Highly-Exposed Co-CoO Derived from Nanosized ZIF-67 on N-Doped Porous Carbon Foam as Efficient Electrocatalyst for Zinc-Air Battery.

Non-precious-metal based electrocatalysts with highly-exposed and well-dispersed active sites are crucially needed to achieve superior electrocatalytic performance for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) toward zinc-air battery (ZAB). Herein, Co-CoO heterostructures derived from nanosized ZIF-67 are densely-exposed and strongly-immobilized onto N-doped porous carbon foam (NPCF) through a self-sacrificial pyrolysis strategy. Benefited from the high exposure of Co-CoO heterostructures and the favorable mass and electron transfer ability of NPCF, the Co-CoO/NPCF electrocatalyst exhibits remarkable performance for both ORR (E1/2  = 0.843 V vs RHE) and OER (Ej = 10 mA cm-2  = 1.586 V vs RHE). Further application of Co-CoO/NPCF as the air-cathode in rechargeable ZAB achieves superior performance for liquid-state ZAB (214.1 mW cm-2 and 600 cycles) and flexible all-solid-state ZAB (93.1 mW cm-2 and 140 cycles). Results from DFT calculations demonstrate that the electronic metal-support interactions between Co-CoO and NPCF via abundant C-Nx sites is favorable for electronic structure modulation, accounting for the remarkable performance.

Significantly Stabilizing Hydrogen Evolution Reaction Induced by Nb-Doping Pt/Co(OH)2 Nanosheets.

High stability and efficiency of electrocatalysts are crucial for hydrogen evolution reaction (HER) toward water splitting in an alkaline media. Herein, a novel nano-Pt/Nb-doped Co(OH)2 (Pt/NbCo(OH)2 ) nanosheet is designed and synthesized using water-bath treatment and solvothermal reduction approaches. With nano-Pt uniformly anchored onto NbCo(OH)2 nanosheet, the synthesized Pt/NbCo(OH)2 shows outstanding electrocatalytic performances for alkaline HER, achieving a high stability for at least 33 h, a high mass activity of 0.65 mA µg-1 Pt, and a good catalytic activity with a low overpotential of 112 mV at 10 mA cm-2 . Both experimental and theoretical results prove that Nb-doping significantly optimizes the hydrogen adsorption free energy to accelerate the Heyrovsky step for HER, and boosts the adsorption of H2 O, which further enhances the water activation. This study provides a new design methodology for the Nb-doped electrocatalysts in an alkaline HER field by facile and green way.

One-Dimensional Shaving-like BiVO4 Nanobelts: Synthesis, Characterization and Photocatalytic Activity with Methylene Blue.

One-dimensional shaving-like BiVO4 nanobelts were successfully synthesized via the oxide hydrothermal method (OHS), using V2O5 and Bi2O3 as raw materials and PEG 10000 (polyethylene glycol 10000) as a template. Multiple techniques, including XRD, SEM, TEM, HRTEM, UV-Vis, XPS, and photoelectrochemical measurements, were applied to characterize the obtained materials. The thickness of the BiVO4 nanobelt was approximately 10 nm, while the width was approximately 500 nm. EIS results showed that visible-light illumination caused the photogenerated charge of the BiVO4 nanobelts to have a faster transfer and a higher separation efficiency. Photocatalytic experiments indicated that with BiVO4 nanobelts as a catalyst, the degradation rate of MB (methylene blue) was close to 92.4%, and it disintegrated after two hours. Moreover, the pseudo-first-order kinetic model can be used to describe the photodecomposition reaction of MB catalysed by BiVO4 nanobelts. And this excellent photocatalytic activity of the shaving-like BiVO4 nanobelts may be related to their special morphology, narrow band gap (~2.19 eV), faster transfer and the separation efficiency of the photogenerated charge, leading to strong absorption in the visible region and improving the separation of the photogenerated electron-hole pairs. These novel monoclinic BiVO4 nanobelts exhibited great photocatalytic activity and are thus a promising candidate for application in visible-light-responsive photocatalysts.

Electrochemical Strategy for High-Resolution Nanostructures in Laser-Heat-Mode Resist Toward Next Generation Diffractive Optical Elements.

For achieving high-resolution nanostructures for next-generation diffractive optical elements (DOEs) using an environmentally friendly process, an electrochemical development strategy is proposed and developed using AgInSbTe-based laser heat-mode resist (AIST-LHR). Based on the electrical resistivity difference of amorphous and crystalline phases for this resist, an etching selectivity ratio of ≈30:1 (i.e., the etch ratio between the amorphous and crystalline ones) is achieved through the oxidation of Fe3+ ions with the assisted pitting activation etching using Cl- ions in an acid medium. Nanostructures with a minimum feature size down to 41 nm are successfully generated, including grating patterns, meta-surface optical structures, gears, and English characters. Using a post-plasma etching process, the nanostructures are successfully transferred from the AIST-HLR onto silica substrate, and X-ray grating patterns with a line space of 80 nm are created as a demonstration for its potential applications in DOEs.

NiCoPd Inlaid NiCo-Bimetallene for Efficient Electrocatalytic Methanol Oxidation.

Pd-based metallenes have attracted great attention recently as newly burgeoning two-dimensional (2D) materials, attributed to their significantly increased active surface areas and intrinsic electrocatalytic activities. Therefore, they could be used as a potential candidate as the high-performance electrocatalyst for methanol oxidation reactions (MORs) in the direct methanol fuel cell. Herein, a new strategy is proposed to fabricate NiCoPd inlaid NiCo-bimetallene (NiCoPd/NiCo-bimetallene) by the structure directing effect of 18-crown-6 ether under an ultrasonic-pulse interface together with the HCHO reduction and atom-diffusion-aging process. NiCoPd ternary-alloys with uniformly dispersed Pd active sites are decorated onto NiCo-bimetallenes, achieving remarkably enhancing the effective utilization of Pd atoms. What is more, the intrinsic activity is enhanced by the "bifunctional mechanism" of NiCo-bimetallene adsorption of intermediate species and increased Pd-active sites. Moreover, the anti-CO poisoning ability is optimized through the "alloying ligand effect" of NiCoPd. Therefore, the NiCoPd/NiCo-bimetallene exhibits excellent mass activity for MOR, which is higher than commercial Pd/C. This work suggests a new way of the Pd-based metallenes catalyst approach to the efficient electrocatalytic MOR.

Approaching Superfoldable Thickness-Limit Carbon Nanofiber Membranes Transformed from Water-Soluble PVA.

Recent progress in flexible electronics has attracted tremendous attention. However, it is still difficult to prepare superfoldable conductive materials with good biocompatibility, high sensing sensitivities, and large specific surface areas. It is expected that biomimetic methods and water-soluble precursors like poly(vinyl alcohol) (PVA) for electrospinning will be utilized to solve the above problems. Inspired by the multistage water management process of a spider spinning dragline silk, we have established a combined biomimetic technique, hydrocolloid electrospinning coupled with temperature gradient dehydration, with a carbonization technique. PVA-driven superfoldable carbon nanofiber membranes (PVA-SFCNFMs) have been prepared that not only possess a >60% micropore ratio and a 1368.8 m2/g specific surface area but also can withstand 180° real folding for 100 000 cycles, approaching the thickness limit without structure fracture. Furthermore, these membranes provide highly sensitive sensing and superior biocompatible interfaces. The molecular mechanism to improve carbon conversion and the folding mechanism to obtain "three-level dispersing stress" for the PVA-SFCNFMs have been proposed.

Mild Magnetic Hyperthermia-Activated Innate Immunity for Liver Cancer Therapy.

Magnetic hyperthermia therapy (MHT) is noninvasive and features excellent tissue penetration for deep-seated tumors, but unfortunately, it suffers the low therapeutic efficacy due to the limited magneto-thermal efficiency and insufficient intratumor accumulation of conventional intravenous-injected magnetic nanoparticles, which are actually mostly sequestered by the mononuclear phagocyte system, especially the liver. Such a disadvantageous characteristic of preferential liver uptake is here exploited, for the first time as far as we know, to treat orthotopic liver cancer by mild MHT using specially designed composite magnetic nanoparticles. A kind of core-shell-structured and Zn2+-doped Zn-CoFe2O4@Zn-MnFe2O4 superparamagnetic nanoparticles (ZCMF) has been synthesized which exhibits excellent and highly controllable magnetic hyperthermia performance owing to an exchange-coupled magnetism between the core and shell, and Zn2+ doping. The controllable mild MHT at 43-44 °C based on ZCMF demonstrates almost complete inhibition of liver cancer cell proliferation and tumor growth, which is associated with the suppression of heat shock protein 70 (HSP70) expression. More importantly, the mild MHT-treated liver cancer cells are capable of activating natural killer (NK) cells by dramatically upregulating the expression of UL16-binding proteins (ULBPs), ligands of natural killer group 2 member D (NKG2D). As a result, the growth of both xenograft tumors and orthotopic liver tumors were almost completely suppressed under mild MHT via induced NK-cell-related antitumor immunity in vivo. This work not only evidences the great potential of mild MHT but also reveals the underlying immunity activation mechanism in liver cancer treatment by mild MHT.

Ultrastable PtCo/Co3O4-SiO2 Nanocomposite with Active Lattice Oxygen for Superior Catalytic Activity toward CO Oxidation.

A nanostructural catalyst with long-term durability under harsh conditions is very important for an outstanding catalytic performance. Herein, a new ultrastable PtCo/Co3O4-SiO2 nanocatalyst was explored to improve the catalytic performance of carbon monoxide (CO) oxidation by virtue of the surface active lattice oxygen derived from strong metal-support interactions. Such a structure can overcome the issues of Co3O4-SiO2 inactivation by water vapor and the Pt inferior activity at low temperature. Further, Co3O4-SiO2 nanosheets endow superior structure stability under high temperatures of up to 800 °C, which gives long-term catalytic cyclability of PtCo/Co3O4-SiO2 nanocomposites for CO oxidation. Moreover, the large specific surface areas (294 m2 g-1) of the nanosheet structure can expose abundant surface active lattice oxygen, which significantly enhanced the catalytic activity of CO oxidation at 50 °C over 30 days without apparent aggregation of PtCo nanoparticles after 20 cycles from 50 to 400 °C. It can be expected to be a promising candidate as an ultrastable efficient catalyst.

Nanostructured Ni2SeS on Porous-Carbon Skeletons as Highly Efficient Electrocatalyst for Hydrogen Evolution in Acidic Medium.

Nickel dichalcogenides have received extensive attention as promising noble-metal-free nanocatalysts for a hydrogen evolution reaction. Nonetheless, their catalytic performance is restricted by the sluggish reaction kinetics, limited exposed active sites, and poor conductivity. In this work, we report on an effective strategy to solve those problems by using an as-designed new porous-C/Ni2SeS nanocatalyst with the Ni2SeS nanostubs anchored on with porous-carbon skeletons process. On the basis of three advantages, as the enhancement of the intrinsic activity using the ternary sulfoselenide, increased number of exposed active sites due to the 3D hollow substrate, and increased conductivity caused by porous-carbon skeletons, the resulting porous-C/Ni2SeS requires an overpotential of only 121 mV at a current density of 10 mA cm-2 with a Tafel slope of 78 mV dec-1 for hydrogen evolution in acidic media and a good long-term stability. Density functional theory calculations also show that the Gibbs free energy of hydrogen adsorption of the Ni2SeS was -0.23 eV, which not only is close to the ideal value (0 eV) and Pt reference (-0.09 eV) but also is lower than those of NiS2 and NiSe2; large electrical states exist in the vicinity of the Fermi level, which further improves its electrocatalytic performance. This work provides new insights into the rational design of ternary dichalcogenides and hollow structure materials for practical applications in HER catalysis and energy fields.

A Superior Sodium/Lithium-Ion Storage Material: Sea Sponge C/Sn2Fe@GO.

A well-structured anode nanomaterial, which can ensure electron and ion transport and avoid excessive pulverization, is of crucial importance to achieve high capacity with superior cycling stability for both sodium- and lithium-ion batteries (SIBs and LIBs). For the purpose of a superior rate performance, this work here has designed and successfully synthesized a new Na+/Li+ storage nanomaterial of SCS/Sn2Fe@GO through loading of a Sn2Fe nanoalloy on sea-sponge-like carbon spheres (SCSs), followed by a graphene oxide (GO) wrapping process. In such a designed composite, the SCS skeleton ensures electronic conductivity and shorts Na+ and Li+ diffusion pathways, while the Sn2Fe nanoalloy delivers a high capacity and prevents excessive pulverization. The GO shell around SCS/Sn2Fe greatly enhances the cyclability. Used as an anode, the SCS/Sn2Fe@GO nanocomposite enables a high capacity up to 660 mAh g-1 at 50 mA g-1, which is maintained without decay up to 800 cycles in SIBs, and up to 850 mAh g-1 at 500 mA g-1 after 3500 cycles in LIBs, proving its applicability in new-generation SIBs and LIBs.

Near-Infrared-Activated Upconversion Nanoprobes for Sensitive Endogenous Zn2+ Detection and Selective On-Demand Photodynamic Therapy.

As a light-activated noninvasive cancer treatment paradigm, photodynamic therapy (PDT) has attracted extensive attention because of its high treatment efficacy and low side effects. Especially, spatiotemporal control of singlet oxygen (1O2) release is highly desirable for realizing on-demand PDT, which, however, still remains a huge challenge. To address this issue, a novel switchable near-infrared (NIR)-responsive upconversion nanoprobe has been designed and successfully applied for controlled PDT that can be optically activated by tumor-associated disruption of labile Zn2+ (denoted as Zn2+ hereafter) homeostasis stimuli. Upon NIR irradiation, this theranostic probe can not only quantitatively detect the intracellular endogenous Zn2+ in situ but also selectively generate a great deal of cytotoxic reactive oxygen species (ROS) for efficiently killing breast cancer cells under the activation of excessive endogenous Zn2+, so as to maximally avoid adverse damage to normal cells. This study aims to propose a new tumor-specific PDT paradigm and, more importantly, provide a new avenue of thought for efficient cancer theranostics based on our designed highly sensitive upconversion nanoprobes.

Fe3O4/FeNi Embedded Nanostructure and Its Kinetic Law for Selective Catalytic Reduction of p-Nitrophenyl Compounds.

To meet the requirement of high catalytic efficiency toward the reduction of p-nitrophenyl compounds, we designed a new one-dimensional Fe3O4/FeNi embedded-nanostructured catalyst synthesized by a one-pot controlling-growth-reduction process in a solvothermal system, in which Fe3O4 phase was implanted in the base of FeNi alloy. In the Fe3O4/FeNi catalyst system, the Fe3O4 embedded phase attracts the nitro group of p-nitrophenyl compounds by its high-density electrons, which can efficiently promote the activity of amorphous FeNi active centers for selective catalysis toward the reduction of a range of p-nitrophenyl compounds. Moreover, for the para-group in the nitrophenyl compounds, an increasing electron-donating power contributes to a higher catalytic activity, while electron-withdrawing power obtains the reverse case. Additionally, the Fe3O4/FeNi composite nanocatalyst exhibited an outstanding cycling performance over 20 times without obvious performance decay. This work opens an avenue to design more powerful non-noble metal catalysts for green chemistry.

Mesoporous Cubic Nanocages Assembled by Coupled Monolayers With 100% Theoretical Capacity and Robust Cycling.

High capacity and long cycling often conflict with each other in electrode materials. Despite extensive efforts in structural design, it remains challenging to simultaneously achieve dual high electrochemical properties. In this study, we prepared brand-new completely uniform mesoporous cubic-cages assembled by large d-spacing Ni(OH)2 coupled monolayers intercalated with VO4 3- (NiCMCs) using a biomimetic approach. Such unique mesoporous structural configuration results in an almost full atomic exposure with an amazing specific surface area of 505 m2/g and atomic utilization efficiency close to the theoretical limit, which is the highest value and far surpasses all of the reported Ni(OH)2. Thus, a breakthrough in simultaneously attaining high capacity approaching the 100% theoretical value and robust cycling of 10,000 cycles is achieved, setting a new precedent in achieving double-high attributes. When combined with high-performance Bi2O3 hexagonal nanotubes, the resulting aqueous battery exhibits an ultrahigh energy density of 115 Wh/kg and an outstanding power density of 9.5 kW/kg among the same kind. Characterizations and simulations reveal the important role of large interlayer spacing intercalation units and mesoporous cages for excellent electrochemical thermodynamics and kinetics. This work represents a milestone in developing "double-high" electrode materials, pointing in the direction for related research and paving the way for their practical application.

Immobilization of laccase on magnetic mesoporous silica as a recoverable biocatalyst for the efficient degradation of benzo[a]pyrene.

Laccase is an efficient green biocatalyst, widely used for the degradation of various organic pollutants. However, free laccase is unstable and difficult to recover, which limits its practical application. In this study, a multilayer core-shell magnetic mesoporous silica (Fe3O4@d-SiO2@p-SiO2) microsphere with high specific surface area (275 m2 g-1) was fabricated for immobilization of laccase. The unique structure of Fe3O4@d-SiO2@p-SiO2 enabled the successful immobilization of laccase. Under the optimal immobilization conditions of laccase concentration of 1.5 mg mL-1, immobilization time of 6 h, immobilization pH of 6, the loading capacity of laccase was up to 567 mg g-1. Compared with free laccase, immobilized laccase exhibited remarkable pH stability, thermal stability and storage stability. Moreover, the immobilized laccase was easy to achieve magnetic recovery and possessed excellent reusability, with its activity remaining 58.2% after 10 consecutive reuses. More importantly, immobilized laccase had good degradation performance for benzo[a]pyrene (BaP), which can achieve rapid and efficient degradation of low concentration BaP over a wide range of pH and temperature. The removal efficiency of BaP was up to 99.0% within 1 h, and still exceeded 35.0% after 5 cycles. The removal of BaP by immobilized laccase was achieved through both adsorption and degradation. The degradation products and possible degradation pathways were determined by GC-MS analysis. This study indicated that Fe3O4@d-SiO2@p-SiO2 could effectively enhance the stability and biocatalytic activity of laccase, which is expected to provide a new clean biotechnology for the remediation of BaP contaminated sites.

Development of validated quantitative structure-retention relationship models for retention indices of plant essential oils.

Quantitative structure-retention relationship (QSRR) models were developed for the retention indices of 505 frequently reported components of plant essential oils. Multiple linear regression was used to build QSRR models for the dimethyl silicone, dimethyl silicone with 5% phenyl groups, and polyethylene glycol stationary phases. We tried to improve the variable selection and modeling method based on prediction method for selecting the optimum descriptors from the molecular weight, 75 topological indices, and 170 atom-type E-state indices. The three-variable QSRR models perform high correlation coefficients of 0.937 for dimethyl silicone and 0.933 for dimethyl silicone with 5% phenyl groups stationary phase. Four variables were selected to developed QSRR model for the polyethylene glycol stationary phase. The leave-one-out and leave-many-out cross-validations, bootstrapping, and y-randomization test showed the three models are robust and have no chance correlation. The external validation with the test set showed the three models present high externally predictive power. The three models presented high-quality fit, internally, and externally predictive power. It is expected that the models can effectively predict retention indices of essential oils components without experimental value.

Cognitive and mood effects of phenobarbital treatment in people with epilepsy in rural China: a prospective study.

BACKGROUND: Phenobarbital is an effective treatment for epilepsy but concerns remain over its potential neurocognitive toxicity. This prospective study evaluated the effects of phenobarbital treatment on cognition and mood in people with epilepsy in rural China. METHODS: We recruited 144 adults with convulsive seizures and 144 healthy controls from six sites in rural China. People with epilepsy were treated with phenobarbital monotherapy for 12 months. At baseline, and at 3, 6 and 12 months, cases and controls were evaluated with a battery of neuropsychological tests: the Mini-Mental State Examination, the Hamilton Depression Rating Scale, a digit span test, a verbal fluency test, an auditory verbal learning test and a digit cancellation test. Efficacy of phenobarbital treatment was evaluated at the end of follow-up for those with epilepsy. RESULTS: Cognitive test scores and mood ratings were available for 136 (94%) people with epilepsy and 137 (95%) controls at the 12 month follow-up. Both groups showed slightly improved performance on a number of neuropsychological measures. The people with epilepsy showed greater performance gains (p=0.012) in verbal fluency. Nine people with epilepsy complained of memory problems during the treatment period. CONCLUSION: In this study, phenobarbital was not found to have a major negative impact on cognitive function of people with convulsive seizures and some cognitive gains were observed, possibly due to improved seizure control.

Solvothermal synthesis of NiCo alloy icosahedral nanocrystals.

New dimensional NiCo alloy icosahedral nanocrystals with controllable size have been first reported and synthesized through an Ostwald ripening process in a template-absent solvothermal reaction system. The proposed synthesis is corroborated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The as-obtained NiCo icosahedral nanocrystals exhibit the size- and component-dependent magnetic behaviors. The coercivity (H(c)) depends on both the magnetocrystalline and structure anisotropy, and the saturation magnetizations (M(s)) decided by the content of Co. H(c) decreases from 189.02 to 147.95 Oe with the increase of the icosahedral NCs size from 200 to 850 nm. Especially, the H(c) of the icosahedral NCs at 157.38 Oe is higher than that of nanospheres at 104.02 Oe. In addition, M(s) and H(c) increased with the increasing Co content. It can be an ideal building block for applications in magnetic media, sensors, and other devices.

Cognitive dysfunction in people with convulsive seizures in rural China.

One hundred and forty-four people with convulsive seizures (CS) and 144 healthy controls were evaluated for cognitive function, using a battery of neuropsychological tests. People with CS performed significantly worse than the controls on the Mini-Mental State Examination, Hamilton Depression Rating Scale, auditory verbal learning test, digit span test, verbal fluency test, and digit cancellation test. The percentage of patients who had abnormal scores on the Hamilton Depression Rating Scale was higher than that of controls (54.9% vs. 7.6%, p<0.001). Cognitive functional impairment was detected in 65.3% of the patients and 29.2% of the controls (p<0.001). People with CS presented with depressive mood and a wide range of cognitive deficits, particularly deficits in episodic declarative memory, attentional capacity, semantic memory, and mental speed. Years in education were positively associated with the cognitive performance of people with CS (OR=0.655, 95% CI: 0.486-0.882, p=0.005).

Dual Carbon Design Strategy for Anodes of Sodium-Ion Battery: Mesoporous CoS2/CoO on Open Framework Carbon-Spheres with rGO Encapsulating.

Transition metal sulfides and oxides with high theoretical capacities have been regarded as promising anode candidates for a sodium-ion battery (SIB); however, they have critical issues including sluggish electrochemical kinetics and poor long-term stability. Herein, a dual carbon design strategy is proposed to integrate with highly active heterojunctions to overcome the above issues. In this new design, CoS2/CoO hollow dodecahedron heterojunctions are sandwiched between open framework carbon-spheres (OFCs) and a reduced graphene oxide (rGO) nanomembrane (OFC@CoS2/CoO@rGO). The CoS2/CoO heterojunctions effectively promote electron transfer on their surface and provide more electrochemical active sites through their hierarchical hollow structures assembled by nanodots. Meanwhile, the dual-carbon framework forms a highly conductive network that enables a better rate capability. More importantly, the dual carbon can greatly buffer volume expansion and stable reaction interfaces of electrode material during the charge/discharge process. Benefitting from their synergistical effects, the OFC@CoS2/CoO@rGO electrode achieves a high reversible capacity of 460 mAh g-1 at 0.05 A g-1 and still maintains 205.3 mAh g-1 even when current density is increased by 200 times when used as an anode material for SIBs. Their cycling property is also remarkable with a maintained capacity of 161 mAh g-1 after 3500 charging/discharging cycles at a high current density of 1 A g-1. The dual-carbon strategy is demonstrated to be effective for enhanced reaction kinetics and long-term cycling property, providing siginificant guidance for preparing other high-performance electrode materials.