One-dimensional (1D) nanostructured materials have been intensively investigated as building components in electrochemical energy storage 1 and solar energy conversion 2 devices because they provide short diffusion path lengths to ions and excitons, leading to high charge/discharge rates 1 and high solar energy conversion efficiency. 2 More recently, coaxial nanowires have attracted greater attention in this field due to their added synergic properties (e.g., high conductivity) 3a or functionalities (e.g., core/shell p-n junction) 3b,c arising from the combination of different materials. 3 Various materials such as semiconductor/semiconductor, metal/ metal oxide, and metal oxide/metal oxide, have been employed as core/shell in coaxial nanowires. 3 However, there have been few studies on the coaxial nanowires with transition metal oxide and conductive polymer, although both of them are important electroactive materials used in electrochemical energy storage. 4 The combination of these two materials at 1D nanostructures may exhibit excellent electrical, electrochemical, and mechanical properties for electrochemical energy storage. To date, only a few reports have been published on the synthesis of metal oxide/ conductive polymer with core/shell structures. 5 In all of these reports, a stepwise synthetic approach was adopted: metal oxide nanoparticles, 5a nanostrands, 5b or nanotubes 5c were first synthesized and subsequently coated chemically by conductive polymers as shells.In this paper, we introduce a simple one-step method to synthesize MnO 2 /poly(3,4-ethylenedioxythiophene) (PEDOT) coaxial nanowires by coelectrodeposition in a porous alumina template. 6 MnO 2 is one of the most popular electrochemical energy storage materials because of its high energy density, low cost, environmental friendliness, and natural abundance, 7 but it has poor conductivity. 4c PEDOT has merits of excellent conductivity, high stability, and mechanical flexibility, 8 but it provides low electrochemical energy density. Electrodeposition is used here because it is a simple yet versatile method in controlling structures and their composition by tuning applied potentials and electrolyte ingredients. 9 In this report, MnO 2 /PEDOT coaxial nanowires are found to be promising electrochemical energy storage materials. The core MnO 2 provides high energy storage capacity, while the highly conductive, porous, and flexible PEDOT shell facilitates the electron transport and ion diffusion into the core MnO 2 and protects it from structurally significant collapsing and breaking. These combined properties enable the coaxial nanowires to have very high specific capacitances at high current densities.Scheme 1 illustrates the growth of MnO 2 /PEDOT coaxial nanowires. Under a constant potential (typically 0.75 V vs Ag/ AgCl), Mn 2+ (10 mM manganese acetate) is converted to its higher oxidization state, which can readily undergo hydrolysis to yield MnO 2 . 7 Simultaneously, EDOT monomer (80 mM) is electropolymerized into PEDOT in the pores of t...

MnO2 nanoparticle enriched poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires are fabricated by simply soaking the PEDOT nanowires in potassium permanganate (KMnO4) solution. The structures of these MnO2 nanoparticle enriched PEDOT nanowires are characterized by SEM and TEM, which show that the MnO2 nanoparticles have uniform sizes and are finely dispersed in the PEDOT matrix. The chemical constituents and bonding of these composite nanowires are characterized by energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, and infrared spectroscopy, which indicate that the formation and dispersion of these MnO2 nanoparticles into the nanoscale pores of the PEDOT nanowires are most likely triggered by the reduction of KMnO4 via the redox exchange of permanganate ions with the functional group on PEDOT. Varying the concentrations of KMnO4 and the reaction time controls the loading amount and size of the MnO2 nanoparticles. Cyclic voltammetry and galvanostatic charge-discharge are used to characterize the electrochemical properties of these MnO2 nanoparticle loaded PEDOT nanowires. Due to their extremely high exposed surface area with nanosizes, the pristine MnO2 nanoparticles in these MnO2 nanoparticle enriched PEDOT nanowires show very high specific capacitance (410 F/g) as the supercapacitor electrode materials as well as high Li+ storage capacity (300 mAh/g) as cathode materials of Li ion battery, which boost the energy storage capacity of PEDOT nanowires to 4 times without causing excessive volume expansion in the polymer. The highly conductive and porous PEDOT matrix facilitates fast charge/discharge of the MnO2 nanoparticles and prevents them from agglomerating. These synergic properties enable the MnO2 nanoparticle enriched PEDOT nanowires to be promising electrode materials for supercapacitors and lithium ion batteries.

Leveraging nationally representative survey data on 443,680 respondents from January to March 2021, this study examines the temporal, spatial, and sociodemographic variations in COVID-19 vaccine hesitancy in the U.S. Findings reveal multidimensional determinants of vaccination intentions involving confidence, complacency, and circumspection factors. Using descriptive analyses and multilevel mixed-effects regression models, we find persistent partisan divide across states and significant racial disparities, with Blacks more likely to develop vaccine hesitancy due to confidence and circumspection than Whites. Vaccine hesitancy among Blacks declines dramatically across time but varies little across states, indicating new directions to effectively address inequalities in vaccination. Results also show nuanced gender differences, with women more likely to develop hesitancy due to circumspection and men more likely to have hesitancy due to complacency. Moreover, we find important intersection between race, gender, and education that calls for efforts to adequately address the concerns of the most vulnerable and disadvantaged groups.

A photochemical oxidation and ionic liquid ([Bmim]PF 6 ) extraction coupling technique was employed in deep desulphurization of light oil with the presence of photo oxidant H 2 O 2 . In this process, [Bmim]PF 6 was utilized to be the extractant and photochemical reaction medium to promote the oxidation of dibenzothiophene (DBT). The deep oxidative desulfurization, 99.5% removal rate of DBT from n-octane and 90.6% sulfur removal rate of actual light oil, was achieved under mild conditions of room temperature and atmospheric pressure. The ionic liquid [Bmim]PF 6 was recycled eight times with a slight decrease in desulfurization efficiency.

The effects of ice microphysics on rainfall and thermodynamic processes in the tropical deep convective regime are examined based on hourly zonal-mean data from a pair of two-dimensional cloud-resolving simulations: one simulation with ice clouds and the other without ice clouds. The model is integrated for 21 days with the imposed large-scale vertical velocity, zonal wind, and horizontal advections obtained from the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment. The experiment without ice clouds produces a larger amount of cloud water and a smaller surface rain rate than the experiment with ice clouds because of the exclusion of vapor deposition processes in the experiment without ice clouds. The experiment without ice clouds produces cold and moist states simply because it generates a smaller cloud heating rate and consumes a smaller amount of vapor than does the experiment with ice clouds.