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The design of advanced catalysts for organic reactions is of profound significance. During such processes, electrophilicity and nucleophilicity play vital roles in the activation of chemical bonds and ultimately speed up organic reactions. Herein, we demonstrate a new way to regulate the electro- and nucleophilicity of catalysts for organic transformations. Interface engineering in two-dimensional heteronanostructures triggered electron transfer across the interface. The catalyst was thus rendered more electropositive, which led to superior performance in Ullmann reactions. In the presence of the engineered 2D Cu₂S/MoS₂ heteronanostructure, the coupling of iodobenzene and para-chlorophenol gave the desired product in 92 % yield under mild conditions (100 °C). Furthermore, the catalyst exhibited excellent stability as well as high recyclability with a yield of 89 % after five cycles. We propose that interface engineering could be widely employed for the development of new catalysts for organic reactions.

The electrophilicity and nucleophilicity in two-dimensional heteronanostructures can be tuned by interface engineering, which triggers the transfer of electrons across the interface. For example, the Cu₂S/MoS₂ heteronanostructure thus obtained is a superior catalyst for Ullmann couplings with excellent stability and recyclability.

Heterocyclic pyrrole molecules are in situ aligned and polymerized in the ­absence of an oxidant between layers of the 2D Ti₃C₂T_x (MXene), resulting in high volumetric and gravimetric capacitances with capacitance retention of 92% after 25 000 cycles at a 100 mV s⁻¹ scan rate.

A MoS_2(1-x)P_x solid solution (x = 0 to 1) is formed by thermally annealing mixtures of MoS₂ and red phosphorus. The effective and stable electrocatalyst for hydrogen evolution in acidic solution holds promise for replacing scarce and expensive platinum that is used in present catalyst systems. The high performance originates from the increased surface area and roughness of the solid solution.

Dietary iron oxide nanoparticles are shown to ameliorate neurodegeneration in a Drosophelia Alzheimer's disease model. Iron oxide nanoparticles can mimic catalase and can decompose reactive oxygen species (ROS). This has potential therapeutic uses for aging, metabolic disorders, and neurodegenerative diseases, in which increased production of ROS is closely implicated.

Ultrafast charge transfer dynamics in hybrid blend films of a low band-gap polymer poly(2,6-(N-(1-octylnonyl)dithieno[3,2-b:20,30-d]pyrrole)-alt-4,7-(2,1,3-benzothiadiazole)) (PDBT) and PbS quantum dots (QDs) are studied by using ultrafast transient transmission spectroscopy. It is observed that the transient bleaching signal arising from excitons of the PDBT displays a much faster recovery, within the time delay of ≈5 ps, in hybrid films than in the neat PDBT film. In contrast, the bleaching signal resulting from the electron filling of the QDs in hybrid films shows an extra rising component during ≈1–5 ps, which is absent in the pristine QDs. These results indicate the ultrafast electron transfer from the lowest unoccupied molecular orbital energy level of the PDBT to the conduction band of the QDs in the time scale of several ps after laser excitation. A transient absorption signal within 1 ps in the hybrid films is also found, indicating the emergence of charge transfer states (CTs). The CTs formed at the interface of the hybrid blend may facilitate the charge separation and transfer. It is estimated that over 80% of the photoexcited electrons in the PDBT may be transferred into the QDs. The transfer efficiencies show a positive correlation with the power conversion efficiencies of the corresponding hybrid solar cells.

Efficient electron transfer with the time scale of picoseconds in polymer/PbS quantumdot (QD) hybrid films under photoexcitation is observed. The transfer efficiencies show close correlations with the morphology of the hybrid films and the power conversion efficiencies of the solar cells. The appearance of interfacial charge transfer states may facilitate the charge separation for promoting solar cell performance.

A versatile method to fabricate self-supported aerogels of nanoparticle (NP) building blocks is presented. This approach is based on freezing colloidal NPs and subsequent freeze drying. This means that the colloidal NPs are directly transferred into dry aerogel-like monolithic superstructures without previous lyogelation as would be the case for conventional aerogel and cryogel fabrication methods. The assembly process, based on a physical concept, is highly versatile: cryogelation is applicable for noble metal, metal oxide, and semiconductor NPs, and no impact of the surface chemistry or NP shape on the resulting morphology is observed. Under optimized conditions the shape and volume of the liquid equal those of the resulting aerogels. Also, we show that thin and homogeneous films of the material can be obtained. Furthermore, the physical properties of the aerogels are discussed.

A versatile method to fabricate self-supported porous monoliths of extremely low density consisting of nanoparticle (NP) building blocks is presented. Our approach is based on freezing and subsequent freeze drying of aqueous colloidal NPs. The assembly process is highly versatile: cryogelation is applicable for noble metal, metal oxide, and semiconductor NPs, and shaping of the aerogels is easily possible.

Using a complex power amplification system, mantis shrimps ulitize a saddle-shaped biospring to store and quickly release elastic energy, enabling them to deliver deliver ultra-fast strikes on their prey. On page 6437, A. Miserez and co-workers demonstrate that the saddle is a bi-layer material with distinct degrees of mineralization. One layer is used to maximize elastic energy storage during loading, while the other layer provides flexibility and prevents fracture during repeated loading/unloading cycles.

Hierarchical nanomaterials are highly suitable as electrocatalysts and electrocatalyst supports in electrochemical energy conversion devices. The intrinsic kinetics of an electrocatalyst are associated with the nanostructure of the active phase and the support, while the overall properties are also affected by the mesostructure. Therefore, both structures need to be controlled. A comparative state-of-the-art review of catalysts and supports is provided along with detailed synthesis methods. To further improve the design of these hierarchical nanomaterials, in-depth research on the effect of materials architecture on reaction and transport kinetics is necessary. Inspiration can be derived from nature, which is full of very effective hierarchical structures. Developing fundamental understanding of how desired properties of biological systems are related to their hierarchical architecture can guide the development of novel catalytic nanomaterials and nature-inspired electrochemical devices.

Inspired by nature: Hierarchical nanomaterials are highly suitable as electrocatalysts and electrocatalyst supports in electrochemical energy conversion devices. To further improve their design, in-depth research on the effect of materials architecture on reaction and transport kinetics is necessary. Inspiration can be derived from nature, which is full of very effective hierarchical structures.

Metal sulfide hollow nanostructures (MSHNs) have received intensive attention as electrode materials for electrical energy storage (EES) systems due to their unique structural features and rich chemistry. Here, we summarize recent research progress in the rational design and synthesis of various metal sulfide hollow micro-/nanostructures with controlled shape, composition and structural complexity, and their applications to lithium ion batteries (LIBs) and hybrid supercapacitors (HSCs). The current understanding of hollow structure control, including single-shelled, yolk-shelled, multi-shelled MSHNs, and their hybrid micro-/nanostructures with carbon (amorphous carbon nanocoating, graphene and hollow carbon), is focused on. The importance of proper structural and compositional control on the enhanced electrochemical properties of MSHNs is emphasized. A relationship between structural and compositional engineering with improved electrochemical activity of MSHNs is sought, in order to shed some light on future electrode design trends for next-generation EES technologies.

Metal sulfide hollow nanostructures are promising electrode materials for electrochemical energy storage devices including lithium-ion batteries and hybrid supercapacitors. Recent progress in the synthesis of high-quality metal sulfide hollow nanostructures is highlighted. Particular emphasis is given to the importance of rational design in structure/composition and their effects on electrochemical performances.

Defects play important roles in semiconductors (SCs). Unlike those in bulk SCs, defects in two-dimensional (2D) SCs are exposed to the surrounding environment, which can potentially modify their properties/functions. Air is a common environment, yet its impact on the defects in 2D SCs still remains elusive. Here we study the interaction between air and chalcogen vacancies (V_X), the most typical defects in 2D SCs. Although the interaction is weak for most molecules in air, O₂ can be chemisorbed at V_X with a barrier that correlates with the SC cohesive energy and can be overcome even at room temperature for certain SCs. Importantly, the chemisorbed O₂ changes the V_X from commonly believed harmful carrier-traps to electronically benign sites. This unusual behavior originates from the isovalence between O₂ and X when bonded with metal. Based on these findings, a facile approach is proposed to improve the performance of 2D SCs by using air/O₂ to passivate the defects.

The interaction between air and chalcogen vacancies (V_X), the most typical defects in 2D semiconductors (SCs), is calculated. The chemisorbed O₂ changes the V_X from commonly believed harmful carrier-traps to electronically benign sites. This unusual behavior originates from the isovalence between O₂ and X when bonded with metal. A facile approach is proposed from this to improve the performance of 2D SCs by using air/O₂ to passivate the defects.