The delamination of titanium carbide sheets, an intriguing class of two-dimensional materials, has been critically dependent on the extraction of interlayer Al in acidic media, such as concentrated hydrofluoric acid (HF) or a mixture of hydrochloric acid (HCl) and a fluoride salt. Herein, we report an organic-base-driven intercalation and delamination of titanium carbide that takes advantage of the amphoteric nature of interlayer Al. The resulting aluminum-oxoanion-functionalized titanium carbide sheets manifested unusually strong optical absorption in the near-infrared (NIR) region with a mass extinction coefficient as high as 29.1 L g cm at 808 nm. Thus, the performance of this material is comparable or even superior to that of state-of-the-art photoabsorption materials, including gold-based nanostructures, carbon-based materials, and transition-metal dichalcogenides. Preliminary studies show that the titanium carbide sheets serve as efficient photothermal agents against tumor cells.

Inclusion and exclusion of an azobenzene‐containing surfactant with α‐cyclodextrin (α‐CD) can be used to fabricate photostimulus‐responsive vesicle‐like aggregates that can undergo assembly and disassembly reversibly (see picture). The movement of α‐CD is like that of a molecular shuttle.

The water strider is an insect that lives on the surface of ponds, slow streams, marshes, and other quiet waters. [1][2][3][4] Trying to understand the physical mechanism behind its ability to float on the water surface has become a very interesting area for bio-inspired research. [5,6] Hu et al. have demonstrated that there are two kinds of upward forces to support the water strider's weight: the curvature force and the buoyancy force. Through theoretical analysis, they have concluded that the curvature force produced by the insect's legs is much larger than the buoyancy force. [7,8] Furthermore, Cheng, [9] Andersen, [10,11] and Gao and Jiang [12] have discovered that the legs of water striders have superhydrophobic coatings that bear hierarchical structures of many oriented tiny hairs with fine nanogrooves. The superhydrophobic coatings were believed to be responsible for the water striders' floating. However, since many other kinds of insects, such as mosquitoes, can float on the water surface with only normal hydrophobic coatings, it is not clear why superhydrophobic coatings are required for the water strider's legs. In the work reported here, using gold threads that are modified with normal hydrophobic or superhydrophobic coatings as model systems, we studied to what extent the hydrophobicity contributes to the gold thread's floating and movement on the water surface. In addition, combining experimental results and theoretical force analysis, we report, for the first time, that deformation of the gold thread contributes to the total supporting force of the water on the floating gold thread. For easily deformed floating objects, such as very thin gold threads or legs of water striders, the contribution of deformation is significant compared to the other components of the supporting force. Our results suggest that the superhydrophobic coating of a water strider's legs can not only provide a larger supporting force, but also help to decrease the insect's total density beneath the water surface and allow it to move faster on the water surface. Therefore the superhydrophobic coating is indispensable, although the normal hydrophobic coating provides enough supporting force for the water strider merely to float. We anticipate that our results provide a deeper understanding of the mechanism of aquatic insects' floating, and hope that it may lead to further research on drag-reducing materials and rapid underwater motion.In an attempt to understand why a surperhydrophobic surface is needed by water striders, we modified gold threads with superhydrophobic coatings (contact angle > 150°) or normally hydrophobic coatings (contact angle ≈ 110°).[13] By comparing these two kinds of gold threads, we expected to obtain some information on how the supporting force is enhanced by superhydrophobicity. Several techniques have been developed to prepare superhydrophobic coatings; [14][15][16][17][18] however, here we needed a new technique to fabricate superhydrophobic coatings on curved surfaces such as gold threads. In our prev...

The delamination of titanium carbide sheets, an intriguing class of two‐dimensional materials, has been critically dependent on the extraction of interlayer Al in acidic media, such as concentrated hydrofluoric acid (HF) or a mixture of hydrochloric acid (HCl) and a fluoride salt. Herein, we report an organic‐base‐driven intercalation and delamination of titanium carbide that takes advantage of the amphoteric nature of interlayer Al. The resulting aluminum‐oxoanion‐functionalized titanium carbide sheets manifested unusually strong optical absorption in the near‐infrared (NIR) region with a mass extinction coefficient as high as 29.1 L g−1 cm−1 at 808 nm. Thus, the performance of this material is comparable or even superior to that of state‐of‐the‐art photoabsorption materials, including gold‐based nanostructures, carbon‐based materials, and transition‐metal dichalcogenides. Preliminary studies show that the titanium carbide sheets serve as efficient photothermal agents against tumor cells.

Developing efficient but nonprecious bifunctional electrocatalysts for overall water splitting in basic media has been the subject of intensive research focus with the increasing demand for clean and regenerated energy. Herein, we report on the synthesis of a novel hierarchical hybrid electrode, NiFe-layered double hydroxide molecularly ultrathin sheets grown on NiCoO nanowire arrays assembled from thin platelets with nickel foam as the scaffold support, in which the catalytic metal sites are more accessible and active and most importantly strong chemical coupling exists at the interface, enabling superior catalytic power toward both oxygen evolution reaction (OER) and additionally hydrogen evolution reaction (HER) in the same alkaline KOH electrolyte. The behavior ranks top-class compared with documented non-noble HER and OER electrocatalysts and even comparable to state-of-the-art noble-metal electrocatalysts, Pt and RuO. When fabricated as an integrated alkaline water electrolyzer, the designed electrode can deliver a current density of 10 mA cm at a fairly low cell voltage of 1.60 V, promising the material as efficient bifunctional catalysts toward whole cell water splitting.