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Transition metal oxides (TMOs) are recognized as high‐efficiency electrocatalyst systems for restraining the shuttle effect in lithium‐sulfur (Li−S) batteries, owing to their robust adsorption capabilities for polysulfides. However, the sluggish catalytic conversion of Li2S redox and severe passivation effect of TMOs exacerbate polysulfide shuttling and reduce the cyclability of Li−S batteries, which significantly hinders the development of TMOs electrocatalysts. Here, through the anion‐cation doping approach, dual incorporation of phosphorus and molybdenum into MnO2 (P,Mo‐MnO2) was engineered, demonstrating effective mitigation of the passivation effect and allowing for the simultaneous immobilization of polysulfides and rapid redox kinetics of Li2S. Both experimental and theoretical investigations reveal the pivotal role of dopants in fine‐tuning the d‐band center and optimizing the electronic structure of MnO2. Furthermore, this well‐designed configuration processes catalytic selectivity. Specifically, P‐doping expedites rapid Li2S nucleation kinetics by minimizing reaction‐free energy, while Mo‐doping facilitates robust Li2S dissolution kinetics by mitigating decomposition barriers. This dual‐doping approach equips P,Mo‐MnO2 with robust bi‐directional catalytic activity, effectively overcoming passivation effect and suppressing the notorious shuttle effect. Consequently, Li−S batteries incorporating P,Mo‐MnO2‐based separators demonstrate favorable performance than pristine TMOs. This design offers rational viewpoint for the development of catalytic materials with superior bi‐directional sulfur electrocatalytic in Li−S batteries. [ABSTRACT FROM AUTHOR]

The sluggish reaction kinetics of the anodic oxygen evolution reaction (OER) and the inadequate catalytic performance of non‐noble metal‐based electrocatalysts represent substantial barriers to the development of anion exchange membrane water electrolyzer (AEMWE). This study performed the synthesis of a three‐dimensional (3D) nanoflower‐like electrocatalyst (CFMO) via a simple one‐step method. The substitution of Co with Fe in the structure induces a localized oxide path mechanism (LOPM), facilitating direct O−O radical coupling for enhanced O2 evolution. The optimized CFMO‐2 electrocatalyst demonstrates superior OER performance, achieving an overpotential of 217 mV at 10 mA cm−2, alongside exceptional long‐term stability with minimal degradation after 1000 h of operation in 1.0 M KOH. These properties surpass most of conventional noble metal‐based electrocatalysts. Furthermore, the assembled AEMWE system, utilizing CFMO‐2, operates with a cell voltage of 1.65 V to deliver 1.0 A cm−2. In situ characterizations reveal that, in addition to the traditional adsorbate evolution mechanism (AEM) at isolated Co sites, a new LOPM occurred around the Fe and Co bimetallic sites. First‐principles calculations confirm the LOPM greatly reduced the energy barriers. This work highlights the potential of LOPM for improving the design of non‐noble metal‐based electrocatalysts and the development of AEMWE. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) nonlayered metal compounds with porous structure show broad application prospects in electrochemistry‐related fields due to their abundant active sites, open ions/electrons diffusion channels, and faradaic reactions. However, scalable and universal synthesis of 2D porous compounds still remains challenging. Here, inspired by blowing gum, a metal‐organic gel (MOG) rapid redox transformation (MRRT) strategy is proposed for the mass production of a wide variety of 2D porous metal oxides. Adequate crosslinking degree of MOG precursor and its rapid redox with NO3− are critical for generating gas pressure from interior to exterior, thus blowing the MOG into 2D carbon nanosheets, which further act as self‐sacrifice template for formation of oxides with porous and ultrathin structure. The versatility of this strategy is demonstrated by the fabrication of 39 metal oxides, including 10 transition metal oxides, one II‐main group oxide, two III‐main group oxides, 22 perovskite oxides, four high‐entropy oxides. As an illustrative verification, the 2D transition metal oxides exhibit excellent capacitive deionization (CDI) performance. Moreover, the assembled CDI cell could act as desalting battery to supply electrical energy during electrode regeneration. This MRRT strategy offers opportunities for achieving universal synthesis of 2D porous oxides with nonlayered structures and studying their electrochemistry‐related applications. [ABSTRACT FROM AUTHOR]

The pressing demand for large‐scale energy storage solutions has propelled the development of advanced battery technologies, among which zinc‐ion batteries (ZIBs) are prominent due to their resource abundance, high capacity, and safety in aqueous environments. However, the use of manganese oxide cathodes in ZIBs is challenged by their poor electrical conductivity and structural stability, stemming from the intrinsic properties of MnO2 and the destabilizing effects of ion intercalation. To overcome these limitations, our research delves into atomic‐level engineering, emphasizing quantum spin exchange interactions (QSEI). These essential for modifying electronic characteristics, can significantly influence material efficiency and functionality. We demonstrate through density functional theory (DFT) calculations that enhanced QSEI in manganese oxides broadens the O p band, narrows the band gap, and optimizes both proton adsorption and electron transport. Empirical evidence is provided through the synthesis of Ru−MnO2 nanosheets, which display a marked increase in energy storage capacity, achieving 314.4 mAh g−1 at 0.2 A g−1 and maintaining high capacity after 2000 cycles. Our findings underscore the potential of QSEI to enhance the performance of TMO cathodes in ZIBs, pointing to new avenues for advancing battery technology [ABSTRACT FROM AUTHOR]

Transition metal oxides (TMOs) are promising cathode materials for aqueous zinc ion batteries (ZIBs), however, their performance is hindered by a substantial Hubbard gap, which limits electron transfer and battery cyclability. Addressing this, we introduce a heteroatom coordination approach, using triethanolamine to induce axial N coordination on Mn centers in MnO2, yielding N‐coordinated MnO2 (TEAMO). This approach leverages the change of electronegativity disparity between Mn and ligands (O and N) to disrupt spin symmetry and augment spin polarization. This enhancement leads to the closure of the Hubbard gap, primarily driven by the intensified occupancy of the Mn eg orbitals. The resultant TEAMO exhibit a significant increase in storage capacity, reaching 351 mAh g−1 at 0.1 A g−1. Our findings suggest a viable strategy for optimizing the electronic structure of TMO cathodes, enhancing the potential of ZIBs in energy storage technology. [ABSTRACT FROM AUTHOR]

Transition metal oxides (TMOs) are key in electrochemical energy storage, offering cost‐effectiveness and a broad potential window. However, their full potential is limited by poor understanding of their slow reaction kinetics and stability issues. This study diverges from conventional complex nano‐structuring, concentrating instead on spin‐related charge transfer and orbital interactions to enhance the reaction dynamics and stability of TMOs during energy storage processes. We successfully reconfigured the orbital degeneracy and spin‐dependent electronic occupancy by disrupting the symmetry of magnetic cobalt (Co) sites through straightforward strain stimuli. The key to this approach lies in the unfilled Co 3d shell, which serves as a spin‐dependent regulator for carrier transfer and orbital interactions within the reaction. We observed that the opening of these ′spin gates′ occurs during a transition from a symmetric low‐spin state to an asymmetric high‐spin state, resulting in enhanced reaction kinetics and maintained structural stability. Specifically, the spin‐rearranged Al−Co3O4 exhibited a specific capacitance of 1371 F g−1, which is 38 % higher than that of unaltered Co3O4. These results not only shed light on the spin effects in magnetic TMOs but also establish a new paradigm for designing electrochemical energy storage materials with improved efficiency. [ABSTRACT FROM AUTHOR]

The intrinsic activity assessment of transition metal oxides (TMOs) as key electrocatalysts for the oxygen evolution reaction (OER) has not been standardized due to uncertainties regarding their structure and composition, difficulties in accurately measuring their electrochemically active surface area (ECSA), and deficiencies in mass‐transfer (MT) rates in conventional measurements. To address these issues, we utilized an electrodeposition‐thermal annealing method to precisely synthesize single‐particle TMOs with well‐defined structure and composition. Concurrently, we engineered low roughness, spherical surfaces for individual particles, enabling precise measurement of their ECSA. Furthermore, by constructing a conductor‐core semiconductor‐shell structure, we evaluated the inherent OER activity of perovskite‐type semiconductor materials, broadening the scope beyond just conductive TMOs. Finally, using single‐particle nanoelectrode technique, we systematically measured individual TMO particles of various sizes for OER, overcoming MT limitations seen in conventional approaches. These improvements have led us to propose a precise and reliable approach to evaluating the intrinsic activity of TMOs, not only validating the accuracy of theoretical calculations but also revealing a strong correlation of OER activity on the melting point of TMOs. This discovery holds significant importance for future high‐throughput material research and applications, offering valuable insights in electrocatalysis. [ABSTRACT FROM AUTHOR]

Chemical modification is a powerful strategy for tuning the electronic properties of 2D semiconductors. Here we report the electrophilic trifluoromethylation of 2D WSe2 and MoS2 under mild conditions using the reagent trifluoromethyl thianthrenium triflate (TTT). Chemical characterization and density functional theory calculations reveal that the trifluoromethyl groups bind covalently to surface chalcogen atoms as well as oxygen substitution sites. Trifluoromethylation induces p‐type doping in the underlying 2D material, enabling the modulation of charge transport and optical emission properties in WSe2. This work introduces a versatile and efficient method for tailoring the optical and electronic properties of 2D transition metal dichalcogenides. [ABSTRACT FROM AUTHOR]

Alloying Pt catalysts with transition metal elements is an effective pathway to enhance the performance of oxygen reduction reaction (ORR), but often accompanied with severe metal dissolution issue, resulting in poor stability of alloy catalysts. Here, instead of forming traditional alloy structure, we modify Pt surface with a novel Ni−W dimer structure by the atomic layer deposition (ALD) technique. The obtained NiW@PtC catalyst exhibits superior ORR performance both in liquid half‐cell and practical fuel cell compared with initial Pt/C. It is discovered that strong synergistic Ni−W dimer structure arising from short atomic distance induced a stable compressive strain on the Pt surface, thus boosting Pt catalytic performance. This surface modification by synergistic dimer sites offers an effective strategy in tailoring Pt with excellent activity and stability, which provides a significant perspective in boosting the performance of commercial Pt catalyst modified with polymetallic atom sites. [ABSTRACT FROM AUTHOR]

Layered transition metal oxides are extensively considered as appealing cathode candidates for potassium‐ion batteries (PIBs) due to their abundant raw materials and low cost, but their further implementations are limited by slow dynamics and impoverished structural stability. Herein, a layered composite having a P2 and P3 symbiotic structure is designed and synthesized to realize PIBs with large energy density and long‐term cycling stability. The unique intergrowth of P2 and P3 phases in the obtained layered oxide is plainly characterized by X‐ray diffraction refinement, high‐angle annular dark field and annular bright field‐scanning transmission electron microscopy at atomic resolution, and Fourier transformation images. The synergistic effect of the two phases of this layered P2/P3 composite is well demonstrated in K+ intercalation/extraction process. The as‐prepared layered composite can present a large discharge capacity with the remarkable energy density of 321 Wh kg−1 and also manifest excellent capacity preservation after 600 cycles of K+ uptake/removal. [ABSTRACT FROM AUTHOR]

Ion regulation strategy is regarded as a promising pathway for designing transition metal oxide‐based electrocatalysts for oxygen evolution reaction (OER) with improved activity and stability. Precise anion conditioning can accurately change the anionic environment so that the acid radical ions (SO42−, PO32−, SeO42−, etc.), regardless of their state (inside the catalyst, on the catalyst surface, or in the electrolyte), can optimize the electronic structure of the cationic active site and further increase the catalytic activity. Herein, we report a new approach to encapsulate S atoms at the tetrahedral sites of the NaCl‐type oxide NiO to form a tetraoxo‐tetrahedral coordination structure (S‐O4) inside the NiO (S‐NiO ‐I). Density functional theory (DFT) calculations and operando vibrational spectroscopy proves that this kind of unique structure could achieve the S‐O4 and Ni‐S stable structure in S‐NiO‐I. Combining mass spectroscopy characterization, it could be confirmed that the S‐O4 structure is the key factor for triggering the lattice oxygen exchange to participate in the OER process. This work demonstrates that the formation of tetraoxygen tetrahedral structure is a generalized key for boosting the OER performances of transition metal oxides. [ABSTRACT FROM AUTHOR]

The sodium extraction/insertion in layered transition‐metal oxide (TMO) cathode materials are typically accompanied by slab sliding and lattice changes, leading to microstructure destruction and capacity decay. Herein, negative lattice expansion is observed in an O3 type Ni‐based layered cathode of Na0.9Ni0.32Zn0.08Fe0.1Mn0.3Ti0.2O2 upon Na+ extraction. It is attributed to the weak Zn2+−O2− orbital hybridization and increased electron density of the surrounding oxygen for reinforced interlayer O−O repulsive force. This enables gliding of TMO slabs for the intergrowth phase transition of P3→OP2 to alleviate lattice strain with moderate lattice shrinkage, which exhibits general interslab spacings and volume changes as low as 2.4 % and 1.9 %, respectively. The strong Ti−O bonds accommodate the internal distortion of TMO6 octahedra due to the flexibility of TiO6 octahedra during cycling. These endow a high specific capacity of 144.9 mAh g−1 and excellent cycling performance of pouch‐type sodium‐ion batteries with 93 % capacity retention after 3600 cycles. [ABSTRACT FROM AUTHOR]

Compensating the irreversible loss of limited active lithium (Li) is essentially important for improving the energy‐density and cycle‐life of practical Li‐ion battery full‐cell, especially after employing high‐capacity but low initial coulombic efficiency anode candidates. Introducing prelithiation agent can provide additional Li source for such compensation. Herein, we precisely implant trace Co (extracted from transition metal oxide) into the Li site of Li2O, obtaining (Li0.66Co0.11□0.23)2O (CLO) cathode prelithiation agent. The synergistic formation of Li vacancies and Co‐derived catalysis efficiently enhance the inherent conductivity and weaken the Li−O interaction of Li2O, which facilitates its anionic oxidation to peroxo/superoxo species and gaseous O2, achieving 1642.7 mAh/g~Li2O prelithiation capacity (≈980 mAh/g for prelithiation agent). Coupled 6.5 wt % CLO‐based prelithiation agent with LiCoO2 cathode, substantial additional Li source stored within CLO is efficiently released to compensate the Li consumption on the SiO/C anode, achieving 270 Wh/kg pouch‐type full‐cell with 92 % capacity retention after 1000 cycles. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance, caused by persistent adaptation and growing resistance of pathogenic bacteria to overprescribed antibiotics, poses one of the most serious and urgent threats to global public health. The limited pipeline of experimental antibiotics in development further exacerbates this looming crisis and new drugs with alternative modes of action are needed to tackle evolving pathogenic adaptation. Transition metal complexes can replenish this diminishing stockpile of drug candidates by providing compounds with unique properties that are not easily accessible using pure organic scaffolds. We spotlight four emerging strategies to harness these unique properties to develop new targeted antibacterial agents. [ABSTRACT FROM AUTHOR]

High‐capacity Li‐rich layered oxides using oxygen redox as well as transition metal redox suffer from its structural instability due to lattice oxygen escaped from its structure during oxygen redox and the following electrolyte decomposition by the reactive oxygen species. Herein, we rescued a Li‐rich layered oxide based on 4d transition metal by employing an organic superoxide dismutase mimics as a homogeneous electrolyte additive. Guaiacol scavenged superoxide radicals via dismutation or disproportionation to convert two superoxide molecules to peroxide and dioxygen after absorbing lithium superoxide on its partially negative oxygen of methoxy and hydroxyl groups. Additionally, guaiacol was decomposed to form a thin and stable cathode‐electrolyte interphase (CEI) layer, endowing the cathode with the interfacial stability. [ABSTRACT FROM AUTHOR]

Transition metal oxides (TMOs) were one of the first photocatalysts used to produce hydrogen from water using solar energy. Despite the emergence of many other genres of photocatalysts over the years, TMO photocatalysts remain dominant due to their easy synthesis and unique physicochemical properties. Various strategies have been developed to enhance the photocatalytic activity of TMOs, but the solar‐to‐hydrogen (STH) conversion efficiency of TMO photocatalysts is still very low (<2 %), which is far below the targeted STH of 10 % for commercial viability. This article provides a comprehensive analysis of several widely used strategies, including oxygen defects control, doping, establishing interfacial junctions, and phase‐facet‐morphology engineering, that have been adopted to improve TMO photocatalysts. By critically evaluating these strategies and providing a roadmap for future research directions, this article serves as a valuable resource for researchers, students, and professionals seeking to develop efficient energy materials for green energy solutions. [ABSTRACT FROM AUTHOR]

Improving catalytic activity without loss of catalytic stability is one of the core goals in search of low‐iridium‐content oxygen evolution electrocatalysts under acidic conditions. Here, we synthesize a family of 66 SrBO3 perovskite oxides (B=Ti, Ru, Ir) with different Ti : Ru : Ir atomic ratios and construct catalytic activity‐stability maps over composition variation. The maps classify the multicomponent perovskites into chemical groups with distinct catalytic activity and stability for acidic oxygen evolution reaction, and highlights a chemical region where high catalytic activity and stability are achieved simultaneously at a relatively low iridium level. By quantifying the extent of hybridization of mixed transition metal 3d‐4d‐5d and oxygen 2p orbitals for multicomponent perovskites, we demonstrate this complex interplay between 3d‐4d‐5d metals and oxygen atoms in governing the trends in both activity and stability as well as in determining the catalytic mechanism involving lattice oxygen or not. [ABSTRACT FROM AUTHOR]

Conventional solid electrolyte frameworks typically consist of anions such as sulphur, oxygen, chlorine, and others, leading to inherent limitations in their properties. Despite the emergence of sulphide, oxide, and halide‐based solid electrolytes for all‐solid‐state batteries, their utilization is hampered by issues, including the evolution of H2S gas, the need for expensive elements, and poor contact. Here, we first introduce Prussian Blue analogue (PBA) open‐framework structures as a solid electrolyte that demonstrates appreciable Na+ conductivity (>10−2mS cm−1). We delve into the relationship between Na+ conductivity and the lattice parameter of N‐coordinated transition metal, which is attributed to the reduced interaction between Na+ and the framework, corroborated by the distribution of relaxation times and density functional theory calculations. Among the five PBAs studied, Mn‐PBA have exhibited the highest Na+ conductivity of 9.1×10−2mS cm−1. Feasibility tests have revealed that Mn‐PBA have maintained a cycle retention of 95.1 % after 80cycles at 30 °C and a C‐rate of 0.2C. Our investigation into the underlying mechanisms that play a significant role in governing the conductivity and kinetics of these materials contributes valuable insights for the development of alternative strategies to realize all‐solid‐state batteries. [ABSTRACT FROM AUTHOR]

The importance of transition metal catalysis is exemplified by its wide range of applications, for example in the synthesis of chemicals, natural products, and pharmaceuticals. However, one relatively new application is for carrying out new‐to‐nature reactions inside living cells. The complex environment of a living cell is not welcoming to transition metal catalysts, as a diverse range of biological components have the potential to inhibit or deactivate the catalyst. Here we review the current progress in the field of transition metal catalysis, and evaluation of catalysis efficiency in living cells and under biological (relevant) conditions. Catalyst poisoning is a ubiquitous problem in this field, and we propose that future research into the development of physical and kinetic protection strategies may provide a route to improve the reactivity of catalysts in cells. [ABSTRACT FROM AUTHOR]

Transition metal oxide (TMO) anode materials in lithium‐ion batteries (LIBs) usually suffer from serious volume expansion leading to the pulverization of structures, further giving rise to lower specific capacity and worse cycling stability. Herein, by introducing polyoxometalate (POM) clusters into TMOs and precisely controlling the amount of POMs, the MnZnCuOx‐phosphomolybdic acid hybrid sub‐1 nm nanosheets (MZC‐PMA HSNSs) anode is successfully fabricated, where the special electron rich structure of POMs is conducive to accelerating the migration of lithium ions on the anode to obtain higher specific capacity, and the non‐covalent interactions between POMs and TMOs make the HSNSs possess excellent structural and chemical stability, thus exhibiting outstanding electrochemical performance in LIBs, achieving a high reversible capacity (1157 mAh g−1 at 100 mA g−1) and an admirable long‐term cycling stability at low and high current densities. [ABSTRACT FROM AUTHOR]

Deep sodium extraction/insertion of sodium cathodes usually causes undesired Jahn–Teller distortion and phase transition, both of which will reduce structural stability and lead to poor long‐cycle reliability. Here we report a zero‐strain P2‐ Na2/3Li1/6Co1/6Mn2/3O2 cathode, in which the lithium/cobalt substitution contributes to reinforcing the host structure by reducing the Mn3+/Mn4+ redox, mitigating the Jahn–Teller distortion, and minimizing the lattice change. 94.5 % of Na+ in the unit structure can be reversibly cycled with a charge cut‐off voltage of 4.5 V (vs. Na+/Na). Impressively, a solid‐solution reaction without phase transitions is realized upon deep sodium (de)intercalation, which poses a minimal volume deviation of 0.53 %. It attains a high discharge capacity of 178 mAh g−1, a high energy density of 534 Wh kg−1, and excellent capacity retention of 95.8 % at 1 C after 250 cycles. [ABSTRACT FROM AUTHOR]

Layered transition metal oxide cathodes have been one of the dominant cathodes for lithium‐ion batteries with efficient Li+ intercalation chemistry. However, limited by the weak layered interaction and unstable surface, mechanical and chemical failure plagues their electrochemical performance, especially for Ni‐rich cathodes. Here, adopting a simultaneous elemental‐structural atomic arrangement control based on the intrinsic Ni−Co−Mn system, the surface role is intensively investigated. Within the invariant oxygen sublattice of the crystal, a robust surface with the synergistic concentration gradient and layered‐spinel intertwined structure is constructed on the model single‐crystalline Ni‐rich cathode. With mechanical strain dissipation and chemical erosion suppression, the cathode exhibits an impressive capacity retention of 82 % even at the harsh 60 °C after 150 cycles at 1 C. This work highlights the coupling effect of structure and composition on the chemical‐mechanical properties, and the concept will spur more researches on the cathodes that share the same sublattice. [ABSTRACT FROM AUTHOR]

Improving kinetics of solid‐state sulfide conversion in sulfur cathodes can enhance sulfur utilization of metal‐sulfur batteries. However, fundamental understanding of the solid‐state conversion remains to be achieved. Here, taking potassium‐sulfur batteries as a model system, we for the first time report the reducing overpotential of solid‐state sulfide conversion via the meta‐stable S32− intermediates on transition metal single‐atom sulfur hosts. The catalytic sulfur host containing Cu single atoms demonstrates high capacities of 1595 and 1226 mAh g−1 at current densities of 335 and 1675 mA g−1, respectively, with stable Coulombic efficiency of ≈100 %. Combined spectroscopic characterizations and theoretical computations reveal that the relatively weak Cu‐S bonding results in low overpotential of solid‐state sulfide conversion and high sulfur utilization. The elucidation of solid‐state sulfide conversion mechanism can direct the exploration of highly efficient metal‐sulfur batteries. [ABSTRACT FROM AUTHOR]

A fundamental understanding of surface reconstruction process is pivotal to developing highly efficient lattice oxygen oxidation mechanism (LOM) based electrocatalysts. Traditionally, the surface reconstruction in LOM based metal oxides is believed as an irreversible oxygen redox behavior, due to the much slower rate of OH− refilling than that of oxygen vacancy formation. Here, we found that the surface reconstruction in LOM based metal oxides is a spontaneous chemical reaction process, instead of an electrochemical reaction process. During the chemical process, the lattice oxygen atoms were attacked by adsorbed water molecules, leading to the formation of hydroxide ions (OH−). Subsequently, the metal‐site soluble atoms leached from the oxygen‐deficient surface. This work also suggests that the enhancement of surface hydrophilicity could accelerate the surface reconstruction process. Hence, such a finding could add a new layer for the understanding of surface reconstruction mechanism. [ABSTRACT FROM AUTHOR]

The design of metal–organic frameworks (MOFs) having large pore sizes and volumes often requires the use of complex organic ligands, currently synthesized using costly and time‐consuming palladium‐catalyzed coupling chemistry. Thus, in the present work, a new strategy for ligand design is reported, where piperazine and dihydrophenazine units are used as substitutes for benzene rings, which are the basic building block of most MOF ligands. This chemistry, which is based on simple, nucleophilic aromatic substitution (SNAr) reactions, is used for the transition metal catalyst‐free construction of 21 new, carboxylate‐based ligands with varying sizes, shapes, and denticity and 15 linear di‐ and tetra‐nitriles. Moreover, to demonstrate the utility of the ligands as building blocks, 16 new structurally diverse MOFs having surface areas up to 3100 m2 g−1 were also synthesized. [ABSTRACT FROM AUTHOR]

The practical viability of high‐nickel layered oxide cathodes is compromised by the interphasial and structural degradations. Herein, we demonstrate that by applying an in situ interweaved binder, the cycling stability of high‐nickel cathodes can be significantly improved. Specifically, the results show that the resilient binder network immobilizes the transition‐metal ions, suppresses electrolyte oxidative decomposition, and mitigates cathode particles pulverization, thus resulting in suppressed cathode‐to‐anode chemical crossover and ameliorated chemistry and architecture of electrode‐electrolyte interphases. Pouch full cells with high‐mass‐loading LiNi0.8Mn0.1Co0.1O2 cathodes achieve 0.02 % capacity decay per cycle at 1 C rate over 1 000 deep cycles at 4.4 V (vs. graphite). This work demonstrates a rational structural and compositional design strategy of polymer binders to mitigate the structural and interphasial degradations of high‐Ni cathodes in lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Manganese‐rich layered oxide cathodes of sodium‐ion batteries (SIBs) are extremely promising for large‐scale energy storage owing to their high capacities and cost effectiveness, while the Jahn–Teller (J–T) distortion and low operating potential of Mn redox largely hinder their practical applications. Herein, we reveal that annealing in argon rather than conventional air is a universal strategy to comprehensively upgrade the Na‐storage performance of Mn‐based oxide cathodes. Bulk oxygen vacancies are introduced via this method, leading to reduced Mn valence, lowered Mn 3d‐orbital energy level, and formation of the new‐concept Mn domains. As a result, the energy density of the model P2‐Na0.75Mg0.25Mn0.75O2 cathode increases by ≈50 % benefiting from the improved specific capacity and operating potential of Mn redox. The Mn domains can disrupt the cooperative J–T distortion, greatly promoting the cycling stability. This exciting finding opens a new avenue towards high‐performance Mn‐based oxide cathodes for SIBs. [ABSTRACT FROM AUTHOR]

Developing efficient and stable transition metal oxides catalysts for energy conversion processes such as oxygen evolution reaction and oxygen reduction reaction is one of the key measures to solve the problem of energy shortage. The spin state of transition metal oxides is strongly correlated with their catalytic activities. In an octahedral structure of transition metal oxides, the spin state of active centers could be regulated by adjusting the splitting energy and the electron pairing energy. Regulating spin state of active centers could directly modulate the d orbitals occupancy, which influence the strength of metal‐ligand bonds and the adsorption behavior of the intermediates. In this review, we clarified the significance of regulating spin state of the active centers. Subsequently, we discussed several characterization technologies for spin state and some recent strategies to regulate the spin state of the active centers. Finally, we put forward some views on the future research direction of this vital field. [ABSTRACT FROM AUTHOR]

Cation migration often occurs in layered oxide cathodes of lithium‐ion batteries due to the similar ion radius of Li and transition metals (TMs). Although Na and TM show a big difference of ion radius, TMs in layered cathodes of sodium‐ion batteries (SIBs) can still migrate to Na layer, leading to serious electrochemical degeneration. To elucidate the origin of TM migration in layered SIB cathodes, we choose NaCrO2, a typical layered cathode suffering from serious TM migration, as a model material and find that the TM migration is derived from the random desodiation and subsequent formation of Na‐free layer at high charge potential. A Ru/Ti co‐doping strategy is developed to address the issue, where the doped active Ru is first oxidized to create a selective desodiation and the doped inactive Ti can function as a pillar to avoid complete desodiation in Ru‐contained TM layers, leading to the suppression of the Na‐free layer formation and subsequent enhanced electrochemical performance. [ABSTRACT FROM AUTHOR]

The polysulfide (PS) dissolution and low conductivity of lithium sulfides (Li2S) are generally considered the main reasons for limiting the reversible capacity of the lithium‐sulfur (Li‐S) system. However, as the inevitable intermediate between PSs and Li2S, lithium disulfide (Li2S2) evolutions are always overlooked. Herein, Li2S2 evolutions are monitored from the operando measurements on the pouch cell level. Results indicate that Li2S2 undergoes slow electrochemical reduction and chemical disproportionation simultaneously during the discharging process, leading to further PS dissolution and Li2S generation without capacity contribution. Compared with the fully oxidized Li2S, Li2S2 still residues at the end of the charging state. Therefore, instead of the considered Li2S and PSs, slow electrochemical conversions and side chemical reactions of Li2S2 are the determining factors in limiting the sulfur utilization, corresponding to the poor reversible capacity of Li‐S batteries. [ABSTRACT FROM AUTHOR]

In the last decade, the use of graphene supported on solid surfaces has broadened its scope and applications, and graphene has acquire a promising role as a major component of high‐performance electronic devices. In this context, the chemical modification of graphene has become essential. In particular, covalent modification offers key benefits, including controllability, stability, and the facility to be integrated into manufacturing operations. In this Review, we critically comment on the latest advances in the covalent modification of supported graphene on substrates. We analyze the different chemical modifications with special attention to radical reactions. In this context, we review the latest achievements in reactivity control, tailoring electronic properties, and introducing active functionalities. Finally, we extended our analysis to other emerging 2D materials supported on surfaces, such as transition metal dichalcogenides, transition metal oxides, and elemental analogs of graphene. [ABSTRACT FROM AUTHOR]

The application of Li‐rich layered oxides is hindered by their dramatic capacity and voltage decay on cycling. This work comprehensively studies the mechanistic behaviour of cobalt‐free Li1.2Ni0.2Mn0.6O2 and demonstrates the positive impact of two‐phase Ru doping. A mechanistic transition from the monoclinic to the hexagonal behaviour is found for the structural evolution of Li1.2Ni0.2Mn0.6O2, and the improvement mechanism of Ru doping is understood using the combination of in operando and post‐mortem synchrotron analyses. The two‐phase Ru doping improves the structural reversibility in the first cycle and restrains structural degradation during cycling by stabilizing oxygen (O2−) redox and reducing Mn reduction, thus enabling high structural stability, an extraordinarily stable voltage (decay rate <0.45 mV per cycle), and a high capacity‐retention rate during long‐term cycling. The understanding of the structure‐function relationship of Li1.2Ni0.2Mn0.6O2 sheds light on the selective doping strategy and rational materials design for better‐performance Li‐rich layered oxides. [ABSTRACT FROM AUTHOR]

To understand the role of structure imperfections on the performance of electrochromic transition metal oxide (ETMO) is challenging for the design of efficient smart windows. Herein, we investigate the performance evolution with tunable crystallographic imperfections for rutile TiO2 nanowire film (TNF). Structure imperfections, originating mainly from the copious oxygen deficiency, are apt to cumulatively retard the shuttling ions, resulting in the response rate for raw TNF being less than the half that of TNF annealed at 500 °C. We describe ion accommodation sites as a convolution of normal site and abnormal site, in which the normal site performs reversible coloration but the abnormal site contributes only to charge storage, which gives a rationale for the non‐linear coloration and rate capability loss. These findings give a clear picture of the ion shuttling process, which is insightful for enhancing the electrochromic performance via structure reprogramming. [ABSTRACT FROM AUTHOR]

Limited by the electrostatic interaction, the oxidation reaction of cations at the anode and the reduction reaction of anions at the cathode in the electrocatalytic system nearly cannot be achieved. This study proposes a novel strategy to overcome electrostatic interaction via strong complexation, realizing the electrocatalytic reduction of cyanide (CN−) at the cathode and then converting the generated reduction products into nitrogen (N2) at the anode. Theoretical calculations and experimental results confirm that the polarization of the transition metal oxide cathodes under the electric field causes the strong chemisorption between CN− and cathode, inducing the preferential enrichment of CN− to the cathode. CN− is hydrogenated by atomic hydrogen at the cathode to methylamine/ammonia, which are further oxidized into N2 by free chlorine derived from the anode. This paper provides a new idea for realizing the unconventional and unrealizable reactions in the electrocatalytic system. [ABSTRACT FROM AUTHOR]

Limited by the electrostatic interaction, the oxidation reaction of cations at the anode and the reduction reaction of anions at the cathode in the electrocatalytic system nearly cannot be achieved. This study proposes a novel strategy to overcome electrostatic interaction via strong complexation, realizing the electrocatalytic reduction of cyanide (CN−) at the cathode and then converting the generated reduction products into nitrogen (N2) at the anode. Theoretical calculations and experimental results confirm that the polarization of the transition metal oxide cathodes under the electric field causes the strong chemisorption between CN− and cathode, inducing the preferential enrichment of CN− to the cathode. CN− is hydrogenated by atomic hydrogen at the cathode to methylamine/ammonia, which are further oxidized into N2 by free chlorine derived from the anode. This paper provides a new idea for realizing the unconventional and unrealizable reactions in the electrocatalytic system. [ABSTRACT FROM AUTHOR]

Mesoporous silica is a versatile material for energy, environmental, and medical applications. Here, for the first time, we report a flame aerosol synthesis method for a class of mesoporous silica with hollow structure and specific surface area exceeding 1000 m2 g−1. We show its superior performance in water purification, as a drug carrier, and in thermal insulation. Moreover, we propose a general route to produce mesoporous nanoshell‐supported nanocatalysts by in situ decoration with active nanoclusters, including noble metal (Pt/SiO2), transition metal (Ni/SiO2), metal oxide (CrO3/SiO2), and alumina support (Co/Al2O3). As a prototypical application, we perform dry reforming of methane using Ni/SiO2, achieving constant 97 % CH4 and CO2 conversions for more than 200 hours, dramatically outperforming an MCM‐41 supported Ni catalyst. This work provides a scalable strategy to produce mesoporous nanoshells and proposes an in situ functionalization mechanism to design and produce flexible catalysts for many reactions. [ABSTRACT FROM AUTHOR]

Transition metal (e.g. Ni) ions dissolved from layered‐structured Ni‐rich cathodes can migrate to the anode side and accelerate the failure of lithium‐ion batteries. The investigations of the impact and distribution of Ni species on the solid electrolyte interphase (SEI) on the anode are crucial to understand the failure mechanism. Herein, we used time‐of‐flight secondary ion mass spectroscopy (TOF‐SIMS) coupled with multivariate curve resolution (MCR) analysis to intuitively characterize the distribution of Ni species in the SEI. We find that the SEI on the graphite electrode using an EC‐based electrolyte exhibits a multi‐stratum structure. During accelerated aging of the LiNi0.88Co0.08Mn0.04O2/graphite full cell, the dissolution of Ni aggravates significantly upon cycling. A strong correlation between the dissolved‐Ni and organic species in the SEI on graphite is illustrated. The ion‐exchange reaction between Ni2+ and Li+ ions in the SEI is demonstrated to be the main reason for the increase of SEI resistivity. [ABSTRACT FROM AUTHOR]

The capacity of transition metal oxide cathode for Li‐ion batteries can be further enhanced by increasing the charging potential. However, these high voltage cathodes suffer from fast capacity decay because the large volume change of cathode breaks the active materials and cathode‐electrolyte interphase (CEI), resulting in electrolyte penetration into broken active materials and continuous side reactions between cathode and electrolytes. Herein, a robust LiF‐rich CEI was formed by potentiostatic reduction of fluorinated electrolyte at a low potential of 1.7 V. By taking LiCoO2 as a model cathode, we demonstrate that the LiF‐rich CEI maintains the structural integrity and suppresses electrolyte penetration at a high cut‐off potential of 4.6 V. The LiCoO2 with LiF‐rich CEI exhibited a capacity of 198 mAh g−1 at 0.5C and an enhanced capacity retention of 63.5 % over 400 cycles as compared to the LiF‐free LiCoO2 with only 17.4 % of capacity retention. [ABSTRACT FROM AUTHOR]

Many technologically relevant materials for advanced energy storage and catalysis feature reduced transition‐metal (TM) oxides that are often nontrivial to prepare because of the need to control the reducing nature of the atmosphere in which they are synthesized. Herein, we show that an ab initio predictive synthesis strategy can be used to produce multi‐gram‐scale products of various MgVxOy‐type phases (δ‐MgV2O5, spinel MgV2O4, and MgVO3) containing V3+ or V4+ relevant for Mg‐ion battery cathodes. Characterization of these phases using 25Mg solid‐state NMR spectroscopy illustrates the potential of 25Mg NMR for studying reversible magnesiation and local charge distributions. Rotor‐assisted population transfer (RAPT) is used as a much‐needed signal‐to‐noise enhancement technique. The ab initio guided synthesis method is seen as a step forward towards a predictive synthesis strategy for targeting specific complex TM oxides with variable oxidation states of technological importance. [ABSTRACT FROM AUTHOR]

Oxidative cleavage of alkenes into carbonyl molecules mainly relies on either ozonolysis or Lemieux‐Johnson oxidation involving high valent transition metal oxides. Safety, technical concerns and highly oxidizing conditions of both these procedures limited their adoption in streamlined synthesis. Like ozone, photosensitized nitroarenes can deliver similar types of [3+2] cycloaddition products with alkenes through biradical formation and the resulting "N‐doped" ozonides can safely be converted to the corresponding carbonyl compounds through hydrolysis. The high prevalence of nitroarenes with diverse electronic and steric profiles combined with the mild oxidizing power allow to modulate site‐selectivity and tolerate highly sensitive functional groups ideal for application in complex molecular setup. [ABSTRACT FROM AUTHOR]

Carbon monoxide dehydrogenase (CODH) enzymes are active for the reversible CO oxidation–CO2 reduction reaction and are of interest in the context of CO2 abatement and carbon‐neutral solar fuels. Bioinspired by the active‐site composition of the CODHs, polyoxometalates triply substituted with first‐row transition metals were modularly synthesized. The polyanions, in short, {SiM3W9} and {SiM′2M′′W9}, M, M′, M′′=CuII, NiII, FeIII are shown to be electrocatalysts for reversible CO oxidation–CO2 reduction. A catalytic Tafel plot showed that {SiCu3W9} was the most reactive for CO2 reduction, and electrolysis reactions yielded significant amounts of CO with 98 % faradaic efficiency. In contrast, Fe–Ni compounds such as {SiFeNi2W9} preferably catalyzed the oxidation of CO to CO2 similar to what is observed for the [NiFe]‐CODH enzyme. Compositional control of the heterometal complexes, now and in the future, leads to control of reactivity and selectivity for CO2 electrocatalytic reduction. [ABSTRACT FROM AUTHOR]

Anionic redox is an effective way to boost the energy density of layer‐structured metal‐oxide cathodes for rechargeable batteries. However, inherent rigid nature of the TMO6 (TM: transition metals) subunits in the layered materials makes it hardly tolerate the inner strains induced by lattice glide, especially at high voltage. Herein, P2‐Na0.8Mg0.13[Mn0.6Co0.2Mg0.07□0.13]O2 (□: TM vacancy) is designed that contains vacancies in TM sites, and Mg ions in both TM and sodium sites. Vacancies make the rigid TMO6 octahedron become more asymmetric and flexible. Low valence Co2+/Co3+ redox couple stabilizes the electronic structure, especially at the charged state. Mg2+ in sodium sites can tune the interlayer spacing against O‐O electrostatic repulsion. Time‐resolved in situ X‐ray diffraction confirms that irreversible structure evolution is effectively suppressed during deep desodiation benefiting from the specific configuration. X‐ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations demonstrate that, deriving from the intrinsic vacancies, multiple local configurations of "□‐O‐□", "Na‐O‐□", "Mg‐O‐□" are superior in facilitating the oxygen redox for charge compensation than previously reported "Na‐O‐Mg". The resulted material delivers promising cycle stability and rate capability, with a long voltage plateau at 4.2 V contributed by oxygen, and can be well maintained even at high rates. The strategy will inspire new ideas in designing highly stable cathode materials with reversible anionic redox for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

Transition metal hydroxides (M‐OH) and their heterostructures (X|M‐OH, where X can be a metal, metal oxide, metal chalcogenide, metal phosphide, etc.) have recently emerged as highly active electrocatalysts for hydrogen evolution reaction (HER) of alkaline water electrolysis. Lattice hydroxide anions in metal hydroxides are primarily responsible for observing such an enhanced HER activity in alkali that facilitate water dissociation and assist the first step, the hydrogen adsorption. Unfortunately, their poor electronic conductivity had been an issue of concern that significantly lowered its activity. Interesting advancements were made when heterostructured hydroxide materials with a metallic and or a semiconducting phase were found to overcome this pitfall. However, in the midst of recently evolving metal chalcogenide and phosphide based HER catalysts, significant developments made in the field of metal hydroxides and their heterostructures catalysed alkaline HER and their superiority have unfortunately been given negligible attention. This review, unlike others, begins with the question of why alkaline HER is difficult and will take the reader through evaluation perspectives, trends in metals hydroxides and their heterostructures catalysed HER, an understanding of how alkaline HER works on different interfaces, what must be the research directions of this field in near future, and eventually summarizes why metal hydroxides and their heterostructures are inevitable for energy‐efficient alkaline HER. [ABSTRACT FROM AUTHOR]

Extensive research efforts are currently dedicated to the search for new electrocatalyst materials in which expensive and rare noble metals are replaced with cheaper and more abundant transition metals. Recently, numerous alloys, oxides, and composites with such metals have been identified as highly active electrocatalysts through the use of high‐throughput screening methods with the help of activity descriptors. Up to this point, stability has lacked such descriptors. Hence, we elucidate the role of intrinsic metal/oxide properties on the corrosion behavior of representative 3d, 4d, and 5d transition metals. Electrochemical dissolution of nine transition metals is quantified using online inductively coupled plasma mass spectrometry (ICP‐MS). Based on the obtained dissolution data in alkaline and acidic media, we establish clear periodic correlations between the amount of dissolved metal, the cohesive energy of the metal atoms (Ecoh), and the energy of oxygen adsorption on the metal (ΔHO,ads). Such correlations can support the knowledge‐driven search for more stable electrocatalysts. [ABSTRACT FROM AUTHOR]

The 3d‐transition‐metal (hydro)oxides belong to a group of highly efficient, scalable and inexpensive electrocatalysts for widespread energy‐related applications that feature easily tailorable crystal and electronic structures. We propose a general strategy to further boost their electrocatalytic activities by introducing organic ligands into the framework, considering that most 3d‐metal (hydro)oxides usually exhibit quite strong binding with reaction intermediates and thus compromised activity due to the scaling relations. Involving weakly bonded ligands downshifts the d‐band center, which narrows the band gap, and optimizes the adsorption of these intermediates. For example, the activity of the oxygen evolution reaction (OER) can be greatly promoted by ≈5.7 times over a NiCo layered double hydroxide (LDH) after a terephthalic acid (TPA)‐induced conversion process, arising from the reduced energy barrier of the deprotonation of OH* to O*. Impressively, the proposed ligand‐induced conversion strategy is applicable to a series of 3d‐block metal (hydro)oxides, including NiFe2O4, NiCo2O4, and NiZn LDH, providing a general structural upgrading scheme for existing high‐performance electrocatalytic systems. [ABSTRACT FROM AUTHOR]

For a long time, phosphors with long‐lived emission are dominated by rare earth/transition metal ion‐doped sulfides and oxides. Recently, organic materials capable of emitting long‐lived room‐temperature phosphorescence (RTP) are reported, carbon skeletons are almost the exclusive structural feature of the conjugated luminophores. Herein, we reported that boric acid, a non‐metal and C‐free material, could emit RTP with lifetime up to 0.3 s. Detailed investigations indicated the weak conjugation between the n electrons of the O atoms in the B‐O confined space was the possible origin of RTP. Similar RTP was also found in electron‐rich N/F systems, namely, BN and BF3 (BF4−). Importantly, the vacant pz0 orbital of B was found to contribute to the relevant unoccupied molecular orbitals involved in excitation, which is different from previous reports on phosphorescence from arylboronic acids. The results confirm the unique role of B as a versatile structure motif for construction of new RTP materials. [ABSTRACT FROM AUTHOR]

Coordination compounds are well‐known compounds that are being used as new materials for lithium storage because of their unique advantages, that is, designable structures, abundant active sites, and facile as well as mild synthetic routes. However, the electrode stability, low rate performance, and cycle life of coordination compounds are currently the main issues preventing their application as electrode materials, and the lithium‐storage mechanism in coordination networks is not well understood. Herein, isostructural one‐dimensional coordination compounds were synthesized to study their lithium‐storage performance. Co‐HIPA and Ni‐HIPA showed superior electrolyte stability than other M‐HIPAs, and Co‐HIPA displayed a superior reversible capacity and cycle stability, excellent rate performance, and clear voltage platform. DFT calculations and kinetic analysis revealed the influence of the metal center with different electronic structures on the lithium‐storage mechanism. [ABSTRACT FROM AUTHOR]

Layered lithium‐rich cathode materials have attracted extensive interest owing to their high theoretical specific capacity (320–350 mA h g−1). However, poor cycling stability and sluggish reaction kinetics inhibit their practical applications. After many years of quiescence, interest in layered lithium‐rich cathode materials is expected to revive in answer to our increasing dependence on high‐energy‐density lithium‐ion batteries. Herein, we review recent research progress and in‐depth descriptions of the structure characterization and reaction mechanisms of layered lithium‐rich manganese‐based cathode materials. In particular, we comprehensively summarize the proposed reaction mechanisms of both the cationic redox reaction of transition‐metal ions and the anionic redox reaction of oxygen species. Finally, we discuss opportunities and challenges facing the future development of lithium‐rich cathode materials for next‐generation lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

The structural phase of a metal oxide changes with temperature and pressure. During phase transitions, component ions move in multidimensional metal–oxygen networks. Such macroscopic structural events are robust to changes in particle size, even at scales of around 10 nm, and size effects limiting these transitions are particularly important in, for example, high‐density memory applications of ferroelectrics. In this study, we examined structural transitions of the molecular metal oxide [Na@(SO3)2(n‐BuPO3)4MoV4MoVI14O49]5− (Molecule 1) at approximately 2 nm by using single‐crystal X‐ray diffraction analysis. The Na+ encapsulated in the discrete metal‐oxide anion exhibited a reversible order–disorder transition with distortion of the Mo–O molecular framework induced by temperature. Similar order–disorder transitions were also triggered by chemical pressure induced by removing crystalline solvent molecules in the single‐crystal state or by substituting the countercation to change the molecular packing. [ABSTRACT FROM AUTHOR]

Water electrolysis offers a promising green technology to tackle the global energy and environmental crisis, but its efficiency is greatly limited by the sluggish reaction kinetics of both the cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER). In this work, by growing amorphous multi‐transition‐metal (cobalt and iron) oxide on two‐dimensional (2D) black phosphorus (BP), we develop a bifunctional electrocatalyst (CoFeO@BP), which is able to efficiently catalyze both HER and OER. The overpotentials for the hybrid CoFeO@BP catalyst to reach a current density of 10 mA cm−2 in 1 m KOH are 88 and 266 mV for HER and OER, respectively. Based on a series of ex‐situ and in situ investigations, the excellent catalytic performance of CoFeO@BP is found to result from the adaptive surface structure under reduction and oxidation potentials. CoFeO@BP can be transformed to CoFe phosphide under reduction potential, in situ generating the real active catalyst for HER. [ABSTRACT FROM AUTHOR]