Developing efficient electrocatalysts for alkaline water electrolysis is central to substantial progress of alkaline hydrogen production. Herein, a Ni5P4 electrocatalyst incorporating single‐atom Ru (Ni5P4‐Ru) is synthesized through the filling of Ru3+ species into the metal vacancies of nickel hydroxides and subsequent phosphorization treatment. Electron paramagnetic resonance spectroscopy, X‐ray‐based measurements, and electron microscopy observations confirm the strong interaction between the nickel‐vacancy defect and Ru cation, resulting in more than 3.83 wt% single‐atom Ru incorporation in the obtained Ni5P4‐Ru. The Ni5P4‐Ru as an alkaline hydrogen evolution reaction catalyst achieves low onset potential of 17 mV and an overpotential of 54 mV at a current density of 10 mA cm‐2 together with a small Tafel slope of 52.0 mV decade‐1 and long‐term stability. Further spectroscopy analyses combined with density functional theory calculations reveal that the doped Ru sites can cause localized structure polarization, which brings the low energy barrier for water dissociation on Ru site and the optimized hydrogen adsorption free energy on the interstitial site, well rationalizing the experimental reactivity.

Two-dimensional (2D) magnets with intrinsic ferromagnetic/antiferromagnetic (FM/AFM) ordering are highly desirable for future spintronic devices. However, the direct growth of their crystals is in its infancy. Here we report a chemical vapor deposition approach to controllably grow layered tetragonal and non-layered hexagonal FeTe nanoplates with their thicknesses down to 3.6 and 2.8 nm, respectively. Moreover, transport measurements reveal these obtained FeTe nanoflakes show a thickness-dependent magnetic transition. Antiferromagnetic tetragonal FeTe with the Néel temperature ( T N ) gradually decreases from 70 to 45 K as the thickness declines from 32 to 5 nm. And ferromagnetic hexagonal FeTe is accompanied by a drop of the Curie temperature ( T C ) from 220 K (30 nm) to 170 K (4 nm). Theoretical calculations indicate that the ferromagnetic order in hexagonal FeTe is originated from its concomitant lattice distortion and Stoner instability. This study highlights its potential applications in future spintronic devices.

It is still a great challenge to improve deformability and fatigue-resistance of stretchable conductors when maintaining their high-level conductivity for practical use. Herein, a high-performance stretchable conductor with hierarchically ternary network and self-healing capability is demonstrated through in situ polymerizing N-isopropylacrylamide (NIPAM) on well-defined sulfur-containing molecule-modified Ag nanowire (AgNW) aerogel framework. Owing to hierarchical architecture from nanoscale to microscale and further to macroscale and strong interactions of polymer chains and AgNWs, the composite exhibits good conductivity of 93 S cm−1, excellent electromechanical stability up to superhigh tensile strain of 800% and strong fatigue-resistant ability through well accommodating the applied deformations and sharing external force in the network. Furthermore, the composite delivers a fast and strong healing capability induced by reversible Ag–S bonds, which enables the healed conductor to hold an impressive electromechanical property. These prominent demonstrations confirm this material as top performer for use as flexible, stretchable electronic devices.

Surface defects in semiconductors have a significant role to tune the photocatalytic reactions. However, the dominant studied defect type is oxygen vacancy, and metal cation vacancies are seldom explored. Herein, bismuth vacancies are engineered into BiOBr through ultrathin structure control and employed to tune photocatalytic CO 2 reduction. V Bi -BiOBr ultrathin nanosheets deliver a high selective CO generation rate of 20.1 μmol g −1 h −1 in pure water, without any cocatalyst, photosensitizer, and sacrificing reagent, roughly 3.8 times higher than that of BiOBr nanosheets. The increased CO 2 reduction activity is ascribed to the tuned electronic structure, optimized CO 2 adsorption, activation, and CO desorption process over V Bi -BiOBr ultrathin nanosheets. This work offers new opportunities for designing surface metal vacancies to optimize the CO 2 photoreduction performances.

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Transition metal nitrides are promising energy storage materials in regard to good metallic conductivity and high theoretical specific capacity, but their cycling stability is impeded by the huge volume change caused by the conversion reaction mechanism. Here, a simple strategy to produce an intercalation pseudocapacitive‐type vanadium nitride (VN) by one‐step ammonification of V2C MXene for sodium‐ion batteries is reported. Profiting from a distinctive layered structure pillared by Al atoms in the layer spacing, it delivers a high capacity of 372 mA h g−1 at 50 mA g−1 and a desirable rate performance. More importantly, it shows remarkably long cycling stability over 7500 cycles without capacity attenuation at 500 mA g−1. As expected, it is found that the intercalation pseudocapacitance plays an important role in the excellent performance, by using in situ X‐ray diffraction and ex situ X‐ray absorption structure characterization. Even more remarkable, are the high energy and power density of the sodium‐ion capacitor after coupling with a carbon‐based cathode. The hybrid device possesses an energy density of 78.43 Wh kg−1 at power density of 260 W kg−1. The results clearly show that such a unique‐layered VN with outstanding Na storage capability is an excellent new material for energy storage systems.

Hydrogen production from electrochemical water splitting is very promising but still challenging. In article number 1906972, Li Song and co‐workers develop nickel phosphide nanocatalysts incorporated with single‐atomic noble metal for highly efficient alkaline water electrolysis. The doped metallic sites can cause localized structure polarization, largely promoting the hydrogen evolution from phosphide catalysts.

A carbon microtube aerogel (CMA) with hydrophobicity, strong adsorption capacity, and superb recyclability was obtained by a feasible approach with economical raw material, such as kapok fiber. The CMA possesses a great adsorption capacity of 78–348 times its weight. Attributed to its outstanding thermal stability and excellent mechanical properties, the CMA can be used for many cycles of distillation, squeezing, and combustion without degradation, which suggests a potential practical application in oil–water separation. In addition, the adsorption capacity still retained 98% by distillation, 97% by squeezing, and 90% by combustion after 10 cycles. Therefore, the obtained CMA has a broad prospect as an economical, efficient, and environmentally friendly adsorbent.