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This research provides a feasible strategy for the development and application of a novel nanosized photocatalyst and an innovative approach for the treatment of freshwater aquaculture wastewater.

Recently, photoassisted charging has been demonstrated as a green and sustainable approach to successfully enhance the capacitance of supercapacitors with low cost and good efficiency. However, their light-induced capacitance enhancement is relatively low and is lost quickly when the illumination is off. In this work, a novel active material system is developed for supercapacitors with the photoassisted charging capability by the decoration of a small amount of Bi2WO6 nanoparticles on an h-WO3 submicron rod surface in situ, which forms a typical type II band alignment heterostructure with a close contact interface through the co-sharing of W atoms between h-WO3 submicron rods and Bi2WO6 nanoparticles. The photogenerated charge carrier separation and transfer are largely enhanced in the h-WO3/Bi2WO6 submicron rod electrode, which subsequently allows more charge carriers to participate in its photoassisted charging process to largely enhance its capacitance improvement under simulated solar illumination than that of the h-WO3 submicron rod electrode. Furthermore, the h-WO3/Bi2WO6 submicron rod electrode could retain its photoinduced capacitance enhancement in the dark for an extended period of time from the photocatalytic memory effect. Thus, our work provides a solution to the two major drawbacks of reported supercapacitors with the light-induced capacitance enhancement property, and supercapacitors based on active materials with the photocatalytic memory effect could be utilized in various technical fields.

The development of high-performance micro-supercapacitors (MSCs) highlights two-dimensional (2D) carbon materials with pseudocapacitive charge storage capacity. However, improving the electrochemical performances of these electrode materials is still challenging. Here, we synthesized 2D borocarbonitride nanomesh (BCNN) by carbonizng gel precursor of milk powder and boron oxide in 700, 800, and 900 °C, respectively, denoted as BCNN700, BCNN800, and BCNN900, as electrode for MSCs. By tailoring defects and atomic contents of BCNN, the areal capacitance increases from 30.5 mF cm−2 for BCNN700-MSCs to 80.1 mF cm−2 for BCNN900-MSCs with a hydrogel electrolyte. Notably, BCNN900-MSCs can provide a high energy density of 67.6 mWh cm−3with an ion-gel electrolyte, efficiently powering a liquid crystal display for 328 s. In addition, a first principles simulation verifies the effects of the dopants and pores on improving the total capacitance of BCNN by enhancing qauntam capacitance. Therefore, BCNN exhibits tremendous potential for applying on future energy storage devices.

Lithium-ion capacitors (LICs), shrewdly integrating a battery-type negative electrode and a capacitive-type carbon positive electrode, are expected to inherit simultaneously both the high specific energy of lithium-ion batteries (LIBs) and high specific power of electrochemical capacitors (ECs). However, state-of-the-art LICs are approaching their specific energy limits yet are still far away from that dictated by LIBs. Herein, we report an aprotic Li-metal capacitor (LMC) strategy to solve this problem through coupling a Li-metal negative electrode with a three-dimensional scaffold activated carbon (3D-SAC) positive electrode. The employment of metal Li negative electrode leads to an ultrahigh specific capacitance up to 280 F gpositive electrode−1 within high potential range from 1.5 to 4.3 V vs Li/Li+, giving a remarkable specific energy of 633 Wh kgpositive electrode−1. Combing with theoretical simulation and advanced characterizations, it is revealed that such a high capacitance is the contribution resulting from multiple electrical double-layer mechanisms on carbon positive electrode that involves the desorption of PF6− anions, the exchange between adsorbed PF6− anions and solvated cation clusters, and the adsorption of solvated cation clusters. The unique desolvation behavior and the electrochemical adsorption of desolvated Li+-related cations boost the specific capacitance and specific energy at low current rates. This is completely different from the reported LICs. This findings provide a new strategy for developing high-energy-and-power capacitors and batteries.

Perovskite-type oxides, characterized by excellent multifunctional physical and chemical properties, have been widely used in ferroelectric, piezoelectric, energy conversion, and storage applications. We show here that the perovskite-type SrVO3 can achieve excellent electrochemical performance as lithium-ion battery anodes thanks to its high electrically and ionically conductivity. Conducting additive-free SrVO3 electrodes can deliver a high specific capacity of 324 mAh g-1 at a safe and low average working potential of ∼0.9 V versus Li/Li+ together with excellent high-rate performance. A high areal capacity of ∼5.4 mAh cm-2 is obtained using an ultrathick (∼120 um) electrode. Moreover, the fully lithiated SrVO3 electrode exhibits only 2.3% volume expansion that is explained by a simple solid solution Li+ storage mechanism, resulting in good cycling stability of the electrode. This study highlights the perovskite-type SrVO3 as a promising Li+ storage anode and provides opportunities for exploring a variety of perovskite oxides as next-generation metal-ion battery anodes. This article is protected by copyright. All rights reserved.

Layered ternary carbides and nitrides, also known as MAX phases, have attracted enormous attention for many applications, especially as precursors to produce 2D metal carbides and nitrides called MXenes. However, it is still challenging to tune and control the shape/morphology of MAX phase particles at the nanoscale, as they are typically manufactured as large grains using ceramic technology. Herein, nanostructured Ti-Al-C MAX phases with fine-tuned morphology of nanofibers and nanoflakes are prepared by using 1D and 2D carbon precursors at a synthesis temperature of 900 °C. The nanostructured MAX phases are used as precursors to produce nanosized multilayered MXenes, with a considerably shorter etching time and a low reaction temperature. These nanosized MXenes exhibit good electrochemical lithium-ion storage properties and a pseudocapacitive electrochemical signature. The obtained Ti

Perovskite SrVO

Lithium metal capacitors (LMCs), inheriting the merits of lithium metal batteries with a high energy density and an outstanding power capability comparable to that of supercapacitors (SCs), exhibit tremendous potential for next-generation energy storage systems. However, the application of a Li metal anode is plagued by the formation of Li dendrites, which results in uncontrollable volume expansion, potential safety hazards and even premature failure. Here, a high-performance LMC based on a dendrite-free and resource-efficient three-dimensional Li composite anode with a robust solid-electrolyte interphase (SEI) is reported. The constructed LMC with this advanced Li composite anode achieves a record-high energy density of 492 W h kg−1 (∼1.8 times higher than the state-of-the-art value for lithium-ion hybrid capacitors, LICs) and a comparable power density of 28.5 kW kg−1 to SCs, as well as a long-term cyclability of over 2500 cycles. Furthermore, the overall performance of the LMC was further evaluated by employing a Li dendrite-free flexible carbon nanotube network current collector, and the constructed LMC based on the weight of the entire device still delivered a high energy density of 115.6 W h kg−1. This work provides a very efficient strategy for boosting the performance of LMCs by constructing dendrite-free Li metal composite anodes.

It is extremely desirable to explore high-efficient, affordable and robust oxygen electrocatalysts toward rechargeable Zn-air batteries (ZABs). A 3D porous nitrogen-doped graphene encapsulated metallic Ni3 Fe alloy nanoparticles aerogel (Ni3 Fe-GA1 ) was constructed through a facile hydrothermal assembly and calcination process. Benefiting from 3D porous configuration with great accessibility, high electrical conductivity, abundant active sites, optimal nitrogen content and strong electronic interactions at the Ni3 Fe/N-doped graphene heterointerface, the obtained aerogel showed outstanding catalytic performance toward the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Specifically, it exhibited an overpotential of 239 mV to attain 10 mA cm-2 for OER, simultaneously providing a positive onset potential of 0.93 V within a half-wave potential of 0.8 V for ORR. Accordingly, when employed in the aqueous ZABs, Ni3 Fe-GA1 achieved higher power density and superior reversibility than Pt/C-IrO2 catalyst, making it a potential candidate for rechargeable ZABs.

Volumetric and areal capacitance are as important as gravimetric capacitance for small energy storage devices. However, achieving both a high volumetric and a high areal capacitance is still a big challenge. Here we report a dense redox organic molecules/graphene network, in which highly redox active sodium anthraquinone-2-sulfonate (AQS) molecules are anchored on interconnected and highly conductive graphene sheets by noncovalent π–π interactions to form high-performance supercapacitors (SCs). The AQS/graphene (AQS/G) has a high volumetric specific capacitance of up to 650 F cm−3 and an excellent rate capability (422 F cm−3 even at 30 A g−1), as well as a good cycling stability. A maximum areal specific capacitance of 13.3 F cm−2 is achieved at a high mass loading of 32 mg cm−2 (200 μm in thickness), which is amongst the highest values recorded for organic-based materials for SCs. An asymmetric SC constructed with AQS/G and RuO2/graphene delivers a maximum volumetric energy density of 44 W h L−1. This outstanding performance is attributed to the excellent electron conduction and ion transport provided by the dense but interconnected graphene network. This work suggests a new way for organic-based high-performance electrode materials to be used in electrochemical energy storage devices.

Electrochemical quartz crystal microbalance (EQCM) is a powerful technique to screen the gravimetric response of electrochemical electrodes. In this study, a straightforward mathematical method is proposed for extracting and deconvoluting the real-time fluxes and ionic currents of two species based on the EQCM measurement results. We creatively propose the concept of flux cyclic voltammograms (CVs) and ionic current CVs of various species and apply them to the real-time analyses of molecules/ions dynamics. For proof of concept, Ti3C2Tx MXene, a most studied two-dimensional metal carbide, is investigated as a supercapacitor electrode in a 1M H2SO4 electrolyte. The H2O and H+ flux CV plots are highly symmetrical, indicating reversible inserting/deserting species fluxes. The highest fluxes along with maximum hydration numbers are obtained at the peak current potential. This suggests the significant contribution of double-layer capacitance originates from the insertion of hydrated H+. The H+ CV with the ionic current induced by H+ flux overlaps the real CV, confirming that H+ is the only interactive ion for screening the electrode charge. Lastly, we also validate the proposed strategy using Ti3C2Tx MXene electrode in 1M KCl electrolyte and YP80 porous carbon electrode in 1 M LiCl electrolyte.

Recently, photoassisted charging has been demonstrated as a green and sustainable approach to successfully enhance the capacitance of supercapacitors with low cost and good efficiency. However, their light-induced capacitance enhancement is relatively low and is lost quickly when the illumination is off. In this work, a novel active material system is developed for supercapacitors with the photoassisted charging capability by the decoration of a small amount of Bi

To investigate the effects of different running intensities on interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in patients with early knee osteoarthritis (KOA).Clinical comparative study.Department of Orthopedics, Longyan First Affiliated Hospital of Fujian Medical University, Fujian, China, from January 2019 to January 2021.A total of 131 patients with early KOA admitted to Longyan First Hospital Affiliated to Fujian Medical University from January 2019 to January 2021 were selected and randomly divided into four groups using the random number table method: Group A (static control group, 34 cases), Group B (walking group, 32 cases), Group C (brisk walking group, 32 cases), and Group D (jogging group, 33 cases), and the training duration of the four groups was 6 months. Moreover, the levels of IL-6 and TNF-α, the activity of daily living (ADL), Fugl-Meyer assessment scale (FMA) scores, and adverse events before and after training were compared between the four groups.No statistical significance was observed in the differences of TNF-α, IL-6, ADL-advanced ability, ADL-basic ability, FMA-upper limb, and FMA-lower limb among the four groups before training (p0.05). After training, the levels of TNF-α and IL-6 of the four groups were decreased, while the scores of FMA and ADL were increased. Group C had the highest FMA-upper limb and FMA-lower limb scores, ADL- advanced ability and ADL-basic ability after training, which were higher than those in groups A, B, and D (p0.05). No statistical significance could be observed in the difference in the adverse event rate among the four groups during training (X2=3.339, p0.05).Exercise training of different intensities, such as slow walking, brisk walking, and jogging, is touted to enhance the overall recovery of patients with early KOA. The exercise intensity of brisk walking training is moderate, and the activity of daily living and exercise ability of patients are significantly improved after training, while the levels of TNF-α and IL-6 are obviously decreased.Knee osteoarthritis, Interleukin-6, Exercise training, Exercise intensity, Tumor necrosis factor α.

Perovskite-type oxides, characterized by excellent multifunctional physical and chemical properties, are widely used in ferroelectric, piezoelectric, energy conversion, and storage applications. It is shown here that the perovskite-type SrVO

The effects of nanoconfined water and the charge storage mechanism are crucial to achieving the ultrahigh electrochemical performance of two-dimensional transition metal carbides (MXenes). We propose a facile method to manipulate nanoconfined water through surface chemistry modification. By introducing oxygen and nitrogen surface groups, more active sites were created for Ti3C2 MXene, and the interlayer spacing was significantly increased by accommodating three-layer nanoconfined water. Exceptionally high capacitance of 550 F g–1 (2000 F cm–3) was obtained with outstanding high-rate performance. The atomic scale elucidation of the layer-dependent properties of nanoconfined water and pseudocapacitive charge storage was deeply probed through a combination of ‘computational and experimental microscopy’. We believe that an understanding of, and a manipulation strategy for, nanoconfined water will shed light on ways to improve the electrochemical performance of MXene and other two-dimensional materials.

A current trend is to implement dam risk management. Dam risk analysis is the premise of dam risk management. Methods such as PRA, FMEA/FMECA, FTA, ETA, and group dam risk analysis have been proposed in studies at home and abroad. In practice, it is found that dam breaks or accidents occur even though the dam risk calculated by the existing methods meets the acceptable risk standard, and that many occurred accidents are at variance with dam risk analysis. This indicates that the existing methods have systematic defects, and the dam risk calculated based on such methods is only a part of the actual risk. This paper reviews the dam risk analysis theory and technical research and practice, discusses and analyzes the applicability and existing defects of the dam risk analysis theory, and proposes the future development direction of the dam risk analysis theory. It is concluded that the current dam risk assessment theories are tantamount to the traditional safety factor method coupled with probability analysis. The correlation among influencing factors of dam system risk, as well as the uncertainties of the said factors are not fully considered. Difficulties and opportunities coexist in China to link the existing dam safety standard system with the dam risk management system. The next step is to use system theory to carry out theoretical research on dam operation risk assessment, strengthen the connection between dam risk theory and management status, and formulate risk prevention regulations and technical standards.

Highlights Small size V2SnC MAX phase was prepared by the molten salt method. V2SnC MAX phase electrode is able to deliver high gravimetric capacity up to 490 mAh g−1 and volumetric capacity of 570 mAh cm−3 A charge storage mechanism with V2C-Li redox and Sn–Li alloying dual reactions was proposed Supplementary Information The online version contains supplementary material available at 10.1007/s40820-021-00684-6., MAX phases are gaining attention as precursors of two-dimensional MXenes that are intensively pursued in applications for electrochemical energy storage. Here, we report the preparation of V2SnC MAX phase by the molten salt method. V2SnC is investigated as a lithium storage anode, showing a high gravimetric capacity of 490 mAh g−1 and volumetric capacity of 570 mAh cm−3 as well as superior rate performance of 95 mAh g−1 (110 mAh cm−3) at 50 C, surpassing the ever-reported performance of MAX phase anodes. Supported by operando X-ray diffraction and density functional theory, a charge storage mechanism with dual redox reaction is proposed with a Sn–Li (de)alloying reaction that occurs at the edge sites of V2SnC particles where Sn atoms are exposed to the electrolyte followed by a redox reaction that occurs at V2C layers with Li. This study offers promise of using MAX phases with M-site and A-site elements that are redox active as high-rate lithium storage materials. Supplementary Information The online version contains supplementary material available at 10.1007/s40820-021-00684-6.

MXenes are 2D transition metal carbides or nitrides with high electrical conductivity that have attracted great attention as promising electrode materials that supersede carbon-based material designed for supercapacitors. However, the aggregation and self-restacking of MXene 2D nanosheets limit their high-rate performance. In this work, flexible and conductive Ti3C2Tx MXene/carbon nanotubes (CNTs) composite film was prepared through a simple vacuum filtration of the Ti3C2Tx MXene and CNTs suspension mixture. The CNTs integrated MXene nanosheets can effectively prevent the restacking while creating fast ion transport channels for enhanced capacitance. The designed films exhibit excellent performance as supercapacitor electrodes with high capacitance of 300 F g−1 at 1 A g−1 with superior rate performance of 199 F g−1 even at 500 A g−1, together with excellent cyclic stability of 92% capacitance retention after 10000 cycles at 20 A g−1. The excellent workability demonstrates potential application of the system for flexible, portable and highly integrated supercapacitors.

Electrochemical quartz crystal microbalance (EQCM) is a powerful technique to screen the gravimetric response of electrochemical electrodes. In this study, a straightforward mathematical method is proposed for extracting and deconvoluting the real-time fluxes and ionic currents of two species based on the EQCM measurement results. We creatively propose the concept of Flux cyclic voltammograms (CVs) and ionic current CVs of various species and apply them to the real-time analyses of molecules/ions dynamics. For proof of concept, Ti3C2T x MXene, a most studied two-dimensional metal carbide, is investigated as a supercapacitor electrode in a 1M H2SO4 electrolyte. The H2O and H+ flux CV plots are highly symmetrical, indicating reversible inserting/deserting species fluxes. The highest fluxes along with maximum hydration numbers are obtained at the peak current potential. This suggests the significant contribution of double-layer capacitance originates from the insertion of hydrated H+. The H+ CV with the ionic current induced by H+ flux overlaps the real CV, confirming that H+ is the only interactive ion for screening the electrode charge. Lastly, we also validate the proposed strategy using Ti3C2T x MXene electrode in 1M KCl electrolyte and YP80 porous carbon electrode in 1 M LiCl electrolyte.

Here, thermodynamic stability and lithium storage properties of double transition metal M2TiAlC2 o-MAX phases (M = Cr, V, Mo, Nb, Ta, Hf, Zr, Sc, Y, La) are theoretically investigated by density functional theory (DFT) calculation. M2TiAlC2 with a larger M atomic radius shows larger interlayer space that may benefit the Li-ion intercalation. A promising theoretical capacity of 276.87 mAh g-1 is predicted for Sc2TiAlC2. The low Li-ion diffusion barriers (0.57���0.64 eV) for M2TiAlC2 indicate the possibility to achieve fast Li-ion diffusion that is crucial for designing high-power batteries. This work provides opportunities to explore MAX phases as promising Li-ion storage materials. This work investigates the thermostability and lithium storage properties of double transition metal o-MAX phases by DFT calculation and provides a guideline for exploring MAX phases for lithium storage applications.

Rongcheng is a natural kelp production base due to its unique geographical environment and climatic advantages. Since the 1930s, the Rongcheng kelp industry has played an important role in the development of the Chinese kelp industry. Rongcheng's kelp output ranked first in China for more than ten years, from 2010 to 2021. Its kelp production accounts for nearly half of total Chinese kelp production. This paper analyzes the current development of the Rongcheng kelp industry cluster from six perspectives: natural environment and resources of kelp farming, supporting infrastructure of kelp farming and processing enterprises, main bodies in Rongcheng kelp industry cluster, relevant assistance of Rongcheng municipal government to kelp industry, development of relevant supporting industries in kelp industry. Then it concludes that there are four problems in the current development stage of Rongcheng kelp industry cluster and the development of Rongcheng kelp industry cluster's domestic and foreign markets. It then concludes that there are four issues in the current development stage of the Rongcheng kelp industry cluster. Based on the analysis of the problems and countermeasures, it is concluded that the current development stage of the Rongcheng kelp industry cluster has four problems: low cluster efficiency, an imperfect market system, a lack of technological innovation, and a weak influence of regional brands. It assists the Rongcheng kelp industry cluster in achieving high-quality development based on an analysis of the problems and countermeasures.