Excluding the Trouble from Interfacial Water by Covalent Organic Polymer to Realize Extremely Reversible Zn Anode

The side reactions related to water are the major issue hindering practical application of Zn metal batteries. To exclude the trouble from interfacial water, a covalent organic polymer (COP) layer with N, N′-Bis(salicylidene)ethylenediamine structure is designed, whose strong coordination ability with Zn²⁺ enhances the de-solvation kinetics of solvated Zn²⁺ which is conducive to interfacial water removal thus alleviating the side reactions related to water. This function has been certified by density functional theory along with molecular dynamics analysis. Moreover, measurements including in situ electrochemical gas chromatography, in situ optical microscopy, in situ X-ray diffraction and in situ Raman spectroscopy verify the weakened side reactions (including hydrogen evolution and corrosion) along with homogenous Zn deposition contributed from the covalent organic polymer layer. Benefiting from these merits, when assemble into cells based on common ZnSO₄-based aqueous electrolyte, the COP layer-decorated anode exhibits excellent electrochemical performance of a high average Coulombic efficiency value 99.5% at a high capacity of 5.0 mA h cm⁻². What's more, the symmetric cells can operate at −20 °C and the full cell with N/P ratio as low as 1.2 can cycle stably for 100 cycles, which would carry forward the promising practical application of Zn metal batteries.     

Deciphering Electrolyte Selection for Electrochemical Reduction of Carbon Dioxide and Nitrogen to High-Value-Added Chemicals

Electrochemical reduction of CO₂ (CO₂RR) and nitrogen (NRR) constitute alternatives to fossil fuel-based technologies for the production of high-value-added chemicals. Yet their practical application is still hampered by the low energy and Faradaic efficiencies although numerous efforts have been paid to overcome the fatal shortcomings. To date, most studies have focused on designing and developing advanced electrocatalysts, while the understanding of electrolyte, which would significantly influence the reaction microenvironment, are still not enough to provide insight to construct highly active and selective electrochemical systems. Here, a comprehensive review of the different electrolytes participating in the CO₂RR and NRR is provided, including acidic, neutral, alkaline, and water-in-salt electrolyte as aqueous electrolytes, as well as organic electrolyte, ionic-liquids electrolyte, and the mixture of the two as non-aqueous electrolytes. Through the discussion of the roles of these various electrolytes, it is aimed to grasp their essential function during the electrochemical process and how these functions can be used as design parameters for improving electrocatalytic performance. Finally, priorities for future studies are suggested to support the in-depth understanding of the electrolyte effects and thus guide efficient selection for next-generation gas-involving electrochemical reactions.     

基于条纹式转盘的共聚焦三维形貌测量技术

由于共聚焦显微镜的光学切片特性，可通过三维测量采集工业表面缺陷和粗糙度等信息，因此在表面计量领域有着广泛的应用和研究价值。本文结合孔径相关技术和加权最小二乘拟合及迭代算法，低成本地搭建了条纹转盘共聚焦测量系统，其测量速度比商用共聚焦系统快约38%。     

FBAR: An effective method for resolving large-scale IPv6 aliases

With the promotion and application of IPv6 in the world, there is a growing demand for IPv6 alias resolution. How to resolve IPv6 alias efficiently and accurately becomes an urgent problem to be solved. After analyzing the features of IPv6 addresses, this paper proposes a large-scale adaptive IPv6 alias resolution method based on fingerprint information by combining Too-Big Trick, UAv6, APD, and other alias resolution algorithms. It sends ICMPv6 probe packets to different types of IPv6 addresses to get the fingerprint information of target hosts. After filtering the classified addresses, our proposed alias resolution method is adaptively selected to resolve alias addresses. In the experiment, we use multi-thread method to resolve the aliases of large-scale IPv6 addresses, which greatly improves the efficiency of detection. Meanwhile, we use IPv6 datasets collected from the organizations RIPE and CAIDA. By comparing with Speedtrap and Too-Big Trick, we confirm the accuracy of this method and obtain more alias pairs.     

Mo-Mediated Transition of the Lattice to Long-Range Disorder Enables Ultra-High Current Density Hydrogen Production at Low Potentials

High-current hydrogen production at low potential toward hydrogen evolution reaction (HER) is a fatal factor restricting the large-scale production of green hydrogen. Here, a Mo-mediated nickel-based chalcogenides electrocatalyst (U-MoNiS) with long-range disordering through heterogeneous atom-mediated strategies, is proposed. The optimal U-MoNiS is scalable to meet the urgent application needs and it requires an extermely low overpotential (305 mV) to achieve ultra-high current density of 2243 mA cm^-2, which is 16.6-fold higher than the noble Pt/C (135 mA cm^-2). Strikingly, the U-MoNiS can function well under an ultra-high current up to ~5 A. Operando experiments and calculations reveal the Mo-mediated transition of lattice model to a long-range disordering and regulate the microenvironment of dominant crystal plane, and the surface energy of (110) and (211) drops from 0.180 and 0.165 to 0.077 and 0.100 eV Å^-2, respectively. Which exceedingly minimizes the free energy barrier and then accelerates the H* adsorption, and fundamentally contributes to the achievement of efficient hydrogen production at high current density. The proposed strategy to produce hydrogen at ultra-high current would fulfill the dream to create ‘a high effiective catalyst designed as simply as possible'.     

Awakening (220) as One More Active Facet of PtMo Alloy via Single-Atom Doping to Boost Ammonia Electrooxidation in Direct Ammonia Fuel Cell

As the core of low-temperature direct ammonia fuel cell (DAFC) technology, electrocatalytic ammonia oxidation reaction (AOR) has proven to be most active on platinum-based catalysts. However, the AOR is extremely surface sensitive that only the Pt (200) facet exhibits high reaction activity, whereas other facets usually do not make contributions. Herein, the inert (220) surface of PtMo nano-alloy is successfully awakened as one more active facet in addition to (200) via directional single-atom Ni-doping. The introduction of Ni triggers a targeted electron accumulation around Pt sites at the (220) facet that significantly reduces the AOR energy barrier while maintaining the activity of the (200) surface. With a greatly enlarged active surface, the Ni-decorated PtMo catalyst exhibits a significantly facilitated AOR kinetics with a low onset potential of 0.49 V versus reversible hydrogen electrode and a superior peak current density of 94.96 A g⁻¹ at 5 mV s⁻¹. Notably, the DAFC equipped with such an electrocatalyst reaches a remarkable peak power density of 16.70 mW cm⁻² at low temperatures. It is believed that this strategy sheds light on exploiting the intrinsic activity of Pt-based electrocatalysts, and drives the low-temperature DAFC technology to a more practical level.