202 research outputs found

    Scholars' data reuse behaviors in disciplinary context: A meta-synthesis study

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    Data reuse plays a pivotal role in science research in the data era. Given that the impact of discipline culture on data reuse is deeply rooted, we explore data reuse behaviors of the two groups of scholars with significantly different qualities, the nature science and the humanities and social science. Relying on the meta-synthesis and inductive coding approach, information about intentions, influence factors, data processing and using and data reuse barriers were extracted from 37 qualified articles and then analyzed. Results show: 1) informal channels perform a vital role in data reuse in both two communities; 2) there is a distinct correlation between data reuse and disciplinary context. 3) clear distinctions exist between two fields in data reuse barriers, disciplinary practice degrees and data reuse patterns. The results imply the urgency to establish data managers, link publications and data, and enhance data organization

    Photothermal catalysis: From fundamentals to practical applications

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    Photothermal catalysis is an innovative approach that integrates photochemical and thermocatalytic processes to enable an efficient use of full-spectrum sunlight in catalyzing various chemical reactions for energy conversion and environmental governance. This approach has demonstrated competitive performance and energy efficiency compared to conventional techniques, making it suitable for large-scale applications. In this review, we will comprehensively examine the fundamentals and classification of photothermal catalysis and discuss detailed design principles of various types of photothermal catalysts, focusing on enhancing solar light absorption, improving internal electric field for more energetic hot carriers (EHC) and localized thermal energy (LTE), interfacial engineering for robust and directed EHC transferring, and regulating EHC and LTE for continuous 24/7 operation. We will also report photothermal catalysis in a diverse range of chemical reactions. Moreover, we will introduce the latest technologies for synthesizing robust photothermal catalysts and advanced solar concentrators for pilot testing in the production of solar fuels at scale. Finally, the future opportunities and challenges of the promising but fledging field will be discussed, which is expected to transform conventional chemical industries into a clean and sustainable manner

    Persulfate Activation on Crystallographic Manganese Oxides: Mechanism of Singlet Oxygen Evolution for Nonradical Selective Degradation of Aqueous Contaminants

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    Minerals and transitional metal oxides of earth-abundant elements are desirable catalysts for in situ chemical oxidation in environmental remediation. However, catalytic activation of peroxydisulfate (PDS) by manganese oxides was barely investigated. In this study, one-dimension manganese dioxides (a- and ß-MnO2) were discovered as effective PDS activators among the diverse manganese oxides for selective degradation of organic contaminants. Compared with other chemical states and crystallographic structures of manganese oxide, ß-MnO2 nanorods exhibited the highest phenol degradation rate (0.044 min-1, 180 min) by activating PDS. A comprehensive study was conducted utilizing electron paramagnetic resonance, chemical probes, radical scavengers, and different solvents to identity the reactive oxygen species (ROS). Singlet oxygen (1O2) was unveiled to be the primary ROS, which was generated by direct oxidation or recombination of superoxide ions and radicals from a metastable manganese intermediate at neutral pH. The study dedicates to the first mechanistic study into PDS activation over manganese oxides and provides a novel catalytic system for selective removal of organic contaminants in wastewater

    Platinum single atoms anchored on ultra-thin carbon nitride nanosheets for photoreforming of glucose

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    Photoreforming of biomass is a fascinating process that harnesses renewable sunlight and biomass to produce hydrogen under ambient conditions, holding a significant promise for future energy sustainability. However, the main challenge lies in developing highly active and stable photocatalysts with high light harvesting efficiency. In this study, we adopted a simple yet effective approach that combines thermal exfoliation and photodeposition to anchor Pt single atoms onto ultra-thin g-C3N4 nanosheets (MCNN). The incorporation of Pt single atoms induced a distinct red-shift in the visible light region, augmenting the solar energy absorption capacity, while the enlarged surface area of g-C3N4 nanosheets improved the mass transfer. Moreover, the enhanced photoelectric properties further contributed to the superior performance of Pt-MCNN-3.0 % in the photoreforming of glucose for hydrogen evolution. Remarkably, Pt-MCNN-3.0 % demonstrated an impressive hydrogen generation rate, approximately 59 times higher than that of MCNN, after a 3 h visible-light irradiation, maintaining a satisfied photo-stability. This work addresses the critical need for design of efficient photocatalysts, bringing us one step closer to realizing the potential of biomass photoreforming as a sustainable and clean energy conversion technology

    Selective adsorption of rare earth ions from aqueous solution on metal-organic framework HKUST-1

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    Recovery of rare earth ions from wastewater holds an important strategy for the use of the precious resources. In this study, we found that a metal-organic framework (MOF), HKUST-1, exhibited a high affinity and selectivity towards adsorptive recovery of rare earth ions (Ce3+ and La3+) in aqueous solutions. The adsorbent showed a remarkable adsorption capacity of 234 mg/g and 203 mg/g for Ce3+ and La3+ at pH = 6, respectively. More importantly, its adsorption selectivity of the rare earth ions was about 87% against other metal ions. The adsorption isotherm, kinetics, and mechanism in the process were also investigated. The adsorption process can be better fit by the Freundlich model in isotherm and the pseudo-second-order model in kinetics. A plausible mechanism for the adsorption of metal ions on the HKUST-1 was proposed by considering ion exchange and the covalent bonding between the adsorbent and metal ions. The selectivity can be attributed to the different bonding abilities to metal ions

    Two−dimensional nanomaterials confined single atoms: New opportunities for environmental remediation

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    Two−dimensional (2D) supports confined single−atom catalysts (2D SACs) with unique geometric and electronic structures have been attractive candidates in different catalytic applications, such as energy conversion and storage, value−added chemical synthesis and environmental remediation. However, their environmental applications lack of a comprehensive summary and in−depth discussion. In this review, recent progresses in synthesis routes and advanced characterization techniques for 2D SACs are introduced, and a comprehensive discussion on their applications in environmental remediation is presented. Generally, 2D SACs can be effective in catalytic elimination of aqueous and gaseous pollutants via radical or non−radical routes and transformation of toxic pollutants into less poisonous species or highly value−added products, opening a new horizon for the contaminant treatment. In addition, in−depth reaction mechanisms and potential pathways are systematically discussed, and the relationship between the structure−performance is highlighted. Finally, several critical challenges within this field are presented, and possible directions for further explorations of 2D SACs in environmental remediation are suggested. Although the research of 2D SACs in the environmental application is still in its infancy, this review will provide a timely summary on the emerging field, and would stimulate tremendous interest for designing more attractive 2D SACs and promoting their wide applications

    Ultra-sustainable Fe 78 Si 9 B 13 metallic glass as a catalyst for activation of persulfate on methylene blue degradation under UV-Vis light

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    Stability and reusability are important characteristics of advanced catalysts for wastewater treatment. In this work, for the first time, sulfate radicals (SO4') with a high oxidative potential (Eo = 2.5-3.1 V) were successfully activated from persulfate by a Fe78Si9B13 metallic glass. This alloy exhibited a superior surface stability and reusability while activating persulfate as indicated by it being used for 30 times while maintaining an acceptable methylene blue (MB) degradation rate. The produced SiO2 layer on the ribbon surface expanded strongly from the fresh use to the 20th use, providing stable protection of the buried Fe. MB degradation and kinetic study revealed 100% of the dye degradation with a kinetic rate k = 0.640 within 20 min under rational parameter control. The dominant reactive species for dye molecule decomposition in the first 10 min of the reaction was hydroxyl radicals (OH,Eo = 2.7 V) and in the last 10 min was sulfate radicals (SO4'), respectively. Empirical operating variables for dye degradation in this work were under catalyst dosage 0.5 g/L, light irradiation 7.7 µW/cm2, and persulfate concentration 1.0 mmol/L. The amorphous Fe78Si9B13 alloy in this work will open a new gate for wastewater remediation. © 2016 The Author(s)

    An insight into metal organic framework derived N-doped graphene for the oxidative degradation of persistent contaminants: formation mechanism and generation of singlet oxygen from peroxymonosulfate

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    The synthesis of carbonaceous materials from a metal organic framework (MIL-100), organic linker and N-precursor was comprehensively investigated, and the structures of the products were characterized. It was found that simple pyrolysis of mixed MIL-100 (Fe)/dicyandiamide (DCDA) could produce nitrogen-doped graphene (N-graphene). The N-graphene showed excellent performances in peroxymonosulfate (PMS) activation, which were superior to those of counterparts of graphene, iron(ii, iii) oxide, manganese(iv) oxide and cobalt(ii, iii) oxide. With PMS activation, N-graphene exhibited efficient catalytic degradation of various organic pollutants such as phenol, 2,4,6-trichlorophenol (TCP), sulfachloropyridazine (SCP) and p-hydroxybenzoic acid (PHBA). Electron paramagnetic resonance (EPR) spectroscopy and radical quenching tests were employed to investigate the PMS activation and organic degradation processes. It was found that singlet oxygen (1O2) was mainly produced during the activation of PMS by N-graphene, and contributed to the catalytic oxidation instead of sulfate and/or hydroxyl radicals. These findings provide new insights into PMS activation by metal-free carbon catalysis
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