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The inadequate stability of organic-inorganic hybrid perovskites remains a significant barrier to their widespread commercial application in optoelectronic devices. Aging phenomena profoundly affect the optoelectronic performance of perovskite-based devices. In addition to enhancing perovskite stability, the real-time detection of aging status, aimed at monitoring the aging progression, holds paramount importance for both fundamental research and the commercialization of organic-inorganic hybrid perovskites. In this study, the aging status of perovskite was real-time investigated by using terahertz time-domain spectroscopy. Our analysis consistently revealed a gradual decline in the intensity of the absorption peak at 0.968 THz with increasing perovskite aging. Furthermore, a systematic discussion was conducted on the variations in intensity and position of the terahertz absorption peaks as the perovskite aged. These findings facilitate the real-time assessment of perovskite aging, providing a promising method to expedite the commercialization of perovskite-based optoelectronic devices.
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Electrochemically converting NO3- compounds into ammonia represents a sustainable route to remove industrial pollutants in wastewater and produce valuable chemicals. Bimetallic nanomaterials usually exhibit better catalytic performance than the monometallic counterparts, yet unveiling the reaction mechanism is extremely challenging. Herein, we report an atomically precise [Ag30Pd4 (C6H9)26](BPh4)2 (Ag30Pd4) nanocluster as a model catalyst toward the electrochemical NO3- reduction reaction (eNO3-RR) to elucidate the different role of the Ag and Pd site and unveil the comprehensive catalytic mechanism. Ag30Pd4 is the homoleptic alkynyl-protected superatom with 2 free electrons, and it has a Ag30Pd4 metal core where 4 Pd atoms are located at the subcenter of the metal core. Furthermore, Ag30Pd4 exhibits excellent performance toward eNO3-RR and robust stability for prolonged operation, and it can achieve the highest Faradaic efficiency of NH3 over 90%. In situ Fourier-transform infrared study revealed that a Ag site plays a more critical role in converting NO3- into NO2-, while the Pd site makes a major contribution to catalyze NO2- into NH3. The bimetallic nanocluster adopts a tandem catalytic mechanism rather than a synergistic catalytic effect in eNO3-RR. Such finding was further confirmed by density functional theory calculations, as they disclosed that Ag is the most preferable binding site for NO3-, which then binds a water molecule to release NO2-. Subsequently, NO2- can transfer to the vicinal exposed Pd site to promote NH3 formation.
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The rapid development of miniaturized electronic devices has greatly stimulated the endless pursuit of high-performance on-chip micro-supercapacitors (MSCs) delivering both high energy and power densities. To this end, an advanced three-dimensional (3D) microelectrode architecture design offers enormous opportunities due to high mass loading of active materials, large specific surface areas, fast ion diffusion kinetics, and short electron transport pathways. In this review, we summarize the recent advances in the rational design of 3D architectured microelectrodes including 3D dense microelectrodes, 3D nanoporous microelectrodes, and 3D macroporous microelectrodes. Furthermore, the emergent microfabrication strategies are discussed in detail in terms of charge storage mechanisms and structure-performance correlation for on-chip MSCs. Finally, we conclude with a perspective on future opportunities and challenges in this thriving field.
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Hybrid composite electrolytes incorporate polymer matrixes and garnet filler attract the focus of concern for all-solid-state batteries, which possess high ionic conductivity, superior electrochemical stability, and wide electrochemical window of ceramic electrolyte advantages, and exhibit excellent flexibility and tensile shear strength from polymer electrolyte benefits. Hence, the unique structure design of solid-state electrolytes resolves the existing defects that the use of either single garnet or polymer electrolytes implemented into battery devices. This review summarizes Li7 La3 Zr2 O12 (LLZO)/polymer solid composite electrolytes (SCEs), comprising LLZO/polymer SCEs with various structures and different ratios of LLZO fillers, LLZO/polymer with different kinds of polymers matrix and hybrid lithium-salt, and Li+ transport pathways within the LLZO/polymers SCEs interface. The purpose here is to propose the viewpoints and challenges of LLZO/polymer SCEs to promote the development of next-generation solid electrolytes.
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We presented a strategy for enhancing the sensitivity of terahertz glucose sensing with a hydrogel platform pre-embedded with Au nanoparticles. Physiological-level glucose solutions ranging from 0 to 0.8 mg/mL were measured and the extracted absorption coefficients can be clearly distinguished compared to traditional terahertz time domain spectroscopy performed directly on aqueous solutions. Further, Isotherm models were applied to successfully describe the relationship between the absorption coefficient and the glucose concentration (R2 = 0.9977). Finally, the origin of the sensitivity enhancement was investigated and verified to be the pH change induced by the catalysis of Au nanoparticles to glucose oxidation.
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Flexible electrodes that are multilayer, multimaterial, and conformal are pivotal for multifunctional wearable electronics. Traditional electronic circuits manufacturing requires substrate-supported transfer printing, which limits their multilayer integrity and device conformability on arbitrary surfaces. Herein, a "shrinkage-assisted patterning by evaporation" (SHAPE) method is reported, by employing evaporation-induced interfacial strain mismatch, to fabricate auto-detachable, freestanding, and patternable electrodes. The SHAPE method utilizes vacuum-filtration of polyaniline/bacterial cellulose (PANI/BC) ink through a masked filtration membrane to print high-resolution, patterned, and multilayer electrodes. The strong interlayer hydrogen bonding ensures robust multilayer integrity, while the controllable evaporative shrinking property of PANI/BC induces mismatch between the strains of the electrode and filtration membrane at the interface and thus autodetachment of electrodes. Notably, a 500-layer substrateless micro-supercapacitor fabricated using the SHAPE method exhibits an energy density of 350 mWh cm-2 at a power density of 40 mW cm-2 , 100 times higher than reported substrate-confined counterparts. Moreover, a digital circuit fabricated using the SHAPE method functions stably on a deformed glove, highlighting the broad wearable applications of the SHAPE method.
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Rechargeable aqueous zinc (Zn) batteries are promising for large-energy storage because of their low cost, high safety, and environmental compatibility, but their implementation is hindered by the severe irreversibility of Zn metal anodes as exemplified by water-induced side reactions (H2 evolution and Zn corrosion) and dendrite growth. Here, we find that the introduction of a hydrophobic carbonate cosolvent into a dilute aqueous electrolyte exhibits a much stronger ability to address the reversible issues facing Zn anodes than that with hydrophilic ones. Among the typical carbonates (ethylene carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate (DEC)), DEC as the most hydrophobic additive enables the strongest breaking of water's H-bond network and replaces the solvating H2O in a Zn2+-solvation sheath, which significantly reduces the water activity and its decomposition. Additionally, DEC molecules preferentially adsorb onto the Zn surface to create an H2O-poor electrical double layer and render a dendrite-free Zn2+-plating behavior. The formulated hybrid 2 m Zn(OTf)2 + 7 m DEC electrolyte endows the Zn electrode with an ability to achieve high cycling stability (over 3500 h at 5 mA cm-2 with 2.5 mA h cm-2) and supports the stable operation of Zn||V2O5·nH2O full battery. This efficient strategy with hydrophobic cosolvent suggests a promising direction for designing aqueous battery chemistries.
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All-solid-state sodium batteries (ASSBs) have attracted ever-increasing attention due to their enhanced safety, high energy density, and the abundance of raw materials. One of the remaining key issues for the practical ASSB is the lack of good superionic and electrochemical stable solid-state electrolytes (SEs). Design and manufacturing specific functional materials used as high-performance SEs require an in-depth understanding of the transport mechanisms and electrochemical properties of fast sodium-ion conductors on an atomic level. On account of the continuous progress and development of computing and programming techniques, the advanced computational tools provide a powerful and convenient approach to exploit particular functional materials to achieve that aim. Herein, this review primarily focuses on the advanced computational methods and ion migration mechanisms of SEs. Second, we overview the recent progress on state-of-the-art solid sodium-ion conductors, including Na-ß-alumina, sulfide-type, NASICON-type, and antiperovskite-type sodium-ion SEs. Finally, we outline the current challenges and future opportunities. Particularly, this review highlights the contributions of the computational studies and their complementarity with experiments in accelerating the study progress of high-performance sodium-ion SEs for ASSBs.
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Developing highly efficient anchoring materials to suppress sodium polysulfides (NaPSs) shuttling is vital for the practical applications of sodium sulfur (Na-S) batteries. Herein, we systematically investigated pristine graphene and metal-N4@graphene (metal = Fe, Co, and Mn) as host materials for sulfur cathode to adsorb NaPSs via first-principles theory calculations. The computing results reveal that Fe-N4@graphene is a fairly promising anchoring material, in which the formed chemical bonds of Fe-S and N-Na ensure the stable adsorption of NaPSs. Furthermore, the doped transition metal iron could not only dramatically enhance the electronic conductivity and the adsorption strength of soluble NaPSs, but also significantly lower the decomposition energies of Na2S and Na2S2 on the surface of Fe-N4@graphene, which could effectively promote the full discharge of Na-S batteries. Our research provides a deep insight into the mechanism of anchoring and electrocatalytic effect of Fe-N4@graphene in sulfur cathode, which would be beneficial for the development of high-performance Na-S batteries.
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In this paper, the band-gap tunability of three monolayer semiconductors under hydrostatic pressure was intensively investigated based on first-principle simulations with a focus on monolayer antimony (Sb) as a semiconductor nanomaterial. As the benchmark study, monolayer black phosphorus (BP) and monolayer molybdenum disulfide (MoS2) were also investigated for comparison. Our calculations showed that the band-gap tunability of the monolayer Sb was much more sensitive to hydrostatic pressure than that of the monolayer BP and MoS2. Furthermore, the monolayer Sb was predicted to change from an indirect band-gap semiconductor to a conductor and to transform into a double-layer nanostructure above a critical pressure value ranging from 3 to 5 GPa. This finding opens an opportunity for nanoelectronic, flexible electronics and optoelectronic devices as well as sensors with the capabilities of deep band-gap tunability and semiconductor-to-metal transition by applying mechanical pressure.
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Layer-structured black phosphorus (BP) demonstrating high specific capacity has been viewed as a very promising anode material for future high-energy-density Li-ion batteries (LIBs). However, its practical application is hindered by large volume change of BP and poor mechanical stability of BP anodes by traditional slurry casting technology. Here, a free-standing flexible anode composed of BP nanosheets and nanocellulose (NC) nanowires is fabricated via a facile vacuum-assisted filtration approach. The constructed free-standing BP@NC composite anode offers three-dimensional (3D) mixed-conducting network for Li+/e- transports. The substrate of NC film has a certain flexibility up to 10.2% elongation that can restrain the volume change of BP and electrode during operation. In addition, molecular dynamic (MD) simulation and density function theory (DFT) show the greatly enhanced Li+ diffusion in BP@NC composite where the Li ions receive less repulsive force at the interface of BP interlayer and nanocellulose. Benefiting from above multifunction of nanocellulose, the BP@NC composite exhibits high capacities of 1020.1 mAh g-1 at 0.1 A g-1 after 230 cycles and 994.4 mAh g-1 at 0.2 A g-1 after 400 cycles, corresponding to high capacity retentions of 87.1% and 84.9%, respectively. Our results provide a low-cost and effective strategy to develop advanced electrodes for next-generation rechargeable batteries.
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In this paper, we provide a straightforward method to predict the terahertz absorption spectrum based on a fixed charge model with classic molecular dynamics calculations. The absorption features in the frequency range between 1 and 3.4 THz of stearic acid B-form and between 1 and 2.7 THz of C-form were successfully calculated. Most of the absorption peaks from the simulation correspond well with those from the measurements. By calculating the spatial and time-dependent energy accumulation in the molecular system, the core idea of our calculation method is further validated. Compared with the ab initio calculations, our method provides a computationally inexpensive way to accurately predict the locations of absorption features. With regard to the traditional molecular dynamic simulations, our method is able to extract the spatial distribution of the energy accumulation as well as the local motions in the molecular system.
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Water shortage is one of the most concerning global challenges in the 21st century. Solar-inspired vaporization employing photothermal nanomaterials is considered to be a feasible and green technology for addressing the water challenge by virtue of abundant and clean solar energy. 2D nanomaterials aroused considerable attention in photothermal evaporation-induced water production owing to their large absorption surface, strong absorption in broadband solar spectrum, and efficient photothermal conversion. Herein, the recent progress of 2D nanomaterials-based photothermal evaporation, mainly including emerging Xenes (phosphorene, antimonene, tellurene, and borophene) and binary-enes (MXenes and transition metal dichalcogenides), is reviewed. Then, the optimization strategies for higher evaporation performance are summarized in terms of modulation of the intrinsic photothermal performance of 2D nanomaterials and design of the complete evaporation system. Finally, the challenges and prospective of various kinds of 2D photothermal nanomaterials are discussed in terms of the photothermal performance, stability, environmental influence, and cost. One important principle is that solutions for water challenges should not introduce new environmental and social problems. This Review aims to highlight the role of 2D photothermal nanomaterials in solving water challenges and provides a viable scheme toward the practical use in photothermal materials selection, design, and evaporation systems building.
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For future pollution-free renewable energy production, platinum group metal (PGM)-free electrocatalysts are highly required for oxygen reduction reaction (ORR) to avoid all possible Fenton reactions and to make fuel cell more economical. Therefore, in this study, to overcome traditional electrocatalyst limitations, we applied facile method to synthesize robust mesoporous CrN-reduced graphene oxide (rGO) nanocomposite with MnO (thereafter, Cr/rGO composite with MnO) as an electrocatalyst by efficient one-step sol-gel method by ammonolysis at 900°C for 9 h. Synthesized porous structures of Cr/rGO nanocomposite with MnO have the highest estimated surface area of 379 m2·g-1, higher than that of the carbon black (216 m2· g cat - 1 ) support, and almost uniform pore size distribution of about 4 nm. The Cr/rGO nanocomposites with MnO exhibit enhanced electrocatalytic ORR properties with estimated high half-wave potential of 0.89 V vs. the reversible hydrogen electrode (RHE) and current density of 5.90 mA·cm-2, compared with that of benchmark 20% Pt/C electrode (0.84 V, 5.50 mA·cm-2), with noticeable methanol tolerance and significantly enhanced stability in alkaline media. Hence, the Cr/rGO nanocomposites with MnO showed superior performance to 20 wt.% Pt/C; their half-wave potentials were 50 mV high, and the limiting current density was 0.40 mA·cm-2 high. In alkaline anion exchange membrane fuel cell (AAEMFC) setup, this cell delivers a power density of 309 mW·cm-2 for Cr/rGO nanocomposite with MnO, demonstrating its potential use for energy conversion applications. The nanosized Cr/rGO metallic crystalline nanocomposites with MnO gave a large active surface area owing to the presence of rGO, which also has an effect on the charge distribution and electronic states. Hence, it may be the reason that Cr/rGO nanocomposites with MnO, acting as more active and more stable catalytic materials, boosted the electrocatalytic properties. The synergistic consequence in nanosized Cr/rGO composite with MnO imparts the materials' high electron mobility and thus robust ORR activity in 0.1 M of KOH solution. This potential method is highly efficient for synthesis of large-scale, non-noble-metal-based electrocatalytic (NNME) materials (i.e., Cr/rGO nanocomposite with MnO) on the gram level and is efficient in preparing novel, low-cost, and more stable non-PGM catalysts for fuel cells.
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Two-dimensional (2D) materials have a wide platform in research and expanding nano- and atomic-level applications. This study is motivated by the well-established 2D catalysts, which demonstrate high efficiency, selectivity and sustainability exceeding that of classical noble metal catalysts for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and/or hydrogen evolution reaction (HER). Nowadays, the hydrogen evolution reaction (HER) in water electrolysis is crucial for the cost-efficient production of a pure hydrogen fuel. We will also discuss another important point related to electrochemical carbon dioxide and nitrogen reduction (ECR and N2RR) in detail. In this review, we mainly focused on the recent progress in the fuel cell technology based on 2D materials, including graphene, transition metal dichalcogenides, black phosphorus, MXenes, metal-organic frameworks, and metal oxide nanosheets. First, the basic attributes of the 2D materials were described, and their fuel cell mechanisms were also summarized. Finally, some effective methods for enhancing the performance of the fuel cells based on 2D materials were also discussed, and the opportunities and challenges of 2D material-based fuel cells at the commercial level were also provided. This review can provide new avenues for 2D materials with properties suitable for fuel cell technology development and related fields.
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LiNi0.5Mn1.5O4 (LNMO) is a potential cathode material for lithium-ion batteries with outstanding energy density and high voltage plateau (>4.7 V). However, the interfacial side reaction between LNMO and the liquid electrolyte seriously causes capacity fading during cycling at the high voltage. Here, p-toluenesulfonyl isocyanate (PTSI) is used as the electrolyte additive to overcome the above problem of LNMO. The results show that the specific capacity of LNMO/Li cell with 0.5 wt.% PTSI at the first cycle is effectively enhanced by 36.0 mAh/g and has better cycling performance than that without PTSI at 4.98 V. Also, a stable solid electrolyte interface (SEI) film derived from PTSI is generated on the electrode surface, which could alleviate the strike of hydrofluoric acid (HF) caused by electrolyte decomposition. These results are explained by the molecular structure of PTSI, which contains SO3. The S=O groups can delocalize the nitrogen nucleus to block the reactivity of PF5.
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Rapidly-growing demand for wearable and flexible devices is boosting the development of flexible lithium ion batteries (LIBs). The exploitation of flexible electrodes with high mechanical properties and superior electrochemical performances has been a key challenge for the rapid practical application of flexible LIBs. Herein, a flexible composite electrode was prepared from the mixed solutions of Li[Li0.2Ni0.13Co0.13Mn0.54]O2 (LLOs), carbon nanotubes(CNTs), and nanofibrillated celluloses (NFCs) via a vacuum filtration method. The resulting LLOs/CNTs/NFCs electrode delivered an initial discharge capacity of 253 mAh g-1 at 0.1 C in the voltage range from 2.0 to 4.6 V, and retained a reversible capacity of 178 mAh g-1 with 83% capacity retention after 100 cycles at 1 C. The LLOs/CNTs/NFCs electrode exhibited excellent flexibility along with repeated bending in the bending test. The LLOs/CNTs/NFCs electrode after bending test remained a discharge capacity of 149 mAh g-1 after 100 cycles at 1 C, and the corresponding capacity retentions was 76%. The excellent electrochemical performance and high flexibility can be ascribed to the framework formed by CNTs with high conductivity and NFCs with good mechanical properties. The results imply that the as-fabricated electrode can be a promising candidate for the flexible LIBs.
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In this study, silicon/carbon composite nanofibers (Si@CNFs) were prepared as electrode materials for lithium-ion batteries via a simple electrospinning method and then subjected to heat treatment. The morphology and structure of these materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show that the structure provides good electrical conductivity and affords sufficient space to accommodate volume expansion during charging/discharging. Furtherly, electrochemical performance tests show that the optimized Si@CNFs have an initial reversible capacity of 1,820 mAh g-1 at a current density of 400 mA g-1 and capacity retention of 80.7% after 100 cycles at a current density of 800 mA g-1. Interestingly, the optimized Si@CNFs have a superior capacity of 1,000 mAh g-1 (400 mA g-1) than others, which is attributed to the carbon substrate nanofiber being able to accommodate the volume expansion of Si. The SEI resistance generated by the Si@CNFs samples is smaller than that of the Si nanoparticles, which confirms that SEI film generated from the Si@CNFs is much thinner than that from the Si nanoparticles. In addition, the connected carbon substrate nanofiber can form a fiber network to enhance the electronic conductivity.
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This manuscript presented a large scale synthesis of Graphitic Shells like carbon nano onions (GS-CNOs) by direct solution method using mayenite electride as a catalyst for synthesis of CNOs. Thermal characterization, microstructural analysis, and high resolution electron microscopy have confirmed the graphitization and revealed the resulting GS-CNOs with particle size about 15 nm, maximum BET surface area of 214 m2.g-1, and moderate conductivity of 250 S.cm-1, thus providing a new approach to synthesize GS-CNOs. The reported GS-CNOs, which acts as more active but less expensive electrocatalysts with onset potential of 1.03 V, half wave potential of 0.88 V vs. the reversible hydrogen electrode (RHE), and limited current density of 5.9 mA.cm-2, higher than that of benchmark 20% Pt/C (1.02 eV, 0.82 V, 5.2 mA.cm-2). The synthesized nano-powder acts as an origin of ORR activity via a four electron (4e-) pathway, along with significantly enhanced stability, in alkaline media. The high ORR activity is ascribed to GS-CNOs embedded sufficient metallic C12A7:e- particles, which favor faster electron movement and better adsorption of oxygen molecules on catalyst surface. Hence, we explored first time large scale synthesis of GS-CNOs with gram level and provide efficient approach to prepare novel, lowest cost, potential non-noble metals catalyst for fuel cells.
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Psoriasis vulgaris (PsV), also known as plaque psoriasis, is a life-threatening autoimmune skin disease. Inflammatory factors may contribute to the development of PsV. Present study aimed to explore the association of endoplasmic reticulum aminopeptidase 1 (ERAP1) gene polymorphisms (rs26653 and rs27524) with PsV susceptibility in a Chinese Han population. Subgroup analysis was also performed based on the onset of PsV.Present case-control study included 143 patients with PsV and 149 healthy controls. Direct sequencing method was used for genotyping ERAP1 polymorphisms. Chi-squared test was used to estimate the association between ERAP1 polymorphisms and PsV susceptibility. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess association strength.The polymorphism rs26653 was positively correlated with PsV susceptibility (CC vs GG, Pâ=â.047, ORâ=â1.964, 95% CIâ=â1.006-3.834; C vs G, Pâ=â.042, ORâ=â1.403, 95% CIâ=â1.011-1.946). Meanwhile, its CC genotype and C allele were positively associated with the early onset of PsV (Pâ=â.036, ORâ=â2.080, 95% CIâ=â1.044-4.145; Pâ=â.034, ORâ=â1.443, 95% CIâ=â1.028-2.024) and increased PsV risk in the subgroup with family history (Pâ=â.029, ORâ=â2.149, 95% CIâ=â1.075-4.296; Pâ=â.027, ORâ=â1.466, 95% CIâ=â1.044-2.059).ERAP1 gene rs26653 polymorphism may increase the risk of PsV in Chinese Han population.