Preparation and Electrochemical Characterization of Carbonaceous Thin Layer

Current research is largely focused on the preparation of carbon complexes for eventual applications in electrochemical energy storage systems. A carbonaceous thin layer (CT) was synthesized on a fluorine‐doped tin oxide (FTO) substrate by the carbonization of glucose. The morphological image from scanning electron microscopy showed the high uniformity of CT with full coverage on the FTO substrate. The carbon content increased from 40 % in glucose to 62 % in CT by the carbonization process. Furthermore, when CT was thermally treated under a constant flow of nitrogen gas (400 °C for 9 h, CT‐9), the carbon content increased from 62 to 79 %. The proficient interaction of CT on the FTO substrate was suitable for the electrochemical characterization and application. The CT on FTO was suitable to be used as a blocking layer for the electrochemical reaction. On the other hand, the CT‐9 showed completely different electrochemical behaviors. CT‐9 showed the significantly enhanced capacitive behavior resulted from the higher porosity of CT‐9, which was electrochemically interrogated by a redox reaction of FcMeOH/FcMeOH⁺.     

Facile synthesis of Montroseite VOOH, Paramontroseite VO2 and V2O3-VO2 carbonaceous core-shell microspheres

Hydrothermal carbonization of sucrose was used to controllably synthesize Montroseite VOOH and Paramontroseite VO₂ nanoparticles carbonaceous core-shell microspheres. After calcinations, V₂O₃-VO₂-C core-shell microspheres were obtained. When they were used as cathode materials in lithium-ion battery (LIB), it was found that Montroseite VOOH carbonaceous core-shell microspheres exhibited higher discharge capacity than Paramontroseite VO₂ counterpart, while the content of V₂O₃ had some large effects on the electrochemical properties of V₂O₃-VO₂C core-shell microspheres.     

Carbonized Hemoglobin Nanofibers for Enhanced H2O2 Detection

Electrospun hemoglobin (Hb) microbelts were used as a novel precursor to produce a new class of carbon nanofibers (Hb‐CNFs) containing Fe species (Fe₂O₃ and/or Fe‐N₄ moiety). The Hb‐CNFs modified glassy carbon electrode (Hb‐CNFs/GCE) exhibits significant oxidation/reduction towards H₂O₂. The observed H₂O₂ oxidation/reduction starting at ca. +0.26 V and +0.15 V (vs. Ag/AgCl) are significantly lower than the values observed at other CNFs modified GCE. The Hb‐CNFs/GCE was also applied to the amperometric detection of H₂O₂ and the results showed fast response, high sensitivity, excellent reproducibility, good selectivity, and wide dynamic range with good limit of detection.     

Treatment of colored effluent of the textile industry in Bangladesh using zinc chloride treated indigenous activated carbons

The adsorption of colored compounds from the textile dyeing effluents of Bangladesh on granulated activated carbons produced from indigenous vegetable sources by chemical activation with zinc chloride was studied. The most important parameters in chemical activation were found be the chemical ratio of ZnCl₂ to feed (3:1), carbonization temperature (450-465 °C) and activation time (80 min). The adsorbances at 511 nm (red effluent) and 615 nm (blue effluent) were used for color estimation. It is established that at optimum temperature (50 °C), time of contact (30-40 min) and adsorbent loading (2 g l⁻¹), activated carbons developed from Segun saw-dust and water hyacinth showed substantial capability to remove coloring materials from the effluents. It is observed that adsorption of reactive dyes by all sorts of activated carbons is higher than disperse dyes. It is explained that activated carbon, because of its acidic nature, can better adsorb reactive dye particles containing large number of nitrogen sites and -SO₃Na group in their structure. The use of carbons would be economical, as saw-dust and water hyacinth are waste products and abundant in Bangladesh.     

Catalytic ability of MgO to break CH bonds during slurry oil carbon deposition

Although MgO has been widely used for the MgO-templated synthesis of carbon materials, little attention has been paid to MgO’s catalytic function during carbon deposition. Here, a systematic analysis of the products of slurry oil (SO) carbonization with and without MgO templates present indicates that MgO catalytically promoted the breakage of CH bonds by immobilizing heavy oil molecules on MgO surfaces and the attractive interaction between hydrogen and MgO. Compared with the carbonization of SO alone, a notably higher H₂ concentration and a lower hydrocarbon concentration was observed in the tail gas, a higher solid yield and a lower degree of graphitization of the carbon product were observed when MgO was also present. Furthermore, treatment at 900 °C in the presence of MgO efficiently enhanced the capacitance and rate capability of the as-obtained porous carbon when tested as an electrode material for supercapacitors. These results suggest that the catalytic function of MgO could exist in all MgO-templated syntheses and in the heat treatment of porous carbons and graphene.     

制备生物炭的结构特征及炭化机理的XRD光谱分析

XRD光谱分析是研究物质内部结晶结构物质的重要手段。利用X射线技术分析了不同物料来源和制备方式对生物炭结晶结构特征及其炭化机理。结果表明：生物炭均含有d₁₀₁和d₀₀₂晶面衍射峰类石墨微晶纤维素炭,但炭化后析出的盐分随不同物料,差异较大,如牛粪、蓖麻粕以及糠醛渣的CaCO₃含量要高于其他生物炭,而仅牛粪与蓖麻粕含有CaMg(CO₃)₂。随温度升高,玉米秸秆炭中半纤维素优先分解,然后为纤维素石墨微晶化,结晶度提高,向更稳定的碳化合物转化。其中的矿物盐分随着炭化裂解温度升高,由稀土类氧化物→醋酸盐类物质→碳酸盐类物质逐步析出,CaCO₃的含量也随之增多。不同炭化方法的炭化机理不同,先干燥后炭化可促进半纤维素的分解,高温微波处理则是强烈震荡,主要促进物质多键断裂分解,碳酸盐类物质析出相对较少。通过X射线衍射分析可以很好研究生物炭内部结构结晶特征,可有效反映其炭化过程裂解机理。     

氧化铅@碳纳米复合材料的制备与表征

以淀粉为碳源, 高温碳化含有硝酸铅的淀粉干凝胶, 制备了氧化铅@碳纳米复合材料,氧化铅颗粒无团聚, 粒径可调, 近于单分散, 且分布均匀, 可作为铅酸电池的电极材料, 有望提高其充放电性能和使用寿命.     

MALDI-ToF investigation of furanic polymer foams before and after carbonization: Aromatic rearrangement and surviving furanic structures

A MALDI-ToF investigation of furanic foams before and after carbonization at 900 °C has been carried out. Comparison between MALDI-ToF spectra, before and after carbonization, shows how original building blocks of the network are modified, rearranged or survived during the process. Even if most of the constituents are transformed to more stable aromatic structures, some of the starting compounds resist intact the process of carbonization. The results appeared to indicate that some furanic oligomers are particularly stable and unaffected by carbonisation. The hypothesis that these may be cyclic furanic oligomers has been checked by molecular mechanics calculation of their relative energies.     

Microstructure and performance of carbonization products of component from soft coal pitch

Pitch is constituted of aromatic hydrocarbon, which is one kind of organic liquid with high viscosity. The soft coal pitch was divided into different group components by solvent extraction, and the different fractions of soft coal pitch were carbonized separately. The relationship between the microstructures of carbonization products and the chemical compositions of group components was investigated in this paper. Results show that the structure and morphology of the carbonization products from pitch were significantly influenced by the chemical composition of the group components. The main microstructure of the toluene soluble (TS) fraction-derived carbonization products is streamline and partial regional type. The microstructure of products from toluene insoluble (TI) fraction is mosaic and regional type. The structure of toluene insoluble-quinoline soluble (TI-QS) fraction-derived carbonization product is mainly streamline type. Nevertheless, the carbonization product from quinoline insoluble (QI) fraction is constituted with isotropy micron grade isotropic particles.     

Effect of different superficial treatments on structural,morphological and superficial area of Kraft lignin based charcoal

Lignin is a biomass derived from an abundant renewable source, rich in carbon and with potential application in modern society. The goal of this work is to add more value to lignin through its thermal conversion in charcoal, as well contribute to solutions linked to environmental preservation. Charcoal was obtained from Kraft lignin and its surface was modified using chemical (acid attack) and physical (microwave plasma) methods, in order to get charcoals different characteristics. In this work, the prepared charcoals were characterized by field emission gun - scanning electron microscope (FEG-SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and superficial area by BET analyses. Microscopic analyses evidenced morphological differences in the samples as consequence of the used superficial treatments. Raman spectroscopy results point to an increase in the carbon material disorder after chemical and physical treatments. The acid attack of charcoal increased its superficial area by 40% (403 m²/g) in relation to the charcoal without chemical treatment (287 m²/g). Physical treatment based on microwave plasma promoted a further increase in superficial area of 63% (468 m²/g). FT-IR showed that chemically treated charcoals presented more functional groups. Based on these results, it can be verified that the production of activated charcoal from lignin is viable and its superficial area can be increased using acid and plasma treatments, the latter being a more efficient and clean method.