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A series of coal-based hierarchical porous carbons with adjustable pores were successfully prepared with the assistance of the soluble salt Zinc chloride (ZnCl2). During the carbonization process, ZnCl2, with a low melting point (238 °C), “in situ occupied” and “occupied” within the coal solids to generate interconnected pores, which acted as a template. Simultaneously, the activation of ZnCl2 reduced the oxygen content of products and further improves their electrical conductivity. Optimization of the mass of the salt and the carbonization temperature resulted in targeted product with a suitable specific surface area (1581 m2 g−1) and unique pores (Vmeso/Vtotal = 45%), which exhibited a high specific capacitance (470.7 F g−1 at 0.5 A g−1) in 6 M KOH electrolyte. The symmetrical supercapacitor of targeted product has favorable rate performance (256.7 F g−1 at 0.5 A g−1, 84.8% capacity retention at 30 A g−1) and excellent cycling performance (after 10000 cycles, the specific capacitance increases to 115% of the initial capacity at 10 A g−1). In the EMIMBF4 electrolyte system, the energy density is 95.31 Wh kg−1 at 213.13 W kg−1. Therefore, this work provides an effective method to improve the green and efficient use of coal.

In this paper, we have proposed different deployment strategies and have applied area-wise clustering along with modified Ant Colony Optimization to minimize energy consumption. Background: Previously, some deployment strategies were used to enhance the lifetime of WSN. In our research, we have applied some novel deployment strategies like random, spiral, and S-pattern along with a novel area-wise clustering process to get better results than the existing literature, as shown in Table 4. Objective: The main objective of the research article is to enhance the lifetime of Wireless Sensor Network with the help of different deployment strategies like random, spiral, and S-pattern). A novel clustering process (i.e., area-wise clustering), and a Meta-heuristic algorithm (modified ACO) are applied. Methods: We have applied different methods for deployment strategies (random, spiral, and S-pattern). A novel clustering process (i.e., area-wise clustering), and a Meta-heuristic algorithm (modified ACO) are applied to get the desired results. Results: Random Deployment: 11.15 days to 15.09 days. Spiral Deployment: 11.25 days to 15.23 days. S-Pattern Deployment: 11.33 days to 15.33 days. Conclusion: In this paper, efficient Wireless Sensor Networks have been configured considering energy minimization as the prime concern. To minimize the energy consumption, a modified ACO algorithm has been proposed. In our work, the minimization of energy consumption leads to an increment of the lifetime of WSN to a significant margin theoretically. The obtained result has been compared with the existing literature and it has been found that the proposed algorithm produced a better result than the existing literature.

Lignite resource is abundant in China. Its high moisture and high self-ignition tendency have limited its utilization as a fuel. Preparing humic acids is considered to be an economic choice for the...

Carbon quantum dots (CQDs) modified semiconductor photocatalysts for visible light photodegradation of organic contaminant has attracted increasing attention, but the tedious preparation procedure of CQDs hinders their large-scale application. Coal tar pitch (CTP) is a rich by-product isolated from the coke industry. The molecule of CTP consists of polycyclic aromatic hydrocarbon nucleus and alkyl side chains or heteroatom functional groups attached to the edge of the nucleus, which is similar in structure to CQDs and should be considered as natural CQDs. Based on this perception, we first propose the use of CTP as a natural alternative for CQDs, and prepare effective CTP/TiO2 composite photocatalysts by a simple green one-step solvothermal method. With Rhodamine B (RhB) as target pollutant, the as-prepared CTP/TiO2 composite photocatalysts have higher photocatalytic activity than pure TiO2 under visible light irradiation. The apparent degradation rate constant of the CTP/TiO2 composite photocatalyst with optimum CTP content is 23 times higher than that of pure TiO2. The main active species involved in the photocatalytic degradation of RhB are holes (h+) and hydroxyl radicals (·OH). The usage of cheap raw materials and facile synthesis method paves the way for the large-scale preparation of effective CTP/TiO2 composite photocatalysts.

A green and cost-effective strategy was developed to synthesize porous graphitic carbons from coal tar pitch using commercially available CaCO3 nanoparticles as template without any further activation. The prepared porous graphitic carbons have well-developed hierarchical porous structure with moderate specific surface area (∼236.3 m2 g−1) and large pore volume (∼2.871 cm3 g−1), cross-linked carbon skeleton with relatively high levels of graphitic feature and enriched in oxygen/nitrogen-containing functional groups. Such unique microstructure characteristics of porous graphitic carbons not only can endow sufficient available space or active sites for Li-ions storage, but also can provide favorable and efficient channels for the Li-ions/electrons transportation. The prepared porous graphitic carbon PGC-3 applied as anode for lithium-ion batteries (LIBs) shows a large reversible capacity of 707 mAh g−1 at 0.05 A g−1, and presents a superior rate capability with high reversible capacities of 299 mAh g−1 and 248 mAh g−1 even at the extremely high current densities of 3 A g−1 and 5 A g−1, respectively. Moreover, such porous graphitic carbon also exhibits an outstanding long-term electrochemical stability and excellent cycling performance with over 93.5% capacity retention after 1000 cycles. This study paves a promising and universal way for large-scale production of porous graphitic carbons porous from coal tar pitch for high performance anode materials used in LIBs.

The effects of an industrial sludge (IS) on three high ash-fusion-temperature (AFT) coals (Jincheng coal (JC), Fuxing coal (FX) and Jiaozuo coal (JZ)) were investigated by an AFT detector, X-ray diffraction (XRD) analyzer, and thermo-physical modeling software. The results showed that IS could reduce the AFTs of three high AFT coals. The effect of IS on the AFTs of JC and JZ coals was clearly different from its effect on FX coal. When adding 18% IS ash to three coal ashes, the flow temperatures (FTs) of JC-IS and JZ-IS mixtures were reduced to below 1380 °C, which met the requirement of entrained-flow bed gasification, and the FT of FX-IS mixture was still higher than 1380 °C. After adding iron-rich IS ash (Fe2O3 > 41%) into three coal ashes, under reducing atmosphere, the Fe3+ was converted into Fe2+, the interactions of Fe2+ and Al2O3 led to the formation of a large amount of low melting-point (MP) hercynite (FeAl2O4). And some CaO could easily react with Al2O3 and SiO2 in the mixed ashes to produce anorthite (CaAl2Si2O8), restraining the formation of high MP mullite, which decreased the AFTs of these three mixtures. At 1100 °C, no mullite was detected in JC-IS and JZ-IS mixed ashes, and some mullite still existed in FX-IS mixed ash when the IS ash mass ratio even reached 30%, which might be the main reason for the decrease in the AFTs of JC and JZ was different from that of FX.

Here, we present a facile and green route to cleanly and efficiently utilize low-rank lignite to produce carbon quantum dots (CQDs) in high yields and in situ synthesize CQDs/TiO2 heterostructure nanocomposites. Unlike other CQDs, the lignite-derived CQDs exhibit obvious concentration-dependent red-shifted absorption, unusual aggregation-induced different color emissions and strong orange-red solid-state fluorescence. Through the optimization of the CQD loading proportion, the 2 wt% CQDs/TiO2 shows the optimal photocatalytic performance under visible light. We highlight the CQDs/TiO2 heterostructure nanocomposites by focusing on their dynamic photoinduced charge transfer properties triggered by the heterostructure interface and their application as a photocatalyst under visible light. Our detailed work about the transfer behavior of photoinduced charges in coal-derived carbon quantum dot/TiO2 heterostructure nanocomposites may shed light on the intrinsic reasons for CQD/semiconductor enhanced photocatalytic activity.

Herein, we report a facile strategy for microstructure modification of B–N co-doped porous carbons induced by nickel salts. Nickel chloride mainly plays a pore-forming role in the formation of resultant BNHC-L, leading to a high surface area (SSA) of 1000 m2 g−1, and favors high-level heteroatom doping and enhancement of graphitization degree simultaneously. Contrastively, nickel acetate facilitates the generation of Ni–B–N multi-doping porous carbon (BNHC-Y) but seriously hinders the fabrication of nanopores. BNHC-L exhibits superior specific capacitance of 342 F g−1 at 0.5 A g−1 in the three-electrode system due to higher SSA and heteroatom content, and enhanced electrical conductivity than BNHC-Y. BNHC-Y shows better rate performance with a capacitance retention of 60.4% from 0.5 to 100 A g−1 based on its higher mesopore ratio and better wettability than BNHC-L. Notably, as supercapacitor electrode with commercial-level mass loading (~180 µm, ~13 mg cm−2), BNHC-L2Y2 prepared with the dual nickel salts can deliver a high specific capacitance of 245 F g−1 at 0.05 A g−1, superior capacitance retention of 86.1% at 5 A g−1, and excellent cycling stability (94.8% of its initial specific capacitance after 10,000 cycles) because of its considerable SSA, optimal PSD, suitable surface chemistry and enhanced electrical conductivity.

Background: As an emerging carbon nanomaterial, Graphene Quantum Dots (GQDs) have shown great potential application in new energy storage devices due to their unique small size effect and abundant edge active sites. This work introduces the main synthesis strategies of GQDs, which include top-down and bottom-up methods; the application examples of GQDs and GQDsbased composites in energy storage are reviewed, moreover, the unique advantages of GQDs in supercapacitors, Lithium-Ion Batteries (LIBs) and Lithium-sulfur batteries (Li–S batteries) are highlighted. The problems and development prospects in this growing area are also discussed. Methods: We conducted a detailed search of “the application of GQDs in energy storage devices” in the published papers and the public patents based on the Web of Science database in the period from 2014 to 2020. The corresponding literature was carefully evaluated and analyzed. Results: Sixty papers and twenty-eight recent patents were included in this mini-review. The significant advances in recent years are summarized with comparative and balanced discussion. Thanks to the unique properties of large specific surface area, high conductivity and abundant active sites, GQDs have unparalleled potential application for new energy storage, especially improving the specific capacity and cycle stability of supercapacitors, LIBs and Li-S batteries. Conclusion: The findings of this mini-review confirm the importance of GQDs, show the enhanced electrochemical performance in supercapacitors, LIBs and Li-S batteries, and also provide a helpful guide to design and fabricate high-efficiency electrode materials.

Graphene quantum dots (GQDs) hybrid compositions have aroused wide attention with regard to their application in energy storage; however, complex procedures for their separation, purification and functionalization hinder their practical application. The present study put forward a facile and environmentally friendly coprecipitation approach to prepare Fe3O4@CTP QDs composites using coal tar pitch (CTP) as “natural GQDs” for the first time. When used as anode in lithium ion batteries (LIBs), the Fe3O4@CTP QDs-2 composite demonstrates high reversible capacity of 810 mAh g−1 over 200 cycles at the current density of 100 mA g−1. Moreover, at a high current density of 2000 mA g−1, the reversible capacity reaches 547 mAh g−1, which is 6 times that of pure Fe3O4 (91 mAh g−1). The marked ameliorated electrochemical performance is attributed to the fact that the successful coupling between Fe3O4 and CTP QDs can not only improves the overall conductivity but also effectively help preserving the structural integrity during cycling. This facile method does not require any cost precursor, harsh reagents, and complicated synthesis processes and can be developed into an eco-friendly way to large-scale production of CTP QDs hybrid materials for applications in energy storage.

Adopting an impregnation strategy, the homogeneous and efficient pore-creating are simultaneously achieved by one-pot KOH activation making full use of the swelling feature of hydrophilic soybean protein gels in alkaline solution. N, O co-doped porous carbons (NOPCs) have been fabricated using soybean meal as carbon, nitrogen and oxygen sources for an abundance of protein with a smaller amount of corrosive KOH. The as-obtained NOPCs exhibit advantageous characteristics for electrochemical energy storage including unique honeycomb-like morphology with interconnected carbon frameworks, high specific surface area, hierarchical porosity and controllable surface chemistry, which provides a large number of favorable nanochannels with suitable surface property for fast electrolyte diffusion and efficient electron transfer in the carbon networks. When tested as supercapacitor electrodes with symmetric configuration in 3 M KOH electrolyte, the NOPC-700 electrode prepared at 700 °C with a KOH/soybean meal mass ratio of 0.25 presents a high specific capacitance (330 F g−1 at 0.5 A g−1), remarkable cycling stability (94.6% capacitance retention after 10000 cycles at 2.5 A g−1), and superior rate capability (270 F g−1 at 5 A g−1). Furthermore, the NOPC-700//NOPC-700 supercapacitor delivers a maximum energy density of 8.4 Wh kg−1. The coordination between protein-rich soybean meal and one-pot KOH activation plays an important role in efficiently synthesizing porous carbons with robust energy storage performance for supercapacitors.

The hierarchical porous carbon/MnO composites were prepared from the homogenous mixture of potassium humate and manganese nitrate via one-step carbonization at 700 °C. Manganese nitrate in precursors has a synergistic catalysis effect with potassium element on the pore forming, also leads to an increased oxygen content of as-prepared composite. The PH-Mn-0.1 displays a hierarchical porosity with a moderate surface area of 776 m2 g−1 and total pore volume of 0.487 cm3 g−1, and MnO nanoparticles were uniformly deposited on the porous carbon matrix with a Mn content of 6.7 wt%. When used as electrode material for two-electrode symmetric supercapacitor, the PH-Mn-0.1 delivers higher volumetric capacitance of 276 F cm−3 at a current density of 50 mA g−1, consisting of pseudocapacitance related to MnO nanoparticles and electric double layer capacitance, a maximum energy density of 7.45 Wh kg−1 and low electrochemical resistance. Moreover, the PH-Mn-0.1 shows an enhanced rate capability due to its improved wettability, and novel cycle performance with an increasing specific capacitance during the 1000 charge–discharge cycles at 2500 mA g−1.

An earth-abundant and low cost bituminous coal was used as precursor to prepare synthetic graphite materials through preliminary carbonization coupled with further high temperature graphitization treatment at 2000–2800 °C. The microstructure characteristics of the obtained synthetic graphite materials were characterized by means of X-ray diffraction, scanning electron microscope, transmission electron microscope, Raman spectroscopy and nitrogen adsorption–desorption. The results show that the microstructures of synthetic graphite materials are strongly dependent on the graphitization temperature. The synthetic graphite graphitized at 2800 °C has perfect ordered layered structure with high graphitization degree and relatively large surface area with well-developed mesopores, which offers a favorable pathway for the electrochemical intercalation-deintercalation of lithium ions in carbon matrix. Such synthetic graphite applied as anode materials for lithium-ion batteries presents a maximum reversible capacity of 310.3 mAh·g − 1 at current rate of 0.1C and still remains as high as 143.9 mAh·g − 1 at current rate of 5C. Moreover, the synthetic graphite also exhibits superior rate capability and outstanding cycling performance with over 95.3% initial capacity retention after 100 cycles. This study demonstrates a promising feasibility for large-scale production of synthetic graphite materials from bituminous coal for high performance lithium-ion batteries.

Carbon quantum dots (CQDs) have demonstrated tremendous potential in enhancing the photocatalytic performance of TiO2; however, the fabrication of CQDs/TiO2 composite photocatalysts typically involves harsh reagents/conditions, cumbersome purification procedures and external energy supplies. In this work, we present a facile and energy-efficient impregnation method for the preparation of effective CQDs/TiO2 composite photocatalysts at room temperature employing coal tar pitch (CTP) as “natural CQDs”. The characterization results indicate that TiO2 and CQDs can be successfully coupled together by forming Ti‒O‒C bonds. The fabricated CQDs/TiO2 composites show remarkably improved photodegradation performances of rhodamine B (RhB) under visible-light irradiation, which are far higher than pure TiO2. At the optimum CQDs content (6 wt%), the degradation rate constant is 43.7-fold higher than that of pure TiO2. The marked ameliorated photocatalytic performance is attributed to the fact that the successful coupling between TiO2 and CQDs can ameliorate the absorption ability of visible light, accelerate the separation/transfer of charge carriers and restrain the recombination of photogenerated electron–hole (e−–h+) pairs. This research provides a facile method for large-scale preparation of CQDs modified semiconductor photocatalysts that can potentially be used in environmental and energy applications.

The influences of two red mud (RM) samples (ZZ and ZM) on fusion behaviors of three high ash fusion temperature (AFT) coals (FZ, JC and JZ) were investigated. It was evaluated by determining AFTs of coals, RMs, and the mixtures of coal ash with RM, as well as their compositions of ashes and mineral. The results showed that the contents of CaO, Fe2O3, and Na2O in RMs were higher than those in coal ashes, which caused RMs’ AFTs lower than those of coals. The formation of high melting-point mullite might be the main factor causing coal AFTs higher. With the increase in RM mass ratio, the increasing amount of low-melting eutectic (anorthite (CaAl2Si2O8), fayalite (Fe2SiO4), and anorthite (Na-rich) (Ca,Na)(Si,Al)4O8)) and amorphous matter made AFTs lower. ZZ reduced AFTs obviously than ZM because the content of Na2O in ZZ was higher than that in ZM. Owing to lower ion potential of Na+ than those of Ca2+ and Fe2+, Na+ is easier to enter into the lattice of mullite and results in the reduction of AFTs.

A novel grafting-template method is proposed to prepare three-dimensional hierarchical porous carbons (MGSExKy) simultaneously possessing high surface area (~3000 m2 g−1) and electrical conductivity (~1200 S m−1). The ethylenediamine is chemically grafted into calcium lignosulfonate precursor with the presence of KOH under hydrothermal condition, subsequently being removed to generate abundant nanopores in MGSExKy. Meanwhile, increased C/O atom ratio and graphitization degree are achieved. The mesopore/micropore volume ratio of MGSExKy can be regulated by varying the dosages of ethylenediamine and KOH. Consequently, MGSE1K0.5 yields a large specific capacitance of 250 F g−1 at 0.25 A g−1 and excellent rate capability (198 F g−1 at 50 A g−1) in a two-electrode system using 3 M KOH as electrolyte. The symmetric supercapacitor based on MGSE1K0.5 electrodes delivers high energy densities of 48.3 W h kg−1 and 28.7 W h kg−1 at the power densities of 395.0 W kg−1 and 10.3 kW kg−1 in 1 M (C2H5)4NBF4/PC electrolyte, respectively. More importantly, a remarkable energy density of 101.4 W h kg−1 at 457.3 W kg−1 can be harvested for the symmetric supercapacitor based on MGSE1K0.5 electrodes in ion liquid electrolyte, retaining an impressive value of 38.4 W h kg−1 at an ultrahigh power density of 14.9 kW kg−1.

Porous graphitic carbon nanosheets (MNC-x) with well-developed porosity and appropriate heteroatom doping are prepared by directly carbonizing sodium lignosulfonate in inert atmosphere. Interestingly, MNC-900 prepared at 900 °C shows sharp increases in specific surface area, carbon to oxygen atom ratio, graphitization degree and electrical conductivity compared with MNC-800 prepared at 800 °C, which are mainly attributed to the quinonyl decomposition accompanied by formation of graphitic carbons. The high oxygen content (20.1 at. %) and mesopore ratio (71.0%) of MNC-800, large specific surface area (1400 cm3 g−1) and superior conductivity (2208 S m−1) of MNC-900 make them suitable for supercapacitor electrodes in aqueous and organic electrolytes, respectively. Specifically, MNC-800 electrode shows large specific capacitance (196 F g−1 at 0.25 A g−1), superior rate capability (170 F g−1 at 20 A g−1) and outstanding cycling stability (96% capacitance retention after 10,000 cycles) in symmetrical supercapacitor using 3 M KOH electrolyte. For MNC-900 based symmetrical supercapacitor with 1 M (C2H5)4NBF4/PC electrolyte, an impressive energy density of 30.2 Wh kg−1 at a power density of 309.8 W kg−1 is achieved, which remains 15.2 Wh kg−1 even at 9.9 kW kg−1.

Reduced graphite oxide material (RGOM) has been prepared from potassium humate via a straightforward carbonization process at 700 °C for an hour. Potassium humate consists of a skeleton of alkyl/aromatic units cross-linked by a wide variety of oxygen-containing functional groups, and is considered as functionalized graphene platelets. The as-prepared RGOM possesses a specific surface area of 463 m 2 g −1 and typical layered structure with a carbon/oxygen atomic ratio of 6.3, similar to the reduced graphite oxide (RGO) reported in literatures. The RGOM based electrode delivers high volumetric capacitance of 144 F cm −3 at a current density of 0.05 A g −1 , as well as novel cycle performance. Its volumetric capacitance increases gradually during repeated galvanostatic charge-discharge (GC) in 3 M KOH electrolyte, and reaches to be (∼150% of the initial cycle) after 2000 cycles at a high current density of 2.5 A g −1 . The novel cycle performance is mainly attributed to the intercalation of OH − and K + into the interlayer of RGOM during charge-discharge process, and the increase of the available surface area for charge storage.

Highly efficient nanocomposite with low-cost is greatly desired in dye-contaminated wastewater in recent years. Herein, a facile and cost-effective strategy was developed to synthesize TiO2/coal-based graphene aerogel (TCGA) through mild hydrothermal reduction coupled with freeze-drying using graphene oxide from graphitized bituminous coal as precursor. The obtained TCGAs have well-developed three-dimensional (3D) porous structure with high mechanical strength and ultra-low density, and contain uniform distribution of anatase TiO2 nanoparticles in cross-linked carbon skeleton as well as enriched in oxygen functional groups. Such unique structure features of TCGA not only can endow sufficient available space or active sites for dyes adsorption in aqueous solution, but also can provide efficient frameworks for photogenerated electrons stereo transportation in dyes photocatalytic decolorization process. When used as photocatalysts for the removal of dyes in aqueous solution, these prepared TCGAs have an excellent adsorption-photocatalysis synergistic effect, and exhibit a significantly enhanced photocatalytic activity, reliable reusability as well as good adaptability. The loading amount of TiO2 in such aerogels significantly affects the removal rate of dyes in adsorption-decolorization process. The optimized TCGA-40% shows a high removal capacity of 122.19 mg g−1 for rhodamine B, 134.38 mg g−1 for crystal violet, 113.78 mg g−1 for methyl orange, 113.45 mg g−1 for acid red and 99.55 mg g−1 for amino black in aqueous solution under ultraviolet light irradiation. Moreover, such TCGA-40% also exhibits an outstanding recyclability with 81.0% removal efficiency after experiencing 4 cycles use. This study paves a promising and universal way for large-scale production of TiO2/graphene aerogel composite for the elimination of organic dyes in wastewater.

The oxygen-rich hierarchical porous carbon (MOHPC) has been prepared through Mn(NO3)2-assisted KOH activation of humic acid with low-dose activating agent. We demonstrate that Mn(NO3)2 can promote the micropore formation, suppress the mesopore fabrication, and increase oxygen conent, thanks to the low-temperature pre-functionalization effect and synergistic activation effect with KOH at relatively low temperature of 700 °C. The MOHPC exhibits large specific surface area (1656 m2 g−1), high oxygen content (21.88 at.%), and optimized hierarchical porous structure possessing rich micropores, appropriate mesopore ratio with narrow mesopore size distribution, and interconnected macropores. Expectedly, MOHPC electrode delivers ultrahigh specific capacitances of 515 F g−1 and 402 F g−1 at 0.2 A g−1, 206 F g−1 and 233 F g−1 at 100 A g−1 in 1 M H2SO4 and 6 M KOH, respectively. Moreover, as symmetric supercapacitor electrode with commercial-level mass loading (~200 μm, ~11.30 mg cm−2), MOHPC also displays a high specific capacitance of 304 F g−1 at 0.057 A g−1, superior rate capability (246 F g−1 at 5.7 A g−1), and excellent cycling stability in 3 M KOH. The assembled supercapacitor device delivers a considerable energy density of 30 Wh kg−1 at the power density of 43.6 W kg−1 in organic electrolyte.

The behavior and kinetics of coal char steam gasification under microwave heating are investigated. The influence of the coal char particle size, water injection rate, and reaction temperature on the carbon conversion rate and gas product evolution during microwave heating gasification are considered and compared to the results from coal char steam gasification using conventional heating under the same conditions. The results show that microwave heating can accelerate the reaction rate of coal char steam gasification and improve the quality of the gas product. It was found that at temperatures varying from 600 to 900 °C, the coal char steam gasification reaction was well described using the shrinking core model (SCM). Activation energies of 82.8 kJ/mol and 114.3 kJ/mol were obtained for microwave heating and conventional electric heating, respectively.

A modified red mud- (MRM-) supported Fe catalyst (xFe/MRM) was prepared using the homogeneous precipitation method and applied to methane decomposition to produce hydrogen. The TEM and SEM-EDX results suggested that the particle sizes of the xFe/MRM catalysts were much smaller than that of raw red mud (RM), and the active metal Fe was evenly distributed over the catalyst structure. Moreover, BET results indicated that the surface areas and pore volumes of the catalysts were significantly improved, and the pore sizes of xFe/MRM were distributed from 5 to 12 nm, which is typical for a mesoporous material. The activities of those catalysts for the catalytic decomposition of methane were studied at atmospheric pressure at a moderate temperature of 650°C; the results showed that the xFe/MRM catalysts were more active than RM and MRM. The methane conversion curves of xFe/MRM catalysts exhibited similar variation tendencies (three-step) during the reaction despite different Fe contents, and the loading amount of Fe clearly affected the activity of the catalysts.

A series of iron nitride nano-crystalline granular thin films with different thickness and different angle of oblique sputtering have been fabricated on Si(1 0 0) by oblique RF reactive sputtering. The microstructure and magnetic properties of these samples have been investigated. Iron nitride thin films are composed of irregular spherical particles of 3–18 nm diameters with disordered face-centered-cubic structure. These particles are embedded in the amorphous iron nitride matrix with average spacing of ∼3 nm, and the films exhibit an in-plane uniaxial magnetic anisotropy. The results show that both thickness of iron nitride thin films and oblique angle have important effects on the magnetic properties of the films and magnetic resonant frequency of the films can also be tailored by these two factors. The in-plane uniaxial magnetic anisotropy fields of samples deposited for 30 min can be adjusted from 156 to 360 Oe by increasing the oblique angle from 3° to 32°. As a consequence, the resonance frequencies of films continuously increase from 2.87 to 6.05 GHz.

A type of nanomesoporous modified red mud (MRM) catalyst was prepared and utilized for catalytic methane decomposition (CMD) to produce hydrogen. The modification process significantly simplified the mineral composition of the red mud (RM); in the meantime, the physical and chemical structure of RM was changed. TEM images suggested that MRM was a kind of nanomesoporous material assembled by a number of uniformly nanoscale particles, BET results showed that the pore size distributions of MRM were ranged from 3 to 12 nm, and the specific surface area and total pore volumes of red mud improved from 8.00 m2/g and 0.08 cm3/g to 190.61 m2/g and 0.39 cm3/g, respectively. The catalytic performance of the catalysts has been tested at 800°C; the results showed that MRM exhibited much higher activity and stability than RM for CMD.

The pesent paper decribed the effects of additive on temperature rising characteristic during coal pyrolysis at different temperature in microwave field. Different mixture rate of carboncoal with coal and different final temperature on coal pyrolysis tempereature rising characteristics were studied in the work. The results indicate: Coal is a poorly microwave absorbing material, and its pyrolysis in microwave field need to add a certain amount of microwave absorbent for higher heating rate; Because carbocoal can be fast heated in microwave field, so it can be used as additive for coal pyrolysis. Carbocoal otained from different pyrolysis temperature have different heating rate, along with the increase of carbocoal pyrolysis temperature, carbocoal heating rate increases in microwave field. Using charcoal as microwave absorbent for coal rapid pyrolysis in microwave field is feasible.

In this article, we investigated the interactions between oxidized single-wall carbon nanotubes and three amino acids. A simple and environmental benign method to realize solubility of oxidized single-wall carbon nanotubes (OSWNT) in water was described. The amino acids used in this study include l-glycine (Gly), l-lysine (Lys), and l-phenylalanine (Phe). The OSWNT became soluble in water under ambient conditions and formed a stable suspension when amino acids (AA) were adsorbed on it. The interactions between OSWNT and three AA were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The results indicate that there is an increasing in the diameter of OSWNT after AA adsorption. The OSWNT with different diameters were separated as a result of AA adsorption. The smaller the diameter of OSWNT, the more the AA adsorption amount is. The adsorbed amount of different...

Coal tar pitch (CTP), a by-product of coking industry, has a unique molecule structure comprising an aromatic nucleus and several side chains bonding on this graphene-like nucleus, which is very similar to the structure of graphene quantum dots (GQDs). Based on this perception, we develop a facile approach to convert CTP to GQDs only by oxidation with hydrogen peroxide under mild conditions. One to three graphene layers, monodisperse GQDs with a narrow size distribution of 1.7 ± 0.4 nm, are obtained at high yield (more than 80 wt. %) from CTP. The as-produced GQDs are highly soluble and strongly fluorescent in aqueous solution. This simple strategy provides a feasible route towards the commercial synthesis of GQDs for its cheap material source, green reagent, mild condition, and high yield.

A simple and green approach was proceeded to obtain a stable single-walled carbon nanotubes (SWNTs)/L-phenylalanine (Phe) solution. The oxidized SWNTs (OSWNT) were used in this work. The scanning electron microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), Raman spectrometer, Fourier transform-infrared resonance (FT-IR), Ultraviolet-visible (UV-vis) spectroscopy, Thermogravimetric analysis (TGA) and High performance liquid chromatography (HPLC) were joined together to investigate the interaction between OSWNT and Phe. The OSWNT became soluble in the water and formed a stable solution since the Phe was adsorbed. The absorbed amount of Phe on the OSWNT is around 33 wt%. Adsorption of the Phe was mainly carried out on the OSWNT with smaller diameters. The Phe molecules were absorbed on the OSWNT by conjunct interaction of the pi-pi stacking, hydrogen bond and part of covalent bond.

Single-walled carbon nanotubes (SWNTs) became soluble in water and formed a stable solution when l-phenylalanine (Phe) was adsorbed. The adsorption selectivity of Phe zwitterions for larger diameter SWNTs was confirmed by analysis of Fourier transform infrared spectra and by differential thermogravimetric analysis. Enhanced adsorption of Phe on the oxidized single-walled carbon nanotubes (OSWNT) was observed in comparison with that of the purified single-walled carbon nanotubes (PSWNT). The Phe zwitterions are thought to adsorb on the surface of OSWNT by joint interaction of the π−π stacking, hydrogen bond, and part of the covalent bond. The π−π stacking is the dominant interaction in the sidewall of OSWNT without defects. The hydrogen bond and covalent bond formed with oxygen-containing groups becomes dominant on the end of OSWNT. For the PSWNT system, π−π stacking is an important factor to realize the adsorption of Phe zwitterions on the sidewall of PSWNT. The intermolecular hydrogen bond between Phe zw...

In this paper, a two-step desulfurization process for high-sulfur coal was investigated. Two Chinese coals with the addition of 10 wt % potassium hydroxide or sodium hydroxide were pyrolyzed under an atmosphere of nitrogen or hydrogen in a fixed-bed reactor at 600 °C, and then the obtained chars were washed with hot water. The results indicated that, without the addition of an alkali component, the sulfur removal of these two coals by pyrolysis and hydropyrolysis is ∼40%−50% and the sulfur content of chars is reduced only slightly, in comparison with the original coals; with the addition of 10 wt % potassium hydroxide or sodium hydroxide into the original coals and the chars being washed with hot water, the sulfur removal is ∼70%−80% and the sulfur content in chars is reduced dramatically. The combustion behavior of chars was also investigated, using thermogravimetric analysis. The results showed that those chars that had an added alkali component and were subjected to water-washing were more reactive and...

Chinese Yima coal and its HCl/HF and HCl/HF/HNO 3 treated samples were pyrolyzed in a fixed bed reactor under a pressure of 2 MPa. The effect of mineral on organic and pyrite sulfur transformation was investigated along with the effect of decomposition of pyrite on organic sulfur removal during pyrolysis. The results showed that the inherent mineral in coal has little effect on the decomposition of pyrite. The problems to hinder sulfur removal from coal during pyrolysis mainly include following three aspects: (I) large proportion of sulfide was produced from alkaline mineral matter in coal reacting with sulfur containing gas; (II) pyrite sulfur transformed into organic sulfur; (III) iron sulfide produced by decomposition of pyrite, which is more difficult to decompose at low temperature.

Two Chinese coals, Shenfu subbituminous coal and Huolingele lignite, were used to investigate the effect of mineral matter in coal on reactivity and kinetic characteristics of coal pyrolysis. The experiments were carried out by using thermogravimetry to check the pyrolysis behavior of raw coal, HCl/HF demineralized coal and demineralized coal with inorganic matter (CaO, K 2 CO 3 and Al 2 O 3 ) added, respectively. The results showed that inherent mineral in coal had no evident effect on the reactivity and kinetics of coal pyrolysis. CaO, K 2 CO 3 and Al 2 O 3 all had a catalytic effect on the reactivity of coal pyrolysis, their effects were closely related to temperature region and coal types. The pyrolysis process of all the samples studied can be described by three independent first order kinetic model. Addition of inorganic matter the activation energy decreased and the characteristic temperature of coal changed.

A simple and green approach was proceeded to obtain a stable single-walled carbon nanotubes (SWNTs)/L-phenylalanine (Phe) solution. The oxidized SWNTs (OSWNT) were used in this work. The scanning electron microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), Raman spectrometer, Fourier transform-infrared resonance (FT-IR), Ultraviolet-visible (UV-vis) spectroscopy, Thermogravimetric analysis (TGA) and High performance liquid chromatography (HPLC) were joined together to investigate the interaction between OSWNT and Phe. The OSWNT became soluble in the water and formed a stable solution since the Phe was adsorbed. The absorbed amount of Phe on the OSWNT is around 33 wt%. Adsorption of the Phe was mainly carried out on the OSWNT with smaller diameters. The Phe molecules were absorbed on the OSWNT by conjunct interaction of the pi-pi stacking, hydrogen bond and part of covalent bond.