Effects of Manganese Doping into Nickel Hydroxides for the Electrochemical Conversion of KA Oil

Selective oxidative cleavage of C(OH)–C or C(O)–C bonds in cyclohexanol and cyclohexanone (KA oil) to produce adipic acid (AA), a monomer for the synthesis of nylon-66, is of significant importance for the petrochemical industry. Herein, we report an electrochemical method to improve the efficiency for upgrading KA oil into AA. Free-standing electrodes consisting of hydroxides (Ni(OH)2 and Mn-doped Ni(OH)2) supported by carbon paper were fabricated via an in situ electrodeposition process and further examined for KA oil conversion. The morphology and structures of the samples were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The electrochemical performance of the samples was studied by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. The products of KA oil oxidation were analyzed by high-performance liquid chromatography. The introduction of manganese into nickel hydroxides enhanced the catalytic performance in terms of activity and product selectivity. Specifically, the optimal sample exhibited a current density of 50 mA mg–1 and selectivity of 46.8%, which are superior to those of pure nickel hydroxides. Such enhancement was attributed to the electronic interaction of manganese with nickel hydroxides, thereby modifying the adsorption of the substrates. Interestingly, the introduction of Mn into nickel hydroxides had negligible effects in the oxygen evolution reaction. The effects of critical parameters including substrate composition, reaction temperatures, KOH concentrations, and electrolysis time on the conversion of KA oil were investigated

Sulfonated Graphene Nanosheets as a Superb Adsorbent for Various Environmental Pollutants in Water

Graphene nanosheets, as a novel nanoadsorbent, can be further modified to optimize the adsorption capability for various pollutants. To overcome the structural limits of graphene (aggregation) and graphene oxide (hydrophilic surface) in water, sulfonated graphene (GS) was prepared by diazotization reaction using sulfanilic acid. It was demonstrated that GS not only recovered a relatively complete sp²-hybridized plane with high affinity for aromatic pollutants but also had sulfonic acid groups and partial original oxygen-containing groups that powerfully attracted positively charged pollutants. The saturated adsorption capacities of GS were 400 mg/g for phenanthrene, 906 mg/g for methylene blue and 58 mg/g for Cd²⁺, which were much higher than the corresponding values for reduced graphene oxide and graphene oxide. GS as a graphene-based adsorbent exhibits fast adsorption kinetic rate and superior adsorption capacity toward various pollutants, which mainly thanks to the multiple adsorption sites in GS including the conjugate π region sites and the functional group sites. Moreover, the sulfonic acid groups endow GS with the good dispersibility and single or few nanosheets which guarantee the adsorption processes. It is great potential to expose the adsorption sites of graphene nanosheets for pollutants in water by regulating their microstructures, surface properties and water dispersion

Coupling Glycerol Conversion with Hydrogen Production Using Alloyed Electrocatalysts

Herein, uniform precious alloys including PtAg, PdAg, and PtPdAg nanoparticles were synthesized as electrocatalysts for glycerol oxidation reaction (GOR). The structures of the samples were characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectrometry. The catalytic performance of the samples was evaluated in both alkaline and acidic electrolytes. Among the samples, PtPdAg exhibited superior activity with the largest current density of 3.77 mA cm–2 in alkaline solutions, which is 4.1 and 7.7 times those of Pd/C and Pt/C, respectively. In acidic solutions, the PtPdAg catalyst shows the highest current density of 0.58 mA cm–2, which is 1.8 times that of the Pt/C catalyst. The products of GOR were analyzed by high-performance liquid chromatography. Eight products including oxalic acid, tartronic acid, glyoxylic acid, glyceric acid, glyceraldehyde (GLAD), glycolic acid, lactic acid, and dihydroxyacetone were detected. Notably, in acidic solutions, PtAg and PtPdAg yielded the largest GLAD selectivity of 92.2% at 0.6 and 0.8 V, respectively. Using the alloyed catalysts, electrolysis processes coupling the GOR with the hydrogen evolution reaction were conducted. The conversion of glycerol and production of hydrogen were determined. To highlight the energy efficiency, a solar-panel-powered electrolysis process was conducted for the simultaneous production of hydrogen and high-valued products

Creating optical centrifuge for rapid optical clearing and separation

Optical centrifuge has emerged as a promising tool for achieving centrifuge motion of particles in many fields. Herein, we report a novel optical centrifuge, as driven by optical lateral force arising from transverse phase gradient of light in holographic optical tweezers. It has remarkable advantages, including rapid speed, small footprint, flexible design and easy control. The optical clearing and sorting as application examples have been experimentally demonstrated by using Au and polystyrene nanoparticles. The results show that the optical centrifuge exhibits excellent performance, while used as optical clearing and optical sorting. For instance, its centrifuge velocity in optical clearing can reach its peak speed of 120 {\mu}m/s in a short time, which is highly desirable for optical manipulation of various particles in microfluidic systems. This study opens a way for realizing novel functions of optical manipulation including optical clearing and optical sorting

Electroorganic Synthesis Using a Fluoride Ion Mediator under Ultrasonic Irradiation:¹ Synthesis of Oxindole and 3-Oxotetrahydroisoquinoline Derivatives

Anodic intramolecular cyclization of α-(phenylthio)acetamides using a fluoride ion mediator was realized. Under ultrasonic irradiation, cyclization was accelerated markedly to give desired cyclized products in moderate to good yields. The local heating effect of ultrasonic irradiation seems to be more advantageous than usual heating

Scalable and Environmentally Friendly Synthesis of Hierarchical Magnetic Carbon Nanosheet Assemblies and Their Application in Water Treatment

Large-scale assembling of graphitic carbon nanosheets to a three-dimensional hierarchical structure is a great challenge. Herein we report a facile synthesis of hierarchical magnetic carbon nanosheet assemblies (MCNSAs) via an ambient-pressure chemical vapor deposition method. To explore the formation mechanism, the as-prepared MCNSAs as well as the intermediates of synthesis were extensively characterized. It was revealed that two different carbon deposition processes, i.e., the dissolution–precipitation process and graphitic defects triggered catalytic decomposition of methane, were involved in the formation of MCNSAs. The disclosed method is simple and environmentally friendly, which is favorable for large-scale production. The resulting MCNSAs possess large surface areas, bimodal pore structures, abundant defective sites, excellent chemical stability, and sufficient magnetism. Such features afford significant advantages for application in water cleaning. As a proof of concept, the sorption performance of MCNSAs is demonstrated by using Congo red and Pb²⁺ as model pollutants. The characteristics of the sorption process including kinetics, isotherms, recovery, regeneration, and recycling are investigated. The results indicate that the MCNSAs are a promising sorbent for water cleaning

Environmental Applications of Three-Dimensional Graphene-Based Macrostructures: Adsorption, Transformation, and Detection

Just as graphene triggered a new gold rush, three-dimensional graphene-based macrostructures (3D GBM) have been recognized as one of the most promising strategies for bottom-up nanotechnology and become one of the most active research fields during the last four years. In general, the basic structural features of 3D GBM, including its large surface area, which enhances the opportunity to contact pollutants, and its well-defined porous structure, which facilitates the diffusion of pollutant molecules into the 3D structure, enable 3D GBM to be an ideal material for pollutant management due to its excellent capabilities and easy recyclability. This review aims to describe the environmental applications and mechanisms of 3D GBM and provide perspective. Thus, the excellent performance of 3D GBM in environmental pollutant adsorption, transformation and detection are reviewed. Based on the structures and properties of 3D GBM, the removal mechanisms for dyes, oils, organic solvents, heavy metals, and gas pollutants are highlighted. We attempt to establish “structure–property–application” relationships for environmental pollution management using 3D GBM. Approaches involving tunable synthesis and decoration to regulate the micro-, meso-, and macro-structure and the active sites are also reviewed. The high selectivity, fast rate, convenient management, device applications and recycling utilization of 3D GBM are also emphasized

Additional file 1 of Multiomics data analyses to identify SLC25A17 as a novel biomarker to predict the prognosis and immune microenvironment in head and neck squamous cell carcinoma

Additional file 1. The clinicopathlogical characteristics of TCGA-HNSC cohort

The great start of the day is morning? the roles of diurnal variations and interaction modes for investment decisions in lending-based crowdfunding

Crowdfunding has empowered individual investors to make investment decisions anytime and anywhere. However, research exploring the time of day effect and the ensuing time–IT relationship in the crowdfunding context still lags. This study proposes a novel theoretical framework of diurnal variations in investment decisions. We collect and analyse data from a large lending-based crowdfunding platform in China. We find robust evidence that investors invest most in the morning, moderately in the afternoon, and least in the evening; they invest fastest in the afternoon, moderately in the morning, and slowest in the evening. Furthermore, the diurnal variations in terms of investment amounts and speed become more prominent in mobile-based interactions than in desktop-based interactions. Our findings contribute to the crowdfunding literature and provide managerial implications for crowdfunding platforms.</p

Electrolysis of Glycerol by Non-Noble Metal Hydroxides and Oxides

A series of free-standing electrodes consisting of hydroxides (Ni­(OH)2, Co­(OH), NiFeLDH, and CoFeLDH) and oxides (NiO, Co3O4, NiFe2O4, and CoFe2O4) supported by carbon paper were fabricated via an in situ hydrothermal process and further examined for glycerol conversion. The morphology and structures of the samples were characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The performance of the samples was studied by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. The products of glycerol oxidation were analyzed by high-performance liquid chromatography. Operando electrochemical Raman spectroscopy was employed to monitor the variations on the active sites and intermediates. Among the samples, the NiO exhibited superior activity with the largest current density of 0.8 mA cm–2 at 1.7 V and selectivity of 97% for formic acid. Furthermore, coupling the hydrogen evolution reaction with the glycerol electro-oxidation reaction (GOR), we explored the electrolysis of water and glycerol. The potential of the electrolysis process was negatively shifted from 1.68 to 1.28 V by replacing the oxygen evolution reaction with GOR. The strategy reported in this work could afford a sustainable approach to produce hydrogen and value-added chemicals with high energy efficiency