The electrosynthesis of syngas (H2 + CO) from CO2 and H2O can reduce greenhouse gas emissions and address the energy crisis. In the present work, silver (Ag) foam was employed as a catalytic ...electrode for the electrochemical reduction of CO2 in aqueous solution to design different syngas ratios (H2:CO). In addition to H2 and CO, a small amount of formic acid was found in the liquid phase. By contrast, the planar polycrystalline Ag yields CO, formic acid, methane and methanol as the carbon-containing products. During the potential-controlled electrolysis, the Ag foam displayed a relatively higher activity and selectivity in the electroreduction of aqueous CO2 to CO compared with its smooth surface counterpart, as evidenced by the lower onset potential, higher partial current density and Faradic efficiency at the same bias voltage. Moreover, the electrode remained stable after three successive cycles. Based on the characterization using X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, potential step determination and density functional theory calculations, superior performance was credited to the three-dimensional structure of Ag foam constructed with coral-like Ag particles, in which the numerous edge sites are beneficial for the stabilization of the surface adsorbed COOH species and the exposed {111} facets favor the desorption of adsorbed CO species.
Electrochemically activated peroxymonosulfate with mixed metal oxide electrodes (EA-PMS-MMO/MMO) is an emerging advanced oxidation process. It performed well on the degradation of sulfadiazine (SDZ), ...whose removal rate reached 81.13% within 30 min. Both the MMO anode and cathode played an irreplaceable role in PMS activation. HO•, SO4•-, O2•- and 1O2 were confirmed to be the major reactive species in the system, among which 1O2 was the most abundant. The generation mechanism of the reactive species and the overall mechanism of the system were proposed. Four degradation pathways of SDZ were speculated based on density functional theory. The acute and chronic toxicity of SDZ and its degradation intermediates was evaluated by the quantitative structure-activity relationship method, and the overall toxicity was significantly reduced after the degradation by EA-PMS-MMO/MMO. The results show that EA-PMS-MMO/MMO affords a reliable technology for the degradation of organic contaminants and has promising potential for application.
Display omitted
•Both the MMO anode and cathode play an irreplaceable role in the activation of PMS.•1O2 was the most abundant reactive specie among HO.•, SO4•-, O2•- and 1O2.•The degradation pathways of SDZ are speculated based on DFT and LC-MS detection.•The toxicity of SDZ can be significantly reduced after full oxidation by EA-PMS-MMO/MMO.
AbstractThe novel Fe-doped MoS2/granulated activated carbon (GAC) particle electrodes (FMG PEs) were controllably synthesized by a hydrothermal method and used in the three-dimensional (3D) ...electroactivation of peroxydisulfate (E-PDS-FMG) for carbamazepine (CBZ) degradation. The performance, mechanism, and influencing factors of CBZ degradation by the E-PDS-FMG system were systematically discussed. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) analyses showed that the E-PDS-FMG system has an excellent conductivity and a high electron transfer rate and exhibited a superior electrocatalytic performance for CBZ degradation. A CBZ removal rate greater than 99% can be achieved within 25 min under the conditions of FMG dosage of 0.4 g L−1, PDS concentration of 2.0 mM, current density of 1.0 mA cm−2, and initial pH value of 5. Sulfate radicals (SO4·−) and hydroxyl radicals (OH) were recognized as the major active species through quenching experiments and electron paramagnetic resonance (EPR) measurement. In addition, Fe (IV) was also involved in the E-PDS-FMG system according to the transformation of methyl phenyl sulfoxide (PMSO) to methyl phenyl sulfone (PMSO2). Furthermore, the possible mechanism of the E-PDS-FMG system was proposed. FMG PEs were applied as the catalyst and particle electrodes for PDS activation, improving the yield of OH, SO4·−, and Fe (IV). The increase of FMG dosage and PDS concentration accelerated the degradation of CBZ, and the E-PDS-FMG system exhibited a high degradation ability on CBZ removal in a wide pH range. The results all indicate that the E-PDS-FMG system is a promising technology for organic pollutant removal from water due to its excellent electrocatalytic performance and remarkable stability.
New Urbanism proposed a TND (traditional neighborhood development) model and a series of laws of form, to deal with this issue from the urban typology levels to face the suburbanization of America. ...Current Chinese urban environment is becoming more sophisticated, to deal with all kinds of urban problems by blindly applying New Urbanism law is impossible. This paper proposes a new unit of neighborhood paradigm based on the way of life under the Chinese context, trying to experience the type of development approach, from the topological level to deal with urban Chinese context.
Pd was electro-deposited on Ni foam using nitrogen-doped carbon as an inter-layer (EDPd/CNx/Ni). The as-prepared material was employed as the cathode for the electrochemical dechlorination of ...3,6-dichloropicolinic acid (3,6-D) in an aqueous solution. When compared to the electrodes that direct the electrodeposition or chemical deposition of Pd on Ni foam, EDPd/CNx/Ni exhibited higher activity and selectivity during the electrocatalytic hydrogenation of 3,6-D to form the intermediates 3-chloropicolinic acid and 6-chloropicolinic acid, as well as the final product, 2-picolinic acid. Furthermore, the modified electrode maintained its high dechlorinating activity after continuous operation for three batches. On the basis of physical-chemical characterization and electrochemical measurements, it is proposed that the superior performance of the EDPd/CNx/Ni electrode benefits sufficiently from the accelerated generation of adsorbed hydrogen (Hads). The electrodeposition method facilitates the generation of Pd with a higher percentage of exposed {111} facets. The CNx functions as an efficient support for the enlargement of the electrochemically active surface area, the reduction of Pd particle size, and improvement of the Pd dispersion. Moreover, CNx may also act as an electrocatalyst for the water-splitting reaction and favors the stabilization of chemisorbed active hydrogen.
Display omitted
•Pd was electro-deposited on Ni foam using nitrogen-doped carbon as an inter-layer.•CNx facilitated the electrochemical dechlorination of 3,6-dichloropicolinic acid.•Accelerated generation of adsorbed hydrogen.
Photoelectrocatalytic (PEC) water splitting provides an alternative to direct solar-to-fuel production. In this study, a novel heterostructure formed between a conjugated polymer ...poly-2,6-diaminopyridine (PDAP) and three-dimensional TiO2 microspheres was grown in situ on a Ti substrate (PDAP-3DTiO2MSs/Ti) and used as photoanode for water oxidation in alkaline media under AM 1.5G illumination. The PDAP-3DTiO2MSs/Ti can produce applied bias photon-to-current efficiency of 0.85% at 0.44 V vs. Pt and a photocurrent density of 1.56 mA cm−2 at 1.23 V vs. RHE. Moreover, PDAP-3DTiO2MSs/Ti displays impressive photoelectrochemical stability with 93% of its initial photocurrent being retained after 4 h of reaction. Based on physical-chemical characterization and photo-/electro-chemical measurements, the superior PEC water splitting performance of PDAP-3DTiO2MSs/Ti should benefit from the coexistence of Ti3+ and Ti4+ in 3DTiO2MSs, the light harvest capability of PDAP and the type II heterojunction formed between 3DTiO2MSs and PDAP, which result in the enhanced generation and separation of photocarriers.
Display omitted
•A novel heterostructure formed between PDAP and 3DTiO2 microspheres.•The photoanode achieved a high applied bias photon-to-current efficiency at low bias.•A photocurrent density of 1.56 mA cm−2 at 1.23 V vs. RHE under AM 1.5G.•Type II heterojunction and coexistence of Ti3+ and Ti4+ improved the PEC performance.
Neuroimaging research requires purpose-built analysis software, which is challenging to install and may produce different results across computing environments. The community-oriented, open-source ...Neurodesk platform ( https://www.neurodesk.org/ ) harnesses a comprehensive and growing suite of neuroimaging software containers. Neurodesk includes a browser-accessible virtual desktop, command-line interface and computational notebook compatibility, allowing for accessible, flexible, portable and fully reproducible neuroimaging analysis on personal workstations, high-performance computers and the cloud.
Although the prevalence of digital innovation has attracted increasing attention from policymakers, academics, and practitioners, it remains under-theorized. Using the attention-based view, we ...examine why and how government digital-initiative intensity drives a firm’s digital innovation. Using a mixed-methods approach and the unique context of China’s aspirant economy, we find that managerial digital attention mediates the link between government digital-initiative intensity and firm digital innovation. Firm political guanxi and digital leadership have moderating effects on the relationship between government digital-initiative intensity and managerial digital attention, and the relationship between managerial digital attention and firm digital innovation. These findings have important theoretical and practical implications.
•Government digital initiatives draw firm’s attention and then influence firm digital innovation.•Digital leadership is a key approach for firms to allocate digital attention and direct digital attention into concrete action.•Firm political guanxi with governments acts as a channel for firms to notice, and interpret government digital initiative.
PDF
