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The controlled fabrication of single-crystal twelve-pointed graphene grains is demonstrated for the first time by ambient pressure chemical vapor deposition on a liquid Cu surface. An edge-diffusion limited mechanism is proposed. The highly controllable growth of twelve-pointed graphene grains presents an intriguing case for the fundamental study of graphene growth and should exhibit wide applications in graphene-based electronics.

Near-infrared (NIR) light-driven bilayer actuators capable of fast, highly efficient, and reversible bending/unbending motions toward periodic NIR light irradiation are fabricated by exploiting the photothermal conversion and humidity-sensitive properties of polydopamine-modified reduced graphene oxide (PDA-RGO). The bilayer actuator comprises a PDA-RGO layer prepared by a filtration method, and this layer is subsequently spin-coated with a layer of UV-cured Norland Optical Adhesive (NOA)-63. Given the hydrophilicity of PDA, the PDA-RGO layer can absorb water to swell and lose water to shrink. The intrinsic NIR absorbance of RGO sheets convertes NIR light into thermal energy, which transfers the humidity-responsive PDA-RGO layer to be NIR light-responsive. Considering that the shape of the NOA-63 layer remains unchanged under NIR light, periodic NIR light irradiation leads to asymmetric shrinkage/expansion of the bilayer, which enables fast and reversible bending/unbending motions of the bilayer actuator. We demonstrate that compared with a poly(ethylenimine)-modified graphene oxide layer, the PDA-RGO layer is unique in fabricating highly efficient bilayer actuators. A NIR light-driven walking device capable of performing quick worm-like motion on a ratchet substrate is built by connecting two polyethylene terephthalate plates as claws on opposite ends of the PDA-RGO/NOA-63 bilayer actuator.

Near-infrared (NIR) light-driven bilayer actuators are fabricated by exploiting the photothermal conversion and humidity-sensitive properties of polydopamine-modified reduced graphene oxide. The bilayer actuator is capable of fast, highly efficient, and reversible bending/unbending motions toward periodic NIR light irradiation. The bilayer actuator is also utilized to build a NIR light-driven walking device capable of performing quick worm-like motion.

The synthesis of ultrathin films (UTFs) of NiFe-LDHs has been achieved by means of an in situ hydrothermal approach, leading to a flat disposition of the LDH crystallites on the substrate, in clear contrast to the most common perpendicular orientation reported to date. Experimental factors like time of synthesis or the nature of the substrate, seem to play a crucial role during the growing process. The 2D morphology of the NiFe-LDH crystallites was kept after a calcination procedure, leading to a topotactic transformation into mixed-metal oxide platelets. Hereby, in order to study the catalytic behavior of our samples, a chemical vapor deposition process is explored upon the as-synthesized films. In presence of a carbon source (ethylene), these films catalyze a preferential low-temperature (550 °C) growth of bamboo-like carbon nanotubes, in stark contrast to the different mixture of carbon nanoforms obtained from the bulk samples. This work opens the door for the development of UTFs based on LDHs, which may be of utmost importance in a wide range of potential applications ranging from magnetic storage, catalysis or biomedical applications, to electrochemical batteries, anti-corrosion and superhydrophobic coatings.

The synthesis of ultrathin films of NiFe-LDHs with a parallel disposition of the crystallites is achieved by means of an in situ hydrothermal approach. The growing mechanism is unveiled, highlighting the tremendous influence exerted by the substrate surface. Moreover, the potential applications of these films are demonstrated by the catalytic CVD preferential growth of bamboo-like carbon nanotubes.

While debonding and subsequent pullout at fiber-matrix interfaces can improve fracture toughness in ceramic nanocomposites, the magnitudes of these contributions are currently the subject of ongoing debate. To provide quantitative insight into these mechanisms, ceramic matrix nanocomposites were fabricated with a polymer-derived ceramic matrix, using multiwalled carbon nanotubes (MWCNTs) that exhibit relatively long pullout lengths. In situ micromechanical pullout tests on individual MWCNTs were used to directly measure the strength of the fiber-matrix interface. Similar pullout lengths were also observed in bulk and thin film composites, where the fracture toughness of the composite films was measured and found to be higher than that of the matrix material. The interfacial properties from the micromechanical test and the pullout lengths from the composite films were then used to estimate the energy release rates for fiber debonding and pullout. Based on the observed MWCNT and composite failure mechanisms, these results are discussed in terms of their relation to previous estimates of toughening in MWCNT-ceramic nanocomposites, and in terms of design possibilities for further fracture toughness improvements.

High-strength MWCNTs enable measurements of the interfacial shear strength in ceramic-CNT nanocomposites, via novel single-CNT pullout tests. These measurements show brittle failure of the interface, and provide a basis for quantitative analysis of toughness contributions using classical fiber-toughening mechanics. These results are then compared with toughness improvements in analogous nanocomposite films prepared from the same materials.

Metal sulfides are an important class of functional materials possessing exceptional electrochemical performance and thus hold great promise for rechargeable secondary batteries. In this work, we deposited gallium sulfide (GaS_x, x = 1.2) thin films by atomic layer deposition (ALD) onto single-walled carbon nanotube (SWCNT) powders. The ALD GaS_x was performed at 150 °C, and produced uniform and conformal amorphous films. The resulting core-shell, nanostructured SWCNT-GaS_x composite exhibited excellent electrochemical performance as an anode material for lithium-ion batteries (LIBs), yielding a stable capacity of ≈575 mA g^–1 at a current density of 120 mA g^–1 in the voltage window of 0.01–2 V, and an exceptional columbic efficiency of >99.7%. The GaS_x component of the composite produced a specific capacity of 766 mA g^–1, a value two times that of conventional graphite anodes. We attribute the excellent electrochemical performance of the composite to four synergistic effects: 1) the uniform and conformal ALD GaS_x coating offers short electronic and Li-ion pathways during cycling; 2) the amorphous structure of the ALD GaS_x accommodates stress during lithiation-delithiation processes; 3) the mechanically robust SWCNT framework also accommodates stress from cycling; 4) the SWCNT matrix provides a continuous, high conductivity network.

Single-walled carbon nanotubes (SWCNTs) are uniformly infiltrated and coated with amorphous GaS_x using atomic layer deposition (ALD). The resulting SWCNT-GaS_x, core–shell nanocomposites exhibit reliable cycling and sustained high capacity as lithium-ion battery anodes compared to pure SWCNTs and commercial microsized Ga₂S₃. This work demonstrates a general strategy for the design and synthesis of functional nanomaterials.

Nanohybrid heterojunction (NH-HJ) solar cells are developed on page 4042 by M. A. El Khakani and co-workers using pulsed laser deposition (PLD) to decorate TiO₂ nanorods and single carbon nanotubes with PbS nanoparticles, and to integrate the formed nanohybrids directly into photovoltaic devices. This approach offers the latitude to achieve the direct assembly of different nanomaterials, thereby forming novel nanohybrids. By optimizing the size of the particles and tube lengths, NH-HJ solar cells exhibiting power conversion efficiencies as high as 5.3% are achieved.

On page 4051, S. J. Zeng, H. R. Liu, J. H. Hao, and co-workers report an Mn²⁺ doping strategy for a new type of multifunctional upconversion nanoprobe based on a NaLnF₄:Yb/Er system with controlled phase/size, tunable multi-color output, and dominant red upconversion emission. The nanoprobe can be used for multi-modal upconversion luminescence and X-ray bioimaging with deep tissue penetration. Most importantly, the blood vessels of the lung can be visualized, which promises faster and more accurate prognosis of pulmonary vascular diseases.

On page 4481, H. Abe, K. Ariga, S. Ishihara, and co-workers demonstrate that single-crystalline {001} nanoplates of an abundantly available copper oxide, when interleaved with each other in the form of a flower-like microstructure, remediate toxic nitrogen oxides into environmentally benign nitrogen more efficiently at low temperatures than preciousmetal catalysts such as platinum, palladium, and even rival rhodium.

The back cover image illustrates an innovative scheme for the fabrication of elaborate plasmonic core–shell nanohybrid architectures using multi-purpose mussel-inspired polydopamine nanolayers. The design flexibility and simplicity provides an effective way to develop plasmon-enhanced solar-energy-conversion platforms. By coupling plasmonic resonators and photosensitizers on a sub-nanometer scale through a simple solution-based process, light absorption in photocatalytic systems can be greatly enhanced to boost artificial photosynthetic reactions, as shown by C. B. Park, J. Shin, and co-workers on page 4463.

On page 4510, the pioneering work by K.-H. Jeong and co-workers experimentally reveals a universal and quantitative correlation between plasmon resonance and surface-enhanced Raman scattering (SERS) signals by using a novel active plasmonic device with a large tuning span and precise tuning resolution, termed a deformable nanoplasmonic membrane. The image shows the variation in SERS gain under precise tuning of the plasmon resonance by 1 nm over the Raman Stokes shift range.

A novel device architecture of an integrated coaxial cable that functions both as electrical cable and energy-storage device is demonstrated by J. Thomas and Z. Yu, on page 4279. The unique design of this innovative lightweight, flexible, and space-saving cable makes it very attractive for many applications including all-electric and hybrid vehicles, aircraft, heavy machinery, solar energy storage, and many others.

PGCS-NPs (40 nm) with excellent photo­thermal activity are developed, on the surface of which affibody peptides with specific affinity for EGFR and many small gold dots (1–3 nm) are densely presented. The IV-injected PGCS-NPs into EGFR-expressing tumor-bearing mice successfully perform targeted and photothermal therapy of cancer. It seems that the small gold dots released from disassembled PGCS-NPs are easily removed and never cause in vivo toxicity problems.

A low-cost, high-throughput, lift-off-free nanolithographic method is developed for creating hexagonal arrays of sub-30-nm-sized pores on a metal film, achieving uniform coverage over an entire wafer of 10 cm in diameter. Spherical nanodomains of poly(methyl methacrylate) are demonstrated to be well-controlled and self-aligned within a polystyrene matrix layer on a metal thin film without any intermediary coating. After removal of PMMA, the porous PS thin film acts as an etch mask for defining nanoscale pores in the metal underlayer by Ar ion beam milling, resulting in wafer-scale patterning with great fidelity.

By incorporating three-dimensional microvascular networks within a woven glass fiber-reinforced polymer composite N. R. Sottos, S. R. White, and co-workers demonstrate on page 4302 the full recovery (>100%) of mode-I fracture resistance after multiple damage events. This optical image of a fracture plane reveals efficient delivery, mixing and polymerization of the fluorescently dyed, two-part reactive healing chemistry.