Ir-Sn pair-site triggers key oxygen radical intermediate for efficient acidic water oxidation.

The anode corrosion induced by the harsh acidic and oxidative environment greatly restricts the lifespan of catalysts. Here, we propose an antioxidation strategy to mitigate Ir dissolution by triggering strong electronic interaction via elaborately constructing a heterostructured Ir-Sn pair-site catalyst. The formation of Ir-Sn dual-site at the heterointerface and the resulting strong electronic interactions considerably reduce d-band holes of Ir species during both the synthesis and the oxygen evolution reaction processes and suppress their overoxidation, enabling the catalyst with substantially boosted corrosion resistance. Consequently, the optimized catalyst exhibits a high mass activity of 4.4 A mgIr-1 at an overpotential of 320 mV and outstanding long-term stability. A proton-exchange-membrane water electrolyzer using this catalyst delivers a current density of 2 A cm-2 at 1.711 V and low degradation in an accelerated aging test. Theoretical calculations unravel that the oxygen radicals induced by the π* interaction between Ir 5d-O 2p might be responsible for the boosted activity and durability.

Dual-Atom Support Boosts Nickel-Catalyzed Urea Electrooxidation.

Nickel-based catalysts have been regarded as one of the most promising electrocatalysts for urea oxidation reaction (UOR), however, their activity is largely limited by the inevitable self-oxidation reaction of Ni species (NSOR) during the UOR. Here, we proposed an interface chemistry modulation strategy to trigger the occurrence of UOR before the NSOR via constructing a 2D/2D heterostructure that consists of ultrathin NiO anchored Ru-Co dual-atom support (Ru-Co DAS/NiO). Operando spectroscopic characterizations confirm this unique triggering mechanism on the surface of Ru-Co DAS/NiO. Consequently, the fabricated catalyst exhibits outstanding UOR activity with a low potential of 1.288 V at 10 mA cm-2 and remarkable long-term durability for more than 330 h operation. DFT calculations and spectroscopic characterizations demonstrate that the favorable electronic structure induced by this unique heterointerface endows the catalyst energetically more favorable for the UOR than the NSOR.

Ru-Co Pair Sites Catalyst Boosts the Energetics for the Oxygen Evolution Reaction.

Manipulating the coordination environment of the active center via anion modulation to reveal tailored activity and selectivity has been widely achieved, especially for carbon-based single-atom site catalysts (SACs). However, tuning ligand fields of the active center by single-site metal cation regulation and identifying the effects on the resulting electronic configuration is seldom explored. Herein, we propose a single-site Ru cation coordination strategy to engineer the electronic properties by constructing a Ru/LiCoO2 SAC with atomically dispersed Ru-Co pair sites. Benefitting from the strong electronic coupling between Ru and Co sites, the catalyst possesses an enhanced electrical conductivity and achieves near-optimal oxygen adsorption energies. Therefore, the optimized catalyst delivers superior oxygen evolution reaction (OER) activity with low overpotential, the high mass activity of 1000 A goxide -1 at a small overpotential of 335 mV, and excellent long-term stability. It also exhibits rapid kinetics with superior rate capability and outstanding durability in a zinc-air battery.

Carambola-like Bi2Te3 superstructures with enhanced photoabsorption for highly efficient photothermal therapy in the second near-infrared biowindow.

Photothermal therapy (PTT) stimulated by light in the second near-infrared (NIR-II) biowindow shows great superiorities in the penetration ability of tissue and maximum permissible exposure (MPE). Exploring new photothermal agents with good optical absorbance in the NIR-II region is highly desirable for efficient cancer therapy. Herein, we successfully prepare carambola-like bismuth telluride (Bi2Te3) superstructures modified with PEGylated phospholipid (Bi2Te3@PEG) for CT imaging-guided PTT in the NIR-II biowindow. Attributing to their superstructures, Bi2Te3@PEG exhibited enhanced photoabsorption with higher photothermal conversion efficiency (55.3% for 1064 nm) compared with that of Bi2Te3 nanoparticles. Furthermore, the good X-ray attenuation capacity of Bi endows Bi2Te3@PEG with an outstanding performance as computed tomography (CT) contrast agents. Bi2Te3@PEG superstructures have been confirmed to effectively eliminate tumor in vitro and in vivo with negligible long-term toxicities, offering them great potential to act as theranostic platforms for cancer diagnosis and treatment.

Robust Synthesis of Gold-Based Multishell Structures as Plasmonic Catalysts for Selective Hydrogenation of 4-Nitrostyrene.

A robust self-template strategy is used for facile and large-scale synthesis of porous multishell gold with controllable shell number, sphere size, and in situ surface modification. The process involved the rapid reduction of novel Au-melamine colloidal templates with a great amount of NaBH4 in presence of poly(sodium-p-styrenesulfonate) (PSS). After soaking the templates in other metal salt solution, the obtained bimetallic templates could also be generally converted into bimetallic multishell structures by same reduction process. In the hydrogenation of 4-nitrostyrene using NH3 BH3 as a reducing agent, the porous triple-shell Au with surface modification (S-PTSAu) exhibited excellent selectivity (97 %) for 4-aminostyrene in contrast with unmodified triple-shell Au. Furthermore, it also showed higher enhancement of catalytic activity under irradiation of visible light as compared to similar catalysts with fewer shells.

A meta-analysis of the relationship between paraoxonase 1 polymorphisms and cancer.

Some previous studies already explored associations between paraoxonase 1 (PON1) polymorphisms and cancer, with conflicting findings. Here, we aimed to better analyse the relationship between PON1 polymorphisms and cancer in a larger combined population by performing a meta-analysis. We searched PubMed, Embase, and Web of Science for related articles. We calculated odds ratio (OR) and 95% confidence interval (CI) to estimate whether there are genetic associations between PON1 polymorphisms and cancer. Forty studies were included for this meta-analysis. The PON1 rs854560 polymorphism (L55M) was found to be significantly associated with cancer in general population (dominant comparison: p = .04, OR = 0.85, 95%CI 0.73-0.99; recessive comparison: p = .007, OR = 1.27, 95%CI 1.07-1.51; allele comparison: p = 0.02, OR = 0.85, 95%CI 0.75-0.97). Subgroup analyses indicated that the significant findings were mainly driven by the haematological tumours and breast cancer subgroups. We did not observe any positive findings for PON1 rs662 polymorphism (Q192R) in combined analyses. In summary, this meta-analysis proved that PON1 rs854560 polymorphism could be used to identify individual with elevated susceptibility to cancer, especially for haematological tumours and breast cancer.

Plasmonic Pt Superstructures with Boosted Near-Infrared Absorption and Photothermal Conversion Efficiency in the Second Biowindow for Cancer Therapy.

Photothermal therapy triggered by near-infrared light in the second biowindow (NIR-II) has attracted extensive interest owing to its deeper penetration depth of biological tissue, lower photon scattering, and higher maximum permissible exposure. In spite of noble metals showing great potential as the photothermal agents due to the tunable localized surface plasmon resonance, the biological applications of platinum are rarely explored. Herein, a monocomponent hollow Pt nanoframe ("Pt Spirals"), whose superstructure is assembled with three levels (3D frame, 2D layered shells, and 1D nanowires), is reported. Pt Spirals exhibit outstanding photothermal conversion efficiency (52.5%) and molar extinction coefficients (228.7 m2 mol-1 ) in NIR-II, which are much higher than those of solid Pt cubes. Simulations indicate that the unique superstructure can be a significant cause for improving both adsorption and the photothermal effect simultaneously in NIR-II. The excellent photothermal effect is achieved and subsequently verified in in vitro and in vivo experiments, along with superb heat-resistance properties, excellent photostability, and a prominent effect on computed tomography (CT) imaging, demonstrating that Pt Spirals are promising as effective theranostic platforms for CT imaging-guided photothermal therapy.

Tunable bimetallic Au-Pd@CeO2 for semihydrogenation of phenylacetylene by ammonia borane.

The fabrication of a bimetallic core and ceria shell nanostructure is considered a promising way to promote catalytic performance and stability. Here, we report an Au-Pd@CeO2 core-shell structure with a tunable Au/Pd ratio through a self-assembly autoredox reaction approach. This process involves the sequence reduction of Au and Pd precursors and then self-assembly of CeO2 nanoparticles to encapsulate the noble metal core. The as-obtained samples exhibit excellent activity and selectivity towards the ammonia borane initiated hydrogenation of phenylacetylene with an enhanced stability owing to the protection from outside CeO2 nanoparticles. Through the construction of an Au-Pd bimetallic structure, an electron modification of Pd due to charge transfer between Au and Pd results in an enhanced catalytic performance. Such a strategy is promising for the synthesis of other bimetallic noble core and ceria shell structures for further applications.

Surfactant-Guided Synthesis of Porous Pt Shells with Ordered Tangential Channels, Coated on Pd Nanostructures, and Their Enhanced Catalytic Activities.

High-quality (Pd cube)@(Pt helix) core@shell nanoparticles, with a novel spiral-structured shell and highly-ordered tangential channels are successfully fabricated through a facile wet chemistry method with the help of N,N-dimethyloctadecyl ammonium bromide acetate sodium (OTAB-Na). A bottom-up synthesis strategy provides accurate control of layers by simply changing the molar ratio of Pt/Pd with a uniform layer thickness of 2 nm maintained in all (1-3)-rounds samples. The irregular Pt superstructures of the shells, and sophisticated core@shell hybrid materials endow the as-produced samples with highly enhanced catalytic properties, when evaluated for hydrogenation of nitrobenzene as a probe reaction.

Hierarchical Bi2 Te3 Nanostrings: Green Synthesis and Their Thermoelectric Properties.

Bi2 Te3 hierarchical nanostrings have been synthesized through a solvothermal approach with the assistance of sucrose. The hierarchical Bi2 Te3 was supposed to be fabricated through a self-assembly process. Te nanorods first emerge with the reduction of TeO32- followed by heterogeneous nucleation of Bi2 Te3 nanoplates on the surface and tips of Te nanorods. Te nanorods further transform into Bi2 Te3 nanorods simultaneously with the nanoplates' growth leading to a hierarchical structure. By controlling the reaction kinetics by adding different amount of ethylene glycol, the length of nanorods and the number of nanoplates could be tailored. The use of sucrose is vital to the formation of hierarchical structure because it not only serves as a template for the well-defined growth of Te nanorods but also promotes the heterogeneous nucleation of Bi2 Te3 in the self-assembly process. The Bi2 Te3 nanomaterial shows a moderate thermoelectric performance because of its hierarchical structure. This study shows a promising way to synthesize Bi2 Te3 -based nanostructures through environmental friendly approach.

Co9 S8 Nanoparticles-Embedded N/S-Codoped Carbon Nanofibers Derived from Metal-Organic Framework-Wrapped CdS Nanowires for Efficient Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) with tunable compositions and morphologies are recognized as efficient self-sacrificial templates to achieve function-oriented nanostructured materials. Moreover, it is urgently needed to develop highly efficient noble metal-free oxygen evolution reaction (OER) electrocatalysts to accelerate the development of overall water splitting green energy conversion systems. Herein, a facile and cost-efficient strategy to synthesize Co9 S8 nanoparticles-embedded N/S-codoped carbon nanofibers (Co9 S8 /NSCNFs) as highly active OER catalyst is developed. The hybrid precursor of core-shell ZIF-wrapped CdS nanowires is first prepared and then leads to the formation of uniformly dispersed Co9 S8 /N, S-codoped carbon nanocomposites through a one-step calcination reaction. The optimal Co9 S8 /NSCNFs-850 is demonstrated to possess excellent electrocatalytic performance for OER in 1.0 m KOH solution, affording a low overpotential of 302 mV to reach the current density of 10 mA cm-2 , a small Tafel slope of 54 mV dec-1 , and superior long-term stability for 1000 cyclic voltammetry cycles. The favorable results raise a concept of exploring more MOF-based nanohybrids as precursors to induce the synthesis of novel porous nanomaterials as non-noble-metal electrocatalysts for sustainable energy conversion.

Ultrafast Synthesis of Novel Hexagonal Phase NaBiF4 Upconversion Nanoparticles at Room Temperature.

Upconversion (UC) nanoparticles (UCNPs) have evoked considerable attention in many fields owing to their fascinating features. However, rigorous synthesis conditions and expensive raw materials often limit their further applications. Here, a novel hexagonal phase NaBiF4 UC matrix through a very facile method (one min only at room temperature) is synthesized. The nanoparticles show good monodispersity with uniform size. Under the 980 nm irradiation, Yb3+ /Ln3+ (Ln = Er, Ho, Tm) codoped NaBiF4 nanoparticles show excellent UC luminescence (UCL). This super facile synthesis strategy and excellent matrix materials enable to achieve UCL in such low temperature, opening a new gateway for the UCNPs applied to a variety of areas in the future.

Multishelled Nix Co3-x O4 Hollow Microspheres Derived from Bimetal-Organic Frameworks as Anode Materials for High-Performance Lithium-Ion Batteries.

Metal-organic frameworks (MOFs) featuring versatile topological architectures are considered to be efficient self-sacrificial templates to achieve mesoporous nanostructured materials. A facile and cost-efficient strategy is developed to scalably fabricate binary metal oxides with complex hollow interior structures and tunable compositions. Bimetal-organic frameworks of Ni-Co-BTC solid microspheres with diverse Ni/Co ratios are readily prepared by solvothermal method to induce the Ni x Co3-x O4 multishelled hollow microspheres through a morphology-inherited annealing treatment. The obtained mixed metal oxides are demonstrated to be composed of nanometer-sized subunits in the shells and large void spaces left between adjacent shells. When evaluated as anode materials for lithium-ion batteries, Ni x Co3-x O4 -0.1 multishelled hollow microspheres deliver a high reversible capacity of 1109.8 mAh g-1 after 100 cycles at a current density of 100 mA g-1 with an excellent high-rate capability. Appropriate capacities of 832 and 673 mAh g-1 could also be retained after 300 cycles at large currents of 1 and 2 A g-1 , respectively. These prominent electrochemical properties raise a concept of synthesizing MOFs-derived mixed metal oxides with multishelled hollow structures for progressive lithium-ion batteries.