Higher Specific Volume Research Articles

Amine-functionalized macroporous resin for direct air capture with high CO2 capacity in real atmospheric conditions: Effects of moisture and oxygen

Direct air capture (DAC) is an important negative carbon emission technology that has attracted increasing attention. Amine-functionalized porous CO2 adsorbents are promising materials for DAC because of their high CO2 capacities, fast adsorption and desorption kinetics, and low energy costs during regeneration. In this study, inexpensive macroporous resins with high specific surface areas and pore volumes were selected as carriers of tetraethylenepentamine (TEPA) or polyethyleneimine (PEI). Their DAC performances in relation to their microstructures were explored under different humidity and oxygen conditions. Moisture simultaneously enhanced the CO2 capacity and slowed the adsorption/desorption process. Oxygen did not react with the resin and amine under ambient conditions, but physically adhered to the active sites of the adsorbents and caused a slight decrease in the CO2 uptake capacity. The optimized material reached adsorption equilibrium in 7269 s with CO2 uptake capacity of 5.4 mmol g−1 and desorbed CO2 in 1611 s with CO2 desorption capacity of 5.0 mmol g−1. After five cycles, the materials retained 82.2 % of the adsorption capacity. The findings indicate that amine-functionalized macroporous resins are promising DAC adsorbents under atmospheric conditions.

Preparation of mesoporous biogas residue biochar via a self-template strategy for efficient removal of ciprofloxacin: Effect of pyrolysis temperature

Biochar preparation and application is an anticipated pathway for the resource utilization of biogas residue. In this study, biochars were prepared by the pyrolysis of biogas residue from food waste anaerobic digestion (named as BRBCs) under various pyrolysis temperatures (300, 500, 700, and 900 °C), and the effect of pyrolysis temperatures on the physicochemical characteristics of BRBCs was examined. The adsorption performance toward ciprofloxacin (CIP), a typical antibiotic in waterbodies, was also investigated. The results showed that pyrolysis temperature significantly changed the physicochemical properties of BRBCs. In addition, the minerals in the biogas residue, especially SiO2, were rearranged to form a mesoporous structure in biochar through a self-template strategy (without activator). BRBC prepared at 900 °C exhibited a high specific surface area and pore volume, well-developed mesopore structure, and more carbon structure defects, and exhibited the largest CIP adsorption capacity with 70.29 mg g−1, which was ascribed to the combined interaction of pore diffusion, π–π interactions, hydrogen bonding, complexation, and electrostatic forces. Furthermore, the adsorption of CIP by BRBC900 was well described by two-compartment kinetic and Langmuir isotherm models. BRBC900 showed good adsorption performance toward CIP at pH 7–9. The adsorption of CIP by BRBC is a spontaneous, exothermic, entropy-increasing process. Moreover, BRBC also presented a good recycling potential. Therefore, the preparation of mesoporous biochar based on a self-template strategy not only provides an option for the resource utilization of biogas residue but also offers a new option for the treatment of antibiotic wastewater.

Design and preparation of reticular superabsorbent hydrogel material with nutrient slow-release and high shear strength for ecological remediation of abandoned mines with steep slopes

In order to solve ecological remediation issues for abandoned mines with steep slopes, a kind of hydrogels with high cohesion and water-retaining were designed by inorganic mineral skeleton combining with polymeric organic network cavities. This eco-friendly hydrogel (MFA/HA-g-p(AA-co-AM)) was prepared with acrylic acid (AA)-acrylamide (AM) as network, which was grafted with humic acids (HA) as network binding point reinforcement skeleton and polar functional group donors, KOH-modified fly ash (MFA) as internal supporter. The maximum water absorption capacities were 1960 g/g for distilled water, which followed the pseudo-second-order model. This super water absorption was attributed to the first stage of 62 % fast absorption due to the high specific surface area, pore volume and low osmotic pressure, moreover, the multiple hydrophilic functional groups and network structure swell contributed to 36 % of the second stage slow adsorption. In addition, the pore filling of water in mesoporous channels contributed the additional 2 % water retention on the third stage. The high saline-alkali resistance correlated with the electrostatic attraction with MFA and multiple interactions with oxygen-containing functional groups in organic components. MFA and HA also enhanced the shear strength and fertility retention properties. After 5 cycles of natural dehydration and reabsorption process, these excellent characteristics of reusability and water absorption capacity kept above 97 %. The application of 0.6 wt% MFA/HA-g-p(AA-co-AM) at 15° slope could improve the growth of ryegrass by approximately 45 %. This study provides an efficient and economic superabsorbent material for ecological restoration of abandoned mines with steep slopes.

Production of γ–aminobutyric acid–enriched sourdough bread using an isolated Pediococcus pentosaceus strain JC30

A γ–aminobutyric acid (GABA)–producing strain JC30 was isolated from traditional kimchi, which was identified as Pediococcus pentosaceus by 16S rDNA sequencing. P. pentosaceus JC30 was highly tolerant to acid, bile salt, and high temperatures. The survival rate of JC30 in MRS medium (pH 2.5) for 3 h was 60.96 %. Furthermore, the survival rate of JC30 in MRS medium with 3 mg/mL bile salt for 24 h was 86.62 %. The survival rate of JC30 in MRS medium at 56 °C and 58 °C for 10 min was 97.17 % and 78.20 %, respectively. When 2 % v/v JC30 (8.0 log10 CFU/mL) was added to prepare sourdough and the sourdough was then used to make bread, the bread had a higher specific volume (5.13 ± 0.12 mL/g) and GABA content (3.32 ± 0.04 mg/g DW) than the control.

Dipole-induced hydrogen bonds enhanced P/O co-doped Lyocell-based porous carbon fiber cloth for hydrogen storage under ambient pressure

Currently, the hydrogen storage application of carbon-based adsorbent materials is mostly implemented under the pressure conditions of 30–300 bar, while there is few targeted studies conducted on the unsaturated adsorption under ambient pressure conditions. Therefore, based on industrialized Lyocell biopolymer fiber precursors and the enhancement effects of dipole-induced hydrogen bonds (DIHB), this work presents a facile construction strategy for P/O co-doped Lyocell-based porous carbon fiber cloth (Ly-ACF-F40). By the technical route of thermal stabilization---sonication assisted phosphoric acid activation---hydrogen bonds introduced by interfacial fluorination, the constructed Ly-ACF-F40 acquires a high specific surface area (1870 m2/g) and total pore volume (1.277 cm3/g), and an excellent hydrogen storage capacity of 3.22 wt% under ambient pressure conditions (77 K, 1 bar). The study directly demonstrated in the experiment that dipole induced hydrogen bonding H(I)-H(II)···F can effectively enhance the atmospheric hydrogen storage density on the basis of other eliminating influencing factors of specific surface area. The simple construction strategy of porous carbon-based materials can provide reference for the research of unsaturated adsorption hydrogen storage materials under ambient pressure conditions, also assist in the application and promotion of low-cost solid hydrogen storage materials.

Development of Gluten-Free Bread Based on Maize and Buckwheat and Enriched with Aromatic Herbs and Spices

This work aimed to develop high-quality gluten-free bread based on maize and buckwheat with good palatability and texture properties. Different aromatic herbs and spices were incorporated as ingredients to evaluate whether their addition could influence the acceptability of consumers by improving the sensory properties of the final product. The bread formulation was first optimized through a response surface methodology. Accordingly, high specific volume, high springiness, and low hardness provided the best theoretical bread quality. However, when developing the product, some sensory defects were detected. Therefore, the addition of other ingredients (e.g., oil, sugar, and yeast) was tested. Finally, five different gluten-free bread with different combinations of aromatic herbs and spices were obtained. They were nutritionally characterized and subjected to sensory analysis by a panel of 140 consumers. The chemical composition of all bread was very similar, with only slight differences among them. Likewise, all of them received acceptable sensory scores (>5) from consumers, and some combinations of herbs and spices obtained scores higher than in the control bread (without herbs and spices). Overall, the gluten-free bread formulated with the combination of basil and oregano was the one that consumers significantly liked the most.

Effect of bread ingredients and baking techniques on Bacillus coagulans GBI-30 viability during baking and in vitro digestion

This study aimed to investigate the effect of bread ingredients and baking techniques on the viability of Bacillus coagulans GBI-30 spores during baking and in vitro digestion conditions. After baking, the highest B. coagulans viability were observed in the bread formulation with low sugar and high oil content. Among the baking techniques, steam-assisted baking (ST-HA) resulted in the highest B. coagulans count (7.46 log CFU/g) and viability (95.31%). Conversely, microwave-assisted baking (MW-HA) yielded the lowest B. coagulans count (6.91 log CFU/g) and viability (75.50%). The in vitro digestion test results indicated that the highest B. coagulans count was measured with ST-HA in both gastric and intestinal phases with 86.91% and 96.85, respectively. It revealed that B. coagulans probiotic spores are highly resistant to gastric conditions in bread matrix. Furthermore, it was determined that B. coagulans GBI-30 spores incorporated into the bread can germinate under digestion conditions. Different baking techniques also affected the physical quality characteristics of probiotic bread. The highest specific volume was measured in MW-HA, with a value of 3.54 mL/g. However, MW-HA negatively affected the texture properties of bread, as indicated by the highest hardness and chewiness values observed in these bread samples.

Hierarchical porous cobalt nanoparticles encapsulated in heteroatom-doped hollow carbon as an enhancing multifunctional catalyst for hydrolysis of sodium borohydride and hydrogenation of bromate in water

Multifunctional heterogeneous catalysts have been consistently explored in recent years because of their distinctive catalytic activity in different catalysis areas at once. Here, a cobalt (Co) nanoparticles encapsulated in nitrogen-doped hollow carbon (denoted as Co@NHC) is prepared by two-step modifications of acid etching and high temperature carbonization in the inert atmosphere using a peculiar polyhedral configuration Co-ZIF as an initial template. Benefiting from an intriguing polyhedral configuration hollow structure with high specific surface area and pore volume supplying plentiful active sites, Co@NHC shows exceptional catalytic activity in catalyzing hydrolysis of NaBH4 and hydrogenation of toxic bromate in water. From experimental results, Co@NHC could efficiently enhance the generation of H2 with a H2 generation rate of 1515.4 mL min−1 gcat−1 meanwhile the activation energy (Ea) calculated from Co@NHC/NaBH4 system was only 12.6 kJ mol−1. Besides, the combination of Co@NHC and NaBH4 could further reduce toxic bromate ions into bromide via catalytic hydrogenation with a maximum bromate removal capacity of 390.6 μmol g−1. More importantly, due to its strong magnetization, Co@NHC could be simply recovered after reactions, making it well-preserve the unique structure as well as catalytic activity for multiple continuous recycles in both catalytic applications. Additionally, the plausible reaction mechanisms in catalyzing hydrolysis of NaBH4 and hydrogenation of bromate were also proposed. This work has pioneered a promising approach on preparing an engrossing magnetic heterogeneous Co-based catalyst that is practically applicable in various areas of catalysis.

Lanthanum-modified tobermorite synthesized from fly ash for efficient phosphate removal.

Phosphate removal from water by lanthanum-modified tobermorite synthesized from fly ash (LTFA) with different lanthanum concentrations was studied. LTFA samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer‒Emmett‒Teller specific surface area analysis. The results showed that the LTFA samples were mainly composed of mesoporous tobermorite-11Å, and LTFA1 with a lanthanum concentration of 0.15M had a high specific surface area (83.82 m2/g) and pore volume (0.6778 cm3/g). The phosphate adsorption capacities of LTFA samples were highest at pH 3 and gradually decreased with increasing pH. The phosphate adsorption kinetics data on LTFA samples were most accurately described by the Elovich model. The adsorption isotherms were in the strongest agreement with the Temkin model, and LTFA1 showed the highest phosphate adsorption capacity (282.51mg P/g), which was higher than that of most other lanthanum-modified adsorbents. LTFA1 presented highly selective adsorption of phosphate with other coexisting ions (HCO3-, Cl-, SO42-, and NO3-). In addition, phosphate was adsorbed onto LTFA samples by forming inner-sphere phosphate complexes and amorphous lanthanum phosphate. This study provides technical support for development of efficient fly ash-based phosphate adsorbents.

In-situ template method to synthesize metal/non-metal doped carbon for SO2 adsorption at low concentration: DFT and experimental studies

SO2 is one of the most significant air molecular contaminants (AMC). The development of materials for capturing low-concentration SO2 at room temperature is of great importance for industrial production and environmental safety. In this study, hierarchical porous carbon materials with Zn–N–C active structures were synthesized in one step using an in-situ template method. Among them, Zn/AC-2 exhibited a high specific surface area (1143.73 m2/g) and micropore volume (0.42 cm3/g). Dynamic adsorption tests were conducted under the conditions of an inlet concentration of 90 ppm, with a temperature of 23 °C and a humidity of 50%. The results indicated that the material showed an excellent capturing performance for SO2, with a breakthrough adsorption capacity of 3.37 mmol/g. Through characterization techniques including XPS, XRD, and SEM-EDS, it was found that the metal elements were dispersed in atomic form within the carbon framework, demonstrating the effectiveness of the modification method. A comparative study of the new adsorbent and spent adsorbent proved that SO2 reacts with extremely high catalytic efficiency on the material surface to generate SO3, revealing the reaction mechanism on the material surface. Finally, based on density functional theory, the microscopic reaction mechanism of the interaction between SO2 and the prepared material surface was studied at the molecular level. The results showed that the reaction energy barrier on the material surface is only 1.01 eV, and the reaction releases 3.14 eV of energy, indicating that the reaction can spontaneously occur at room temperature.

Thermochemical heat storage performance of Fe-doped MgO/Mg(OH)2: Experimental and DFT investigation

MgO/Mg(OH)2 thermochemical heat storage system can realize large-scale energy storage by repetitive hydration/dehydration reactions to enhance the stability of solar energy utilization. However, slow interconversion and incomplete reactions caused by agglomeration restrict the cyclic heat storage capability of MgO/Mg(OH)2. In this work, a low-cost efficient Fe-doped MgO was prepared by a simple wet-mixing method and its energy released performance and kinetics in MgO/Mg(OH)2 heat storage progress were examined in a twin fixed-bed reactor and a simultaneous thermal analyzer. Additionally, density functional theory calculations were used to examine the impact of Fe on the mechanisms of MgO/Mg(OH)2 heat storage process. The results shows that when the molar ratio of MgO to Fe is 95:5, the energy released density of Fe-doped MgO is about 400 % higher than that of MgO after 10 heat storage cycles. In preparation process, the existence of Fe leads to the generation of MgFe2O4, which forms layered microstructure with the high specific surface area and pore volume and mitigates agglomeration behavior of MgO. It improves the cyclic stability of MgO and reduces the dehydration temperature of Mg(OH)2, and simultaneously the activation energy of the dehydration stage is reduced by 33.2 %. Fe enhances the interaction of H2O with the MgO surface and promotes the dissociation of H2O on Mg(OH)2 surface. Combined with economic analysis, Fe-doped MgO is a suitable material for MgO/Mg(OH)2 heat storage cycles.

Renewal of electrical energy by green hydrogen using a metal organic framework with Fe3O4 cluster

Recently, metal-–organic frameworks (MOFs) with high porosity have drawn extensive attention in water splitting. The present study reports the synthesis of a porous Fe-based MOF by a modified precursor made of magnetite (Fe3O4). Subsequently, a series of undoped and lanthanide -doped (MOFs) are prepared using the solvothermal method. The synthesis provided a high surface area with a high specific surface and pore volume. The synthesized electrocatalyst with a high surface area is demonstrated as an excellent electrocatalyst for the hydrogen evolution reaction(HER) investigated in acidic media. The electrochemical results demonstrated low Tafel slopes (81 and 166 mV dec–−1), high exchange current, high ssurface area (Cdl) (148.29 and 150.57 mV), and high stability for Au/MIL-53 (Fe)/Gd-Fe3O4 and glassy carbon electrode GCE/MIL-53 (Fe)/La-Fe3O4. The high activity is attributed to the large surface area of the synthesized Fe/ Fe3O4-based MOF, which is porous and magnetic. The effect of base metal on catalyst performance was discussed. Through the unification of two catalytically active metals as lanthanide, a new opportunity opens up for the development of synergistic systems in multiple applications.

Effect of goji berry incorporation on the texture, physicochemical, and sensory properties of wheat bread.

The regular intake of Lycium barbarum (goji berry) is supposed to play an important role in the promotion of human health. Regarding, its incorporation into staple foods, including bread, seems to be effective. However, it requires the evaluation of dough behavior and final product quality. This study investigated the effect of goji berry incorporation at levels of 10, 15, 20, 25, and 30% ww-1 on the textural, physicochemical, and sensory properties of wheat bread. Results indicated a significant enhancement of water absorption and gelatinization temperature in composite flour via the inclusion of goji berry powder (p < 0.05). Using goji berry powder up to 20% ww-1 has shown to obtain the structure able to restore gases through the baking process and provide enhancement in a specific volume at about 10%. Alongside, the hardness of composite bread decreased, and the optimal hardness was observed at formulations containing 20% w/w goji berry powder with a value equal to 1199.95 ± 0.05 g, which is supposed to be induced by the higher specific volume and lower moisture content of bread samples. Moreover, color and sensory perception have been found to be significantly changed by goji berry substitution. Goji berry substitution up to 20% ww-1 is found to be preferred by the consumer, and a drop in overall acceptability was observed at its higher inclusion. The technological characteristic changes induced by goji berry incorporation are induced by its gluten dilution impact. However, the gel-like structure formed by the high fiber content of goji berries compensates for this adverse impact up to 20% w/w substitution level.

The Effect of Whey Protein Concentrate, Soy Protein Isolate, and Xanthan Gum on Textural and Rheological Characteristics of Gluten-Free Batter and Cake

The market of gluten-free food products has been growing exponentially in recent years. Consequently, it is necessary to conduct research on the effects of various compounds to enhance the quality of these products. The present study is aimed at investigating the effects of adding whey protein concentrate (WPC) and soy protein isolate (SPI) at three levels (0%, 5%, and 10%) and xanthan gum (XG) (0%, 0.15%, and 0.3%) on the textural and rheological characteristics of gluten-free batter and cake based on rice flour. The results showed that increasing the levels of XG, WPC, and SPI improved the apparent viscosity of the batter samples. The effect of WPC on the apparent viscosity was more pronounced than that of SPI, as the highest value (21.9 Pa·s) was related to the sample containing 10% WPC and 0.3% XG. The loss tangent values of the batter samples, measured at a frequency of 1 Hz, ranged from 0.531 to 0.8 for different levels of WPC/XG and from 0.466 to 0.699 for SPI/XG, indicating a gel-like behavior of the batter samples. The sample containing 10% SPI and 0.3% XG displayed the strongest gel with higher storage modulus (982.112 Pa) and loss modulus (458.039 Pa) compared to other samples. Increasing the levels of XG, WPC, and SPI resulted in higher specific volume, porosity, firmness, and springiness of the samples compared to the control sample (P&lt;0.05). The addition of WPC, SPI, and XG improved the overall acceptability of the cake samples, with the samples containing WPC/XG combination being the most preferred. Ultimately, the cake sample containing 10% WPC along with 0.3% XG introduced as optimal sample. This formulation not only can enhance the characteristics of gluten-free cake but also meets parts of the nutritional needs of consumers, particularly those with celiac disease.

Lignin-derived nitrogen doped hierarchical porous carbon spheres for highly efficient dichloromethane adsorption

Biomass-prepared porous carbon materials are promising solid adsorbents for the removal of volatile organic compounds (VOCs). However, their application is hindered due to the insufficient number of pores and poor surface activity. In this study, a lignin-derived nitrogen-doped hierarchical porous carbon sphere (NHPCS-0.5) with abundant surface active sites was synthesised through spray drying and carbonisation–activation methods. The optimised NHPCS-0.5 displayed a high BET specific surface area (2961 m2·g−1) and total pore volume (1.57 cm3·g−1), developed hierarchical porous distribution with micro-/meso-/macropores and satisfactory surface nitrogen content. Moreover, it exhibited an excellent dichloromethane adsorption capacity of 156 mg·g−1 and maintained 86% of initial capacity after five regeneration cycles, indicating an outstanding regenerative ability. The nitrogen introduction improved the micropore volume and adsorption capacity. Adsorption mechanism reveals that micropore filling and enhanced van der Waals interaction of carbon surface with dichloromethane molecule by N-containing functional groups played a vital role in adsorption, and mesopores contributed to the high adsorption rates. The above results indicate the potential of NHPCS-0.5 as an adsorbent for VOC removal and provide new ideas for the utilisation of lignin and design of carbon sphere materials.

Cherry blossom derived micron carbon sheets loaded with Co based particles served as sulfur host for lithium sulfur batteries

In order to effectively alleviate the shuttle effect in lithium-sulfur batteries (LSBs), cherry blossom-derived micron carbon sheets loaded with a small amount of Co-based nano-particles are synthesized in this work. After the thermal decomposition of ZIF-67, the composite shows a high specific surface area (2768.2 m² g−1) and pore volume (1.63 cm³ g−1), which can enhance the physical adsorption of polysulfides. Moreover, the Co-N and Co nano-particles obtained by ZIF-67 have strong catalytic and polar adsorption abilities. Not only can they accelerate the electrochemical reaction, but also effectively inhibit the shuttle effect of polysulfides, which in turn improves the electrochemical performance of lithium-sulfur batteries. Thus, the initial discharge capacity of the Co-PB@S electrodes reached 933 mAh g−1, with a remaining capacity of 550 mAh g−1 after 500 cycles at 0.5 C. This work may provide a practical way for the application of LSBs and the field of electrocatalysis.

Impact of Heat Moisture Treatment and Pregelatinization of Corn Starch on the Functional and Nutritional Properties of Breads Supplemented with Corn Germ

Properties of modified starch are of great interest to the bakery industry. Moreover, corn germ incorporation in bread has multiple health benefits. The aim of this study was the formulation of Brotchen bread with corn germ flour (0, 10, 20, and 30% w/w) and modified corn starch (0, 10, 20, and 30% w/w). The effect of heat‐moisture treatment (HMT) and pregelatinization (PG) of starch was investigated on the rheological and physicochemical properties of bread. The addition of corn germ flour and modified starch increased some farinograph properties, i.e., water absorption, consistency, and dough development time, and decreased dough stability. The degree of softening of the dough increased after 12 min after supplementation. The farinograph quality number in the dough containing HMT was the highest value. By replacing corn germ flour and modified starch, extensograph parameters such as dough resistance were strengthened and dough extensibility was weakened. Also, the energy of the dough increased. The highest fat, protein, fiber, and moisture content was observed in the treatment containing 30% corn germ flour and HMT starch (HMT3). Also, the HMT3 treatment had the highest specific volume and porosity and the lowest weight loss and hardness (p &lt; 0.05). Regarding the color parameters, HMT3 treatment showed the highest lightness (L∗) and the lowest yellowness (b∗). Enriched bread by corn germ had more iron, calcium, potassium, magnesium, and phosphorus compared to wheat bread. Regarding overall acceptability, no significant difference was observed between treated and untreated bread (p &gt; 0.05). Therefore, the corn germ flour and modified starch in the formulation of bread improved the functional and nutritional properties of bread and can be used in the bread formulation especially at a concentration of 30%.

Role of tailored sourdough fermentation in the flavor of wholegrain-oat bread

Sourdough technology has been known for its role in the improvement of texture, flavor, and quality of mainly wheat and rye-based breads for decades. However, little is reported about its use in the improvement of whole-grain oat bread, especially concerning flavor formation, which is one major consumer drivers. This study investigated the effects of sourdough obtained by different lactic acid bacteria and yeast starters consortia on the texture and flavor of 100% oat bread. Four different consortia were selected to obtain four oat sourdoughs, which were analyzed to assess the main features due to the different starter fermentation metabolism. Sourdoughs were added to breads as 30% dough weight. Bread quality was technologically monitored via hardness and volume measurements. Sourdough breads were softer and had higher specific volume. The sensory profile of sourdoughs and breads was assessed by a trained panel in sensory laboratory conditions, and the volatile profile was analyzed by HS-SPME-GC-MS. Sourdoughs were rated with higher intensities than untreated control for most of attributes, especially concerning sour aroma and flavor attributes. Sourdough breads were rated with higher intensities than control bread for sour vinegar flavor and total odor intensity, in addition they had richer volatile profile. Our results confirmed that sourdough addition can lead to an enhanced flavor, moreover, it demonstrated that the use of different consortia of lactic acid bacteria and yeast strains leads to the improvement of texture and altered sensory profile of whole-oat bread.

Bio-based sunflower carbon/polyethylene glycol shape-stabilized phase change materials for thermal energy storage.

The exploitation of shape-stabilized phase change materials with high thermal conductivity and energy storage capacity is an effective strategy for improving energy efficiency. In this work, sunflower stem carbon/polyethylene glycol (SS-PEG) and sunflower receptacle carbon/polyethylene glycol (SR-PEG) shape-stabilized phase change materials, utilizing sunflower stem and receptacle biomass carbon with high specific surface area and pore volume obtained by carbonization as frameworks and polyethylene glycol as an energy storage material, were prepared by the vacuum impregnation method. The ability to load polyethylene glycol into the pore structure of carbon materials in different sunflower parts was mainly investigated, and the micro-morphology, compositional structure and thermal properties were characterized and analyzed using SEM, IR spectroscopy, XRD, DSC and TG techniques. The results showed that the carbonized sunflower stems maintained the sieve pore structure, and the carbonized sunflower receptacle was a macroporous structure containing a large number of three-dimensional interconnections. At the same time, the interaction between polyethylene glycol and each carbon material occurred through physisorption. The melting enthalpies of SS-PEG and SR-PEG shape-stabilized phase change materials were 153.4 J g-1 and 171.5 J g-1, respectively, and the loading rates reached 81.9% and 91.5%, with initial thermal decomposition temperatures (T 5%) of 344 °C and 368 °C.

Regeneration of LiNi0.6Co0.2Mn0.2O2 material from spent lithium-ion batteries by solution combustion synthesis method

LiNi0.6Co0.2Mn0.2O2 (NCM622) material was regenerated by solution combustion synthesis method using metal precursors obtained from the spent lithium-ion batteries. The structural, microstructural, and electrochemical properties of the regenerated cathode material were evaluated as a function of fuel type including citric acid, polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), and a mixture of CTAB and PVP fuels. The mixed CTAB-PVP fuel led to the layered crystal structure and porous microstructure with high specific surface area and pore volume. The regenerated cathode powders prepared by a mixture of CTAB and PVP fuels had a specific capacity of 156 mAh g−1 at 0.1C with a capacity retention of 94 % following 100 charge/discharge cycling at a current rate of 0.5C.