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Efficient electrochemical overall water splitting requires bi‐functional catalysts that work for both hydrogen and oxygen evolution reactions (HER/OER). A heterostructure is thus proposed to maintain its optimal interactions with H/O‐containing intermediates. A so‐called "orbital occupancy self‐equilibrium" strategy is employed theoretically and experimentally to design such bi‐functional catalysts, namely the incorporation of the V species into a NiS/NiS2 heterostructure. Owing to the variable valences of both Ni and V species, the electrons are controllably reoriented over the interfacial V─S─Ni bond. The as‐generated dynamic and self‐equilibrium of the electron environment modify an optimal adsorption harmony toward various H/O‐containing intermediates on this heterointerface, enhancing intrinsic activity and reaction kinetics for the HER, the OER, and overall water splitting. This V‐NiS/NiS2 catalyst exhibits an overpotential of only 94 and 220 mV at a current density of 10 mV cm–2 for the HER and the OER, respectively. This proposed strategy is expected to be workable for other catalysts with variable metal valences and provide insights for an agile interfacial electron allocation on heterostructure catalysts. [ABSTRACT FROM AUTHOR]

The catalytic activity of metal nanoparticles is closely pertinent to the substrate, while the influence of the support on the catalytic activity is acquainted scarcely. Herein, the edge selective decoration of noble metal nanoparticles into an edge‐rich carbon foam (CF) matrix for efficient pH‐universal hydrogen evolution (HER) reaction is reported. The highly localized density of states of the graphene edges enables increased reactivity to noble metal nanoparticles and tunes their electronic states. As expected, the Pt nanoparticles decorated on CF (Pt NPs@CF) exhibit low overpotentials (η10) of only 35, 49, and 53 mV under acidic, alkaline, and neutral conditions, respectively. Moreover, it can deliver the ampere‐level current density of 1000 mA cm−2 with an overpotential of 97 mV in acidic solutions. Above all, the other noble metal NPs decorated on CF also possess efficient pH‐universal HER performance. This work presents a new avenue for developing high‐activity electrocatalysts via support engineering. [ABSTRACT FROM AUTHOR]

Transition metal nitrides (TMNs) with high theoretical capacity and excellent electrical conductivity have great potential as anode materials for lithium-ion batteries (LIBs), but suffer from poor rate performance due to the slow kinetics. Herein, taking the Fe 2 N for instance, Co doping is utilized to enhance the work function of Fe 2 N, which accelerates the charge transfer and strengthens the adsorption of Li + ions. The Fe 2 N nanoparticles with various Co dopants are anchoring on the surface of honeycomb porous carbon foam (named Co x -Fe 2 N@C). Co-doping can enlarge the work function of pristine Fe 2 N and thereby optimize the charging/discharging kinetics. The work function can be increased from 5.23 eV (pristine Fe 2 N) to 5.67 eV for Co 0.3 -Fe 2 N@C and 5.56 eV for Co 0.1 -Fe 2 N@C. As expected, the Co 0.1 -Fe 2 N@C electrode exhibits the highest specific capacity (673 mA h g -1 at 100 mA g -1 ) and remarkable rate capability (375 mA h g -1 at 5 000 mA g -1 ), outperforming most reported TMNs electrodes. Therefore, this work provides a promising strategy to design and regulate anode materials for high-performance and even commercially available LIBs., (© 2024 Wiley‐VCH GmbH.)

The dynamics rate of traditional metal carbides (TMCs) is relatively slow, severely limiting its fast-charging capacity for lithium-ion batteries (LIBs). Herein, the core-shell W@W x C heterostructure is developed to form Mott-Schottky heterostructure, thereby simultaneously accelerating the electronic and ionic transport kinetics during the charging/discharging process. The W nanoparticles are partially reduced into W x C to form a particular core-shell structure with abundant heterogeneous interfaces. Benefiting from the Mott-Schottky effect, the electrons at the metal/semiconductor heterointerface can migrate spontaneously to realize an equal work function on both sides. In addition, the independent nanoparticle as well as the unique core-shell structure facilitate the ionic diffusion kinetics. As expected, the W@W x C electrode exhibits excellent electrochemical stability for LIBs, whose capacity can be maintained at 173.8 mA h g -1 after 1600 cycles at a high current density of 5 A g -1 . When assembled into a full cell, it can achieve an energy density of 360.2 Wh kg -1 . This work presents a new avenue to promote the electronic and ionic kinetics for LIBs anodes by constructing the unique Mott-Schottky heterostructure., (© 2023 Wiley-VCH GmbH.)

Ta 2 O 5 holds great potential for lithium storage due to its high theoretical capacity and long-life cycling. However, it still suffers from an unsatisfactory rate capability because of its low conductivity and significant volume expansion during the charging/discharging process. In this study, a zero-strain strategy was developed to composite Ta 2 O 5 with zero-strain TaC as an anode for lithium-ion batteries (LIBs). The zero-strain TaC, featuring negligible lattice expansion, can alleviate the volume variation of Ta 2 O 5 when cycling, thereby enhancing the rate capacity and long-term cycling stability of the whole electrode. Further, the formation of a heterostructure between Ta 2 O 5 and TaC was confirmed, giving rise to an enhancement in the electrical conductivity and structural stability. As expected, this anode displayed a reversible specific capacity of 395.5 mA h g -1 at 0.5 A g -1 after 500 cycles. Even at an ultrahigh current density of 10 A g -1 , the Ta 2 O 5 /TaC anode delivered a high capacity of 144 mA h g -1 and superior durability with a low-capacity decay rate of 0.08% per cycle after 1000 cycles. This zero-strain strategy provides a promising avenue for the rational design of anodes, sequentially contributing to the development of high-rate capacity and long cycling LIBs., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)