Halogen-free organophosphorus flame retardants have promising application prospects due to their excellent safety and environmental protection properties. A cobalt-coordinated cyclic phosphonitrile flame retardant (Co@CPA) was synthesized via a hydrothermal method using hexachlorocyclotriphosphonitrile (HCCP), 5-amino-tetrazolium (5-AT), and cobalt nitrate hexahydrate (Co(NO)2∙6HO) as starting materials. The structure was characterized using Fourier transform infrared (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA).
View Article and Find Full Text PDFThis study uses a data-driven approach to mine the distribution of personality traits among Chinese people in the Chinese social context. Based on the hypothesis of personality lexicology, word embedding technology was employed in machine learning to mine personality vocabulary from Tencent's word embedding database. More than 10,000 Chinese personality descriptors were extracted and analyzed using Gaussian Mixture Model Cluster and Hierarchical clustering analysis.
View Article and Find Full Text PDFThis research focuses on the development of a highly efficient electrocatalyst, CuO/NPC@CoO/NPC-10-7, for detecting glucose and ascorbic acid. In a 0.1 M NaOH solution, the modified electrode exhibits a sensitivity of 3314.
View Article and Find Full Text PDFTransition metal sulfides are widely regarded as the most promising electrode materials for supercapacitors. Herein, we utilized a straightforward electrodeposition method to prepare an iron-cobalt bimetallic sulfide nanosheet-assembled nanosphere on nickel foam (FeCoS/NF). The synergistic effect between bimetals and the unique three-dimensional structure significantly improved its capacitive performance.
View Article and Find Full Text PDFIn this paper, the sesame residue, a common biomass waste, was used as a precursor to synthesize N,O co-doped porous carbon materials via a simple pre-carbonization and KNOactivation two-step strategy. The apparent morphology and supercapacitor performance of the obtained materials can be regulated by changing the pre-carbonization temperature (0 °C, 300 °C and 600 °C). The consequences demonstrate that a large number of C-C and C-O bonds in sesame residue undergo cleavage and form abundant pore structure at the pre-carbonization temperature of 300 °C.
View Article and Find Full Text PDFUnlabelled: High-speed rail has been operating in more than 25 countries (mainly in Asia, Europe and North America), and has become an important part of global economic development. However, the cleaning and maintenance of high-speed rail is a comprehensive task, which may easily cause environmental pollution. This study aims to analyze and improve the sustainability of the formulation and production process of a concentrated complex enzyme detergent used as the maintenance agent for high-speed trains via the life cycle assessment (LCA) method.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2023
The recovery of rare earth elements (REEs) from discharged electronic devices or mineral waste water is highly essential but still facing challenges. In this work, two amino-functionalized carboxyl-UiO-66 (UiO-66-COOH-TETA and UiO-66-(COOH)-ED) prepared via the postmodification method were employed as the adsorbents for Yb(III) capture. The experimental results revealed their superior adsorption capacities of 161.
View Article and Find Full Text PDFThe removal of rare earth elements in mineral processing wastewater is highly desirable but still challenging. In this study, three bimetallic Prussian blue analogues (PBA) and six corresponding oxides are prepared by co-precipitation and calcination methods, and then utilized to adsorb aqueous Yb(III) solution. The results of XRD, SEM, BET, and XPS indicate the successful synthesis of all the adsorbents.
View Article and Find Full Text PDFThe COVID-19 outbreak brought online learning to the forefront of education. Scholars have conducted many studies on online learning during the pandemic, but only a few have performed quantitative comparative analyses of students' online learning behavior before and after the outbreak. We collected review data from China's massive open online course platform called icourse.
View Article and Find Full Text PDFHeteroatom-doped carbon materials used in supercapacitors are low in cost and demonstrate extraordinary performance. Here, ethylenediamine tetraacetic acid (EDTA) with intrinsic N and O elements is selected as a raw material for the preparation of heteroatom self-doped porous carbon. Furthermore, N/O self-doped porous carbon with a large surface area has been successfully prepared using KCO as the activator.
View Article and Find Full Text PDFFirst-row non-precious metal-based catalysts are widely studied and recognized as potential substitutes for precious metal-based catalysts in the oxygen evolution reaction (OER) for hydrogen generation but their application remains challenging. In this study, a unique class of Co-Fe selenide hollow nanospheres (CoSe@FeSe2) is well-designed through a facile hydrothermal method. The in situ formed hybrid composites possess numerous interfaces allowing partial electron transfer via O2- bridges to optimize the adsorption feature of the reaction intermediates, *OH, *O, and *OOH, on the catalysts.
View Article and Find Full Text PDFDevelopment of sustainable routes to synthesize precious metal supported catalysts is of great importance because of their wide applications in the catalysis field. This paper reported a controllable and recyclable cation-assisted reduction route to fabricate a palladium nanoparticle supported catalyst. At 323 K, highly dispersed Pd/AlO-CAR was prepared through introducing M (M = Mn, Zn or Cu) ions to promote the reduction of HPdCl in ethylene glycol-water solution, and the residual filtrate after preparation could be recycled to prepare Pd/AlO catalysts.
View Article and Find Full Text PDFDue to strong activity, it is very difficult to remove low concentrations of bromide in medical wastewater by traditional method, thus highly effective and greener adsorbents should be utilized to design. In this work, the cellulose beads (CBs) were modified by the TEMPO-mediated oxidation and then bonded with Fe to fabricate Fe(III)-complexed carboxylated cellulose beads (Fe-CCBs) adsorbents. Structure and properties of Fe-CCBs were analyzed using Energy dispersive spectrum (EDS), Scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), total acidity and basicity groups, X-ray diffraction (XRD), N adsorption-desorption and Thermogravimetric (TGA).
View Article and Find Full Text PDFIn this work, a novel material that was based on mesoporous carbon and ceria nanoparticles composite (MC⁻CeNPs) was synthesized, and a modified electrode was fabricated. When compared with a bare glass electrode, the modified electrode exhibited enhanced electrocatalytic activity towards the simultaneous determination of hydroquinone (HQ) and catechol (CC), which is attributed to the large specific area and fast electron transfer ability of MC⁻CeNPs. Additionally, it exhibited linear response ranges in the concentrations of 0.
View Article and Find Full Text PDFThe poor corrosion resistance of magnesium alloys is one of the main obstacles preventing their widespread usage. Due to the advantages of lower cost and simplicity in operation, chemical conversion coating has drawn considerable attention for its improvement of the corrosion resistance of magnesium alloys. In this study, a calcium phosphate coating was prepared on magnesium alloy AZ91D by chemical conversion.
View Article and Find Full Text PDFA route for the formation of carboxyl-introduced chitosan (CI-CS) with C amine groups protected (CIAP-CS) was investigated to improve copper (II) adsorption. First, the C amine groups of the chitosan (CS) were protected via a Schiff-base reaction by benzaldehyde. Then the product was obtained by the introduction of pyromellitic dianhydride to the C hydroxyl groups on CS via epichlorohydrin.
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