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Sodium‐oxygen batteries are emerging as new battery systems. Deep understanding of the origin of overpotential and the kinetic process in sodium‐oxygen batteries remain challenging yet critical. We apply a method of distribution of relaxation time (DRT) to decipher the electrochemical impedance spectroscopy (EIS), allowing us to monitor the changes of different kinetic processes during the discharging and charging. The origin of the overpotential in a battery was further comprehensively investigated combining DRT analysis with differential electrochemical mass spectrometry, Raman and other characterizations. Overpotential is found to primarily stem from oxygen mass transport during discharging, and from poor solid‐solid contact at the electrode surface during charging. Our work demonstrates the study of kinetic processes using DRT analysis, and suggests effective ways to improve the performances of sodium‐oxygen batteries. [ABSTRACT FROM AUTHOR]

Decorating plasmonic Au nanoparticles on TiO2 nanotube arrays with high specific surface area is an efficient strategy for constructing high-performance surface-enhanced Raman scattering (SERS) substrates. Direct deposition of a Au thin film on a TiO2 support, followed by dewetting at elevated temperatures, is economical for scale-up production of Au nanoparticles. The thermal diffusion behavior of Au on a high-curvature surface, however, makes it difficult to meet an optimized distribution of Au nanoparticles that is required for forming electromagnetic SERS hotspot regions. Herein, we proposed a layer-by-layer deposition method to prepare Au-decorated TiO2 nanotube arrays using ZnO nanowires as structural templates. Au nanoparticles could be loaded on either the interior or exterior of the TiO2 nanotubes or buried in the walls simply by switching the sequence of magnetron sputtering of Au and atomic layer deposition of TiO2. We revealed that regulating the thermal diffusion of the Au thin film in the confined ZnO/TiO2 interlayer favors an optimal distribution of the dewetted Au nanoparticles at the interstices. By virtue of the size and interspace of the Au nanoparticles balancing each other, Au–TiO2 featuring Au nanoparticles dispersed on the inner walls of TiO2 nanotubes provided abundant localized electromagnetic field hot spots with a small amount of Au consumption. This Au–TiO2 substrate presented high SERS activity, e.g. a detection limit of 10−9 M for the R6G molecule. This substrate could also achieve self-cleaning through photocatalytic degradation of adsorbed organic analytes, which is required for repeated SERS sensing. [ABSTRACT FROM AUTHOR]

Rechargeable sodium‐carbon dioxide batteries utilize CO2 directly and use abundant and low‐cost sodium instead of lithium. Sodium carbonate is an important discharge product in Na‐CO2 batteries and its oxidative decomposition during charging determines cell performance (i.e., overpotentials and cyclability) but the decomposition mechanism has not been addressed yet. Herein, it is found that Na2CO3 decomposition during the charging process follows a different pathway to lithium carbonate decomposition. It proceeds via a reactive CO3•− intermediate instead of a singlet oxygen intermediate, and thus CO and O2 evolution are not identified during charging. Calculation results show that the OO distance between two adjacent CO3•− in solid Na2CO3 is longer than that in lithium carbonate and thus forming the C2O62− dimer and singlet oxygen is kinetically disfavored in Na2CO3. Surprisingly, the carbon element in Na2CO3 and carbon substrate can exchange via a Na2CO3•C composite after ball milling. By forming the Na2CO3•C composite, carbon can participate in the charging process and be fully oxidized. Therefore, designing a catalyst to encourage the reversible formation/decomposition of Na2CO3•C might be the key to realizing the reversible cycling of Na‐CO2 batteries. [ABSTRACT FROM AUTHOR]

The effects of cold surface temperature, wet air state (temperature and humidity) and original drop size on frost dendrites growth of two neighboring separate frozen water drops of same size under natural convection conditions were investigated by quantitative measurement. It was determined that for different cold plate surface temperature conditions, i.e., the ordinary-low temperature and the cryogenic temperature range, the frost formation mechanism is different. Under the conditions that the air temperature is not too high and absolute humidity is not too excessive, the influence of frozen water drop size on the longest dendrite of frost crystals becomes more and more obvious with the decrease in cold plate temperature. The changes in air temperature and relative humidity both change air absolute humidity, so they have similar effects on the growth of dendrites. However, the effect of wet air state on the growth of frost dendrites is not monotonous, which needs to be considered comprehensively in combination with heat and mass transfer and the existence of heavy phase layer. The thickness of 'the initial continuous frost layer' was measured and it was disclosed that the initial frost layer thickness is 1.7–3.0 times that of the height of the frozen water drop diameter. This value may be possibly used as initial frost layer thickness in heat and mass transfer-based frost layer growth prediction models, at least for ordinary-low temperature conditions. [ABSTRACT FROM AUTHOR]

Background: Anti‐synthetase syndrome (ASS) is a chronic multisystemic autoimmune disease characterized by detectable anti‐aminoacyl‐transfer‐RNA antibodies. Interstitial lung disease (ILD) in anti‐synthetase syndrome patients is often severe and rapidly progressive. Anti‐Zo (phenylalanyl) antibody is reported rarely in ASS. Therefore, the appropriate treatment of anti‐Zo positive ASS is unclear. Case presentation: Here we present a case of anti‐Zo‐positive ASS with rapid progressive ILD (RP‐ILD) in a Chinese patient successfully treated with a combination of systemic corticosteroids and tacrolimus. Conclusion: We reviewed 13 anti‐Zo‐positive ASS patients (including our case) and summarized clinical features that have some differences with other ASS. Anti‐Zo‐positive ASS is a rare autoimmune disease with a high burden of ILD, is often severe and rapidly progressive. Corticosteroids with tacrolimus may improve patient outcomes in anti‐Zo antibody positive ASS with RP‐ILD. [ABSTRACT FROM AUTHOR]

Efficient catalysts are highly desirable for the selective electrochemical CO2 reduction reaction (CO2RR). Ni single-atom catalysts are known as promising CO2RR catalysts, while Ni NPs are expected to catalyze the competing HER. In this work, we have modified the Ni NPs by encapsulating them into porous Ni–N–C nanosheets (Ni@Ni–N–C), to boost the synergy between Ni NPs and dispersed Ni–N species towards CO2RR. The CO faradaic efficiency (FECO) reached 96.4% at −0.9 V and retained over 90% in a wide potential window. More importantly, FECO values of over 94% have been obtained from −50 to −170 mA cm−2 with a peak FECO of 99% in a flow cell. Our work demonstrates that the surface modification of Ni NPs can inhibit the unexpected HER and activate the surface sites, offering a practical design strategy for CO2RR catalysts. [ABSTRACT FROM AUTHOR]

Zn–air batteries are promising energy devices for future sustainable development. It is crucial to promote the cathodic reaction, oxygen reduction reaction (ORR), by applying active electrocatalysts. Herein, a metal-free ORR electrocatalyst has been fabricated by doping S and N atoms into carbon sheets (S–N–C), and it displays high ORR activity and outstanding performance in Zn–air batteries. The S–N–C electrocatalyst exhibits remarkable ORR activity with a half-wave potential of 0.89 V, which is far exceeding that of the commercial Pt/C benchmark and most reported carbon-based electrocatalysts. A full-cell Zn–air battery device with S–N–C as a cathode catalyst is demonstrated, which delivers high power density and good durability. [ABSTRACT FROM AUTHOR]

In this paper, we present an effective route for boosting the photoelectrochemical overall water splitting to produce hydrogen and oxygen by modified TiO2 nanowire arrays (NWAs) photoanode. Such modification includes the synthesis of branched TiO2 NWAs and followed by the deposition of Au nanoparticles (NPs) via the magnetron sputtering and post-annealing for the dewetting of Au films. The physical deposition of Au on the TiO2 substrate with a hierarchical structure provides a feasible strategy to produce metal NPs with uniform size and distribution by the space confinement of the branched TiO2 NWAs. Those Au NPs rendered the intensified visible light absorption in a narrow band region due to the surface plasmon resonance (SPR) effect. The amplified electromagnetic field through the SPR excitation of the Au NPs and their passivation upon the surface of TiO2 NWAs led to the efficient generation and transfer of charge carriers. The synergistic effect between branched TiO2 NWAs and Au NPs resulted in the drastic enhancement of the photoelectrochemical overall water splitting to produce hydrogen and oxygen in the stoichiometric ratio. This work provides a facile method for the preparation of hierarchical metal/semiconductor composite photoelectrode with great potential in the efficient photoelectrochemical water splitting for hydrogen energy production and other applications in solar energy conversion. [ABSTRACT FROM AUTHOR]

Oxygen and hydrogen evolution reactions (OER and HER) are crucial for electrochemical water splitting, which is however hindered by the high cost of noble metal catalysts. Here, we present that by designing the core‐shell distribution of Prussian blue analogues, NiFe‐P@CoFe‐P nanocubes with various shell‐thickness are obtained to unlock the synergy of metal phosphides. The NiFe‐P@CoFe‐P nanocubes display a low overpotential of 248 mV at 10 mA cm−2 and great stability that outperform commercial RuO2 catalyst towards OER. We find that the OER and HER activity of NiFe‐P@CoFe‐P are dependent on the shell thickness, suggesting both the surface and sublayers determine the catalytic performance. Moreover, we demonstrate the water splitting under alkaline condition in an H‐cell powered by commercial photovoltaics using NiFe‐P@CoFe‐P catalyst, which is a promising approach for the conversion of solar energy. [ABSTRACT FROM AUTHOR]

Ni-ethylenediaminetetraacetic acid (Ni-EDTA) poses serious threats to the ecological environment and human health, due to its acute toxicity and low biodegradability. The decomplexation efficiency of Ni-EDTA through the conventional Fenton process has been constrained to pH; thus, other appropriate approaches are required to destroy the stable chelate structure at a neutral pH. In this study, the effect of operating parameters such as the pH, Fe2+ concentration, particle electrode dosage, current density, and coexisting ions was studied. The results revealed that the 3D-EF system owned advantages for the removal of Ni-EDTA in the broadening of the pH application window. The Ni-EDTA removal efficiency in the 3D-EF system reached 84.89% after 120 min at a pH of 7. In addition, the presence of coexisting ions slightly affected the decomplexation efficiency of Ni-EDTA. [ABSTRACT FROM AUTHOR]

Multi-step real-time prediction based on the spatial correlation of wind speed is a research hotspot for large-scale wind power grid integration, and this paper proposes a multi-location multi-step wind speed combination prediction method based on the spatial correlation of wind speed. The correlation coefficients were determined by gray relational analysis for each turbine in the wind farm. Based on this, timing-control spatial association optimization is used for optimization and scheduling, obtaining spatial information on the typical turbine and its neighborhood information. This spatial information is reconstructed to improve the efficiency of spatial feature extraction. The reconstructed spatio-temporal information is input into a convolutional neural network with memory cells. Spatial feature extraction and multi-step real-time prediction are carried out, avoiding the problem of missing information affecting prediction accuracy. The method is innovative in terms of both efficiency and accuracy, and the prediction accuracy and generalization ability of the proposed method is verified by predicting wind speed and wind power for different wind farms. [ABSTRACT FROM AUTHOR]

Large-scale application of rechargeable Zn–air batteries requires low-cost electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) as alternatives to noble metals. Herein, FeCo nanoparticles embedded in N-doped carbon (FeCo/N–C) were prepared by a two-step pyrolysis route. FeCo/N–C exhibits excellent activities toward both the ORR (half-wave potential of 0.84 V) and OER (overpotential of 345 mV at 10 mA cm−2), which are comparable to those of commercial Pt/C and RuO2, and by far exceeding their counterparts Fe/N–C and Co/N–C. Furthermore, the FeCo/N–C catalyst was evaluated in a rechargeable Zn–air battery for the full-cell test. The FeCo/N–C based battery is more durable with a smaller round-trip overpotential after 800 cycles than the battery using an expensive Pt/C + RuO2 mixture catalyst. [ABSTRACT FROM AUTHOR]

High‐performance electrocatalysts, especially those consisting of earth abundant elements with low cost, are highly desirable for oxygen reduction reaction (ORR). However, design of well‐dispersed ORR catalysts that are efficient in both acidic and alkaline media remains challenging. Herein, we report a phosphate‐regulated synthesis with phytic acid, by dispersing the active sites in the carbon nanosheets to obtain Fe2P/FeP nanoparticles encapsulated in P, N‐doped carbon (PNC). The active sites of Fe2P/FeP particles and P, N‐doping sites have a synergistic effect on the ORR reaction. The Fe2P/FeP‐PNC catalyst exhibits good ORR performance and stability in alkaline media. The half‐wave potential (0.85 V), and 5 mV shift after 5000 cycles of stability test for Fe2P/FeP‐PNC catalyst exceed those of commercial Pt/C (E1/2=0.84 V, 20 mV shift) under alkaline condition. The catalyst presents a half‐wave potential of 0.70 V and limited current density of 5.31 mA cm−2 in acidic media. We demonstrate a Zn‐air battery and a PEMFC with the Fe2P/FeP‐PNC as the cathodes, showing a high power density of 156.68 mW cm−2 and 144 mW cm−2 respectively in either the alkaline or acidic electrolytes. [ABSTRACT FROM AUTHOR]

Au/TiO2-based systems with the right combination of electronic configuration, structural dynamics, and stability have recently attracted wide attention in photoelectrochemical (PEC) water splitting for hydrogen generation. Here, we used the masking effect of Au nanoparticles that were dewetted from sputtered Au thin films to fabricate TiO2 nanowire arrays with restricted planar coalescence on flat nucleation layers. The well-spaced vertically aligned TiO2 nanowires allowed for effective coating of another Au thin film by sputtering. A further thermal dewetting process led to a uniform distribution of Au nanoparticles along the nanowire surface. When this sample was used as a photoanode for PEC water splitting, significantly increased photocurrent density and improved PEC activity toward water oxidation were achieved. Systematic electrochemical and PEC characterization demonstrated that the dual functions of the dewetted Au nanoparticles in regulation and surface passivation of TiO2 nanowires were indispensable for the efficient generation, transfer, and separation of photogenerated charge carriers and the consequential boosted PEC water oxidation performance. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes (SPEs) have been treated as a viable solution to build high‐performance solid‐state lithium metal batteries (SSLMBs) at the industrial level, bypassing the safety and energy density dilemmas experienced by today's lithium‐ion battery technology. To promote a wider application of SPEs‐based SSLMBs, the chemical and electrochemical characteristics of lithium metal (Li°) electrode in SPEs have to be clearly elucidated. In this work, the morphological evolution of Li° electrode in the SPEs‐based SSLMBs is comprehensively investigated, via a customized electrochemical cell allowing optical microscopic analyses. The results demonstrate that differing from inorganic solid electrolytes, the elastic feature of SPEs eliminates the “memory effect” of the dendrite formation, in which the previously formed dendrites can be dissolved and the resulting space can be simultaneously occupied by electrolyte components, instead of leaving for a second‐round growth of Li° dendrites. Furthermore, the largely increased electronic conductivities of the as‐formed interphases between Li° electrode and SPEs are found to be responsible for the notoriously soft short‐circuit behavior observed during cycling. These findings bring a fresh understanding of the formation and evolution of lithium dendrites in SPE‐based cells, which are vital for improving the long‐term stability of SSLMBs and other related high‐energy battery systems. [ABSTRACT FROM AUTHOR]

Assembly of functional superstructure microparticles into large‐scale transferable ensembles is a practical approach to elaborate collective properties for catalytic and sensing applications. Here, a two‐step assembly process is proposed to fabricate a mosaic‐like highly oriented monolayer consisting of densely packed CuI superstructure microparticles (s‐CuI) over a large area. First, optimized synthesis and Cl doping of rectangular sheet‐like s‐CuI is achieved by antisolvent crystallization. Then, a steep capillary gradient is created along the water surface to compress the pre‐dispersed s‐CuI into a centimeter‐sized mosaic‐like highly oriented monolayer, which can be integrally transferred onto fluorine‐doped tin oxide glass substrates. The s‐CuI monolayer with optimal Cl doping exhibits a highly sensitive electrochemical response to glucose in a nonenzymatic weakly alkaline environment. A photoelectrochemical response to glucose can also be achieved in nonenzymatic neutral solution. The high performances are ascribed to large surface area, excellent electrical contact, and consistently exposed Cu+ active sites of the s‐CuI building blocks. [ABSTRACT FROM AUTHOR]

This work provides a novel strategy of optimal utilization of fluoroethylene carbonate to generate a uniform and compact solid electrolyte interface film, enhancing the cycle life of potassium ion batteries. With K foil being treated with fluoroethylene carbonate prior to use, enhanced cycling performance up to 1200 hours was achieved. Combining in situ electrochemical impedance spectroscopy with the distribution of relaxation time analysis and XPS analysis, the solubility of KF in the electrolyte is proposed as a crucial factor to determine the quality of a solid electrolyte interface. Our work contributes to understanding the role and manipulating the usage of the fluoroethylene carbonate additive in potassium ion batteries. [ABSTRACT FROM AUTHOR]

FeOOH is one of the earth abundant and high-capacity anode materials for lithium-ion batteries (LIBs), but faces problems of inevitable structure collapse and thus poor capacity retention. Herein, we report a composite of β-FeOOH/Ti3C2Tx MXene sandwich by an intercalation of β-FeOOH nanorods within single-layer Ti3C2Tx MXene flakes. After 100 cycles, the β-FeOOH/Ti3C2Tx composite retains a capacity of 937.5 mA h g−1 at 200 mA g−1, and 671.4 mA h g−1 at 1 A g−1. The composite as an anode in LIB delivers improved cyclability and better high-rate performance compared to pristine β-FeOOH, which result from the excellent conductivity of single-layer MXene, facilitating mass transport by the sandwich structure. This work provides a strategy for the design of electrodes, particularly in Na-ion and K-ion batteries, which involve active materials that experience volume change and structural damage during cycling. [ABSTRACT FROM AUTHOR]

Efficient yet low‐cost electrocatalysts for the oxygen reduction reaction (ORR) are highly desirable for energy systems such as metal‐air batteries and fuel cells. Herein, we report the synthesis of efficient cobalt‐modified nitrogen‐doped carbon (N−C/Co) electrocatalysts by using a one‐pot pyrolysis. The abundant source of N in g‐C3N4 contributes to the in situ N doping in the carbon matrix, which favors the formation of Co‐related catalytic active sites. The N−C/Co‐1 (prepared with 1 mmol Co salt) sample exhibits the best performance towards the ORR, with a positive half‐wave potential of 0.86 V (vs. the reversible hydrogen electrode, RHE), high stability and excellent methanol tolerance, which outperforms the commercial Pt/C catalyst. We find that the high performance is dependent on the optimal content of Co that can achieve the maximum amount of Co−Nx catalytic species. In addition, we reveal that the size effect of Co nanoparticles is not the determining factor for the ORR activity in the current system, as the kinetics of the ORR reaction is dominantly determined by the active sites derived from Co−Nx species. By exploiting the N−C/Co‐1 sample as an air cathode catalyst, the assembled Zn‐air battery presents a maximal power density of 153 mW cm−2 as well as good durability during continuous cycle tests. [ABSTRACT FROM AUTHOR]

Coupling semiconducting metal–organic frameworks (MOFs) with metal oxide (MO) semiconductor nanowires is an efficient solution to tune the photoelectric properties of both the parties. In this report, we demonstrate a facile surfactant-free growth strategy for modification of zinc oxide (ZnO) single-crystal nanowire arrays (NWAs) with the MOF zinc glycolate (noted as Zn-GA) that contains an embedded continuous 3D Zn–O network. Due to the structural resemblance of the Zn–O network between Zn-GA and ZnO, the prepared ZnO@Zn-GA nanowires present a tight contact at the core–shell interface in a partially epitaxial manner, and the loading amount of Zn-GA can be well controlled in the synthetic process. The inherent p-type Zn-GA in combination with the widely available n-type ZnO assures the construction of tandem n–p heterojunctions at the core–shell interface, which is confirmed by Mott–Schottky analysis. By implementation of the ZnO@Zn-GA NWAs as photoanodes for photoelectrochemical oxidation of water and oxalic acid, improved photocurrent responses are obtained relative to the primary ZnO NWAs. The most significant photoresponse is observed in the ZnO nanowires shelled by a compact Zn-GA particulate thin film with the largest junction region. These results are elucidated by the enhanced spatial separation efficiency of photogenerated charge carriers, which is favored by the built-in electric field at the interface of the n–p heterojunctions. [ABSTRACT FROM AUTHOR]

Rechargeable lithium‐oxygen batteries, especially the nonaqueous lithium‐oxygen batteries have attracted much attention in recent years due to their high energy densities. However, few critical challenges remain to be overcome, including the low round‐trip efficiency, high charge overpotential, poor cycling performance, decomposition of electrolyte, and instability of the carbon‐based electrode. Among these, the instability of the carbon‐based electrode is one of the major problems that hindered the practical application of the Li−O2 batteries. Much work has been done to solve this problem and there are two widely‐applied strategies: modification of carbon and designing a "carbon‐free" cathode. In this review, we will introduce recent achievements of both strategies. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • One-step synthesis of carbon dots (CDs) embedded zincone. • Low-cost fluorescence probe with sensitive and selective Cr 2 O 7 2– sensing ability. • Bifunctional feature of both detection and efficient Cr 2 O 7 2– removal capacity. • Hexamethylenetetramine for the first time revealed as CDs source. Abstract Hexavalent chromium [Cr(VI)] is a carcinogenic and toxic pollutant and has brought severe environmental risks. Therefore, detection and removal of chromium ions with sensitive and economic materials are highly desirable. In this work, we develop a facile one-step synthesis of carbon dots (CDs) embedded zincone microspheres (CDs/zincone), which can act as low-cost and highly selective sensors for Cr(VI) based on the inner filter effect (IFE). A wide concentration linear range of dichromate ions (Cr 2 O 7 2–) from 1 to 1000 μM can be detected by a small dose of the powders, and the detection process can be accomplished within 150 s. In addition, the CDs/zincone can also demonstrate efficient Cr 2 O 7 2– removal with an uptake capacity of 47.5 mg/g. The in situ hydrolysis of zincone is shown to play a key role in the sensing and uptake of Cr 2 O 7 2–. This CDs/zincone composite is the first bifunctional zincone material reported for both detection and removal of Cr 2 O 7 2–. Moreover, hexamethylenetetramine (HMTA) is revealed as a new source for CDs in our system. This novel hybrid CDs/zincone material, which can be easily obtained by environmentally friendly synthesis, has potential applications for Cr(VI) detection and water treatment. [ABSTRACT FROM AUTHOR]