N-CoFeP/NF electrocatalyst for coupling hydrogen production and oxidation reaction of various alcohols.

Replacing the oxygen evolution reaction with the alcohols oxidation reaction (AOR) in electrolytic water is not only expected to reduce the overall energy consumption, but also realize the green synthesis of high value-added chemicals. However, designing high-activity electrocatalysts toward AOR yet faces a daunting challenge due to the indefinite conversion mechanism of different alcohols. Herein, a self-supported N-CoFeP/NF electrocatalyst on a nickel foam is synthesized via hydrothermal method, followed by low temperature nitriding and phosphating. The N-CoFeP/NF exhibits a fine nanorod nanostructure and high crystallinity. The AOR using N-CoFeP/NF catalysts requires a significantly lower potential (1.38-1.42 V vs. RHE) at 100 mA cm-2, reducing the energy input and the improvement of the overall efficiency. Moreover, alcohols with secondary hydroxyl groups located in the middle of the carbon chain underwent CC bond breakage during oxidation, yielding primarily formic acid (FE = 74 %) and acetic acid (FE = 50 %), which exhibits more attractive performance than alcohols with primary hydroxyl groups located at the end group did not undergo chemical bond breakage at a high current density of 400 mA cm-2. This study provides a novel and effective method to design TMPs and the selection of alcohols for anodic reaction, which can be used as a versatile strategy to improve the performance of anodic AOR coupled hydrogen evolution.

Effects of Ketanserin, M100907 and Olanzapine on hallucinogenic like action induced by 2,5-dimethoxy-4-methylamphetamine.

2,5-dimethoxy-4-methylamphetamine (DOM) is a kind of hallucinogen of phenylalkylamine. Psychedelic effects mainly include audiovisual synesthesia, complex imagery, disembodiment etc. that can impair control and cognition leading to adverse consequences such as suicide. By now, there are no specific drugs regarding the management of classic hallucinogen use clinically. We evaluated the effects of three 5-HT 2A receptor antagonists ketanseirn, M100907 and olanzapine on hallucination-like behavior in therapeutic and preventive administration with male C57BL/6J mice. Two models were used to evaluate the therapeutic potential of antagonists, one is head-twitch response (HTR) and the other is locomotion. Effects of ketanserin, M100907 and olanzapine on DOM-induced HTR were studied in preventive and therapeutic administration, respectively. In the preventive administration, the ID 50 values of ketanseirn, M100907 and olanzapine were 0.4 mg/kg, 0.005 mg/kg and 0.25 mg/kg. In the therapeutic administration, the ID 50 values of ketanseirn, M100907 and olanzapine were 0.04 mg/kg, 0.005 mg/kg and 0.03 mg/kg. Secondly, locomotor activity induced by DOM was performed to further evaluate the efficacy of three compounds. In locomotion, M100907(0.005 mg/kg) whenever in preventive or therapeutic administration, reduced the increase of movement distance induced by DOM. Although ketanserin (0.4 mg/kg) in the preventive administration also decreased the movement distance induced by DOM, it was alone administrated to influence the locomotor activity. Through HTR and locomotion, we compared the efficacy and latent side effects of ketanserin, M100907 and olanzapine against hallucinogenic like action induced by DOM. Our study provided additional experimental evidence on specific therapeutic drugs against hallucinogenic behavior induce by representative hallucinogen DOM.

Using mobile phone big data to discover the spatial patterns of rural migrant workers' return to work in China's three urban agglomerations in the post-COVID-19 era.

Knowing how workers return to work is a key policymaking issue for economic recovery in the post-COVID-19 era. This paper uses country-wide time-series mobile phone big data (comparing monthly and annual figures), obtained between February 2019 and October 2019 and between February 2020 and October 2020, to discover the spatial patterns of rural migrant workers' (RMWs') return to work in China's three urban agglomerations (UAs): the Beijing-Tianjin-Hebei Region, the Yangtze River Delta and the Pearl River Delta. Spatial patterns of RMWs' return to work and how these patterns vary with location, city level and human attribute were investigated using the fine-scale social sensing related to post-pandemic human mobility. The results confirmed the multidimensional spatiotemporal differentiations, interaction effects between variable pairs and effects of the actual situation on the changing patterns of RMWs' return to work. The spatial patterns of RMWs' return to work in China's major three UAs can be regarded as a comprehensive and complex interaction result accompanying the nationwide population redistribution, which was affected by various hidden factors. Our findings provide crucial implications and suggestions for data-informed policy decisions for a harmonious society in the post-COVID-19 era.

Microphase Separation Engineering toward 3D Porous Carbon Assembled from Nanosheets for Flexible All-Solid-State Supercapacitors.

Although hierarchitectures could energize carbon materials to address the challenges encountered in emerging flexible energy storage, how to make the trade-offs among specific surface area, pore configuration, and conductivity is still a lingering issue. Herein, 3D porous carbon assembled by nanosheets (HCAs) with tunable hierarchical porous structure is acquired from amphiphilic coal tar pitch and chitosan by means of a facile microphase separation strategy without any templates. The polar molecular chains of chitosan and the surrounding pitch molecules with strong π-π* bonds self-assemble respectively to form hierarchical pores and a network of nanosheets in a stepped pyrolysis process. Due to the combined effects of the meso-dominant porous structure, high specific surface area, and nitrogen-rich nature, the as-assembled symmetric all-solid-state supercapacitor with a wide voltage range of 0-1.8 V delivers a specific capacitance of 296 F g-1 at 0.2 A g-1 and an energy density of 27 Wh kg-1 at a power density of 450 W kg-1. The strategy of microphase separation is proposed originally to design and to fabricate carbon materials with multilevel nanoarchitectural trade-offs for high-performance supercapacitors.

Analysis of changes in population's cross-city travel patterns in the pre- and post-pandemic era: A case study of China.

The coronavirus disease (COVID-19) outbreak has immensely changed people's travel behaviour. The changes in travel behaviour have had a huge impact on different industries, such as consumption, entertainment, commerce, office, and education. This study investigates the impact of COVID-19 on population travel patterns from three aspects: total trips, travel recovery degree, and travel distance. The result indicates that COVID-19 has reduced the total number of cross-city trips and flexible non-work travel; in the post-pandemic era, cross-city travel is mainly short-distance (distance <100 km). This study has significant policymaking implications for governments in countries where the population shares a similar change in travel behaviour.

Strong coordination ability of sulfur with cobalt for facilitating scale-up synthesis of Co9S8 encapsulated S, N co-doped carbon as a trifunctional electrocatalyst for oxygen reduction reaction, oxygen and hydrogen evolution reaction.

High activity trifunctional non-noble electrocatalysts, targeting oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen evolution reaction (OER), are rationally designed by integrating the merits of both Co9S8 nanoparticles and carbons nanosheets. Herein, Co9S8 loaded with S, N co-doped carbon core-shell catalyst (Co9S8@SNC) was reasonably designed and synthesized by using the strong coordination effect between Co2+ and CS at the molecular level. The significant synergistic effect between the S, N co-doped carbon shell and Co9S8 core endows the catalyst with excellent catalytic performance for ORR, HER, and OER reactions. The carbon shell enhances the conductivity of the hybrid material, while the Co9S8 core provides the main catalytic active sites. More specifically, the half-wave potential for ORR is 0.846 mV, and the overpotential at 10 mA cm-2 for OER and HER are 320 mV and 170 mV, respectively. To test its practical application, zinc-air battery assembled by Co9S8@SNC shows a high power density of 239 mW cm-2, excellent rechargeability, and long cyclic stability. This work provides a promising and extensible method to in-situ synthesize core-shell metal sulfides loaded S, N co-doped carbon composites, which can be a promising candidate for electrocatalytic material in energy storage and conversion devices.

Rational Surface Tailoring Oxygen Functional Groups on Carbon Spheres for Capacitive Mechanistic Study.

Porous carbons represent a typical class of electrode materials for electric double-layer capacitors. However, less attention has been focused on the study of the capacitive mechanism of electrochemically active surface oxygen groups rooted in porous carbons. Herein, the degree and variety of oxygen surface groups of HNO3-modified samples (N-CS) are finely tailored by a mild hydrothermal oxidation (0.0-3.0 mol L-1), while the micro-meso-macroporous structures are efficiently preserved from the original sample. Thus, N-CS is a suitable carrier for separately discussing the contribution of oxygen functional groups to the electrochemical property. The optimized N-CS shows a high capacitance of 279.4 F g-1 at 1 A g-1, exceeding 52.8% of pristine carbon sphere (CS) (182.8 F g-1 at 1 A g-1) in KOH electrolyte. On further deconvoluting the redox peaks of cyclic voltammetry curves, we find that the pseudocapacitance not only associates with the surface-controlled faradic reaction at high scan rate but also dramatically stems from the diffusion-controlled capacitance through potassium and hydroxyl ion insertion/deinsertion into the underutilized micropores at low scan rate. The assembled supercapacitor based on N-CS presents a stable energy density of 5 Wh kg-1 over a wide range of power density of 250-5000 W kg-1, which is higher than 0.0N-CS in KOH electrolyte. In TEABF4 electrolyte, the N-CS supercapacitor has an energy density of 26.9 Wh kg-1 at the power density of 1350 W kg-1 and exhibits excellent cycling stability with a capacitance retention of 93.2% at 2 A g-1 after 10 000 cycles. These results demonstrate that surface oxygen groups alter the capacitive mechanism and contribution of porous carbons.

Facile synthesis of hierarchical mesopore-rich activated carbon with excellent capacitive performance.

Mesoporous carbons attract increasing attention owing to their potential applications in supercapacitors. So far, controlled synthesis of mesoporous carbons with a narrow pore size distribution relies largely on the complicated template methods. To avoid the use of templates, a surfactant-free emulsion polymerization method is presented for the fabrication of a melamine-modified phenolic resin microrod (MPRR) assembled by micron-sized spherical cells and thin walls. In addition, one-step KOH activation strategy is adopted to synthesize hierarchical mesoporous activated carbon with 2-10 nm narrow mesopores by using MPRR as carbon precursors. The as-prepared mesoporous activated carbon has a high specific surface area of about 2758 m2 g-1 and a mesopore volume of 0.54 cm3 g-1 (calculated by density functional theory), comprising ∼43.5% of total pore volume (∼1.43 cm3 g-1). Hierarchical mesopores can significantly accelerate ion transfer and increase micropore accessibility, which endow the carbon with high specific capacitance equal to 409 F g-1 at 0.1 A g-1 and 268 F g-1 at 100 A g-1 in 6 M KOH electrolyte, with a high capacitance retention of 66%. Moreover, the assembled symmetric supercapacitor also exhibits good cycling stability in KOH electrolyte and delivers high power density equal to 12080 W kg-1 when energy density is 5.02 Wh kg-1. This finding provides an insight into directional tailoring of mesoporous structures of phenolic resin-based carbon materials at the molecular level for high-performance supercapacitors.

Oxygen-rich hierarchically porous carbons derived from pitch-based oxidized spheres for boosting the supercapacitive performance.

Oxygen-rich hierarchically porous carbons are prepared by employing one-step KOH activation of pitch-based oxidized spheres (POS) as carbon precursors. The activation temperatures not only allow directed tailoring the porosity of carbon but also guarantee the preservation of moderate oxygen functional groups from POS, which are beneficial for efficiently integrating the electrical double layer capacitance and pseudocapacitance in one electrode. The as-prepared pitch-based activated carbons (PAC) possesses a high specific surface area of 2245 m2 g-1 with well-developed micropores, appropriate meso-macropores, and rich oxygen doping of 15.9 at%. Benefiting from the synergistic effect of hierarchical porosity and pseudocapacitive oxygen groups, PAC exhibit high specific capacitance of 427F g-1 and 302F g-1 at 0.5 A g-1 and 50 A g-1, respectively, as well as excellent capacitance retention of 71% in a three-electrode system with 6 M KOH electrolyte. Moreover, the as-assembled symmetrical supercapacitor displays a high energy of 5.79 Wh kg-1 at a power density of 9918 W kg-1 with excellent cycling stability with capacitance retention of 95% at 5 A g-1 after 10,000 cycles, which is higher than that of commercial Kuraray YP-50F. This finding demonstrates that one-step KOH activation coupled with oxygen-rich pitch may act as an optimal component to finely tailor the porosity and oxygen doping on activated carbons for energy storage applications.

Nitrogen and sulfur Co-doped microporous activated carbon macro-spheres for CO2 capture.

Millimeter-sized nitrogen and sulfur co-doped microporous activated carbon spheres (NSCSs) were first synthesized from poly(styrene-vinylimidazole-divinylbenzene) resin spheres through concentrated H2SO4 sulfonation, carbonization and KOH activation. Styrene (ST) and N-vinylimidazole (VIM) were carbon and nitrogen sources, while the sulfonic acid functional groups introduced by the simple concentrated sulfuric acid sulfonation worked simultaneously as cross-linking agent and sulfur source during the following thermal treatments. It was found that the surface chemistries, textural structures, and CO2 adsorption performances of the NSCSs were significantly affected by the addition of VIM. The NSCS-4-700 sample with a molar ratio of ST: VIM = 1: 0.75 showed the best CO2 uptake at different temperatures and pressures. An exhaustive adsorption evaluation indicated that CO2 sorption at low pressures originated from the synergistic effect of surface chemistry and micropores below 8.04 Å, while at the moderate pressure of 8.0 bar, CO2 uptake was dominated by the volume of micropores. The thermodynamics suggested the exothermic and orderly nature of the adsorption process, which was dominated by a physisorption mechanism. The high CO2 adsorption capacity, fast kinetic adsorption rate, and great regeneration stability of the nitrogen and sulfur co-doped activated carbon spheres indicated that the as-prepared carbon adsorbents were good candidates for large-scale CO2 capture.

Co3O4/MnO2/Hierarchically Porous Carbon as Superior Bifunctional Electrodes for Liquid and All-Solid-State Rechargeable Zinc-Air Batteries.

The design of efficient, durable, and affordable catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is very indispensable in liquid-type and flexible all-solid-state zinc-air batteries. Herein, we present a high-performance bifunctional catalyst with cobalt and manganese oxides supported on porous carbon (Co3O4/MnO2/PQ-7). The optimized Co3O4/MnO2/PQ-7 exhibited a comparable ORR performance with commercial Pt/C and a more superior OER performance than all of the other prepared catalysts, including commercial Pt/C. When applied to practical aqueous (6.0 M KOH) zinc-air batteries, the Co3O4/MnO2/porous carbon hybrid catalysts exhibited exceptional performance, such as a maximum discharge peak power density as high as 257 mW cm-2 and the most stable charge-discharge durability over 50 h with negligible deactivation to date. More importantly, a series of flexible all-solid-state zinc-air batteries can be fabricated by the Co3O4/MnO2/porous carbon with a layer-by-layer method. The optimal catalyst (Co3O4/MnO2/PQ-7) exhibited an excellent peak power density of 45 mW cm-2. The discharge potentials almost remained unchanged for 6 h at 5 mA cm-2 and possessed a long cycle life (2.5 h@5 mA cm-2). These results make the optimized Co3O4/MnO2/PQ-7 a promising cathode candidate for both liquid-type and flexible all-solid-state zinc-air batteries.

Self-Assembled 3D Graphene-Based Aerogel with Co3 O4 Nanoparticles as High-Performance Asymmetric Supercapacitor Electrode.

Using graphene oxide and a cobalt salt as precursor, a three-dimensional graphene aerogel with embedded Co3 O4 nanoparticles (3D Co3 O4 -RGO aerogel) is prepared by means of a solvothermal approach and subsequent freeze-drying and thermal reduction. The obtained 3D Co3 O4 -RGO aerogel has a high specific capacitance of 660 F g(-1) at 0.5 A g(-1) and a high rate capability of 65.1 % retention at 50 A g(-1) in a three-electrode system. Furthermore, the material is used as cathode to fabricate an asymmetric supercapacitor utilizing a hierarchical porous carbon (HPC) as anode and 6 M KOH aqueous solution as electrolyte. In a voltage range of 0.0 to 1.5 V, the device exhibits a high energy density of 40.65 Wh kg(-1) and a power density of 340 W kg(-1) and shows a high cycling stability (92.92 % capacitance retention after 2000 cycles). After charging for only 30 s, three CR2032 coin-type asymmetric supercapacitors in series can drive a light-emitting-diode (LED) bulb brightly for 30 min, which remains effective even after 1 h.

Synthesis of polybenzoxazine based nitrogen-rich porous carbons for carbon dioxide capture.

Nitrogen-rich porous carbons (NPCs) were synthesized from 1,5-dihydroxynaphthalene, urea, and formaldehyde based on benzoxazine chemistry by a soft-templating method with KOH chemical activation. They possess high surface areas of 856.8-1257.8 m(2) g(-1), a large pore volume of 0.15-0.65 cm(3) g(-1), tunable pore structure, high nitrogen content (5.21-5.32 wt%), and high char yields. The amount of the soft-templating agent F127 has multiple influences on the textural and chemical properties of the carbons, affecting the surface area and pore structure, impacting the compositions of nitrogen species and resulting in an improvement of the CO2 capture performance. At 1 bar, high CO2 uptake of 4.02 and 6.35 mmol g(-1) at 25 and 0 °C was achieved for the sample NPC-2 with a molar ratio of F127:urea = 0.010:1. This can be attributed to its well-developed micropore structure and abundant pyridinic nitrogen, pyrrolic nitrogen and pyridonic nitrogen functionalities. The sample NPC-2 also exhibits a remarkable selectivity for CO2/N2 separation and a fast adsorption/desorption rate and can be easily regenerated. This suggests that the polybenzoxazine-based NPCs are desirable for CO2 capture because of possessing a high micropore surface area, a large micropore volume, appropriate pore size distribution, and a large number of basic nitrogen functionalities.

Nitrogen-enriched hierarchically porous carbons prepared from polybenzoxazine for high-performance supercapacitors.

Nitrogen-enriched hierarchically porous carbons (HPCs) were synthesized from a novel nitrile-functionalized benzoxazine based on benzoxazine chemistry using a soft-templating method and a potassium hydroxide (KOH) chemical activation method and used as electrode materials for supercapacitors. The textural and chemical properties could be easily tuned by adding a soft template and changing the activation temperature. The introduction of the soft-templating agent (surfactant F127) resulted in the formation of mesopores, which facilitated fast ionic diffusion and reduced the internal resistance. The micropores of HPCs were extensively developed by KOH activation to provide large electrochemical double-layer capacitance. As the activation temperature increased from 600 to 800 °C, the specific surface area of nitrogen-enriched carbons increased dramatically, micropores were enlarged, and more meso/macropores were developed, but the nitrogen and oxygen content decreased, which affected the electrochemical performance. The sample HPC-800 activated at 800 °C possesses a high specific surface area (1555.4 m(2) g(-1)), high oxygen (10.61 wt %) and nitrogen (3.64 wt %) contents, a hierarchical pore structure, a high graphitization degree, and good electrical conductivity. It shows great pseudocapacitance and the largest specific capacitance of 641.6 F g(-1) at a current density of 1 A g(-1) in a 6 mol L(-1) KOH aqueous electrolyte when measured in a three-electrode system. Furthermore, the HPC-800 electrode exhibits excellent rate capability (443.0 F g(-1) remained at 40 A g(-1)) and good cycling stability (94.3% capacitance retention over 5000 cycles).

Disproportionation in Li-O2 batteries based on a large surface area carbon cathode.

In this paper we report on a kinetics study of the discharge process and its relationship to the charge overpotential in a Li-O2 cell for large surface area cathode material. The kinetics study reveals evidence for a first-order disproportionation reaction during discharge from an oxygen-rich Li2O2 component with superoxide-like character to a Li2O2 component. The oxygen-rich superoxide-like component has a much smaller potential during charge (3.2-3.5 V) than the Li2O2 component (∼4.2 V). The formation of the superoxide-like component is likely due to the porosity of the activated carbon used in the Li-O2 cell cathode that provides a good environment for growth during discharge. The discharge product containing these two components is characterized by toroids, which are assemblies of nanoparticles. The morphologic growth and decomposition process of the toroids during the reversible discharge/charge process was observed by scanning electron microscopy and is consistent with the presence of the two components in the discharge product. The results of this study provide new insight into how growth conditions control the nature of discharge product, which can be used to achieve improved performance in Li-O2 cell.

A linear comprehensive adsorption model of hydrogen on super activated carbon under supercritical conditions.

The adsorption isotherms of hydrogen on super activated carbon were measured systematically, covering a temperature range of 93-293 K at 20 K intervals and pressures up to 7 MPa. All the experimental data were linearized by adopting the coordinates ln ln(n) vs 1/(ln P). The results indicate that the adsorption limit (P(lim), n(lim)) exists virtually at high pressure and has a certain physical meaning. Based on the adsorption limit, further analyses were carried out by modeling the adsorption isotherms in the coordinates ln(n(lim)/n) vs ln(RT(ln(P(lim)/P) and a linear comprehensive adsorption model was proposed in the form n (lim)=n.exp(psi T+lambda/T-c/) (beta).[RT ln( P (lim)P )] (b) which can predict the adsorption isotherm of hydrogen on activated carbon in supercritical conditions.