Metal–organic frameworks (MOFs) have attracted tremendous interest due to their promising applications including electrocatalysis originating from their unique structural features. However, it remains a challenge to directly use MOFs for oxygen electrocatalysis because it is quite difficult to manipulate their dimension, composition, and morphology of the MOFs with abundant active sites. Here, a facile ambient temperature synthesis of unique NiCoFe‐based trimetallic MOF nanostructures with foam‐like architecture is reported, which exhibit extraordinary oxygen evolution reaction (OER) activity as directly used catalyst in alkaline condition. Specifically, the (Ni2Co1)0.925Fe0.075‐MOF‐NF delivers a minimum overpotential of 257 mV to reach the current density of 10 mA cm−2 with a small Tafel slope of 41.3 mV dec−1 and exhibits high durability after long‐term testing. More importantly, the deciphering of the possible origination of the high activity is performed through the characterization of the intermediates during the OER process, where the electrochemically transformed metal hydroxides and oxyhydroxides are confirmed as the active species.

Beyond‐lithium‐ion storage devices are promising alternatives to lithium‐ion storage devices for low‐cost and large‐scale applications. Nowadays, the most of high‐capacity electrodes are crystal materials. However, these crystal materials with intrinsic anisotropy feature generally suffer from lattice strain and structure pulverization during the electrochemical process. Herein, a 2D heterostructure of amorphous molybdenum sulfide (MoS3) on reduced graphene surface (denoted as MoS3‐on‐rGO), which exhibits low strain and fast reaction kinetics for beyond‐lithium‐ions (Na+, K+, Zn2+) storage is demonstrated. Benefiting from the low volume expansion and small sodiation strain of the MoS3‐on‐rGO, it displays ultralong cycling performance of 40 000 cycles at 10 A g−1 for sodium‐ion batteries. Furthermore, the as‐constructed 2D heterostructure also delivers superior electrochemical performance when used in Na+ full batteries, solid‐state sodium batteries, K+ batteries, Zn2+ batteries and hybrid supercapacitors, demonstrating its excellent application prospect.

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Sodium and potassium ions energy storage systems with low cost and high energy/power densities have recently drawn increasing interest as promising candidates for grid-level applications, while the lack of suitable anode materials with fast ion diffusion kinetics highly hinders their development. Herein, we develop a nanoscale confined in situ oxidation polymerization process followed by a conventional carbonization treatment to generate phosphorus and nitrogen dualdoped hollow carbon spheres (PNHCS), which can realize superior sodium and potassium ion storage performance. Importantly, the density functional theory calculation and combined characterizations, e.g., in situ Raman spectroscopy and ex situ X-ray photoelectron spectroscopy, decipher that the P/N doping can enhance the electronic transfer dynamics and ion adsorption capability, which are responsible for enhanced electrochemical performance. Inspiringly, the practicability of the PNHCS anode is demonstrated by assembling the potassium ion hybrid capacitors (KIHCs), where the prominent energy density is 178.80 Wh kg −1 at a power density of 197.65 W kg −1 , with excellent cycling stability, can be achieved. This work not only promotes the development of efficient anode material for sodium/potassium ion storage devices but also deciphers the embedded ion storage mechanism.

PNC-MeNTs have been fabricated by a template-assisted method and carbonization treatment, and they exhibit outstanding electrochemical performance for Na+/K+ storage.

Effects of four different concentrations of nano-Cu lubrication additives on contact fatigue properties of GCr15 steel friction pairs were evaluated on a ball-rod contact fatigue tester. The anti-fatigue mechanisms of these additives were analyzed by means of scanning electron microscopy and X-ray photo electron spectroscopy. The test results and analyses show that all of these additives can raise the contact fatigue life of steel ball elements to a certain extent. The action of 10% additive is the better. It is confirmed that the main failure of the steel ball element is fatigue desquamation. The anti-fatigue mechanism of lubrication additives mainly accounts for forming a chemical reaction film on the steel rod and ball surface and decreasing in friction between the ball and rod, enhancing the ability of anti-wear.

Superhydrophobic surfaces were prepared on copper foils via a facile assistant surface oxidation technology and subsequent chemical modification with low free energy materials. The three-dimensional (3D) honeycomb-like porous structures made up of nanoslices of hydroxy cupric phosphate heptahydrate (Cu 8 (PO 3 OH) 2 (PO 4 ) 4 • 7H 2 O) single crystals were constructed by immersing copper foil in an aqueous solution of phosphoric acid and hydrogen peroxide. The pore size of the 3D structure ranges from hundreds of nanometers to two micrometers, and the thickness of the two-dimensional (2D) nanoslices is about 50-100 nm. The wettability of the porous surfaces was transformed from superhydrophilic to superhydrophobic by chemical modification with octadecanethiol (ODT) or 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PDES). It was found that the 3D porous structures of the surfaces helped to amplify the wettability. The resulting static contact angles (CAs) for water were larger than 160°on both of the modified surfaces. Compared with the surface modified with ODT, the PDES-modified surface has lower contact angle hysteresis (CAH) for water droplets. It should provide new insight to prepare novel multifunctional materials with potential industrial applications such as corrosion prevention, drag reduction, self-cleaning, and so forth.

Potassium ion-based energy storage devices have received extensive attention for grid-level applications due to their abundant natural resources and low cost. However, the large ionic radius of K + leads to inferior capacities and cyclic stability, which hinders their practical application. Herein, hierarchical carbonaceous nanotubes with simultaneous ultrasmall Sn cluster incorporation and nitrogen doping (denoted as u-Sn@NCNTs) are fabricated using MnO 2 nanowires as a dual-functional template (in situ polymerization and shape-directing agents) and subsequent carbonization treatment. The u-Sn@ NCNTs exhibit a superior K + storage capability with a high reversible capacity (220.1 mA h g −1 at 0.1 A g −1 ) and long cycling stability (149.9 mA h g −1 at 1 A g −1 after 4000 cycles). Besides, the u-Sn@NCNTs exhibit superior cycling stability up to 10000 cycles at 5 A g −1 for Na + storage. The potassium storage mechanism and kinetics are investigated based on ex situ X-ray photoelectron spectroscopy, in situ Raman spectrum, and galvanostatic intermittent titration technique. More importantly, u-Sn@NCNTs can be used as the anode for potassium ion hybrid capacitors, achieving a superior energy density of 181.4 W h kg −1 at a power density of 185 W kg −1 with excellent cycling capability. This work could push forward the development and application of carbonaceous-based anode materials for next-generation high-performance rechargeable batteries.