superior to existing dielectric polymers and composites. The alicyclic polyimide benefits from a low pyrolytic residual carbon rate, retaining 93% of the dielectric breakdown strength after four electrical breakdown cycles. Distinguishing from the current condensed-phase self-healing concept, for the first time, exploring the self-healing capability of high-temperature polyimide dielectric is presented based on dual self-healing mechanisms of gas-phase and condensed-phase. The high energy density at high temperatures and the superior self-healing capability of alicyclic polyimide further indicate the promise of polyimide dielectric film capacitors for extreme conditions.

A highly capacitive Graphene/Multiholed N‐CNTs hybrid evolved from black humate‐Co‐melamine precursor

Black humic acid (BA) is a black mixture of organic macromolecules isolated from humic acid, which has a greater potential for graphene transformation than fulvic acid and ulmic acid because of more and larger aromatic units and higher molecular weights exceeding 5000 Dalton. Here, chemically bonded BA‐Co‐Melamine precursors are initially constructed using different BA fractions as substrate, Co2+ as bridge bond and melamine as ligand. A series of Graphene/N‐CNTs hybrids (GNCs) is eventually synthesized after the precursor pyrolysis. Resultantly, Fraction Ⅰ, separated at a pH value of 4.16, plays a significant role on constructing the BA‐Co‐Melamine precursor and further producing multiholed GNCs. Due to abundant CNTs, rich mesopores, moderate nitrogen incorporation and a certain graphitized assembly structure, the prepared GNC‐Ⅰ‐b has high capacitance performances. The assembled AC//GNC‐Ⅰ‐b supercapacitor has high specific capacitance (147 F g‐1 at 0.5 A g‐1), rate capability, cycling stability and energy density (16.8 Wh kg‐1 at 14.4 KW kg‐1). The 2032 coin‐type Li//GNC‐Ⅰ‐b half‐cell has high initial discharge capacity (759 mAh g‐1 at 0.03 A g‐1), initial Coulombic efficiency (81.8%), rate performance and cycling stability. Hence, the GNC is a favorable high‐performance carbon material hopefully applied as electrode materials of supercapacitors and LIBs.

Matched Electron-Transport Materials Enabling Efficient and Stable Perovskite Quantum-Dot-Based Light-Emitting Diodes.

Light-emitting diodes (LEDs) based on perovskite quantum dots (QDs), abbreviated as P-QLEDs have been regarded as significantly crucial emitters for lighting and displays. Efficient and stable P-QLEDs still lack ideal electron transport materials (ETM), which could efficiently block hole, transport electron, reduce interface non-radiative recombination and possess high thermal stability. Here, we report 2,4,6-Tris(3'-(pyridine-3-yl) biphenyl-3-yl)-1,3,5-triazine (TmPPPyTz, 3P) with strong electron-withdrawing moieties of pyridine and triazine to modulate the performance of P-QLEDs. Compared with commonly used 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non-radiative recombination caused by the Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole-blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of 3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P-QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2 % and an operational lifetime T50 of 3220 hours at an initial luminance of 100 cd m-2, which is 151 % and about 11-fold improvement compared to control devices (EQE=20 %, T50=297 hours), respectively. These results provide a new concept for constructing the efficient and stable P-QLEDs from the perspective of selective ETM.

Temperature-responsive solvation enabled by dipole-dipole interactions towards wide-temperature sodium-ion batteries

Rechargeable batteries with high durability over wide temperature is needed in aerospace and submarine fields. Unfortunately, Current battery technologies suffer from limited operating temperatures due to the rapid performance decay at extreme temperatures. A major challenge for wide-temperature electrolyte design lies in restricting the parasitic reactions at elevated temperatures while improving the reaction kinetics at low temperatures. Here, we demonstrate a temperature-adaptive electrolyte design by regulating the dipole-dipole interactions at various temperatures to simultaneously address the issues at both elevated and subzero temperatures. This approach prevents electrolyte degradation while endowing it with the ability to undergo adaptive changes as temperature varies. Such electrolyte favors to form solvation structure with high thermal stability with rising temperatures and transits to one that prevents salt precipitation at lower temperatures. This ensures stably within a wide temperature range of ‒60 −55 °C. This temperature-adaptive electrolyte opens an avenue for wide-temperature electrolyte design, highlighting the significance of dipole-dipole interactions in regulating solvation structures.

Coupled Lattice‐Expanded Ni and MoO2 Array for Efficient Alkaline Hydrogen Evolution

AbstractTransition metal oxides have attracted much attention due to their good electrical conductivity, high chemical stability, and easy electronic structure modulation. However, it is still a great challenge to solve the problems of sluggish reaction kinetics and high overpotential in the alkaline hydrogen evolution reaction (HER) due to their poor intrinsic activity. Herein, a lattice‐expanded Ni‐decorated MoO2 array (Ni‐MoO2‐700) catalyst is prepared for the alkaline HER. Unlike most of the reported literature, the decoration of metal heteroatoms may lead to lattice expansion of the carrier catalyst. In contrast, lattice expansion of Ni is also achieved by adjusting the annealing temperature in this work. The Ni‐induced lattice‐expanding effect can not only modulate the electronic structure of the catalyst but also accelerate electron transfer during the reaction, thus increasing its intrinsic activity for the HER. As a result, Ni‐MoO2‐700 exhibits significantly enhanced catalytic activity with an overpotential of 74.9 mV at 10 mA cm−2 in 1.0 m KOH, which is far superior to that of most of the reported advanced Ni‐ and Mo‐based materials. This work provides deep intrinsic insight and a great opportunity to design efficient transition metal oxide catalysts for the alkaline HER.

Constructing Bionic Perovskite Smart Photovoltaic Windows with Switchable Colors and High Cycling Stability.

Smart photovoltaic windows (SPWs) provide a high-efficiency and energy-saving strategy owing to the dual capabilities of electricity generation and sunlight modulation achieved by tunable colors and transmittances. Due to the deterioration of chromic process on photovoltaic layers, SPWs usually suffer from poor cycling stability. Moreover, thermochromic SPWs with a multilayer structure usually change transmittance without reversible color transitions. To address these issues, inspired by chameleon skin, bionic SPWs are designed and constructed by integrating hydrogel, CsPbBr3 semitransparent perovskite solar cells (ST-PSCs), and transparent polymer film. The SPWs realize reversible transitions between transparent green (25°C) and opaque yellow (45°C) states in a short duration (2min) under natural conditions. By optimizing perovskite film and ultrathin-metal electrodes, CsPbBr3 ST-PSCs achieve a good trade-off between transmittance and efficiency, delivering the highest photovoltaic efficiency (8.35%) and a record light utilization efficiency (4.43). Ultimately, the multilayer SPWs maintain stable optical properties and more than 88% initial conversion efficiency after 100 transition cycles, presenting excellent cycling stability. This study proposes a novel approach and device structure for SPWs with high cycling stability, switchable colors, and switchable transmittances. It also paves the way for smart photovoltaic deployment in buildings and many other fields.