Synthesis and Properties of Magnetic Carbon Nanocages Particles for Dye Removal

Magnetic carbon nanocages (MCNCs) with multiform pore structure have been synthesized by a simple low temperature carbonization process. Biorenewable lignin was used as a cheap and carbon-rich precursor for the first time. The products were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, energy dispersive X-ray spectroscopy (EDS), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), and Raman spectrum. XRD pattern and Raman spectrum showed that the product has a high degree of graphitization crystallinity. TEM micrograph indicated that the synthesized MCNCs have the hierarchical pore and cage structure. Due to these characteristics, the obtained magnetic carbon nanocages can be used as efficient and recycled adsorbents in the removal of dye staff from textile wastewater

Inspired by the Seeking Knowledge Strategy for Analects of Confucius to Screen Highly Electrochemically Active Porous Carbon: The Critical Source of Electroactive Sites

In this work, the forestry wastes are converted into a series of porous carbons using H3PO4 activation. These porous carbons feature a large specific surface area (1045.20 m2 g−1) and porosity that combines micro‐, meso‐, and macropores in various amounts depending on the fuel properties recorded for precursors used. Importantly, the C content recorded for forestry waste is one of the crucial factors in defining the specific surface area of the derived porous carbons. In addition, the total capacitance of the pine‐sawdust‐based porous carbon (PS‐C) sample is the highest, such as 220.55 F g−1 upon 5 mV s−1. Notably, the electrical double‐layer capacitance recorded for the samples remains essentially constant with increasing scan rates, such as ≈91.50 F g−1 for the olive‐shell‐based porous carbon, ≈123.70 F g−1 for PS‐C, and ≈105.66 F g−1 for the pine‐needle‐based porous carbon. Encouragingly, the pore‐associated sp3 site holds significant roles in the electrochemical application of the porous carbons. More importantly, the O/C value recorded for the precursor can be employed as a universal predictor of electrochemically active sites produced in porous carbons. In the findings, crucial insights are exhibited into the optimized fabrication of porous carbon with target electrochemically active sites for other applications such as catalysis

Chemical synthesis of niobium diboride nanosheets by a solid-state reaction route

A new process was developed to synthesize niobium diboride (NbB₂) nanosheets with the dimension of about 500 nm and thickness of about 10 nm by using metal niobium, iodine and sodium borohydride as starting materials in an stainless steel autoclave at 700 °C. Iodine was used to facilitate the exothermic reaction between metal niobium and sodium borohydride and the formation of NbB₂. X-ray powder diffraction pattern indicated that the obtained product is hexagonal phase NbB₂ with the calculated lattice constants a = 110 Å and c = 3.2929 Å. The obtained product was also studied by thermogravimetric analysis. It had good oxidation resistance below 400 °C in air.Розроблено новий процес синтезу наношарів дибориду ніобію (NbB₂) розмірами ~ 500 нм і товщиною ~ 10 нм з використанням металічного ніобію, йоду і боргідриду натрію як вихідних матеріалів у автоклаві з нержавіючої сталі при 700 °С. Йод використовували для полегшення екзотермічної реакції між металічним ніобієм і боргідридом натрію для утворення наношарів NbB₂. Рентгенограма порошку показала, що отриманий продукт є гексагональною фазою NbB₂ з розрахованими константами решітки a = 110 Å і c = 3,2929 Å. Отриманий продукт також вивчали термогравіметричним аналізом. Він мав гарну стійкість до окиснення в повітрі за температури нижче 400 °C .Разработан новый процесс синтеза нанослоев диборида ниобия (NbB₂2) размерами ~ 500 нм и толщиной ~ 10 нм с использованием металлического ниобия, йода и боргидрида натрия в качестве исходных материалов в автоклаве из нержавеющей стали при 700 °C. Йод использовали для облегчения экзотермической реакции между боргидридом натрия и ниобием для получения нанослоев NbB₂. Рентгенограмма порошка показала, что полученный продукт представляет собой гексагональную фазу NbB₂ с рассчитанными постоянными решетки a = 110 Å и c = 3,2929 Å. Полученный продукт также изучали с помощью термогравиметрического анализа. Он имел хорошую стойкость к окислению на воздухе при температуре ниже 400 °C

Development of a Novel Terpolymer as a Green and Efficient Decalcifying Agent for Crude Petroleum

A novel environmental decalcifying agent was prepared with allylpolyethoxy amino carboxylate (APEAA), hydroxyethyl acrylate (HEA), and maleic anhydride (MA) by means of free-radical polymerization in an aqueous solution. The morphology and structure of the samples were characterized through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, and ¹H nuclear magnetic resonance (¹H NMR) spectra. The molecular-weight distribution of APEAA–HEA–MA was determined by the gel permeation chromatography method. APEAA–HEA–MA was used as a green decalcifying agent to remove calcium from crude petroleum, and the impact of factors such as monomer ratio, copolymerization time, dosages, and desalination temperature was analyzed. It is found that the decalcification rate of APEAA–HEA–MA could reach to its maximum, and the calcium removal efficiency was approximately 97.88% when the monomer molar ratio of APEAA–HEA–MA was 1:2:5, the reaction time of copolymerization was 2 h, the dosage was 100 ppm, and the desalination temperature was 100 °C. This research work can promote the exploration on facile synthesis of a novel terpolymer and its potential application in refinery desalting processes

Rare‐Earth Lanthanum Tailoring Mott–Schottky Heterojunction by Sulfur Vacancy Modification as a Bifunctional Electrocatalyst for Zinc–Air Battery

Zinc–air battery (ZAB) has considerable potential to be applied in the energy storage field. The main commercial electrocatalysts are Pt/C and RuO2, which are expensive and cannot possess good bifunctional electrocatalytic activities including oxygen reduction reaction and oxygen evolution reaction. Herein, the rare‐earth metal lanthanum is first constructed to be a Mott–Schottky heterojunction, and the S vacancy is introduced into the Mott–Schottky heterojunction. The so‐obtained La/La2O2S1−x shows excellent bifunctional electrocatalytic activity with ΔE of 0.68 V, which is superior to La/La2O2S without S vacancies and the commercial Pt/C + RuO2 system. In addition, the La/La2O2S1−x is assembled into ZABs, showing a high open power density of 212 mW cm−2, and a large specific capacity of 707 mAh g−1, as good cycle stability. The density functional theory calculations reveal the tailoring effect of S vacancy on the Schottky barrier to control the electron transfer concentration and ameliorate over‐strong adsorption, which blocks the reflux of electrons and promotes the unidirectional flow of electrons. In addition, the S vacancy modulates the electron cloud of La‐4f orbit and makes the electrocatalytic pathway closer to the ideal pathway

Influence of Molecular Weight on Structure and Catalytic Characteristics of Ordered Mesoporous Carbon Derived from Lignin

Bio-renewable lignin has been used as a carbon source for the preparation of porous carbon materials. Nevertheless, up to now, there are few studies about the influence of molecular weight of lignin on the structure and morphology of the ordered mesoporous carbon. Here, we synthesized the ordered mesoporous carbon derived from different molecular weights of lignin and Pluronic F127. Fortunately, we found that molecular weight is an important factor for obtaining highly ordered channels, high specific surface area, and ordered mesoporous carbon. More importantly, the narrow well-defined mesoporous channel could exert a spatial restriction effect to some extent, which can serve as nanoreactors for efficient reactions and enhance catalytic performance. The highly ordered mesoporous carbon from lignin is a good candidate for Fischer–Tropsch synthesis catalyst supports