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Heterostructured composites, inheriting the integrated properties of the individual components due to the synergistic effect, have engendered great attention in materials science and energy storage. However, conventional biphasic heterostructures not only optimize the performance of the composites but also aggregate the inevitable drawbacks, which can be addressed with the construction of the triphasic heterostructures by introducing an appropriate intermediate phase, significantly. Herein, a two‐dimensional (2D) double‐heterostructures MoSe2‐TiO2‐MXene anode is architected for Li‐ion storage, which combines the advantages of the high theoretical capacity of MoSe2 and metallic conductivity of MXene. Besides, the in‐situ derived TiO2 can alleviate the irreversible phase transition of MoSe2, arising from the low electronic/ionic conductivities, through electronic coupling effects. Meanwhile, the intermediate phase of TiO2 can further prevent the restacking issue of MXene, thus sustaining its high conductivity. Finally, the three‐dimensional (3D) printing technology is employed to further improve the kinetics of the electrodes for Li‐ion capacitors (LICs), which deliver the power density of 5563 W kg−1 at an energy density of 51 Wh kg−1, and a remarkable cycling stability for 20 000 cycles at 1 A g−1. This work deepens the understanding of the influence of heterostructured engineering on the design of high‐energy/power storage devices. [ABSTRACT FROM AUTHOR]

The synthesis of multi‐carbon products through electrochemical CO2 reduction reactions has attracted great interest from researchers. Herein, nitrogen‐ and carbon‐doped copper nanocatalyst (NC−Cu) containing abundant Cu−N−C active sites was prepared by thermal decomposition of the complexes containing copper and melamine. The NC−Cu catalyst exhibited an ideal current density of 22 mA cm−2 at −0.93 V versus reversible hydrogen electrode (vs. RHE) in CO2‐saturated 0.5 M KHCO3 medium, with ethanol as the predominant product at −0.93 V (vs. RHE) and a maximum Faraday efficiency of 31 %. The current density of the catalyst remained almost unchanged after 20 h of electrolysis, indicating its excellent stability. The excellent catalytic ability is attributed to the abundant Cu−N−C active sites of NC−Cu with 3D porous microstructure. [ABSTRACT FROM AUTHOR]

Wearable electronic devices are the new darling of consumer electronics, and energy storage devices are an important part of them. Here, a wearable lithium‐sulfur (Li‐S) bracelet battery using three‐dimensional (3D) printing technology (additive manufacturing) is designed and manufactured for the first time. The bracelet battery can be easily worn to power the wearable device. The "additive" manufacturing characteristic of 3D printing provides excellent controllability of the electrode thickness with much simplified process in a cost‐effective manner. Due to the conductive 3D skeleton providing interpenetrating transmission paths and channels for electrons and ions, the 3D Li‐S battery can provide 505.4 mAh g−1 specific capacity after 500 cycles with an active material loading as high as 10.2 mg cm−1. The practicality is illustrated by wearing the bracelet battery on the wrist and illuminating the red light‐emitting diode. Therefore, the bracelet battery manufactured by 3D printing technology can address the needs of the wearable power supply. [ABSTRACT FROM AUTHOR]

Abstract: Pyrrole was utilized to induce the cross‐link of graphene oxide, resulting in a stable hydrogel. Following, polypyrrole/graphene composite was prepared using direct microwave treatment of this pyrrole‐induced hydrogel. Where, graphene oxide was chemically reduced and pyrrole in the composite was polymerized. The polypyrrole was homogeneously distributed throughout the graphene sheets. The as‐synthesized composite had a three‐dimensional, cross‐linked structure with advanced electro‐catalytic properties for hydroquinone and catechol. This feature was demonstrated by the superior electrochemical reversibility and good peak separation exhibited by the novel composite material. Accordingly, the detection of the two dihydroxybenzenes using this material produced a detection limit of 0.88 μM for hydroquinone and 0.69 μM for the catechol. [ABSTRACT FROM AUTHOR]

Abstract: A new efficient composite catalyst (CuIMnFeIIIO/NG) for oxygen reduction reaction (ORR) in both alkaline and neutral media, is successfully prepared via a facile, clean, low‐cost and reproducible solvothermal method without any further treatments. The nanoparticles consisting of crystalline phases of Fe2O3, MnCO3 and amorphous Cu2O&MnxOy (CuIMnO), are anchored on nitrogen‐doping graphene (N/C atomic ratio up to 10.56 %), which offer various active sites toward ORR. The synergistic catalytic effect between these components affords excellent ORR performance with comparable onset potential and current density to commercial Pt/C in both pH‐situations, and a 4‐electron‐transfer path during oxygen reduction. Furthermore, comparative experiment results are discussed to describe the different degrees of ORR contribution in different medium from metal species and nitrogen doping. Meanwhile, superior methanol tolerance and high stability of CuIMnFeIIIO/NG can make it a promising alternative for expensive commercial Pt‐based electrocatalysts in corresponding alkaline and neutral fuel cells. [ABSTRACT FROM AUTHOR]

Abstract: The large‐scale, low‐cost preparation of Pt‐based catalysts with high activity and durability for the methanol oxidation reaction is still challenging. The key to achieving this aim is finding suitable supporting materials. In this paper, N‐doped carbon nanofibrous networks are prepared by annealing a gel containing two inexpensive and ecofriendly precursors, that is, bacterial cellulose and urea, for the loading of Pt nanoparticles. An undoped analogue is also prepared for comparison. Meanwhile, the effect of the annealing temperature on the performance of the catalysts is evaluated. The results show that the N doping and higher annealing temperature can improve the electron conductivity of the catalyst and provide more active sites for the loading of ultrafine Pt nanoparticles with a narrow size distribution. The best catalyst exhibits a remarkably high electrocatalytic activity (627 mA mg−1), excellent poison tolerance, and high durability. This work demonstrates an ideal Pt supporting material for the methanol oxidation reaction. [ABSTRACT FROM AUTHOR]