A Double-ligand Chelating Strategy to Iron Complex Anolytes with Ultrahigh Cyclability for Aqueous Iron Flow Batteries.

Aqueous all-iron flow batteries (AIFBs) are attractive for large-scale and long-term energy storage due to their extremely low cost and safety features. To accelerate commercial application, a long cyclable and reversible iron anolyte is expected to address the critical barriers, namely iron dendrite growth and hydrogen evolution reaction (HER). Herein, we report a robust iron complex with triethanolamine (TEA) and 2-methylimidazole (MM) double ligands. By introducing two ligands into one iron center, the binding energy of the complex increases, making it more stable in the charge-discharge reactions. The Fe(TEA)MM complex achieves reversible and stable redox between Fe3+ and Fe2+ , without metallic iron growth and HER. AIFBs based on this anolyte perform a high energy efficiency of 80.5 % at 80 mA cm-2 and exhibit a record durability among reported AIFBs. The efficiency and capacity retain nearly 100 % after 1,400 cycles. The capital cost of this AIFB is $ 33.2 kWh-1 (e.g., 20 h duration), cheaper than Li-ion battery and vanadium flow battery. This double-ligand chelating strategy not only solves the current problems faced by AIFBs, but also provides an insight for further improving the cycling stability of other flow batteries.

Enhancing Oxygen Reduction on Fe Single-Atom Catalysts by Tuning Noncovalent Interactions in Electrode/Electrolyte Interfaces.

Highly efficient electrochemical interfaces are significant for the oxygen reduction reaction (ORR). However, previous efforts have been mainly paid to design catalytic sites with high intrinsic activity and neglect the electrode/electrolyte interfaces, especially the noncovalent interactions in the outer Helmholtz plane (OHP). Herein, an Fe-N-C single-atom catalyst is synthesized and acts as the model catalyst to demonstrate the effect of noncovalent interactions on the ORR performance. Two specific molecules of THA+ and TEA+ with different structures and functional groups have been selected to tune the OHP through noncovalent interactions. TEA+ can adjust the OHP, improve the oxygen diffusion coefficient, and increase the double-layer capacitance. Therefore, TEA+ enhances the activity, selectivity, and stability of Fe-N-C single-atom catalysts toward the ORR. This provides a new approach to finding new directions in designing electrochemical interfaces beyond the intrinsic catalytic sites in acidic electrolytes.

Highly Durable PtNi Alloy on Sb-Doped SnO2 for Oxygen Reduction Reaction with Strong Metal-Support Interaction.

Carbon-supported Pt is currently used as catalyst for oxygen reduction reaction (ORR) in fuel cells but is handicapped by carbon corrosion at high potential. Herein, a stable PtNi/SnO2 interface structure has been designed and achieved by a two-step solvothermal method. The robust and conductive Sb-doped SnO2 supports provide sufficient surfaces to confine PtNi alloy. Moreover, PtNi/Sb0.11 SnO2 presents a more strongly coupled Pt-SnO2 interface with lattice overlap of Pt (111) and SnO2 (110), together with enhanced electron transfer from SnO2 to Pt. Therefore, PtNi/Sb0.11 SnO2 exhibits a high catalytic activity for ORR with a half-wave potential of 0.860 V versus reversible hydrogen electrode (RHE) and a mass activity of 166.2 mA mgPt -1 @0.9 V in 0.1 M HClO4 electrolyte. Importantly, accelerated degradation testing (ADT) further identify the inhibition of support corrosion and agglomeration of Pt-based active nanoparticles in PtNi/Sb0.11 SnO2 . This work highlights the significant importance of modulating metal-support interactions for improving the catalytic activity and durability of electrocatalysts.

Low-cost Zinc-Iron Flow Batteries for Long-Term and Large-Scale Energy Storage.

Aqueous flow batteries are considered very suitable for large-scale energy storage due to their high safety, long cycle life, and independent design of power and capacity. Especially, zinc-iron flow batteries have significant advantages such as low price, non-toxicity, and stability compared with other aqueous flow batteries. Significant technological progress has been made in zinc-iron flow batteries in recent years. Numerous energy storage power stations have been built worldwide using zinc-iron flow battery technology. This review first introduces the developing history. Then, we summarize the critical problems and the recent development of zinc-iron flow batteries from electrode materials and structures, membranes manufacture, electrolyte modification, and stack and system application. Finally, we forecast the development direction of the zinc-iron flow battery technology for large-scale energy storage.

Insights into the Modification of Carbonous Felt as an Electrode for Vanadium Redox Flow Batteries.

The vanadium redox flow battery (VRFB) has been regarded as one of the best potential stationary electrochemical storage systems for its design flexibility, long cycle life, high efficiency, and high safety; it is usually utilized to resolve the fluctuations and intermittent nature of renewable energy sources. As one of the critical components of VRFBs to provide the reaction sites for redox couples, an ideal electrode should possess excellent chemical and electrochemical stability, conductivity, and a low price, as well as good reaction kinetics, hydrophilicity, and electrochemical activity, in order to satisfy the requirements for high-performance VRFBs. However, the most commonly used electrode material, a carbonous felt electrode, such as graphite felt (GF) or carbon felt (CF), suffers from relatively inferior kinetic reversibility and poor catalytic activity toward the V2+/V3+ and VO2+/VO2+ redox couples, limiting the operation of VRFBs at low current density. Therefore, modified carbon substrates have been extensively investigated to improve vanadium redox reactions. Here, we give a brief review of recent progress in the modification methods of carbonous felt electrodes, such as surface treatment, the deposition of low-cost metal oxides, the doping of nonmetal elements, and complexation with nanostructured carbon materials. Thus, we give new insights into the relationships between the structure and the electrochemical performance, and provide some perspectives for the future development of VRFBs. Through a comprehensive analysis, it is found that the increase in the surface area and active sites are two decisive factors that enhance the performance of carbonous felt electrodes. Based on the varied structural and electrochemical characterizations, the relationship between the surface nature and electrochemical activity, as well as the mechanism of the modified carbon felt electrodes, is also discussed.

Double Riveting and Steric Hindrance Strategy for Ultrahigh-Loading Atomically Dispersed Iron Catalysts Toward Oxygen Reduction.

Atomically dispersed iron on nitrogen doped carbon displays high intrinsic activity toward oxygen reduction reaction, and has been identified as an attractive candidate to precious platinum catalysts. However, the loading of atomic iron sites is generally limited to below 4 wt% due to the undesired formation of iron-related particles at higher contents. Herein, this work overcomes this limit by a double riveting and steric hindrance strategy to achieve monodispersed iron with a high-loading of 12.8 wt%. Systematic study reveals that chemical riveting of atomic iron in ZIF-8 framework, chelation of Fe ions with interconfined 1,4-phenylenebisboronic, and physical hindrance are essential to obtain high-loading monodispersed Fe moieties. Resultantly, designed Fe-N-C-PDBA exhibits superior catalytic activity and excellent stability over commercial platinum catalysts toward oxygen reduction reaction in both half-cells and zinc-air fuel cells (ZAFCs). This provides an avenue for developing high-loading single-atom catalysts (SACs) for energy devices.

A Bifunctional Liquid Fuel Cell Coupling Power Generation and V3.5+ Electrolytes Production for All Vanadium Flow Batteries.

All vanadium flow batteries (VFBs) are considered one of the most promising large-scale energy storage technology, but restricts by the high manufacturing cost of V3.5+ electrolytes using the current electrolysis method. Here, a bifunctional liquid fuel cell is designed and proposed to produce V3.5+ electrolytes and generate power energy by using formic acid as fuels and V4+ as oxidants. Compared with the traditional electrolysis method, this method not only does not consume additional electric energy, but also can output electric energy. Therefore, the process cost of producing V3.5+ electrolytes is reduced by 16.3%. This fuel cell has a maximum power of 0.276 mW cm-2 at an operating current of 1.75 mA cm-2 . Ultraviolet-visible spectrum and potentiometric titration identify the oxidation state of prepared vanadium electrolytes is 3.48 ± 0.06, close to the ideal 3.5. VFBs with prepared V3.5+ electrolytes deliver similar energy conversion efficiency and superior capacity retention to that with commercial V3.5+ electrolytes. This work proposes a simple and practical strategy to prepare V3.5+ electrolytes.

Tebentafusp: a novel drug for the treatment of metastatic uveal melanoma.

On January 25, 2022, the U.S. Food and Drug Administration (FDA) approved the use of tebentafusp, a bispecific glycoprotein 100 (gp100) peptide-human leukocyte antigen (HLA)-directed CD3 T-cell activator, for the treatment of HLA-A*02:01-positive adult patients with unresectable or metastatic uveal melanoma (mUM). Pharmacodynamic data indicate that tebentafusp targets a specific HLA-A*02:01/gp100 complex, activating both CD4+/CD8+ effector and memory T cells that induce tumor cell death. Tebentafusp is administered to patients via intravenous infusion daily or weekly, depending on the indication. Phase III trials have documented a 1-year overall survival of 73%, overall response rate of 9%, progression-free survival of 31% and disease control rate of 46%. Common adverse events reported are cytokine release syndrome, rash, pyrexia, pruritus, fatigue, nausea, chills, abdominal pain, edema, hypotension, dry skin, headache and vomiting. Compared to other types of melanomas, mUM presents with a distinct profile of genetic mutations, which phenotypically results in limited survival efficacy when using traditional melanoma treatments. The low current treatment efficacy for mUM, alongside a poor long-term prognosis and high mortality rates, gives precedence for the approval of tebentafusp to be groundbreaking in its clinical impact. This review will discuss the pharmacodynamic and pharmacokinetic profile, and the clinical trials used to evaluate the safety and efficacy of tebentafusp.

The characteristics of nitrogen and phosphorus output in China's highly urbanized Pearl River Delta region.

The nitrogen (N) and phosphorus (P) transportation due to the anthropogenic activities have strong correlations to the water pollution events. In the highly urbanized Pearl River Delta (PRD) region of China, the main input pathways for N and P have been changed. However, their main output pathways have not yet been understood. Based on the modified export coefficient model (ECM), we have quantified the N and P outputs and identified the main factors affecting the N and P outputs in highly urbanized areas such as PRD. The results showed that the N output intensity of the PRD has increased from 3010 to 3970 kg km-2·a-1 from 2008 to 2016. The P output exhibited a similar trend, from 549 to 769 kg km-2·a-1. In terms of spatial distribution, the output intensity gradually increased from economically underdeveloped regions to economically developed regions. N and P emissions in urban wastewater increased significantly with increasing urbanization rates, with output intensities increasing by 640 kg km-2·a-1 and 141 kg km-2·a-1 from 2008 to 2016, respectively. The correlation analysis showed that population density and urbanization rate were the most relevant factors with N and P outputs intensity in highly urbanized areas. This indicates that improving the effluent standards and utilization rates of wastewater treatment plants in these regions are effective measures to control N and P output. Our findings provide some new theoretical basis for the identification and management of pollution sources in highly urbanized areas for other regions, especially developing countries.

Atomically Dispersed Iron with Densely Exposed Active Sites as Bifunctional Oxygen Catalysts for Zinc-Air Flow Batteries.

Atomically dispersed iron embedded carbon is a promising bifunctional catalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), but its exposed iron sites must be increased. Herein, the authors propose a double steric hindrance strategy by using zeolitic imidazolate frameworks-8 as the first barrier skeleton and encapsulated phenylboronic acid as the second space obstruction to realize densely exposed atomic iron sites. Prepared PA@Z8-FeNC has the highest iron content (5.49 wt%) among reported transition-metal-based single-atom oxygen catalysts. Meanwhile, its concave surfaces, hollow structures, and hierarchical pores enable the high utilization rate of iron sites to 88.5 ± 4.5% and exposed active site density to 5.2 ± 0.3 × 1020 sites g-1 . Resultantly, PA@Z8-FeNC exhibits superior activity and stability to commercial Pt/C and IrO2 for the ORR and OER in half-cells and zinc-air flow batteries. This provides insight for developing densely and accessibly active sites in single-atom catalysts.

Inhibition of Zinc Dendrites in Zinc-Based Flow Batteries.

Zinc-based flow batteries have gained widespread attention and are considered to be one of the most promising large-scale energy storage devices for increasing the utilization of intermittently sustainable energy. However, the formation of zinc dendrites at anodes has seriously depressed their cycling life, security, coulombic efficiency, and charging capacity. Inhibition of zinc dendrites is thus the bottleneck to further improving the performance of zinc-based flow batteries, but it remains a major challenge. Considering recent developments, this mini review analyzes the formation mechanism and growth process of zinc dendrites and presents and summarizes the strategies for preventing zinc dendrites by regulating the interfaces between anodes and electrolytes. Four typical strategies, namely electrolyte modification, anode engineering, electric field regulation, and ion transfer control, are comprehensively highlighted. Finally, remaining challenges and promising directions are outlined and anticipated for zinc dendrites in zinc-based flow batteries.

Facile Synthesis of Hierarchical Nanosized Single-Crystal Aluminophosphate Molecular Sieves from Highly Homogeneous and Concentrated Precursors.

The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized. These materials show exceptional properties, including small crystallites (30-150 nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time-dependent study revealed a non-classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.

In Situ Charge Exfoliated Soluble Covalent Organic Framework Directly Used for Zn-Air Flow Battery.

Covalent organic frameworks (COFs) are generally obtained as insoluble, cross-linked powders or films, hindering their superior processable properties especially for device implementation. Here, a soluble COF is created with atomically well-organized positive charged centers constrained in the planar direction, exhibiting exceptional solubility through an in situ charge exfoliation pathway. Once dissolved, the obtained true solution retains homogeneity even after standing over a year. Moreover, the as-designed soluble COF contains ordered N-coordinated Fe single atom centers and conjugated structures, providing a small work function (4.84 eV) and superior catalytic performance for oxygen reduction (high half-wave potential of ∼900 mV). The obtained COF true solution can be directly used as a highly efficient Pt-replaced catalyst for zinc-air flow batteries, generating prominent performance and outstanding stability.

Superior oxygen electrocatalysts derived from predesigned covalent organic polymers for zinc-air flow batteries.

Covalent organic polymers (COPs) as emerging porous materials with ultrahigh hydrothermal stability and well-defined and adjustable architectures have aroused great interest in the electrochemical field. Here, we reported a rational design approach for the preparation of a bifunctional electrocatalyst with the assistance of a predesigned bimetallic covalent organic polymer. With the predesigned nitrogen position and structural features of COP materials, the obtained CCOPTDP-FeNi-SiO2 catalyst affords a remarkable bifunctional performance with a positive half-wave potential (0.89 V vs. reversible hydrogen electrode: RHE, superior to the benchmark Pt/C) for ORR activity, and a low overpotential (0.31 V better than the benchmark IrO2) at 10 mA cm-2 for OER activity in alkaline solution. The potential gap between E1/2 and Ej=10 reaches 0.650 V, in line with that observed in the current state-of-the-art bifunctional oxygen electrode materials. Moreover, a homemade rechargeable Zn-air flow battery using the CCOPTDP-FeNi-SiO2 catalyst as an air cathode exhibits an almost twofold power density (112.8 vs. 64.8 mW cm-2) and a lower charge-discharge voltage gap, compared with a commercialized noble Pt/C + IrO2/C-driven Zn-air flow battery. More importantly, the CCOPTDP-FeNi-SiO2-driven battery maintains a better cycling stability compared to a noble metal-driven battery without performance decay. Accordingly, this work will open up new ways for fabricating practical oxygen electrodes for, but not limited to, metal air based battery applications.

Highly Efficient Oxygen Reduction Reaction Electrocatalysts Synthesized under Nanospace Confinement of Metal-Organic Framework.

The output energy capacity of green electrochemical devices, e.g., fuel cells, depends strongly on the sluggish oxygen reduction reaction (ORR), which requires catalysts. One of the desired features for highly efficient ORR electrocatalytic materials is the richness of well-defined activate sites. Herein, we developed a facile approach to prepare highly efficient nonprecious metal and nitrogen-doped carbon-based ORR catalysts based on covalent organic polymers (COPs) synthesized in situ in the nanoconfined space of highly ordered metal organic frameworks (MOFs). The MOF templet ensured the developed electrocatalysts possess a high surface area with homogeneously distributed small metal/nitrogen active sites, as confirmed by X-ray absorption fine structure measurements and first-principles calculations, leading to highly efficient ORR electrocatalytic activity. Notably, the developed COP-TPP(Fe)@MOF-900 exhibits a 16 mV positive half-wave potential compared with the benchmarked Pt/C.

[SRAP study on genetic diversity of radix plygoni multiflori in chongqing].

OBJECTIVE: To detect the polymorphisms of Radix Plygoni Multiflori in chongqing by means of a new marker system SRAP. METHOD: Different shaples of Radix Plygoni Multiflori from major production areas were collected. The SRAP was used to asses divergence among 16 populations. The data were analyzed using unweighted pairgroup method, based on arithmetic averages (UPGMA) bootstrap analysis. Cluster analyses was performed by using DPSv3.01 software, the alkaloid was extracted from P. ternate with chlorolform. RESULT: 104 combinations generated 250 polymorphie bands, the cluster analysis indicated that 16 materials could be distinguished into two main groups and one special type, Nei&Li similarity coefficient ranged from 0.23-0.99, and the average distance is 0. 44. CONCLUSION: The results of the study showed a potential application of SRAP fingerprinting for identification of Radix Plygoni Multiflori.