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Non‐noble‐metal‐based and earth‐abundant electrocatalysts have been extensively investigated for the hydrogen evolution reaction (HER). However, they still suffer from large Tafel slopes and high overpotentials, resulting in inferior HER catalytic activity. Herein, a novel, cost‐effective, and electrochemically stable catalyst is presented by growing ultrasmall CoSe2 nanoparticles on MoS2 nanofilms using a facile hydrothermal method. The CoSe2/MoS2 hybrid catalyst shows superior catalytic activity in HER to both CoSe2 or MoS2 alone and their physical mixture. With the Tafel slope as small as 37.8 mV dec−1, the CoSe2/MoS2 shows excellent catalytic properties for HER in an acidic solution. The promising performance can be attributed to the synergistic effect of CoSe2 nanoparticles and MoS2 nanofilms. In addition, the catalytic activity of the CoSe2/MoS2 catalyst is almost unchanged after 1000 cyclic voltammetric sweeps, indicating its long‐term durability under acidic conditions. [ABSTRACT FROM AUTHOR]

Lignin is a waste product in the paper industry and lignocellulosic biorefineries, in addition to being the second most abundant renewable biopolymer on Earth. Valorization of useless lignin into high value‐added advanced materials not only helps address the environmentally detrimental biowaste but also satisfies the societal need for energy. While lignin has been converted into porous carbon, made into slurry, and pasted onto metal forms as an electrode for lithium‐ion batteries and supercapacitors, there remains issues with how to scale up the process while achieving great area and mass capacitances in the fabricated lignin‐carbon electrodes. In this work, a thick freestanding electrode coupled by lignin carbon and sodium without any binder and additives was fabricated demonstrating a specific area capacitance of 19.7 F cm−2 at a current density of 1 mA cm−2, which is the highest among to date reported freestanding lignin carbon electrodes with similar thickness. This excellent electrochemical performance originates from high electro‐positivity and oxygen content promoted by the sodium. This work brings a new strategy towards lignin utilization and energy storage through coupling lignin carbon and alkali metals. [ABSTRACT FROM AUTHOR]

Hydrogels with pure hydrophilic network have received much attention due to their excellent low frictional behavior. However, the lubrication performance of hydrogels is not satisfied under high‐speed condition due to the energy dissipation caused by adsorbed polymer chains as well as the failure of lubricating mechanisms accompanied by the transition of lubrication regime. In this work, interpenetrating double‐network organohydrogels were constructed by combining hydrophilic and oleophilic polymer networks to modify the physiochemical properties of surface polymer chains, especially the chain mobility. The oleophilic polymer network spatially restricting the mobility of the swollen hydrophilic network in water, resulted in a low coefficient of friction (ca. 0.01) compared with conventional hydrogels at high speed (0.1 m s−1). Meanwhile, the organohydrogels had superior wear resistance, with almost no wear observed on the sliding track after 5 k cycles of rubbing at high speed. The design concept of organohydrogels can be extended to a variety of low‐wear, highly‐lubricating materials. [ABSTRACT FROM AUTHOR]

The design and synthesis of high‐performance and economical carbon electrodes play a critical role in developing energy‐efficient water desalination technologies. As a sustainable approach, low‐cost and abundant biomass materials are promising candidates to prepare porous carbon for capacitive deionization. In this study, binder‐free porous carbon sheets are successfully prepared using natural balsa, pine, and basswood by thermal carbonization and treated by chemical activation. The carbon electrode materials converted from balsa and pine exhibit a comparable salt adsorption performance by capacitive deionization due to the extensive surface area, substantial electrical property, and superior hydrophilic performance. The following activation treatment of the balsa‐converted carbon further enhances the surface and electrical properties and benefits the desalination performance. The salt adsorption capacity of the activated balsa electrode exhibits 12.45 mg g−1. Additionally, 19.52 mg g−1 Pb2+ and 20.06 mg g−1 Cr3+ heavy metal adsorption capacity is also observed with the activated balsa electrode in 100 mg L−1 PbCl2 and 50 mg L−1 CrCl3, respectively. To the best of authors' knowledge, this is the highest NaCl adsorption capacity performance reported thus far by using pure wood converted carbon as the electrode, and these promising results indicate that activated balsa is an extraordinary material for water desalination. [ABSTRACT FROM AUTHOR]

In this work, a 2D nanosheet (NS) of γ‐cyclodextrin (CD)‐based metal–organic frameworks (MOFs) is synthesized through a facile green chemistry approach. NS‐MOF carrier is constructed using a water system in a simple one‐pot reaction involving CD and potassium carbonate. Particle size optimization is achieved by adjusting the reaction temperature and the introduction of crystal growth suppressor (appropriate proportion of acetone). The NS‐MOF stability in aqueous medium is improved by polymerization reaction of crosslinked CD‐MOF (CL‐CD‐MOF) without blocking its cavity for drug loading. The effects of particle geometry and size of nanoporous materials on their pharmacokinetics during drug delivery are compared between the sheet‐like DXM@CL‐NS‐MOF and 3D‐cubic‐shaped DXM@CL‐CD‐MOF loaded with the same quantity of dexamethasone (DXM). The bioefficiency of these carriers in tear fluids and aqueous humors to deliver DXM is investigated in vivo. The results demonstrate that the 2D‐nanosheet particles significantly improve precorneal residence time and intraocular bioavailability over the commercial Maxidex (0.1% dexamethasone) and its 3D‐cubes counterpart of similar chemical composition. It suggests that the geometry of a carrier play a significant role in the biodistribution, and the carrier of CL‐NS‐MOF is a good candidate for ocular drug delivery. [ABSTRACT FROM AUTHOR]

Abstract: The overall electrocatalytic activity toward hydrogen evolution reaction for layered transition metal dichalcogenides is governed by their intrinsic activity, the corresponding density of active sites, and the electron transfer resistance. Here, nanoengineering strategies to scale down both the lateral size and thickness of layered 1T‐TiS2 powder to quantum dots (QDs) by bath sonication and probing sonication incision are employed. Uniform lateral size of 3–6 nm in the resulting QDs enhances the density of edge sites while the atomic layer thickness (1–2 nm) facilitates the electron transfer from the substrate to the edge sites. The obtained TiS2 QDs exhibit superior hydrogen evolution reaction activity over TiS2 nanosheets and MoS2 QDs prepared by the same method. The turnover frequency of TiS2 QDs with a small loading of 0.7 ng cm−2 in an optimal deposition on electrode reached ≈2.0 s−1 at an overpotential of −0.2 V versus RHE, several orders of magnitude higher than TiS2 nanosheets (0.01 s−1) and MoS2 QDs (0.07 s−1). [ABSTRACT FROM AUTHOR]

Keywords: lignin carbon; sodium; supercapacitors; areal capacitance EN lignin carbon sodium supercapacitors areal capacitance 1 1 1 09/11/23 20230901 NES 230901 B The Cover Feature b illustrates valorization of biowaste lignin into free-standing porous carbon block coupled with alkali metals for supercapacitors to satisfy the societal need for energy. Lignin carbon, sodium, supercapacitors, areal capacitance Cover Feature: Sodium-Dictated Free-Standing Lignin-Carbon Electrode towards Ultrahigh Capacitance (Batteries & Supercaps 9/2023). [Extracted from the article]

Most metallic glasses are brittle as deformation induces low-density sporadic shear bands and severe shear localization proceeding catastrophic failure. Here, it is demonstrated that the introduction of crystalline nanolayers with appropriate dimension can substantially suppress shear localization in metallic glasses, as manifested by ubiquitous ductile dimples in amorphous phase. Furthermore, dimple sizes can be tailored by tuning the dimension of layer thickness. Additionally unlike instantaneous crack propagation occurring in most metallic glasses, crack propagation occurs in a highly periodic and 'zigzag' fashion, and shows clear size dependence for metallic glass nanolaminates. Thus, it is a promising approach to promote ductility in metallic glasses while maintaining high strength by synthesizing metallic glass nanolaminates with certain layer thickness. Molecular dynamics simulations demonstrate that crystalline/amorphous interfaces can block crack propagation in crystalline layers and delocalize strain in amorphous layers, and suggest that 'zigzag' crack propagation could be achieved through dislocation slips in crystalline layers. [ABSTRACT FROM AUTHOR]

Photocatalysis is the most promising method for achieving artificial photosynthesis, but a bottleneck is encountered in finding materials that could efficiently promote the water splitting reaction. The nontoxicity, low cost, and versatility of photocatalysts make them especially attractive for this application. This study demonstrates that small amounts of α-Fe2O3 nanosheets can actively promote exfoliation of g-C3N4, producing 2D hybrid that exhibits tight interfaces and an all-solid-state Z-scheme junction. These nanostructured hybrids present a high H2 evolution rate >3 × 104 µmol g-1 h-1 and external quantum efficiency of 44.35% at λ = 420 nm, the highest value so far reported among the family of g-C3N4 photocatalysts. Besides effectively suppressing the recombination of electron-hole pairs, this Z-scheme junction also exhibits activity toward overall water splitting without any sacrificial donor. The proposed synthetic route for controlled production of 2D g-C3N4-based structures provides a scalable alternative toward the development of highly efficient and active photocatalysts. [ABSTRACT FROM AUTHOR]

Graphene/hexagonal boron nitride (h‐BN) monolayer in‐plane heterostructure offers a novel material platform for both fundamental research and device applications. To obtain such a heterostructure in high quality via controllable synthetic approaches is still challenging. In this work, in‐plane epitaxy of graphene/h‐BN heterostructure is demonstrated on Cu–Ni substrates. The introduction of nickel to copper substrate not only enhances the capability of decomposing polyaminoborane residues but also promotes graphene growth via isothermal segregation. On the alloy surface partially covered by h‐BN, graphene is found to nucleate at the corners of the as‐formed h‐BN grains, and the high growth rate for graphene minimizes the damage of graphene‐growth process on h‐BN lattice. As a result, high‐quality graphene/h‐BN in‐plane heterostructure with epitaxial relationship can be formed, which is supported by extensive characterizations. Photodetector device applications are demonstrated based on the in‐plane heterostructure. The success will have important impact on future research and applications based on this unique material platform. [ABSTRACT FROM AUTHOR]

Molybdenum carbide–graphene hybrid constituting few‐layer graphene and molybdenum carbide nanoparticles is synthesized by carburizing molybdenum disulfide atomic layer substrate. At the elevated temperature and reducing environment, molybdenum disulfide is reduced to molybdenum acting as the catalyst for graphene growth, while simultaneously molybdenum atoms are carburized to form molybdenum carbide. This hybrid has potential applications in heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) layered semiconducting transition-metal dichalcogenides (TMDCs) are promising candidates for next-generation ultrathin, flexible, and transparent electronics. Chemical vapor deposition (CVD) is a promising method for their controllable, scalable synthesis but the growth mechanism is poorly understood. Herein, we present systematic studies to understand the CVD growth mechanism of monolayer MoSe2, showing reaction pathways for growth from solid and vapor precursors. Examination of metastable nanoparticles deposited on the substrate during growth shows intermediate growth stages and conversion of non-stoichiometric nanoparticles into stoichiometric 2D MoSe2 monolayers. The growth steps involve the evaporation and reduction of MoO3 solid precursors to sub-oxides and stepwise reactions with Se vapor to finally form MoSe2. The experimental results and proposed model were corroborated by ab initio Car-Parrinello molecular dynamics studies. [ABSTRACT FROM AUTHOR]

Although a lot of work has been reported on the growth and properties of 2D atomic layered materials, the growth mechanism for these crystals via the chemical vapor deposition method (CVD) has remained elusive. Here, a screw dislocation-driven spiral growth of SnSe2 crystal flakes via CVD is reported. The polymorph of as-synthesized SnSe2 crystals is verified as 1T-phase by both experimental characterization and theoretical calculation. The density functional theory study reveals morphology transformation during the growth process while phase-field modeling unravels the screw dislocation propagation to form the pyramid-like structure of SnSe2. The optical band gap of SnSe2 crystals relates to an indirect band gap of 1.0 eV. The photodetector devices based on SnSe2 crystals exhibit high responsivity and ultrafast response time in the microsecond regime. [ABSTRACT FROM AUTHOR]

The scarcity of inexpensive and efficient electrocatalyst for acid water oxidation to molecular oxygen presents the development of nonprecious catalysts for water oxidation a scientific priority. For water splitting, transition-metal dichalcogenides have attracted great interest as advanced catalysts for hydrogen evolution reaction, but there has been no sincere attention to generate significant anodic current density of oxygen evolution reaction (OER) with these materials. Addressing this unmet need, here, the outstanding catalytic performance of MoS2 and TaS2 in OER is demonstrated. Chemically exfoliated 2D thin sheets of MoS2 and TaS2, in both of their 1T and 2H polymorph, have been employed for OER catalysis in acid medium. The best performance for oxygen evolution, which is also comparable to benchmark IrO2, comes out from 1T-MoS2 followed by 1T-TaS2, 2H-MoS2, and 2H-TaS2. Theoretical study reveals that the dominant catalytic activity is on edge sites instead of surface and corroborates the experimental results of polymorphic dependence of electrocatalytic activity. The materials have also shown moderate durability in the harsh acidic medium. The study brings up new set of electrocatalyst for oxygen evolution in acid regime that hitherto has remained largely unrevealed. [ABSTRACT FROM AUTHOR]

Toughening ceramics has been a long‐standing challenge. By chemically infiltrating B4C into aligned carbon nanotubes (CNTs) sheets, we fabricate a novel CNT/B4C composite with a fracture strength approaching the theoretical maximum of B4C matrix. The CNT/B4C composites simultaneously possess a strongly bonded tube/matrix interface and an amorphous, crack‐free B4C matrix. The fracture strength of the CNT/B4C nanowires is about 1–2 orders of magnitude higher than that of the bulk B4C. [ABSTRACT FROM AUTHOR]

Co-infection with hepatitis delta virus (HDV) and hepatitis B virus (HBV) has been shown to be associated with a more severe form of acute and chronic hepatitis. Cloning and expression of recombinant HDV antigen (rHDAg) in Escherichiacoli are described. Using purified rHDAg, a cost-effective indirect anti-HDV enzyme-linked immunosorbent assay (ELISA) kit was developed. Direct comparison of 15 known HDV-positive sera and 15 HDV-negative sera showed concordance agreement between the new assay kit and the Abbott Murex Anti-Delta (total) kit. In addition, 1,486 hepatitis B surface antigen (HBsAg) positive blood samples collected from various areas of China were tested using this indirect anti-HDV ELISA. It was found that 1.2% (95% CI: 0.7-1.9%) of the samples were anti-HDAg positive. It is suggested that the prevalence of HDV and HBV co-infection in China is relatively low. J. Med. Virol. 84:445-449, 2012. © 2011 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Adaptive materials with reconfigurable surface topography in response to external environments have attracted considerable attention in various fields. Here, adaptive superamphiphilic organohydrogels with reconfigurable surface topography are reported, featuring a high degree of freedom. The organohydrogels can simultaneously adapt to different surrounding mediums and reversibly switch between hydrogel‐ and organogel‐dominated surface reconfigurations to realize adaptive superhydrophilic and superoleophilic transitions. Meanwhile, these adaptive organohydrogels possess a heteronetwork complementary effect to elicit surface self‐healing capacity. Importantly, owing to these organohydrogels' reversible wettability transition, excellent surface morphing performance and bioinspired strategy, various geometrically complex biomimetic topographies can be programmed, offering unique unidirectional transport for opposite‐featured liquids in multimedia environments. Smart organohydrogel‐based microfluidic devices are also developed for on‐demand remote programming of liquid transport. Therefore, the organohydrogels suggest a reconfigurable surface topography design strategy, and would act as adaptive programmable materials for smart surface applications. [ABSTRACT FROM AUTHOR]