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Abstract Ti3C2Tx Quantum dots (QDs)/L‐Ti3C2Tx fiber electrode (Q3M7) with high capacitance and excellent flexibility is prepared by a wet spinning method. The assembled units Ti3C2Tx nanosheets (NSs) with large size (denoted as L‐Ti3C2Tx) is obtained by natural sedimentation screen raw Ti3AlC2, etching, and mechanical delamination. The pillar agent Ti3C2Tx QDs is fabricated by an ultrasound method. Q3M7 fiber electrode gave a specific capacitance of 1560 F cm−3, with a capacity retention rate of 79% at 20 A cm−3, and excellent mechanical strength of 130 Mpa. A wide temperature all‐solid‐state the delaminated montmorillonite (F‐MMT)/Polyvinyl alcohol (PVA) dimethyl sulfoxide (DMSO) flexible hydrogel (DHGE) (F‐MMT/PVA DHGE) Q3M7 fiber supercapacitor is assembled by using Q3M7 fiber as electrodes and F‐MMT/PVA DHGE as electrolyte and separator. It showed a volume specific capacitance of 413 F cm−3 at 0.5 A cm−3, a capacity retention of 97% after 10 000 cycles, an energy density of 36.7 mWh cm−3 at a power density of 311 mW cm−3, and impressive capacitance and flexibility over a wide temperature range of −40 to 60 °C. This work provides an effective strategy for designing and assembling wide temperature all‐solid‐state fiber supercapacitors with optimal balance of capacitive performance and flexibility.

Abstract Photo‐assisted Li–O2 batteries are introduced as a promising strategy for reducing severe overpotential by directly employing photocathodes. Herein, a series of size‐controlled single‐element boron photocatalysts are prepared by the meticulous liquid phase thinning methods by combining probe and water bath sonication, and their bifunctional photocathodes in the photo‐assisted Li–O2 batteries are systematically investigated. The boron‐based Li–O2 batteries have shown incremental round‐trip efficiencies as the sized reduction of boron under illumination. It is noteworthy that the completely amorphous boron nanosheets (B4) photocathode not only delivers an optimizing round‐trip efficiency of 190% on the basis of the ultra‐high discharge voltage (3.55 V) and ultra‐low charge voltage (1.87 V) but also gives a high rate performance and ultralong durability with a round‐trip efficiency of 133% after 100 cycles (200 h) compared with the other‐sized boron photocathodes. This remarkable photoelectric performance of the B4 sample can be attracted to the synergistic effect on the suitable semiconductor property, high conductivity, and strengthened catalytic ability of boron nanosheets coated with ultrathin amorphous boron‐oxides overlayer. This research can open a new avenue to facilitate the rapid development of high‐efficiency photo‐assisted Li–O2 batteries.

Abstract Organic semiconductors have been receiving intensive attention due to the specific advantages of low‐temperature processing ability, low‐fabrication cost, flexibility, and so forth. The charge carrier mobility of higher than 10 cm2 V−1 s−1 for organic semiconductors is of great importance to be studied since it presents a future promising research direction toward commercial microelectronic applications. With the significant progress of the discovery of novel organic molecules and the further improvements of device fabrication technology, some organic molecules can break the limit of our knowledge and show very high mobilities. In this review, organic polymers and small molecules with mobilities above 10 cm2 V−1 s−1 are first introduced to provide the readers with a general understanding of the features and characteristics of high‐performance organic semiconductors. Then, some important parameters, including the molecular structures, the device configurations, and the performance, are discussed in detail. Finally, the clues to obtain high mobility are summarized, and the perspective toward the future possible research directions are also provided.

Sodium-ion batteries (SIBs) have attracted increasing interest as promising candidates for large-scale energy storage due to their low cost, natural abundance and similar chemical intercalation mechanism with lithium-ion batteries. However, achieving superior rate capability and long-life for SIBs remains a major challenge owing to the limitation of favorable anode materials selection. Herein, an elegant one-step solvothermal method was used to synthesize VS4 nanorods and VS4 nanorods/reduced graphene oxide (RGO) nanocomposites. The effects of ethylene carbonate/diethyl carbonate(EC/DEC), ethylene carbonate/dimethyl carbonate(EC/DMC), and tetraethylene glycol dimethyl ether (TEGDME) electrolytes on the electrochemical properties of VS4 nanorods were investigated. The VS4 nanorods electrodes exhibit high specific capacity in EC/DMC electrolytes. A theoretical calculation confirms the advance of EC/DMC electrolytes for VS4 nanorods. Significantly, the discharge capacity of VS4/RGO nanocomposites remains 100 mAh/g after 2000 cycles at a large current density of 2 A/g, indicating their excellent cycling stability. The nanocomposites can improve the electronic conductivity and reduce the Na+ diffusion energy barrier, thereby effectively improving the sodium storage performance of the hybrid material. This work offers great potential for exploring promising anode materials for electrochemical applications.

Black phosphorus (BP), especially for BP nanosheets, with unique layered structure among two dimensional (2D) materials has attracted much attention due to its outstanding physical properties, such as ultra-high mobility, in-plane anisotropic properties. However, the small horizontal-size of reported BP limits its applications in the integrated circuit or some functional devices. In this work, a solvothermal-assisted liquid-phase exfoliation technique is firstly employed for preparing large size and high-quality BP nanosheets. In the high-polar acetonitrile solvent, solvothermal treatment weakens the Van der Waals forces of block BP. Together with the subsequently ultrasonic processing, effective exfoliation of large size and high-quality BP nanosheets are realized. The TEM, AFM and Raman results indicate that the prepared BP nanosheets are high quality with an average thickness of about 2 nm, and the horizontal-size is up to 10 μm. This facile and effective method for exfoliated BP nanosheets provides a promising strategy for the exfoliation of other 2D materials. Keywords: Two dimensional materials black phosphorus, Liquid exfoliation, Solvothermal method

Two dimensional (2D) materials have gained significant attention since the discovery of graphene in 2004. Layered transition metal dichalcogenides (TMDs) have become the focus of 2D materials in recent years due to their wide range of chemical compositions and a variety of properties. These TMDs layers can be artificially integrated with other layered materials into a monolayer (lateral) or a multilayer stack (vertical) heterostructures. The resulting heterostructures provide new properties and applications beyond their component 2D atomic crystals and many exciting experimental results have been reported during the past few years. In this review, we present the various synthesis methods (mechanical exfoliation, physical vapor transport, chemical vapor deposition, and molecular beam epitaxy method) on van der Waals heterostructures based on different TMDs as well as an outlook for future research.