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In this work, a noncoplanar terphenyl served as a building block to synthesize a novel 3,3'-substituted bipyridyl ligand (L1) which further reacted with binuclear half-sandwich units A/B, giving rise to two aesthetic 4 1 metalla-knots in high yields via a coordination-driven self-assembly strategy. Furthermore, given the inherent compactness of the 4 1 metalla-knots, it creates favorable conditions for the emergence of steric repulsion. We focused on progressively introducing nitrogen atoms featuring a lone pair of electrons (LPEs) into ligand L1 to manipulate the balance of H⋅⋅⋅H/LPEs⋅⋅⋅LPEs steric repulsion during the assembly process, ultimately achieving controlled assembly from 4 1 metalla-knots to the pseudo-Solomon link and then to molecular tweezer-like assembly facilitated by stacking interactions. All the assemblies were well characterized by solution-state NMR techniques, ESI-TOF/MS, and single-crystal X-ray diffraction. The evolutionary process of the topological architectures is equivalent to visualizing the synergistic effect of steric hindrance and stacking interactions on structural assembly, providing a new avenue for achieving the controlled synthesis of different topologies., (© 2024 Wiley-VCH GmbH.)

Owing to the extremely limited structural deformation caused by the introduction of guest ions that their rigid structure can sustain, crystalline materials typically fail owing to structural collapse when utilized as electrode materials. Amorphous materials, conversely, are more resistant to volume expansion during dynamic ion transport and can introduce a lot of defects as active sites. Here, The amorphous polyaniline-coated/intercalated V 2 O 5 ·nH 2 O (PVOH) nanowires are prepared by in situ chemical oxidation combined with self-assembly strategy, which exhibited impressive electrochemical properties because of its short-range ordered crystal structure, oxygen vacancy/defect-rich, improved electronic channels, and ionic channels. Through in situ techniques, the energy storage mechanism of its Zn 2+ /H + co-storage is investigated and elucidated. Additionally, this work provides new insights and perspectives for the investigation and application of amorphous cathodes for aqueous zinc ion batteries., (© 2023 Wiley‐VCH GmbH.)

By increasing the content of Ni 3+ , the catalytic activity of nickel-based catalysts for the oxygen evolution reaction (OER), which is still problematic with current synthesis routes, can be increased. Herein, a Ni 3+ -rich of Ni 3 S 4 /FeS on FeNi Foam (Ni 3 S 4 /FeS@FNF) via anodic electrodeposition to direct obtain high valence metal ions for OER catalyst is presented. XPS showed that the introduction of Fe not only further increased the Ni 3+ concentration in Ni 3 S 4 /FeS to 95.02%, but also inhibited the dissolution of NiOOH by up to seven times. Furthermore, the OER kinetics is enhanced by the combination of the inner Ni 3 S 4 /FeS heterostructures and the electrochemically induced surface layers of oxides/hydroxides. Ni 3 S 4 /FeS@FNF shows the most excellent OER activity with a low Tafel slope of 11.2 mV dec -1 and overpotentials of 196 and 445 mV at current densities of 10 and 1400 mA cm -2 , respectively. Furthermore, the Ni 3 S 4 /FeS@FNF catalyst can be operated stably at 1500 mA cm -2 for 200 h without significant performance degradation. In conclusion, this work has significantly increased the high activity Ni 3+ content in nickel-based OER electrocatalysts through an anodic electrodeposition strategy. The preparation process is time-saving and mature, which is expected to be applied in large-scale industrialization., (© 2023 Wiley‐VCH GmbH.)

Due to their unique advantages, single atoms and clusters of transition metals are expected to achieve a breakthrough in catalytic activity, but large-scale production of active materials remains a challenge. In this work, a simple solvent-free one-step annealing method is developed and applied to construct diatomic and cluster active sites in activated carbon by utilizing the strong anchoring ability of phenanthroline to metal ions, which can be scaled for mass productions. Benefiting from the synergy between the different metals, the obtained sub-nano-bimetallic atom-cluster catalysts (FeNi AC -NC) exhibit high oxygen reduction reactions (ORR) activity (E 1/2 = 0.936 V vs. RHE) and a small ORR/oxygen evolution reaction (OER) potential gap of only 0.594 V. An in-house pouch Zn-air battery is assembled using an FeNi AC -NC catalyst, which demonstrates a stability of 1000 h, outperforming previous reports. The existence of clusters and their effects on catalytic activity is analyzed by density functional theory calculations to reveal the chemistry of nano-bimetallic atom-cluster catalysts., (© 2023 Wiley-VCH GmbH.)

Recent progress in synthetic strategies, analysis techniques, and computational modeling assist researchers to develop more active catalysts including metallic clusters to single-atom active sites (SACs). Metal coordinated N-doped carbons (M-N-C) are the most auspicious, with a large number of atomic sites, markedly performing for a series of electrochemical reactions. This perspective sums up the latest innovative and computational comprehension, while giving credit to earlier/pioneering work in carbonaceous assembly materials towards robust electrocatalytic activity for proton exchange membrane fuel cells via inclusive performance assessment of the oxygen reduction reaction (ORR). M-N x -C y are exclusively defined active sites for ORR, so there is a unique possibility to intellectually design the relatively new catalysts with much improved activity, selectivity, and durability. Moreover, some SACs structures provide better performance in fuel cells testing with long-term durability. The efforts to understand the connection in SACs based M-N x -C y moieties and how these relate to catalytic ORR performance are also conveyed. Owing to comprehensive practical application in the field, this study has covered very encouraging aspects to the current durability status of M-N-C based catalysts for fuel cells followed by degradation mechanisms such as macro-, microdegradation, catalytic poisoning, and future challenges., (© 2022 The Authors. Small published by Wiley-VCH GmbH.)

Rechargeable aqueous Zn-Mn batteries have garnered extensive attention for next-generation high-safety energy storage. However, the charge-storage chemistry of Zn-Mn batteries remains controversial. Prevailing mechanisms include conversion reaction and cation (de)intercalation in mild acid or neutral electrolytes, and a MnO 2 /Mn 2+ dissolution-deposition reaction in strong acidic electrolytes. Herein, a Zn 4 SO 4 ·(OH) 6 ·xH 2 O (ZSH)-assisted deposition-dissolution model is proposed to elucidate the reaction mechanism and capacity origin in Zn-Mn batteries based on mild acidic sulfate electrolytes. In this new model, the reversible capacity originates from a reversible conversion reaction between ZSH and Zn x MnO(OH) 2 nanosheets in which the MnO 2 initiates the formation of ZSH but contributes negligibly to the apparent capacity. The role of ZSH in this new model is confirmed by a series of operando characterizations and by constructing Zn batteries using other cathode materials (including ZSH, ZnO, MgO, and CaO). This research may refresh the understanding of the most promising Zn-Mn batteries and guide the design of high-capacity aqueous Zn batteries., (© 2022 Wiley-VCH GmbH.)

Reactions of (NH 4 ) 2 WS 4 with CuCN, CuCN/1,2-bis(4-pyridyl)propane (bppa) or [Cu(MeCN) 4 ]PF 6 /bppa under different reaction conditions afforded a set of two- or three-dimensional W/Cu/S cluster-based coordination polymers including {[Et 4 N] 2 [WS 4 Cu 4 (μ-CN) 2 (μ-I) 2 ]} n (1), [WS 4 Cu 4 (μ-CN) 2 (bppa) 2 ] n (2) and {[WS 4 Cu 4 (bppa) 4 ](PF 6 ) 2 } n (3), respectively. Compound 2 can be readily formed from reaction of 1 with bppa under solvothermal conditions. Compounds 1 and 2 feature two-dimensional networks with a "sql" topology, while 3 possesses a two-fold interpenetrated three-dimensional net with a rare "reo" topology. Compounds 1-3 in DMF exhibited different third-order nonlinear optical responses, and they all showed a reverse saturable absorption while 2 held a strong self-focusing effect., (© 2021 Wiley-VCH GmbH.)

The high energy density of room temperature (RT) sodium-sulfur batteries (Na-S) usually rely on the efficient conversion of polysulfide to sodium sulfide during discharging and sulfur recovery during charging, which is the rate-determining step in the electrochemical reaction process of Na-S batteries. In this work, a 3D network (Ni-NCFs) host composed by nitrogen-doped carbon fibers (NCFs) and Ni hollow spheres is synthesized by electrospinning. In this novel design, each Ni hollow unit not only can buffer the volume fluctuation of S during cycling, but also can improve the conductivity of the cathode along the carbon fibers. Meanwhile, the result reveals that a small amount of Ni is polarized during the sulfur-loading process forming a polar Ni-S bond. Furthermore, combining with the nitrogen-doped carbon fibers, the Ni-NCFs composite can effectively adsorb soluble polysulfide intermediate, which further facilitates the catalysis of the Ni unit for the redox of sodium polysulfide. In addition, the in situ Raman is employed to supervise the variation of polysulfide during the charging and discharging process. As expected, the freestanding S@Ni-NCFs cathode exhibits outstanding rate capability and excellent cycle performance., Competing Interests: The authors declare no conflict of interest., (© 2019 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

Room-temperature Na-S batteries are facing one of the most serious challenges of charge/discharge with long cycling stability due to the severe shuttle effect and volume expansion. Herein, a sodium polysulfides defense system is presented by designing and constructing the cathode-separator double barriers. In this strategy, the hollow carbon spheres are decorated with MoS 2 (HCS/MoS 2 ) as the S carrier (S@HCS/MoS 2 ). Meanwhile, the HCS/MoS 2 composite is uniformly coated on the surface of the glass fiber as the separator. During the discharge process, the MoS 2 can adsorb soluble polysulfides (NaPSs) intermediates and the hollow carbon spheres can improve the conductivity of S as well as act as the reservoir for electrolyte and NaPSs, inhibiting them from entering the anode to make Na deteriorate. As a result, the cathode-separator group applied to room-temperature Na-S battery can enable a capacity of ≈1309 mAh g -1 at 0.1 C and long cycling life up to 1000 cycles at 1 C. This study provides a novel and effective way to develop durable room-temperature Na-S batteries., Competing Interests: The authors declare no conflict of interest., (© 2019 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

Transition-metal phosphides (TMPs) have emerged as promising catalyst candidates for the hydrogen evolution reaction (HER). Although numerous methods have been investigated to obtain TMPs, most rely on traditional synthetic methods that produce materials that are inherently deficient with respect to electrical conductivity. An electrospinning-based reduction approach is presented, which generates nickel phosphide nanoparticles in N-doped porous carbon nanofibers (Ni 2 P@NPCNFs) in situ. Ni 2 P nanoparticles are protected from irreversible fusion and aggregation in subsequent high-temperature pyrolysis. The resistivity of Ni 2 P@NPCNFs (5.34 Ω cm) is greatly decreased by 10 4 times compared to Ni 2 P (>10 4  Ω cm) because N-doped carbon NFs are incorporated. As an electrocatalyst for HER, Ni 2 P@NPCNFs reveal remarkable performance compared to other previously reported catalysts in acidic media. Additionally, it offers excellent catalytic ability and durability in both neutral and basic media. Encouraged by the excellent electrocatalytic performance of Ni 2 P@NPCNFs, a series of pea-like M x P@NPCNFs, including Fe 2 P@NPCNFs, Co 2 P@NPCNFs, and Cu 3 P@NPCNFs, were synthesized by the same method. Detailed characterization suggests that the newly developed method could render combinations of ultrafine metal phosphides with porous carbon accessible; thereby, extending opportunities in electrocatalytic applications., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein, a novel anionic framework with primitive centered cubic (pcu) topology, [(CH3 )2 NH2 ]4 [(Zn4 dttz6 )Zn3 ]⋅15 DMF⋅4.5 H2 O, (IFMC-2; H3 dttz=4,5-di(1H-tetrazol-5-yl)-2H-1,2,3-triazole) was solvothermally isolated. A new example of a tetranuclear zinc cluster {Zn4 dttz6 } served as a secondary building unit in IFMC-2. Furthermore, the metal cluster was connected by Zn(II) ions to give rise to a 3D open microporous structure. The lanthanide(III)-loaded metal-organic framework (MOF) materials Ln(3+) @IFMC-2, were successfully prepared by using ion-exchange experiments owing to the anionic framework of IFMC-2. Moreover, the emission spectra of the as-prepared Ln(3+) @IFMC-2 were investigated, and the results suggested that IFMC-2 could be utilized as a potential luminescent probe toward different Ln(3+) ions. Additionally, the absorption ability of IFMC-2 toward ionic dyes was also performed. Cationic dyes can be absorbed, but not neutral and anionic dyes, thus indicating that IFMC-2 exhibits selective absorption toward cationic dyes. Furthermore, the cationic dyes can be gradually released in the presence of NaCl., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A 2D, extremely stable, metal-organic framework (MOF), NENU-503, was successfully constructed. It displays highly selective and recyclable properties in detection of nitroaromatic explosives as a fluorescent sensor. This is the first MOF that can distinguish between nitroaromatic molecules with different numbers of NO2 groups., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A hexagonal channel-based porous anionic metal-organic framework was successfully constructed. IFMC-3 is stable in air and acidic/basic aqueous solutions at room temperature, and constitutes a selective luminescent sensing material for Ln(3+) ions and a recyclable probe for the sensitive detection of nitrobenzene., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)