A new class of Co9 S8 @MoS2 core-shell structures formed on carbon nanofibers composed of cubic Co9 S8 as cores and layered MoS2 as shells is described. The core-shell design of these nanostructures allows the advantages of MoS2 and Co9 S8 to be combined, serving as a bifunctional electrocatalyst for H2 and O2 evolution.

With the rapid development of mobile electronics and electric vehicles, future electrochemical capacitors (ECs) need to store as much energy as possible in a rather limited space. As the core component of ECs, dense electrodes that have a high volumetric energy density and superior rate capability are the key to achieving improved energy storage. Here, the significance of and recent progress in the high volumetric performance of dense electrodes are presented. Furthermore, dense yet porous electrodes, as the critical precondition for realizing superior electrochemical capacitive energy, have become a scientific challenge and an attractive research focus. From a pore-engineering perspective, insight into the guidelines of engineering the pore size, connectivity, and wettability is provided to design dense electrodes with different porous architectures toward high-performance capacitive energy storage. The current challenges and future opportunities toward dense electrodes are discussed and include the construction of an orderly porous structure with an appropriate gradient, the coupling of pore sizes with the solvated cations and anions, and the design of coupled pores with diverse electrolyte ions.

Tuning surface strain is a new strategy for boosting catalytic activity to achieve sustainable energy supplies; however, correlating the surface strain with catalytic performance is scarce because such mechanistic studies strongly require the capability of tailoring surface strain on catalysts as precisely as possible. Herein, a conceptual strategy of precisely tuning tensile surface strain on Co S /MoS core/shell nanocrystals for boosting the hydrogen evolution reaction (HER) activity by controlling the MoS shell numbers is demonstrated. It is found that the tensile surface strain of Co S /MoS core/shell nanocrystals can be precisely tuned from 3.5% to 0% by changing the MoS shell layer from 5L to 1L, in which the strained Co S /1L MoS (3.5%) exhibits the best HER performance with an overpotential of only 97 mV (10 mA cm ) and a Tafel slope of 71 mV dec . The density functional theory calculation reveals that the Co S /1L MoS core/shell nanostructure yields the lowest hydrogen adsorption energy (∆E ) of -1.03 eV and transition state energy barrier (∆E ) of 0.29 eV (MoS , ∆E = -0.86 eV and ∆E = 0.49 eV), which are the key in boosting HER activity by stabilizing the HER intermediate, seizing H ions, and releasing H gas.

Designing macroscopic, 3D porous multifunctional materials is of great importance in many fields, including energy storage, thermal insulation, sensors, and catalysis. Polar bears have hairs with a membrane-pore structure, which contributes to adaptation to harsh environments. Inspired by polar bear hair, this study reports a facile route to fabricate multifunctional silica nanotube aerogels (SNTAs) via chemical vapor deposition (CVD) of silica onto the sacrificial carbon nanoskeleton of a carbon aerogel (CA). The resulting SNTAs are not only porous, nanotubular, transparent, and lightweight but also hydrophobic, thermal resistant, mechanically robust, and machinable. Moreover, SNTAs show relatively high visible and near-infrared light transmittance and almost no ultraviolet and far-infrared light transmittance, which makes it an ideal material to provide greenhouse effects and protect human beings from an overdose of ultraviolet radiation. Multifunctional SNTAs provide an integrated solution for thermal insulation, daylighting, and UV protection applied in outer space or at high latitudes.

A self-assembled three-dimensional hierarchical porous V2O5/graphene hybrid aerogel for high-performance supercapacitor was synthesized.