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Deep learning has become an essential technique in image steganography. Most of the current deep-learning-based steganographic methods process digital images in the spatial domain. There are problems such as limited embedding capacity and unsatisfactory visual quality. To improve capacity-distortion performance, we develop a steganographic method from the frequency-domain perspective. We propose a module called the adaptive frequency-domain channel attention network (AFcaNet), which makes full use of the frequency features in each channel by a fine-grained manner of assigning weights. We apply this module to the state-of-the-art SteganoGAN, forming an Adaptive Frequency High-capacity Steganography Generative Adversarial Network (AFHS-GAN). The proposed neural network enhances the ability of high-dimensional feature extraction through overlaying densely connected convolutional blocks. In addition to this, a low-frequency loss function is introduced as an evaluation metric to guide the training of the network and thus reduces the modification of low-frequency regions of the image. Experimental results on the Div2K dataset show that our method has a better generalization capability compared to the SteganoGAN, with substantial improvement in both embedding capacity and stego-image quality. Furthermore, the embedding distribution of our method in the DCT domain is more similar to that of the traditional method, which is consistent with the prior knowledge of image steganography. [ABSTRACT FROM AUTHOR]

A traditional image steganography embeds secret information into a cover image to generate a secret-embedded image. The modification traces imposed on the cover image can be easily detected by steganalysis tools. Coverless steganography has been introduced to solve this problem. In this study, coverless steganography is combined with image style transfer, an arbitrary image style transfer network CSST-Net is put forward, and a secret information is encoded into the parameters (an adaptive steganography matrix) of CSST-Net, which is used to restrict the style transfer. Arbitrary image style transfer is performed instructed by the adaptive steganography matrix, and the image style transfer result driven by secret information is directly synthesized. Our experiments show that CSST-Net can not only synthesize any image style transfer result with good visual effect, but also achieve good performance in capacity, anti-steganalysis and security. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (C 3 N 4) is the most widely reported member of the carbon nitride family because of its large pores which serve as alkali-metal atom storage sites. However, adsorption of Li atoms into these triangular pore sites occur at a high adsorption energy (E ad) of ∼4.2 eV which surpasses the desorption energy of bulk Li (3 eV) thereby resulting in ineffective desorption. Lithium storage in C 3 N 4 occurs via an intercalation/deintercalation process therefore the inability of adsorbed Li atoms to desorb from its structure results in structural instability, poor conductivity and limited reversible capacity. Here, we show that by doping Si atoms into the pore sites of C 3 N 4 , the Li E ad can be significantly decreased to 2.51 eV. This suitable E ad enabled effective Li transport, improved charge transfer, modulated the electronic conductivity, decreased the Li diffusion barrier and boosted the lithium storage capacity to 557.7 mAh/g. These results show that Si doping is an effective way to resolve the problems associated with C 3 N 4 and to achieve superior electronic properties and lithium storage capacity. These interesting results show the potential of Si doped C 3 N 4 for lithium ion batteries and this approach can be extended to other carbon nitride structures. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrolyte engineering is considered as an effective strategy to establish stable solid electrolyte interface (SEI), and thus to suppress the growth of lithium dendrites. In a recent study reported in Advanced Functional Materials by Ma group, discovered that strong coordination force could be founded between 15-Crown-5 ether (15-C-5) and Li+, which facilitates the crown ether (15-C-1) to participate in the solvation structure of Li+ in the electrolyte for the same purpose. Such a novel strategy might impact the design of high-performance and safe lithium metal batteries (LMBs). [ABSTRACT FROM AUTHOR]

Silicon has demonstrated great potential as anode materials for next-generation high-energy density rechargeable lithium ion batteries. However, its poor mechanical integrity needs to be improved to achieve the required cycling stability. Nano-structured silicon has been used to prevent the mechanical failure caused by large volume expansion of silicon. Unfortunately, pristine silicon nanostructures still suffer from quick capacity decay due to several reasons, such as formation of solid electrolyte interphase, poor electrical contact and agglomeration of nanostructures. Recently, increasing attention has been paid to exploring the possibilities of hybridization with carbonaceous nanostructures to solve these problems. In this review, the recent advances in the design of carbon-silicon nanohybrid anodes and existing challenges for the development of high-performance lithium battery anodes are briefly discussed. [ABSTRACT FROM PUBLISHER]

Metal–Organic Polymers (MOPs) have attracted growing attention for lithium-ion battery (LIB) applications due to their merits in orderly ionic transportation and robust structure stability in electrochemical reactions. However, they suffer from poor electronic conductivity. In this work, we apply first-principles density functional theory to explore the potential of three one-dimensional (1D) electrically conductive C6H2S4TM (TM = Fe, Co, and Ni) MOPs with the π–d conjugated coordination as anode materials for Li+ ions storage. Our theoretical results reveal that these 1D MOPs possess a superior theoretical capacity of over 748 mA h g−1. In particular, the 1D C6H2S4Ni MOP shows an exceptional theoretical specific capacity of 1110 mA h g−1 based on the three-electron transferring reaction, which significantly outperforms the traditional graphite-based anode material in LIBs. Moreover, the resonant charge transfer between Ni metal and ligand within the 1D C6H2S4Ni MOP reduces the diffusion energy barrier of the Li atoms when they migrate on the surface of the MOP. The ultrahigh theoretical specific capacity of the C6H2S4Ni MOP predicts that it can be a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

There are growing research interests in developing high-performance energy storage systems to meet the demands for large-scale and sustainable energy storage. The lithium-sulfur (Li-S) batteries have drawn numerous attentions due to their exceptionally high energy density compared with other batteries. However, achieving the high capacities with long-term cycle stability and retaining an essentially high sulfur loading remains a tremendous challenge for the designs of Li-S batteries. Graphene is regarded as a very suitable and promising addition to the compositions for Li-S batteries due to its unique two dimensional (2D) structure, high conductivity and superior mechanical flexibility. Besides, the functional groups of graphene surface can be tuned flexibly to immobilize the S/Li2S x on the graphene surface during the cycling process. In this review, the development of graphene-sulfur composites and their applications in Li-S batteries are discussed. The attempts are also devoted to the synthesis approaches of various graphene-based sulfur composites, the graphene-sulfur interaction and the impacts on the electrochemical performances as well as the major issues of Li-S batteries. [ABSTRACT FROM AUTHOR]

Abstract: A photo-electrode of hydrogenated TiO2 nanorod arrays (H-TNRs) was prepared and used as a photoelectrochemical sensor for organic compound detections for the first time. Under visible light, the H-TNR electrode has shown a highly sensitive and steady photocurrent response due to introduction of oxygen vacancy and mid-gap energy levels. The H-TNRs are a promising material for photoelectrochemical detection of organic compounds under visible light. [Copyright &y& Elsevier]

Highlights: [•] Rutile nanowire arrays (RNW-TiO2) were directly grown on conductive Ti foils in a hydrothermal reactor. [•] RNW-TiO2 shows higher photoelectrocatalytic activity than rutile nanorod arrays grown on FTO substrates. [•] RNW-TiO2 is capable of oxidizing a wide spectrum of organic compounds indiscriminately. [•] RNW-TiO2 can be directly used as photoanodes to detect organic compounds. [ABSTRACT FROM AUTHOR]

Abstract: Chemical oxygen demand (COD) is one of the most important parameters in water quality assessment and monitoring. The natural degradation of nitrogenous organic compounds (NOCs) in water requires significant amounts of oxygen. In the determination of standard COD however, NOCs are persistent compounds that cannot be completely oxidized even in the most oxidative chemical environments, i.e. the reaction media that contain high concentrations of dichromate in strong acid at high temperature. Consequently, the measured COD values of wastewater samples containing NOCs are commonly lower than theoretical COD values and do not reflect the actual oxygen demand of the water body. This problem is partially alleviated when the photoelectrochemical method for COD determination (PeCOD) based on nanostructured TiO2 photoanode is utilized. To completely overcome this problem, a synergetic photoelectrochemical oxidation effect in thin layer cells is used to achieve complete oxidation of NOCs. This is done by the simple addition of a hydroxyl organic compound (i.e. glucose) into the test sample before the PeCOD measurement. Preliminary experimental results demonstrate that the synergetic PeCOD method provides an effective and reliable means to measure COD values of NOC-containing pollutants without the need for toxic or expensive reagents. [Copyright &y& Elsevier]

With high performances of image capturing tools, image information can be easily obtained by screenshots that make image copyright protection a challenging task. The existing screen-shooting watermarking algorithms suffer from a huge running time, in addition to their low robustness against different screenshot attacks, such as different distances and capturing angles of the screenshots. In this paper, a fast and robust high-capacity flexible watermarking algorithm for screenshot images is proposed. Firstly, Oriented FAST and Rotated BRIEF (ORB) feature points are extracted from the input image. Secondly, the feature points are then sorted in a descending order according to their response values. Then, the first five non-overlapping feature points are selected for the embedding by using Hamming window-based filtering method. Furthermore, we exploit the multi-resolution property of Discrete Wavelet Transform (DWT) and energy compaction property of Singular Value Decomposition (SVD) to embed the watermark. Therefore, the classical DWT combined with Singular Value Decomposition (SVD) are adopted to improve the robustness and capacity of the proposed watermarking algorithm. At the extraction side, the sum of the response values for the three RGB channels of the color-ripped image is calculated to improve the feature point localization accuracy. Experimental results show that the proposed screen-shooting watermarking algorithm improves running speed while ensuring the robustness. Furthermore, it has less time complexity and high robustness compared with the state-of-the-art watermarking algorithms against different screenshot attacks. [ABSTRACT FROM AUTHOR]

Abstract: Owing to the inherent advantages of nanostructured TiO2 photocatalysts, including high photocatalytic activity, strong oxidation power, low cost, environmental benignity and excellent stability, TiO2 photocatalyts have recently attracted extensive attention from scientific researchers, technology developers and investors for use in sensing applications. The TiO2 sensors can be used for lab-based analyses, on-line and on-site determination of organic pollutants in wastewater. This work reviews the application of TiO2 nanomaterials in photocatalytic and photoelectrocatalytic monitoring of aggregative organic parameters such as total organic carbon (TOC) and chemical oxygen demand (COD), as well as individual organic compounds in aqueous solution. [Copyright &y& Elsevier]

Abstract: TiO2 is n-type, wide band-gap and environmentally friendly semiconductor with good biocompatibility and stability. On the one hand, owing to the large surface area, TiO2 nanomaterials possess unique chemical, physical, optical, electronic and photocatalytic properties. On the other hand, a large amount of the TiO2 nanostructures were synthesized, characterized and available for construction of sensor due to the tremendous efforts from scientists and materials engineers. These bestow the TiO2 nanomaterials be used as an extremely versatile component to construct a wide range of sensing devices for determination of chemicals in aqueous media. This work aims to review the recent applications of the TiO2 nanomaterials for fabrication of electrochemical sensors, electrochemical biosensors, photocatalytic sensors and photoelectrocatalytic sensors. [Copyright &y& Elsevier]

Abstract: Nano-sized polyhedral crystalline Cu2O was evenly loaded throughout the structure of TiO2 nanotube arrays (TNTs) using an electrodeposition method, which resulted in a nanocomposite namely Cu2O/TNTs. The content of Cu2O loaded on the arrays was controlled by varying the electrodeposition charges. Under visible light, the photocurrent for water splitting and photocatalytic decolorization efficiency of dye Acid orange II (AO-II) of the Cu2O/TNTs obtained with the deposition charges of 500mC were about 35 and 18 times that of TNTs, respectively. The polyhedral Cu2O/TNTs would be a promising material for solar energy conversion and organic pollutant degradation. [Copyright &y& Elsevier]

Abstract: A photoelectrochemical detector (PECD) was developed for determination of organic compounds in flow injection analysis (FIA) and high performance liquid chromatography (HPLC) based on the extraordinary oxidation power of nanostructured TiO2 photoanodes under UV illumination. The PECD is a simple, small, and compact photoelectrochemical cell consisting of low cost components such as a TiO2 nanostructured photoanode and a UV-LED. Compared with conventional FIA and HPLC selective detectors, such as UV–Vis detector, electrochemical detector and fluorescent detector, the PECD has the advantage of being low cost, non-selective and sensitive. Using the FIA mode, the analytical principle of the PECD was demonstrated by detecting a large variety of organic compounds, such as sugars, amino acids, alcohol, straight chain carboxylic acids, and aromatic carboxylic acid. The PECD was subsequently coupled with a typical FIA and HPLC system for the determination of sugars. For the application in FIA, under the optimum experimental conditions, the linear ranges for glucose and sucrose were 25–600μM and 25–500μM, respectively, with the same detection limit of 10μM. When the PECD was coupled with a HPLC system, the linear range for both glucose and sucrose was 7.5–200mM with the same detection limit of 1mM under the optimal experimental conditions. [Copyright &y& Elsevier]

Abstract: Microporous suspended bioreactors immobilized with periphytons were submerged between sediments and overlying water to control phosphorus release and cyanobacterial (Microcystis aeruginosa) growth. The results showed that the periphyton mainly consisted of bacteria and diatoms. The application of periphyton bioreactor decreased the levels of exchange phosphorus (Exch-P) in sediments from 1.69 to 0.49mgg−1 and total phosphorus (TP) from 0.75 to 0.30mgL−1. The significant reduction of the total dissolved phosphorus (TDP) content was not only beneficial for the decrease of the cyanobacterial growth, but also stimulates the periphyton to produce natural cyanobacterial inhibitors such as gallic acid and ethyl-2-methylacetoacetate. These synergistic effects led to the growth inhabitation of M. aeruginosa when the initial concentrations of M. aeruginosa were less than 119.3μgL−1. This study provides an environmentally-friendly and publically acceptable method of controlling bacterial blooms when compared to traditional addition of chemicals. [ABSTRACT FROM AUTHOR]

Abstract: An in situ photoelectrochemical method is proposed to determine adsorbed phthalic acid (PA) on the TiO2 surface in a sensitive, reproducible and accurate manner. The pre-adsorbed PA in the dark and the diffused PA from organic solution can be mineralized simultaneously under UV illumination due to the strong UV-induced oxidation power of TiO2. By controlling the UV illumination, the amount of adsorbed PA on TiO2 surface was determined in the presence of PA in a small time scale (e.g., seconds), eliminating the washing step after the adsorption reaction. This provides a convenient and effective alternative to study adsorption behaviour in low concentrations on TiO2. The proposed method was applied to determine the adsorption equilibrium constant of PA. [Copyright &y& Elsevier]

Abstract: A portable, cost-effective, environmental friendly and miniature thin-layer photoelectrochemical system in conjunction with an ultraviolet light emitting diode (UV-LED) is developed for determination of chemical oxygen demand (COD), namely UV-LED PeCOD. The COD value is directly quantified by measuring the amount of electrons captured at a nanostructured TiO2 electrode during the exhaustive photoelectrocatalytic degradation of organic species in the thin-layer cell. The key parameters of the photoelectrochemical system, such as applied potential bias, light intensity and solution pH, were investigated and optimized. Combined with a microelectrochemical system and a laptop computer, the UV-LED PeCOD system enables end-users to perform on-site COD analysis in a simple, rapid, sensitive and accurate manner. Under the optimal conditions, the system can achieve a practical detection limit of 0.2ppm COD with a linear range of 0–300ppm COD. The proposed UV-LED PeCOD technology can potentially make a revolutionary improvement to the conventional COD analysis and may be widely used in water quality monitoring industry. [Copyright &y& Elsevier]

Abstract: A TiO2 organic sol was synthesised for the preparation of a compact TiO2 layer on fluorine-doped tin oxide (FTO) glass by a dip-coating technique. The resultant thin film was used for the fabrication of dye-sensitized solar cells (DSSCs). The compact layer typically has a thickness of ca. 110nm as indicated by its SEM, and consists of anatase as confirmed by the XRD pattern. Compared with the traditional DSSCs without this compact layer, the solar energy-to-electricity conversion efficiency, short-circuit current and open-circuit potential of the DSSCs with the compact layer were improved by 33.3%, 20.3%, and 10.2%, respectively. This can be attributed to the merits brought by the compact layer. It can effectively improve adherence of TiO2 to FTO surface, provide a larger TiO2/FTO contact area, and reduce the electron recombination by blocking the direct contact between the redox electrolyte and the conductive FTO surface. [Copyright &y& Elsevier]

Abstract: Titanium dioxide (TiO2) thin films fabricated with different TiO2 colloids were characterised using photoelectrochemical techniques. TiO2 colloids were firstly prepared via hydrolysis of titanium butoxide and peptisation process with no hydrothermal process (labelled as NP). The resulting colloids were then subjected to different hydrothermal processes, i.e., 15-h convection hydrothermal (labelled as CH) treatment; 5-, 10- and 15-min microwave hydrothermal treatment (labelled as M5, M10 and M15, respectively). The colloids were used to prepare TiO2 thin films on conducting indium-doped tin oxide (ITO) substrates (i.e., CH, M15, M10, M5 and NP electrodes, respectively) using a controlled dip-coating technique. The experimental results demonstrate that the oxidation capacities of the electrodes for water and glucose are in the order of CH>M15>M10>M5>NP. In contrast, the oxidation capacities of the electrodes for potassium hydrogen phthalate (KHP) are in the order of M15>M10>CH. It was also found that the CH electrode could be easily poisoned by high concentration of KHP, while microwave-processed electrodes (M15, M10 and M5) are immune from the KHP poisoning. The results presented demonstrate that microwave hydrothermal processing is a promising alternative method to the traditional convection hydrothermal treatment of colloids that provides electrodes with increased photocatalytic properties for the oxidation processes of adsorption-based organic compounds, such as KHP. [Copyright &y& Elsevier]

This work focuses on the experimental optimisation of a newly developed photoelectrochemical system for the determination of chemical oxygen demand (PECOD). This method is developed based on a photoelectrochemical degradation principle. Chemical oxygen demand (COD) is directly quantified by measuring the amount of electron transferred at a TiO2 nanoporous thin-film electrode during an exhaustive photoelectrocatalytic degradation process in a thin-layer photoelectrochemical cell. In this fashion, the COD value of a sample can be determined in a simple, rapid and accurate manner. The PECOD is a direct and absolute method that requires no calibration. The effects of important experimental conditions, such as light intensity, applied potential bias, supporting electrolyte concentration and oxygen concentration, on analytical performance have been investigated and optimum experimental conditions were obtained. Analytical linear range of 0-360 ppm COD with a practical detection limit of 0.2 ppm COD were achieved. Real sample analyses were also carried out. The results demonstrated that the measured COD values using the PECOD and the standard methods were in an excellent agreement. [Copyright &y& Elsevier]

Chemical Oxygen Demand (COD), as a detection indicator of water pollution, is of particular importance in assessing organic pollution in water. Furthermore, accurate and simple measuring COD methods are essential for water quality assessment and pollution control. However, the photoelectrochemical oxygen demand (PECOD) measurement, as one of the measuring COD methods, is affected by the reaction of water splitting, which is one of the hindrances to the commercialization of the analytical method of the PeCOD measurement. Hence, to overcome this challenge, a new PANI/Ti:Fe2O3 photoanode is constructed by hydrothermal and photoelectrochemical (PEC) deposition methods and investigated their optical properties and photoactivity. Under optimization conditions, it is discovered that the oxidation of organic compounds produces a net steady‐state current (inet) is directly proportional to COD concentration, with a detection limit of 1 mM glucose solution and a wide linear detection range of 1–78.125 mM, which is suitable for high concentration of glucose detection. As has been noted, PANI/Ti:Fe2O3 photoanode overcomes the obstacles to the practical application and eventual commercialization of the PECOD technology. [ABSTRACT FROM AUTHOR]

Offering ultrahigh energy density and exceptional safety, all‐solid‐state lithium–sulfur batteries (ASSLSBs) can be one of the most promising energy storage systems if their inherent challenges, including slow Li+ mass transport and insufficient sulfur utilization efficiency, are completely tackled. In this work, an amide‐based electrolyte additive with a high Gutmann donor number is used to construct a deep eutectic system, a “one‐stone‐two‐birds” solution to address these issues. In particular, an acetamide is used to interact with the insulative Li2S via a strong S─H bond and Li─O bond to boost the electrochemical reaction kinetics of lithium‐sulfur (Li─S) chemistry and sulfur utilization and simultaneously form a deep eutectic LiTFSI‐acetamide system to enhance ionic conductivity of solid polymer electrolytes (SPEs). Such a seamless integration of this system into the solid‐state LSBs helps deliver a high initial discharge specific capacity of 1012 mAh g−1 at 0.05 C and attain a stable cyclability for 1300 cycles at 0.1 C. This remarkable achievement in high performance and stability can effectively facilitate the commercialization of ASSLSBs. [ABSTRACT FROM AUTHOR]

Electrolyte engineering is considered as an effective strategy to establish stable solid electrolyte interface (SEI), and thus to suppress the growth of lithium dendrites. In a recent study reported in Advanced Functional Materials by Ma group, discovered that strong coordination force could be founded between 15-Crown-5 ether (15-C-5) and Li+, which facilitates the crown ether (15-C-1) to participate in the solvation structure of Li+ in the electrolyte for the same purpose. Such a novel strategy might impact the design of high-performance and safe lithium metal batteries (LMBs). [ABSTRACT FROM AUTHOR]

Aqueous zinc‐based energy storage devices have competitive advantages such as high power density, good safety, and wide source. However, because of the direct touch among zinc anode and aqueous electrolyte, dendrite growth and electrode side reactions are easy to occur in the plating and striping process, which seriously hinders the further development of aqueous zinc‐based energy storage devices. Therefore, it is urgent to solve the above problems to expand the existing energy storage devices. In this work, by adding an imidazo[1,2‐b]pyridazine (IP) electrolyte additive, the dendrites' growth and corrosion on the zinc anode surface could be effectively inhibited by the shielding‐anchoring double effects, which are verified by the comprehensive in situ and ex situ characterization techniques as well as the theoretical calculation support. Accordingly, the IP‐based electrolyte encourages extremely high stable zinc anode (cycling 2200 h at 1 mA cm−2) with high average Coulombic efficiency (98.72%). Moreover, the IP‐based Zn‐V2O5 full battery also exhibits excellent reversible capacity, reaching 160.8 mAh g−1 after 400 cycles at 2 A g−1. Through a straightforward alteration to the Zn anode surface, this study considerably enhances the use of highly stable and secure aqueous zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Designing efficient multifunctional electrocatalysts for water and urea splitting to produce green hydrogen presents a significant yet worthwhile challenge. Herein, the morphology and electronic structure of cobalt metaphosphate (Co2P4O12) by vanadium (V) doping, resulting in improved electrocatalytic activity and stability for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and urea oxidation reaction (UOR) are simultaneously regulated. Theory calculations show that V‐doped Co2P4O12 (V‐Co2P4O12) can boost the kinetics of catalytic reactions by optimizing the d‐band center of Co atoms and the binding strength of intermediates, as well as enhancing the density of states. Moreover, the doping of V into Co2P4O12 crystalline structure benefits the formation of a thicker amorphous layer during the catalytic process, which could enhance its alkaline corrosion resistance and stability. Additionally, the multilevel nanostructures of V‐Co2P4O12 provide rich active sites for catalytic reactions. As a result, a two‐electrode electrolyzer assembled by V‐doped Co2P4O12 delivers low voltages for overall water and urea splitting. The superior performance suggests that the proposed V‐doping strategy is a promising way to regulate electrocatalytic activity for catering to green electrocatalytic applications. [ABSTRACT FROM AUTHOR]

Intelligent membranes with adaptive gating channels play a crucial role in cellular functions and separation processes. This study introduces a novel approach to controlling channel expansion using biomimetic adaptive aggregates, fundamentally overcoming the drawbacks of existing methods relying on intertwined polyelectrolyte chains for channel blockage. Specifically, a pH‐responsive 2D material membrane is constructed through the self‐assembling of protein‐mimetic zwitterionic polydopamine (ZPDA) soft molecular aggregates within graphene oxide (GO) interlayers. Similar to the conformational switch of inserted proteins in cellular membranes, the embedded ZPDA in GO nanofluidic channels undergoes an adaptive conformational transformation in response to pH changes. This dynamic adjustment of ZPDA physicochemical properties allows for reversible regulation of GO nanofluidic channel size and charge by external pH modulation. The resulting GO/ZPDA membrane exhibits programmable separation performance for dye molecules (i.e., water permeance of 18.8–35.4 L m−2 h−1 bar−1 and molecular selectivity of 73.7–32.9) and salt ions (i.e., ionic permeance of 0.69–1.25 mol m−2 h−1 and ionic selectivity of 20.8–21.9). This work sheds new light on the engineering of intelligent stimuli‐responsive 2D nanofluidic channels with adaptive gating properties, holding promise across a wide range of applications including separation, drug delivery, sensing, and catalysis. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium‐ion batteries (ASSLIBs) based on sulfide solid‐state electrolytes (S‐SSEs) are considered as one of the most promising choices to address the safety hazards of traditional lithium‐ion batteries. However, the high‐voltage cathodes, such as LiCoO2 (LCO) with high‐valence Co (+3), tend to spontaneously oxidize S‐SSEs, causing polarization increase and rapid degradation. Herein, a self‐sacrificing reductive interphase consisting of CoO/Li2CO3/C, is in situ constructed on LCO surface via a simple carbon‐induced thermal reduction of LCO. With such a design, the Co valence of LCO surface is reduced to +2, reducing the oxidative nature of LCO to avoid reactions with S‐SSEs. As a result, ASSLIBs using Li10GeP2S12 (LGPS) S‐SSEs achieve a high initial capacity of 144.9 mAh g‒1 at 0.2 C and retard 93.1% of initial capacity after 100 cycles. Additionally, excellent rate cyclability of 109.2 mAh g‒1 at 1.0 C with 81.5% retentive capacity for 200 cycles is attained as well. Comprehensive evidence strongly demonstrates the effectiveness of this self‐sacrificing reductive interphase in inhibiting the interfacial reactions and ensuring long‐term cyclability. The proposed concept of a self‐sacrificing reductive interface in this study paves the way for stabilizing the cathode/SSEs interface and offers a novel approach for the design of high‐performance sulfide‐based ASSLIBs. [ABSTRACT FROM AUTHOR]

Blur is an important factor affecting the image quality. This paper presents an efficient no-reference (NR) image blur assessment method based on a response function of singular values. For an image, the grayscale image is computed to the acquire spatial information. In the meantime, the gradient map is computed to acquire the shape information, and the saliency map can be obtained by using scale-invariant feature transform (SIFT). Then, the grayscale image, the gradient map, and the saliency map are divided into blocks of the same size. The blocks of the gradient map are converted into discrete cosine transform (DCT) coefficients, from which the response function of singular values (RFSV) are generated. The sum of the RFSV are then utilized to characterize the image blur. The variance of the grayscale image and the DCT domain entropy of the gradient map are used to reduce the impact of the image content. The SIFT-dependent weights are calculated in the saliency map, which are assigned to the image blocks. Finally, the blur score is the normalized sum of the RFSV. Extensive experiments are conducted on four synthetic databases and two real blur databases. The experimental results indicate that the blur scores produced by our method are highly correlated with the subjective evaluations. Furthermore, the proposed method is superior to six state-of-the-art methods. [ABSTRACT FROM AUTHOR]

The reaction rate bottleneck during interconversion between insulating S8 (S) and Li2S fundamentally leads to incomplete conversion and restricted lifespan of Li−S battery, especially under high S loading and lean electrolyte conditions. Herein, we demonstrate a new catalytic chemistry: soluble semiquinone, 2‐tertbutyl‐semianthraquinone lithium (Li+TBAQ⋅−), as both e‐/Li+ donor and acceptor for simultaneous S reduction and Li2S oxidation. The efficient activation of S and Li2S by Li+TBAQ⋅− in the initial discharging/charging state maximizes the amount of soluble lithium polysulfide, thereby substantially improve the rate of solid–liquid‐solid reaction by promoting long‐range electron transfer. With in situ Raman spectra and theoretical calculations, we reveal that the activation of S/Li2S is the rate‐limiting step for effective S utilization under high S loading and low E/S ratio. Beyond that, the S activation ratio is firstly proposed as an accurate indicator to quantitatively evaluate the reaction rate. As a result, the Li−S batteries with Li+TBAQ⋅− deliver superior cycling performance and over 5 times higher S utilization ratio at high S loading of 7.0 mg cm−2 and a current rate of 1 C compared to those without Li+TBAQ⋅−. We hope this study contributes to the fundamental understanding of S redox chemical and inspires the design of efficient catalysis for advanced Li−S batteries. [ABSTRACT FROM AUTHOR]

The reaction rate bottleneck during interconversion between insulating S8 (S) and Li2S fundamentally leads to incomplete conversion and restricted lifespan of Li−S battery, especially under high S loading and lean electrolyte conditions. Herein, we demonstrate a new catalytic chemistry: soluble semiquinone, 2‐tertbutyl‐semianthraquinone lithium (Li+TBAQ⋅−), as both e‐/Li+ donor and acceptor for simultaneous S reduction and Li2S oxidation. The efficient activation of S and Li2S by Li+TBAQ⋅− in the initial discharging/charging state maximizes the amount of soluble lithium polysulfide, thereby substantially improve the rate of solid–liquid‐solid reaction by promoting long‐range electron transfer. With in situ Raman spectra and theoretical calculations, we reveal that the activation of S/Li2S is the rate‐limiting step for effective S utilization under high S loading and low E/S ratio. Beyond that, the S activation ratio is firstly proposed as an accurate indicator to quantitatively evaluate the reaction rate. As a result, the Li−S batteries with Li+TBAQ⋅− deliver superior cycling performance and over 5 times higher S utilization ratio at high S loading of 7.0 mg cm−2 and a current rate of 1 C compared to those without Li+TBAQ⋅−. We hope this study contributes to the fundamental understanding of S redox chemical and inspires the design of efficient catalysis for advanced Li−S batteries. [ABSTRACT FROM AUTHOR]

Zinc ion batteries (ZIBs) have recently attracted tremendous interest for being low‐cost, environmentally benign, and high energy density. However, the large‐scale practical application of ZIBs is hampered by well‐known undesirable dendrite growth and serious side reactions of the Zn anode during the long‐term cycling process. Herein, a multifunctional water‐glass artificial protection layer with enormous Si─O functional groups is constructed on Zn anode through a simple spin‐coating method. The theoretical and experimental investigation suggests that the as‐constructed interface with rich Si─O hydrophilic functional groups on Zn anode could facilitate the even distribution of electric field distribution and homogeneous wettability, navigate uniform zinc deposition/stripping along the (002) plane, and subsequently lead to well‐suppressed dendrite growth and effective prohibition of oxygen‐involved corrosion. Consequently, the water glass‐modified anode achieves highly reversible Zn plating/stripping over 1500 h at a high current density of 10 mA cm−2 in symmetrical cells, and a high capacity retention ratio of 79.4% at the current density of 5 A g−1 in full cells paired with V2O5 cathode. This proposed water glass coating layer design is cheap, up‐scalable, and facile, which could substantially accelerate the rapid commercialization of zinc anodes and unleash the full potential of renewable ZIBs for next‐generation large‐scale energy storage. [ABSTRACT FROM AUTHOR]

Organic electrode materials (OEMs), valued for their sustainability and structural tunability, have been attracting increasing attention for wide application in sodium‐ion batteries (SIBs) and other rechargeable batteries. However, most OEMs are plagued with insufficient specific capacity or poor cycling stability. Therefore, it′s imperative to enhance their specific capacity and cycling stability through molecular design. Herein, we designed and synthesized a heteroaromatic molecule 2,3,8,9,14,15‐hexanol hexaazatrinaphthalene (HATN‐6OH) by the synergetic coupling of catechol (the precursor of ortho‐quinone)/ortho‐quinone functional groups and HATN conjugated core structures. The abundance of catechol/ortho‐quinone and imine redox‐active moieties delivers a high specific capacity of nine‐electron transfer for SIBs. Most notably, the π–π interactions and intermolecular hydrogen bond forces among HATN‐6OH molecules secure the stable long‐term cycling performance of SIBs. Consequently, the as‐prepared HATN‐6OH electrode exhibited a high specific capacity (554 mAh g−1 at 0.1 A g−1), excellent rate capability (202 mAh g−1 at 10 A g−1), and stable long‐term cycling performance (73 % after 3000 cycles at 10 A g−1) in SIBs. Additionally, the nine‐electron transfer mechanism is confirmed by systematic density functional theory (DFT) calculation, attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR), and Raman analysis. The achievement of the synergetic coupling of the redox‐active sites on OEMs could be an important key to the enhancement of SIBs and other metal‐ion batteries. [ABSTRACT FROM AUTHOR]

Organic electrode materials (OEMs), valued for their sustainability and structural tunability, have been attracting increasing attention for wide application in sodium‐ion batteries (SIBs) and other rechargeable batteries. However, most OEMs are plagued with insufficient specific capacity or poor cycling stability. Therefore, it′s imperative to enhance their specific capacity and cycling stability through molecular design. Herein, we designed and synthesized a heteroaromatic molecule 2,3,8,9,14,15‐hexanol hexaazatrinaphthalene (HATN‐6OH) by the synergetic coupling of catechol (the precursor of ortho‐quinone)/ortho‐quinone functional groups and HATN conjugated core structures. The abundance of catechol/ortho‐quinone and imine redox‐active moieties delivers a high specific capacity of nine‐electron transfer for SIBs. Most notably, the π–π interactions and intermolecular hydrogen bond forces among HATN‐6OH molecules secure the stable long‐term cycling performance of SIBs. Consequently, the as‐prepared HATN‐6OH electrode exhibited a high specific capacity (554 mAh g−1 at 0.1 A g−1), excellent rate capability (202 mAh g−1 at 10 A g−1), and stable long‐term cycling performance (73 % after 3000 cycles at 10 A g−1) in SIBs. Additionally, the nine‐electron transfer mechanism is confirmed by systematic density functional theory (DFT) calculation, attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR), and Raman analysis. The achievement of the synergetic coupling of the redox‐active sites on OEMs could be an important key to the enhancement of SIBs and other metal‐ion batteries. [ABSTRACT FROM AUTHOR]

Review: 156 refs. [ABSTRACT FROM AUTHOR]

High energy and power density alkali‐ion (i.e., Li+, Na+, and K+) batteries (AIBs), especially lithium‐ion batteries (LIBs), are being ubiquitously used for both large‐ and small‐scale energy storage, and powering electric vehicles and electronics. However, the increasing LIB‐triggered fires due to thermal runaways have continued to cause significant injuries and casualties as well as enormous economic losses. For this reason, to date, great efforts have been made to create reliable fire‐safe AIBs through advanced materials design, thermal management, and fire safety characterization. In this review, the recent progress is highlighted in the battery design for better thermal stability and electrochemical performance, and state‐of‐the‐art fire safety evaluation methods. The key challenges are also presented associated with the existing materials design, thermal management, and fire safety evaluation of AIBs. Future research opportunities are also proposed for the creation of next‐generation fire‐safe batteries to ensure their reliability in practical applications. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) currently suffer from severe polysulfide shuttling, slow redox kinetics at the sulfur cathode, and irreversible dendrite growth at the lithium anode. To address these issues, a dual interfacial engineering strategy on both the cathode and anode is proposed. For the cathode, iminated polyaniline (iPANI) is used to achieve energetic engineering to induce mid‐energy level to the adsorption of polysulfides, and catalyze the redox conversion of sulfur species, and realize morphological engineering via self‐assembly of iPANI onto a scaffold integrated by reduced graphene oxide (rGO) and carbon nanotubes (CNTs), namely iPANI@rGO‐CNTs. For the anode, the highly conductive and lithiophilic nature and porous nanostructure of the iPANI@rGO‐CNTs composite facilitates the uniform deposition of lithium‐ions, significantly preventing the growth of lithium dendrites. Density functional theory calculations suggest that the iminated functional group at the excited state in iPANI can significantly suppress the shuttling effect, catalyze the conversion of sulfur species, and enhance the conversion of the sulfur species on the sulfur cathode. With the synergic effects of the iPANI@rGO‐CNTs nanoreactors, the as‐prepared LSBs deliver an excellent rate capability and outstanding cycling life. This large‐scale production and application of the iPANI@rGO‐CNTs nanocomposite may lead to the eventual commercialization of LSBs. [ABSTRACT FROM AUTHOR]

Infrared images have been widely used in many research areas, such as target detection and scene monitoring. Therefore, the copyright protection of infrared images is very important. In order to accomplish the goal of image-copyright protection, a large number of image-steganography algorithms have been studied in the last two decades. Most of the existing image-steganography algorithms hide information based on the prediction error of pixels. Consequently, reducing the prediction error of pixels is very important for steganography algorithms. In this paper, we propose a novel framework SSCNNP: a Convolutional Neural-Network Predictor (CNNP) based on Smooth-Wavelet Transform (SWT) and Squeeze-Excitation (SE) attention for infrared image prediction, which combines Convolutional Neural Network (CNN) with SWT. Firstly, the Super-Resolution Convolutional Neural Network (SRCNN) and SWT are used for preprocessing half of the input infrared image. Then, CNNP is applied to predict the other half of the infrared image. To improve the prediction accuracy of CNNP, an attention mechanism is added to the proposed model. The experimental results demonstrate that the proposed algorithm reduces the prediction error of the pixels due to full utilization of the features around the pixel in both the spatial and the frequency domain. Moreover, the proposed model does not require either expensive equipment or a large amount of storage space during the training process. Experimental results show that the proposed algorithm had good performances in terms of imperceptibility and watermarking capacity compared with advanced steganography algorithms. The proposed algorithm improved the PSNR by 0.17 on average with the same watermark capacity. [ABSTRACT FROM AUTHOR]

Highlights: The state-of-the-art development in electrochemical H2O2 production via the two-electron oxygen reduction reaction is reviewed with emphasis on material science, reaction mechanisms, and fundamental factors that govern the reaction route. General principles and strategies for catalyst design are summarized to understand the inherent relationships between the catalyst properties and electrocatalytic performances. Perspectives and challenges are presented to get insights into the large-scale manufacturing of H2O2 via the electrochemical routes. An environmentally benign, sustainable, and cost-effective supply of H2O2 as a rapidly expanding consumption raw material is highly desired for chemical industries, medical treatment, and household disinfection. The electrocatalytic production route via electrochemical oxygen reduction reaction (ORR) offers a sustainable avenue for the on-site production of H2O2 from O2 and H2O. The most crucial and innovative part of such technology lies in the availability of suitable electrocatalysts that promote two-electron (2e–) ORR. In recent years, tremendous progress has been achieved in designing efficient, robust, and cost-effective catalyst materials, including noble metals and their alloys, metal-free carbon-based materials, single-atom catalysts, and molecular catalysts. Meanwhile, innovative cell designs have significantly advanced electrochemical applications at the industrial level. This review summarizes fundamental basics and recent advances in H2O2 production via 2e–-ORR, including catalyst design, mechanistic explorations, theoretical computations, experimental evaluations, and electrochemical cell designs. Perspectives on addressing remaining challenges are also presented with an emphasis on the large-scale synthesis of H2O2 via the electrochemical route. [ABSTRACT FROM AUTHOR]

Cocatalyst engineering with non‐noble metal nanomaterials can play a vital role in low‐cost, sustainable, and large‐scale photocatalytic hydrogen production. This research adopts slow carburization and simultaneous hydrocarbon reduction to synthesize carbon‐encapsulated Mo/Mo2C heterostructure nanoparticles, namely Mo/Mo2C@C cocatalyst. Experimental and theoretical investigations indicate that the Mo/Mo2C@C cocatalysts have a nearly ideal hydrogen‐adsorption free energy (ΔGH*), which results in the accelerated HER kinetics. As such, the cocatalysts are immobilized onto organic polymer semiconductor g‐C3N4 and inorganic semiconductor CdS, resulting in Mo/Mo2C@C/g‐C3N4 and Mo/Mo2C@C/CdS catalysts, respectively. In photocatalytic hydrogen evolution application under visible light, the Mo/Mo2C@C with g‐C3N4 and CdS can form the Schottky junctions via appropriate band alignment, greatly suppressing the recombination of photoinduced electron‐hole pairs. The surface carbon layer as the conducting scaffolds and Mo metal facilitates electron transfer and electron‐hole separation, favoring structural stability and offering more reaction sites and interfaces as electron mediators. As a result, these catalysts exhibit high H2 production rates of 2.7 mmol h−1 g−1 in basic solution and 98.2 mmol h−1 g−1 in acidic solution, respectively, which is significantly higher than that of the bench‐mark Pt‐containing catalyst. The proposed cocatalyst engineering approach is promising in developing efficient non‐noble metal cocatalysts for rapid hydrogen production. [ABSTRACT FROM AUTHOR]

Electrochromic effect has been discovered in many materials with a wide range of applications from visible to infrared, such as smart windows, electronic displays, infrared camouflage, and color‐changeable tactile sensor. However, conventional electrochromic materials cannot meet the growing demand for electrochromic performance in terms of optical contrast, response time, durability, color diversity, and flexibility, which slows down developments in this area. This is mainly due to the limited number and variety of electrochromic materials. In strong contrast, nanoarchitectonics of 2D materials with atomically thin thickness, large lateral size, and diversified series can be an effective way to address these issues and improve the electrochromic performances. This review highlights the recent achievements of emerging 2D electrochromic materials, namely covalent organic frameworks, coordination nanosheets, and transition metal carbides/nitrides/carbonitrides (MXenes). The structures, electrochromic performances and their structure–performance relationship, and future challenges of these materials have been systematically explored. This review can pave a new avenue for the promotion of the nanoarchitectonic 2D materials for the up‐scaled practical electrochromic applications. [ABSTRACT FROM AUTHOR]

Exploring efficient electrocatalysts for oxygen evolution reaction (OER) is an urgent need to advance the development of sustainable energy conversion. Though defect engineering is considered an effective strategy to regulate catalyst activity for enhanced OER performance, the controllable synthesis of defective oxides electrocatalysts remains challenging. Here, oxygen defects are introduced into NiCo2O4 nanorods by an electrochemical lithiation strategy. By tuning in situ lithiation potentials, the concentration of oxygen defects and the corresponding catalytic activity can be feasibly regulated. In addition, the relationship between the changes in the defect density and electronic structure and the lithiation cut‐off voltages is revealed. The results show that NiCo2O4 nanorods undertook intercalation and two‐step conversion reaction, in which the lithiation‐induced conversion reaction gives rise to a CoO@NiO‐based structure with higher defect density and lower oxidation states. As a result, the defective CoO@NiO‐based catalyst exhibits exceptional OER activity with an overpotential of 270 mV at 10 mA cm−2, which is about 74 mV below the pristine nanomaterials. This research proposes a novel strategy to explore high‐performance catalysts with structural stability and defect control. [ABSTRACT FROM AUTHOR]

Excellent bifunctional oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) activity and rapid mass transport capability are two important parameters of electrocatalysts for high‐performance rechargeable Zn–air batteries (ZABs). Herein, an efficient atomic modulation and structure design to promote bifunctional activity and mass transport kinetics of an ORR/OER electrocatalyst are reported. Specifically, atomic Fe−N4 moieties are immobilized on premade hollow carbon fibers with encapsulated Ni nanoparticles (Fe‐N@Ni‐HCFs). Synchrotron X‐ray absorption spectroscopy and spherical aberration‐corrected electron microscope analyses confirm the atomic distribution of the active sites and unique lung bubble‐like hollow architecture of the catalyst, while theoretical investigations reveal that the encapsulated Ni nanoparticles can induce electron distribution of the atomic Fe−N4 moieties to reduce reaction energy barriers. As a result, the prepared catalyst possesses enhanced bifunctional ORR/OER activity and well‐constructed gas–solid–liquid interfaces for improved mass transfer. These synergetic advantages endow the binder‐free Fe‐N@Ni‐HCFs electrode with the remarkable power density and cycling stability for ZABs, outperforming the commercial Pt/C+Ir/C benchmark. This exceptional performance suggests that the proposed strategy can be extended to the design and fabrication of electrocatalysts for energy conversion and storage. [ABSTRACT FROM AUTHOR]

Not only high efficiency but also high selectivity of the electrocatalysts is crucial for high‐performance, low‐cost, and sustainable energy storage applications. Herein, we systematically investigate the edge effect of carbon‐supported single‐atom catalysts (SACs) on oxygen reduction reaction (ORR) pathways (two‐electron (2 e−) or four‐electron (4 e−)) and conclude that the 2 e−‐ORR proceeding over the edge‐hosted atomic Co−N4 sites is more favorable than the basal‐plane‐hosted ones. As such, we have successfully synthesized and tuned Co‐SACs with different edge‐to‐bulk ratios. The as‐prepared edge‐rich Co−N/HPC catalyst exhibits excellent 2 e−‐ORR performance with a remarkable selectivity of ≈95 % in a wide potential range. Furthermore, we also find that oxygen functional groups could saturate the graphitic carbon edges under the ORR operation and further promote electrocatalytic performance. These findings on the structure–property relationship in SACs offer a promising direction for large‐scale and low‐cost electrochemical H2O2 production via the 2 e−‐ORR. [ABSTRACT FROM AUTHOR]

Not only high efficiency but also high selectivity of the electrocatalysts is crucial for high‐performance, low‐cost, and sustainable energy storage applications. Herein, we systematically investigate the edge effect of carbon‐supported single‐atom catalysts (SACs) on oxygen reduction reaction (ORR) pathways (two‐electron (2 e−) or four‐electron (4 e−)) and conclude that the 2 e−‐ORR proceeding over the edge‐hosted atomic Co−N4 sites is more favorable than the basal‐plane‐hosted ones. As such, we have successfully synthesized and tuned Co‐SACs with different edge‐to‐bulk ratios. The as‐prepared edge‐rich Co−N/HPC catalyst exhibits excellent 2 e−‐ORR performance with a remarkable selectivity of ≈95 % in a wide potential range. Furthermore, we also find that oxygen functional groups could saturate the graphitic carbon edges under the ORR operation and further promote electrocatalytic performance. These findings on the structure–property relationship in SACs offer a promising direction for large‐scale and low‐cost electrochemical H2O2 production via the 2 e−‐ORR. [ABSTRACT FROM AUTHOR]

Highlights: Cyclohexanedodecol (CHD) could facilitate the Zn dendrite-free plating/stripping at a nanoscale. The CHD molecules could effectively modify the hydrated Zn(H2O)62+ structure in aqueous Zn ion batteries. The addition of CHD could establish robust protection layers on the Zn electrode surface. The CHD-modified electrolytes exhibit long-term cycling stability. Aqueous zinc-ion batteries (AZIBs) can be one of the most promising electrochemical energy storage devices for being non-flammable, low-cost, and sustainable. However, the challenges of AZIBs, including dendrite growth, hydrogen evolution, corrosion, and passivation of zinc anode during charging and discharging processes, must be overcome to achieve high cycling performance and stability in practical applications. In this work, we utilize a dual-functional organic additive cyclohexanedodecol (CHD) to firstly establish [Zn(H2O)5(CHD)]2+ complex ion in an aqueous Zn electrolyte and secondly build a robust protection layer on the Zn surface to overcome these dilemmas. Systematic experiments and theoretical calculations are carried out to interpret the working mechanism of CHD. At a very low concentration of 0.1 mg mL−1 CHD, long-term reversible Zn plating/stripping could be achieved up to 2200 h at 2 mA cm−2, 1000 h at 5 mA cm−2, and 650 h at 10 mA cm−2 at the fixed capacity of 1 mAh cm−2. When matched with V2O5 cathode, the resultant AZIBs full cell with the CHD-modified electrolyte presents a high capacity of 175 mAh g−1 with the capacity retention of 92% after 2000 cycles under 2 A g−1. Such a performance could enable the commercialization of AZIBs for applications in grid energy storage and industrial energy storage. [ABSTRACT FROM AUTHOR]

Redox-active polymers are regarded as one of the most promising electroactive materials for non-lithium electrochemical energy storage devices due to the inherent molecular flexibility that can tolerate the structure change during the charge/discharge process. Their diverse functional groups provide abundant active sites to accommodate large-sized electrolyte ions. In this work, for the first time, the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical group, equipped at poly(TEMPO-acrylamide) (PTAm), is employed as an active cathode for potassium dual-ion batteries (KDIBs). Carbon nanotubes (CNTs) assist morphological engineering of the PTAm to create a conductive nanostructured composite, namely PTAm@CNTs. Systematic material characterizations and electrochemical evaluation suggest that the PTAm@CNTs nanocomposite possesses significant surface area and nanopores, enabling enhanced electronic and ionic conductivity. The PTAm@CNTs cathode reversibly stores hexafluorophosphate (PF 6 −) anions in KDIBs, delivering high energy density, rate capability, and robust cycling stability. The fast reaction kinetics of nitroxide radicals (N–O. ), the redox-active groups on the PTAm, and their association with the PF 6 − anions contribute to the dual-ion storage. As a result, the PTAm@CNTs cathode delivers a high specific capacity of 108 mAh g−1 at 2 A g−1 (16.8C) over 300 cycles. The work suggests a promising pathway to design and synthesize functional organic electrode materials for potassium dual-ion batteries. Using organic cathodes in potassium ion batteries avoids the sluggish intercalation/deintercalation kinetics of potassium ions found in inorganic electrodes. This work utilizes nitroxide radical polymers as organic active materials and, through morphology control with CNTs, prepares the first radical polymer potassium dual-ion battery that displays enhanced energy and power density. [Display omitted] • PTAm is prepared as organic cathode materials through post-polymerization modification. • CNTs-assisted morphological engineering of PTAm creates PTAm@CNTs nanocomposites. • The optimised PTAm@CNTs interface enhances electronic conductivity and ionic transport. • Fast anion diffusion of PF 6 − in and out of PTAm facilitates high-rate KDIBs. [ABSTRACT FROM AUTHOR]

Bioinspired asymmetric nanofluidic ion channels with ionic diode behavior that can boost the osmotic energy (so‐called blue energy) conversion are highly desirable, especially if they can be easily constructed and modified. Two‐dimensional (2D) metal carbides and nitrides, known as MXenes, combine hydrophilic surfaces and tunable surface charge properties, providing a shortcut to prepare asymmetric nanofluidic ion channels. Here, we report a mechanically robust, flexible, and scale‐up‐friendly asymmetric Ti3C2Tx MXene‐based ionic diode membrane with a highly rectified current and demonstrate its potential use in reverse electrodialysis osmotic energy conversion. Under the salinity gradient of synthetic seawater and river water, our ionic diode membrane‐based generator's power density is 8.6 W m−2 and up to 17.8 W m−2 at a 500‐fold salinity gradient, outperforming the state‐of‐the‐art membranes. The design of MXene‐based ionic diode‐type membrane provides a facile and general strategy in developing large‐scale 2D nanofluidics and selective ion transport. [ABSTRACT FROM AUTHOR]

Bio‐inspirierte asymmetrische nanofluidische Ionenkanäle mit ionischem Diodenverhalten sind Forschungsziel, weil sie die effektive Umwandlung osmotischer Energie (sogenannte "blaue Energie") in Elektrizität erlauben, insbesondere, wenn sie die Möglichkeit einer weiteren Oberflächenmodifizierung bieten. Zweidimensionale (2D) Metallcarbide und ‐nitride, bekannt als MXene, kombinieren hydrophile Oberflächen mit einstellbaren Oberflächenladungseigenschaften und bieten einen kurzschrittigen Weg zur Herstellung asymmetrischer nanofluidischer Ionenkanäle. Hier berichten wir über eine mechanisch robuste, flexible und scale up‐freundliche asymmetrische Ionen‐Diodenmembran auf Ti3C2Tx‐MXene‐Basis mit einem hochgradig gleichgerichteten Ionenstrom und demonstrieren ihre potenzielle Verwendung in der Wandlung osmotischer in elektrische Energie durch Umkehrelektrodialyse. Unter dem Salzkonzentrationsgradienten von synthetischem Meerwasser und Flusswasser beträgt die Leistungsdichte unseres Ionendioden‐Membran‐basierten Generators 8.6 W m−2 und bis zu 17.8 W m−2 bei einem 500‐fachen Salzgradienten und übertrifft damit den Stand der Technik. Das Design einer ionischen Membran vom Diodentyp auf MXene‐Basis bietet eine einfache und allgemeine Strategie für die Entwicklung von großflächigen 2D‐nanofluiden Systemen mit selektivem unidirektionalem Ionentransport. [ABSTRACT FROM AUTHOR]

Electrochromic materials can tune the illumination and heat exchange of a building with the environment and thereby save energy in lighting, heating, and air conditioning in a cost‐effective way, which is vital in realizing carbon neutrality. 2D frameworks such as coordination nanosheets (CONASHs) that are widely explored for a wide range of applications in energy storage and conversion can be a cluster of novel electrochromic materials. In this work, a series of transition metal benzenehexathiol (TM‐BHT) CONASHs are theoretically investigated via first‐principles simulations. During ion intercalation and deintercalation in TM‐BHTs, changes in lattice structures, lithium diffusion barriers, atomic charges, bond strength, and electronic properties are explored in‐depth. The incurred changes are then correlated with critical electrochromic properties, including the transmittance adjustment ranges in the visible light, near‐infrared, solar spectrum, and mid‐infrared. Among the various TM‐BHT systems, Cu‐BHT and Ag‐BHT are the most promising broadband electrochromic materials for optical and thermal management in the wavelength range from visible to mid‐infrared. The theoretical guidance from this work paves a new path toward electrochromic applications of CONASHs that exploit the versatility of these 2D materials. [ABSTRACT FROM AUTHOR]