Fabrication of a hierarchical NiTe@NiFe-LDH core-shell array for high-efficiency alkaline seawater oxidation.

Herein, a hierarchical NiTe@NiFe-LDH core-shell array on Ni foam (NiTe@NiFe-LDH/NF) demonstrates its effectiveness for oxygen evolution reaction (OER) in alkaline seawater electrolyte. This NiTe@NiFe-LDH/NF array showcases remarkably low overpotentials of 277 mV and 359 mV for achieving current densities of 100 and 500 mA cm-2, respectively. Also, it shows a low Tafel slope of 68.66 mV dec-1. Notably, the electrocatalyst maintains robust stability over continuous electrolysis for at least 50 h at 100 mA cm-2. The remarkable performance and hierarchical structure advantages of NiTe@NiFe-LDH/NF offer innovative insights for designing efficient seawater oxidation electrocatalysts.

Boosting electrocatalytic performance via electronic structure regulation for acidic oxygen evolution.

High-purity hydrogen produced by water electrolysis has become a sustainable energy carrier. Due to the corrosive environments and strong oxidizing working conditions, the main challenge faced by acidic water oxidation is the decrease in the activity and stability of anodic electrocatalysts. To address this issue, efficient strategies have been developed to design electrocatalysts toward acidic OER with excellent intrinsic performance. Electronic structure modification achieved through defect engineering, doping, alloying, atomic arrangement, surface reconstruction, and constructing metal-support interactions provides an effective means to boost OER. Based on introducing OER mechanism commonly present in acidic environments, this review comprehensively summarizes the effective strategies for regulating the electronic structure to boost the activity and stability of catalytic materials. Finally, several promising research directions are discussed to inspire the design and synthesis of high-performance acidic OER electrocatalysts.

Synergistically Coupling Atomic-Level Defect-Manipulation and Nanoscopic-Level Interfacial Engineering Enables Fast and Durable Sodium Storage.

Through inducing interlayer anionic ligands and functionally modifying conductive carbon-skeleton on the transition metal chalcogenides (TMCs) parent to achieve atomic-level defect-manipulation and nanoscopic-level architecture design is of great significance, which can broaden interlayer distance, optimize electronic structure, and mitigate structural deformation to endow high-efficiency battery performance of TMCs. Herein, an intriguing 3D biconcave hollow-tyre-like anode constituted by carbon-packaged defective-rich SnSSe nanosheet grafting onto Aspergillus niger spores-derived hollow-carbon (ANDC@SnSSe@C) is reported. Systematically experimental investigations and theoretical analyses forcefully demonstrate the existence of anion Se ligand and outer-carbon all-around encapsulation on the ANDC@SnSSe@C can effectively yield abundant structural defects and Na+ -reactivity sites, accelerate rapid ion migration, widen interlayer spacing, as well as relieve volume expansion, thus further resolving the critical issues throughout the charge-discharge processes. As anticipated, as-fabricated ANDC@SnSSe@C anode contributes extraordinary reversible capacity, wonderful cyclic lifespan with 83.4% capacity retention over 2000 cycles at 20.0 A g-1 , and exceptional rate capability. A series of correlated kinetic investigations and ex situ characterizations deeply reveal the underlying springheads for the ion-transport kinetics, as well as synthetically elucidate phase-transformation mechanism of the ANDC@SnSSe@C. Furthermore, the ANDC@SnSSe@C-based sodium ion full cell and hybrid capacitor offer high-capacity contribution and remarkable energy-density output, indicative of its great practicability.

Carbon Oxyanion Self-Transformation on NiFe Oxalates Enables Long-Term Ampere-Level Current Density Seawater Oxidation.

Seawater electrolysis is an attractive way of making H2 in coastal areas, and NiFe-based materials are among the top options for alkaline seawater oxidation (ASO). However, ample Cl- in seawater can severely corrode catalytic sites and lead to limited lifespans. Herein, we report that in situ carbon oxyanion self-transformation (COST) from oxalate to carbonate on a monolithic NiFe oxalate micropillar electrode allows safeguard of high-valence metal reaction sites in ASO. In situ/ex situ studies show that spontaneous, timely, and appropriate COST safeguards active sites against Cl- attack during ASO even at an ampere-level current density (j). Our NiFe catalyst shows efficient and stable ASO performance, which requires an overpotential as low as 349 mV to attain a j of 1 A cm-2 . Moreover, the NiFe catalyst with protective surface CO3 2- exhibits a slight activity degradation after 600 h of electrolysis under 1 A cm-2 in alkaline seawater. This work reports effective catalyst surface design concepts at the level of oxyanion self-transformation, acting as a momentous step toward defending active sites in seawater-to-H2 conversion systems.

Ruthenium doping: An effective strategy for boosting nitrite electroreduction to ammonia over titanium dioxide nanoribbon array.

Electrochemical reduction of nitrite (NO2-) not only removes NO2- contaminant but also produces high-added value ammonia (NH3). This process, however, needs efficient and selective catalysts for NO2--to-NH3 conversion. In this study, Ruthenium doped titanium dioxide nanoribbon array supported on Ti plate (Ru-TiO2/TP) is proposed as an efficient electrocatalyst for the reduction of NO2- to NH3. When operated in 0.1 M NaOH containing NO2-, such Ru-TiO2/TP achieves an ultra-large NH3 yield of 1.56 mmol h-1 cm-2 and a super-high Faradaic efficiency of 98.9%, superior to its TiO2/TP counterpart (0.46 mmol h-1 cm-2, 74.1%). Furthermore, the reaction mechanism is studied by theoretical calculation.

Boosting electrochemical nitrate-to-ammonia conversion by self-supported MnCo2O4 nanowire array.

Direct electrocatalytic reduction of nitrate (NO3-) is an efficient route to simultaneously synthesize ammonia (NH3) and remove NO3- pollutants under ambient conditions, however, it is hindered by the lack of efficient and stable catalysts. Herein, a self-supported spinel-type MnCo2O4 nanowire array is demonstrated for exclusively catalyzing the conversion of NO3- to NH3, achieving a high Faradic efficiency of 97.1% and a large NH3 yield of 0.67 mmol h-1 cm-2. Furthermore, density functional analysis reveals that MnCo2O4 (220) surface has high activity for NO3- reduction with a low energy barrier of 0.46 eV for *NO to *NOH.

The parallel computing of node centrality based on GPU.

Many systems in real world can be represented as network, and network analysis can help us understand these systems. Node centrality is an important problem and has attracted a lot of attention in the field of network analysis. As the rapid development of information technology, the scale of network data is rapidly increasing. However, node centrality computation in large-scale networks is time consuming. Parallel computing is an alternative to speed up the computation of node centrality. GPU, which has been a core component of modern computer, can make a large number of core tasks work in parallel and has the ability of big data processing, and has been widely used to accelerate computing. Therefore, according to the parallel characteristic of GPU, we design the parallel algorithms to compute three widely used node centralities, i.e., closeness centrality, betweenness centrality and PageRank centrality. Firstly, we classify the three node centralities into two groups according to their definitions; secondly, we design the parallel algorithms by mapping the centrality computation of different nodes into different blocks or threads in GPU; thirdly, we analyze the correlations between different centralities in several networks, benefited from the designed parallel algorithms. Experimental results show that the parallel algorithms designed in this paper can speed up the computation of node centrality in large-scale networks, and the closeness centrality and the betweenness centrality are weakly correlated, although both of them are based on the shortest path.

Iron-doped cobalt oxide nanoarray for efficient electrocatalytic nitrate-to-ammonia conversion.

Electrochemical nitrate reduction reaction (NO3RR) is an attractive alternative to NH3 production under ambient conditions. Although noble metal-based catalysts exhibit decent NO3RR performance to NH3, the high cost and insufficient supply obstruct its large-scale application. In this work, we report that Fe-doped Co3O4 nanoarray efficiently catalyzes NO3RR for NH3 production in neutral conditions. It achieves a large NH3 yield of 0.624 mg mgcat.-1h-1 and high Faradaic efficiency of 95.5% at -0.7 V versus reversible hydrogen electrode. Besides, this catalyst exhibits good NO3RR stability. Density functional theory calculations reveal favorable adsorption of NO3- on Fe-doped Co3O4, which is conducive to NH3 production in the NO3RR process.

Ambient Ammonia Synthesis via Electrochemical Reduction of Nitrate Enabled by NiCo2 O4 Nanowire Array.

NiCo2 O4 nanowire array on carbon cloth (NiCo2 O4 /CC) is proposed as a highly active electrocatalyst for ambient nitrate (NO3 - ) reduction to ammonia (NH3 ). In 0.1 m NaOH solution with 0.1 m NaNO3 , such NiCo2 O4 /CC achieves a high Faradic efficiency of 99.0% and a large NH3 yield up to 973.2 µmol h-1  cm-2 . The superior catalytic activity of NiCo2 O4 comes from its half-metal feature and optimized adsorption energy due to the existence of Ni in the crystal structure. A Zn-NO3 - battery with NiCo2 O4 /CC cathode also shows a record-high battery performance.

A TiO2-x nanobelt array with oxygen vacancies: an efficient electrocatalyst toward nitrite conversion to ammonia.

Electrocatalytic nitrite reduction not only holds significant potential in the control of nitrite contamination in the natural environment, but also is an attractive approach for sustainable ammonia synthesis. In this communication, we report that a TiO2-x nanobelt array with oxygen vacancies on a titanium plate is able to convert nitrite into ammonia with a high faradaic efficiency of 92.7% and a large yield of 7898 µg h-1 cm-2 in alkaline solution. This monolithic catalyst also shows high durability with the maintenance of its catalytic activity for 12 h. Theoretical calculations further reveal the critical role of oxygen vacancies in nitrite electroreduction.

High-performance NH3 production via NO electroreduction over a NiO nanosheet array.

Electrocatalytic NO reduction controls NO emission and produces NH3 under ambient conditions. Herein, a NiO nanosheet array on titanium mesh is proposed as a highly active and selective electrocatalyst for NO reduction, attaining a faradaic efficiency of up to 90% with a NH3 yield of 2130 µg h-1 cm-2. Its aqueous Zn-NO battery can generate electricity with a power density of 0.88 mW cm-2 and simultaneously offer an NH3 yield of 228 µg h-1 cm-2. The NO electroreduction mechanism on NiO is revealed using theoretical calculations.

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths.

A series of azobenzene-cholesterol organogel compounds (M 0 -M 12 ) with different spacers were designed and synthesized. The molecular structures were confirmed by (1)H NMR and (13)C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV-vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial role in the gelation. Compound M 6 is the only one that can gelate in ethanol, isopropanol and 1-butanol and the reversible gel-sol transitions are also investigated. To obtain visual insight into the microstructure of the gels, the typical structures of the xerogels were studied by SEM. Morphologies of the aggregates change from flower-like, network and rod with different sizes. By using IR and XRD characterization, it is found that intermolecular H-bonding, the solvents and van der Waals interaction are the main contributions to the specific superstructure.

TP53 codon 72 polymorphism and colorectal cancer susceptibility: a meta-analysis.

Colorectal cancer constitutes a significant proportion of the global burden of cancer morbidity and mortality. A number of studies have been conducted to explore whether TP53 codon 72 polymorphism is associated with colorectal cancer susceptibility. However, controversial results were obtained. In order to derive a more precise estimation of the relationship, we systematically searched Medline, Google scholar, and Ovid database for studies reported before May 2010. A total of 3603 colorectal cancer cases and 5524 controls were included. TP53 codon 72 polymorphism was not associated with colorectal cancer risk in all genetic models (for dominant model: OR = 0.99, 95% CI: 0.86-1.15; for recessive model: OR = 1.00, 95% CI: 0.81-1.23; for Arg/Pro vs. Arg/Arg: OR = 1.00, 95% CI: 0.87-1.15; for Pro/Pro vs. Arg/Arg: OR = 0.97, 95% CI: 0.76-1.25). In the subgroup analyses by ethnic groups and sources of controls, no significant associations were found in all models. Taken together, this meta-analysis suggested that the biologically usefulness of TP53 codon 72 polymorphism as a selection marker in colorectal cancer susceptibility may be very limited.