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Interoception, the processing of internal bodily signals, is proposed as the fundamental mechanism underlying emotional experiences. Interoceptive and emotional processing appear distorted in psychiatric disorders. However, our understanding of the neural structures involved in both processes remains limited. To explore the feasibility of enhancing interoception and emotion, we conducted two studies using high‐definition transcranial direct current stimulation (HD‐tDCS) applied to the right anterior insula. In study one, we compared the effects of anodal HD‐tDCS and sham tDCS on interoceptive abilities (sensibility, confidence, accuracy, emotional evaluation) in 52 healthy subjects. Study two additionally included physical activation through ergometer cycling at the beginning of HD‐tDCS and examined changes in interoceptive and emotional processing in 39 healthy adults. In both studies, HD‐tDCS was applied in a single‐blind cross‐over online design with two separate sessions. Study one yielded no significant effects of HD‐tDCS on interoceptive dimensions. In study two, significant improvements in interoceptive sensibility and confidence were observed over time with physical preactivation, while no differential effects were found between sham and insula stimulation. The expected enhancement of interoceptive and emotional processing following insula stimulation was not observed. We conclude that HD‐tDCS targeting the insula does not consistently increase interoceptive or emotional variables. The observed increase in interoceptive sensibility may be attributed to the activation of the interoceptive network through physical activity or training effects. Future research on HD‐tDCS involving interoceptive network structures could benefit from protocols targeting larger regions within the network, rather than focusing solely on insula stimulation. This is the first report on the feasibility of enhancing interoceptive and emotion processing through insula stimulation using HD‐tDCS. In contrast to research suggesting an attenuation of interoceptive and emotional processes through the inhibition of this interoceptive network structure, our findings highlight the complexity of enhancing these processes by neurostimulation of the anterior insula. We derive recommendations to increase the effectiveness of HD‐tDCS in the context of interoceptive abilities stimulation. [ABSTRACT FROM AUTHOR]

An affordable local adsorbent was physically activated and modified to form a novel composite adsorbent. Similar processes were used to activate bentonite and limestone to create this low-cost local adsorbent. Furthermore, when compared to the inexpensive local resources, the innovative composite adsorbent showed improved adsorption capacity. Fouling brought on by sulphate-ion pollution is a significant problem in the wastewater treatment industry. In this work, a composite material known as Limestone and Bentonite composite, was developed, and its capacity to absorb sulphate ions from tainted wastewater was evaluated. Using the scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller theory, the chemical, elemental, and mineralogical properties, as well as the functional group interaction, of the limestone, bentonite, and LB composite were determined. The model wastewater initially included 900 mg/L of sulphate ions; however, the experiment showed that the new (LB) composite absorbed over 729 mg/L of sulphate ions. Its (LB) = 81% strong elimination effectiveness was observed. It was found that the ideal adsorption conditions were 250 rpm, 60 min, 900 mg/L, and 0.5 g/50 mL. Adsorption studies were carried out in batches. With a greater determination coefficient, the Freundlich model provides a more accurate prediction for adsorption processes, bolstering the theory that chemisorption is the actual adsorption process. These results demonstrate the novel composite adsorbent (LB)’s tremendous potential for sulphate ion absorption.

Activated carbon monoliths with developed porosity, high surface area and excellent adsorption properties were successfully prepared from resorcinol-formaldehyde resins using a physical activation method. The primary objective of this study was to examine the impact of key parameters, namely hexamethylenetetramine content (0.08–0.2 g), pyrolysis heating rate (5–20 °C/min) and activation time (1–7 h), on the final characteristics of the activated carbon in order to identify the optimal operating conditions to achieve the desired properties. All the cured resin samples were pyrolyzed at 900 °C under a nitrogen atmosphere, while the activation process took place in the presence of CO2. The evaluation of the activated carbon materials was based on the CO2 adsorption capacity and BET surface area, micropore area and total pore volume, which were employed as the criteria for selecting the optimal activated carbon. The synthesized porous carbon monoliths exhibited good properties: high BET surface area (900 m2/g), high CO2 adsorption capacity (5.33 mmol/g at 0 °C and 1 bar, 3.8 mmol/g at 25 °C and 1 bar) and good CO2 selectivity for CO2/N2 and CO2/CH4 mixtures. These results were obtained with a pyrolysis heating rate of 5 °C/min and a 3 h activation period. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental and analytical study of the physicochemical properties of pyrolyzed biomass for use as alternative energy sources. Shea kernel shell (SKS) and groundnut shell (GS) are known agricultural wastes and were investigated using the slow pyrolysis technique to assess their energy generation potential. In this study, the KSK and GS were pyrolyzed at heating rate of 10 °C/min at ∼ 400, 500, 600 and 700oC respectively and the products (liquid oil, syngas, and activated char) were collected and characterized for their properties. The values for volatile matter (VM) for SKS and GS were reported to be ∼70% whereas their fixed carbon (FC) values were up to ∼ 41% and up to ∼25.67% respectively. The relatively high volatile matter and fixed carbon compositions signify good fuel potential of both feedstocks. The calorific value of the SKS ranged from 19.54 29.91 MJ/kg and 17.24 - ∼27.88 MJ/kg for GS. The hydrogen-to-carbon (H/C) ratios of ∼0.054 – 0.121 and ∼0.057 – 0.124 and oxygen-to-carbon (O/C) ratios of ∼0.736 – 0.845 and ∼0.663 – 0.754 were obtained for the GS products and SKS respectively indicating that, they possess good combustion properties. The aromatic and aliphatic functional properties were also detected with the activated biochar having higher energy densities, good combustion and chemical properties. The application of the products would enhance environmental sustainability through innovative waste management and by-products recycling. The implications of the results are discussed to demonstrate the scale-up potential of agrowastes as reliable sources of energy

A series of new granular carbonaceous adsorbents was prepared via single-stage physical and chemical activation of walnut shells. Their suitability for removing various types of organic pollutants (represented by dyes, surfactants and water-soluble polymers) from the liquid phase was assessed. The activation of the precursor was carried out with CO2 and H3PO4 using conventional heating. Activated biocarbons were characterized in terms of chemical composition, acidic–basic nature of the surface, textural and electrokinetic properties as well as thermal stability. Depending on the type of activating agent used during the activation procedure, the obtained biocarbons differed in terms of specific surface area (from 401 to 1361 m2/g) and the type of porous structure produced (microporosity contribution in the range of 45–75%). Adsorption tests proved that the effectiveness of removing organic pollutants from the liquid phase depended to a large extent on the type of prepared adsorbent as well as the chemical nature and the molecular size of the adsorbate used. The chemically activated sample showed greater removal efficiency in relation to all tested pollutants. Its maximum adsorption capacity for methylene blue, poly(acrylic acid), poly(ethylene glycol) and Triton X-100 reached the levels of 247.1, 680.9, 38.5 and 61.8 mg/g, respectively. [ABSTRACT FROM AUTHOR]

Activated carbons (JSAC45 and JSAC55) were fabricated via both processes of pyrolysis and gasification using steam with burn-off of 45 and 55%. These materials derived from Ziziphus jujube were characterized by the adsorption–desorption of N2, thermogravimetric analyzer coupled with mass spectrophotometer (TGA/MS), electron microscope (SEM), Fourier transform infrared spectroscope (FTIR), Boehm titration, and pHPZC. The specific surface area (SBET) of activated carbons was 953 m2/g for both materials with the predominance of basic character ( pH PZC ≅ 10) . Then, the prepared carbons were used to adsorb BEZAKTIV Red S-Max (RS). The effect of initial RS concentration (10–100 mg/L), contact time (0–1440 min), pH (2–10), and temperature (25–45 °C) on adsorption capacity of JSAC45 and JSAC55 were examined; and it was revealed that RS dye was well adsorbed at pH = 10. The equilibrium adsorption data suggested that the Langmuir model fitted well the RS dye adsorption, and the pseudo-second-order model best fitted the adsorption kinetic data. The maximum of adsorption capacity of RS onto JSAC55 was 113.3 mg/g. Thermodynamics studies of JSAC45 and JSAC55 indicated that the adsorption process was endothermic, spontaneous, and feasible. The activated carbons were reused after applying the thermal regeneration process. The Ziziphus jujube adsorbents could adsorb industrial wastewater (IW) with an elimination rate of about 40% for both adsorbents. These results confirm that the Ziziphus jujube stones may be considered as an inexpensive and promising precursor for commercial activated carbons production. [ABSTRACT FROM AUTHOR]

Electrochemical hydrogen storage is considered as the safest mode compared to the other storage forms, which is why it has attracted a significant research attention in the past decade. Carbon-based porous mediums offer many benefits that favor hydrogen adsorption in it. The presented work investigates the feasibility of coconut shell derived activated carbon for hydrogen adsorption by ascertaining its physical and chemical characteristics. The procedure employed for characterization is disclosed. Brunauer-Emmett-Teller (BET) surface area, average crystalline size of the activated carbon was found to be 51.7 m2/g and average crystalline size using X-Ray Diffraction (XRD) to be 10.69nm, respectively, which is comparable with the published data in literature. The scanning electron microscopy illustration of the field emission revealed the presence of well-developed pores on the surface of the sample activated carbon. The Fourier Transform Infrared Analysis (FTIR) spectrum was employed to determine the existence of essential functional groups. The ultraviolet–visible spectroscopy (UV–V) is used to confirm the presence of π- π* transition within the activated carbon. Working in the similar direction, the presented work is an experimental investigation on ionic hydrogen storage in an activated carbon electrode integrated in a modified reversible polymer electrolyte fuel cell (PEMFC) for transport applications that is carried out. The ingress and egress of hydrogen within the developed PEMFC of 6.25 cm2 active area successfully stored 559.65mAh/g during charging and give out 510.51 mAh/g while discharging. The result analysis revealed the feasibility of the coconut shell based activated carbon to be a suitable candidate for hydrogen storage applications. [ABSTRACT FROM AUTHOR]

The persistent increase in the atmospheric concentration of carbon dioxide (CO2), the primary anthropogenic greenhouse gas contributing to global warming, makes research directed towards carbon capture and storage (CCS) imperative. In the past few years, among the available adsorbents, biochar has drawn significant interest as a promising carbon-based material for low-temperature CO2 capture from flue/fuel gas (such as biogas or gasification-derived syngas) owing to its environmentally friendly nature, cost-effective and facile preparation method, and sustainable adsorption performance. This work provides a review of recent studies on the development of biochar from biomass feedstocks and its subsequent modification through various approaches, including physical, chemical and physicochemical activations for post-combustion CO2 capture. An overview of the factors, including pyrolysis temperature, heating rate and time, and different modification methods, affecting the physicochemical attributes of biochar such as surface area, microporosity, surface properties and functional groups is presented. Biochar with a large micropore volume, a narrow microporosity (0.3–0.8 nm) and basic surface characteristics would be effective in adsorbing CO2 molecules. In this regard, physical modification of biochar is closely related to pore formation, whereas chemical modification emphasizes the creation of oxygen and nitrogen-containing functional groups; hence, they contribute to the enhanced CO2 capture through porosity development and surface chemistry alteration, respectively. Biochar has presented a strong selectivity towards CO2 compared to other gasses and has revealed a sustainable performance in multi-cycles of CO2 adsorption–desorption; these are crucial features to ensure the large-scale application of biochar for CO2 capture. [ABSTRACT FROM AUTHOR]

Beer is one of the most popular drinks in the world. In the process of beer brewing, the main solid by-products are brewers' spent grains. Those malt residues are produced in large quantities. This work focused on the utilization of BSG for the production of activated carbon. The raw material was obtained from the production of standard Pilsner beer. Technical and thermogravimetric analyzes were performed on BSG. The material was then subjected to low temperature carbonization to obtain semicoke, which was processed into activated carbon. During the experiments, two physical activation techniques and one chemical were tested: with CO2, with H2O, and solid NaOH. All of obtained materials were also examined by using FTIR technique. The results showed that steam activated carbon had bigger SBET (636 m2/g) than carbon dioxide activated (551 m2/g). The best results were obtained by using chemical activation by NaOH (3286 m2/g). Activated carbons obtained from BSG may be a feasible and cheap sorbent in water treatment plants, especially those located close to the brewery. [ABSTRACT FROM AUTHOR]

Plastic waste disposal is a major environmental problem worldwide. One recycling method for polymeric materials is their conversion into carbon materials. Therefore, a process of obtaining activated carbons through the carbonization of waste CDs (as the selected carbon precursor) in an oxygen-free atmosphere, and then the physical activation of the obtained material with CO2, was developed. Dyes such as methylene blue (MB) and malachite green (MG) are commonly applied in industry, which contaminate the water environment to a large extent and have a harmful effect on living organisms; therefore, adsorption studies were carried out for these cationic dyes. The effects of the activation time on the physicochemical properties of the activated materials and the adsorption capacity of the dyes were investigated. The obtained microporous adsorbents were characterized by studying the porous structure based on low-temperature nitrogen adsorption/desorption, scanning electron microscopy (SEM-EDS), elemental analysis (CHNS), Raman spectroscopy, X-ray powder diffraction (XRD), infrared spectroscopy (ATR FT-IR), thermal analysis (TG, DTG, DTA), Boehm's titration method, and pHpzc (the point of zero charge) determination. Moreover, adsorption studies (equilibrium and kinetics) were carried out. The maximum adsorption capacities (qm exp) of MB and MG (349 mg g−1 and 274 mg g−1, respectively) were identified for the obtained material after 8 h of activation. The results show that the use of waste CDs as a carbon precursor facilitates the production of low-cost and effective adsorbents. [ABSTRACT FROM AUTHOR]

Activated carbons exhibit a high grade of porosity, which together with structural stability, regenerability and cyclability makes them capable of achieving excellent hydrogen adsorption capacity. A further advantage comes from the ease of production and the use of recyclable and biocompatible materials. A simple way to produce activated carbons from amorphous cellulose involves procedures in which a pyrolysis process is combined with physical activation in CO 2. We used this approach by optimizing the production process tuning the activation times. The aim is to evaluate the influence of this process parameter on the formation of the specific surface area, the pore volume and fraction of micropores with a typical size <2 nm. The influence of these structural parameters on the hydrogen adsorption properties was then evaluated. The textural and adsorption characteristics were investigated using a commercial volumetric apparatus (ASAP 2460, Micromeritics) at −196 °C and pressures between 0 and 1 bar, while the morphological properties were investigated using scanning electron microscopy. The results show that the nanostructured samples are characterized by a very high degree of ultra-microporosity (<0.7 nm) with an average pore size between 0.5 and 0.6 nm and a high specific surface area, reaching maximum values around 1500 m2/g and micropore volume up to 0.58 cc/g. These morphological characteristics strongly influence the hydrogen adsorption properties, where the molecules adsorbed reach values very close to the coverage of ideal monolayer. The synthesized activated carbon samples show a higher hydrogen adsorption capacity than similar commercial materials tested under the same thermodynamic conditions. [Display omitted] • Easily tuning of ultra-microporosity. • Precursor influence on storage performance. • Hierarchical porous carbons and possibility hydrogen storage at low pressure. • Fully reversible hydrogen physisorption. • Amorphous cellulose as sustainable solution. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental and analytical study of the physicochemical properties of pyrolyzed biomass for use as alternative energy sources. Shea kernel shell (SKS) and groundnut shell (GS) are known agricultural wastes and were investigated using the slow pyrolysis technique to assess their energy generation potential. In this study, the KSK and GS were pyrolyzed at heating rate of 10 °C/min at ∼ 400, 500, 600 and 700oC respectively and the products (liquid oil, syngas, and activated char) were collected and characterized for their properties. The values for volatile matter (VM) for SKS and GS were reported to be ∼70% whereas their fixed carbon (FC) values were up to ∼ 41% and up to ∼25.67% respectively. The relatively high volatile matter and fixed carbon compositions signify good fuel potential of both feedstocks. The calorific value of the SKS ranged from 19.54 29.91 MJ/kg and 17.24 - ∼27.88 MJ/kg for GS. The hydrogen-to-carbon (H/C) ratios of ∼0.054 – 0.121 and ∼0.057 – 0.124 and oxygen-to-carbon (O/C) ratios of ∼0.736 – 0.845 and ∼0.663 – 0.754 were obtained for the GS products and SKS respectively indicating that, they possess good combustion properties. The aromatic and aliphatic functional properties were also detected with the activated biochar having higher energy densities, good combustion and chemical properties. The application of the products would enhance environmental sustainability through innovative waste management and by-products recycling. The implications of the results are discussed to demonstrate the scale-up potential of agrowastes as reliable sources of energy [ABSTRACT FROM AUTHOR]

Background: Interoception, the processing and integration of bodily signals, is crucial for emotional experiences and overall well-being. The interoceptive network, including the somatosensory cortices, has been recognized for its role in interoceptive and emotional processing. High-definition transcranial, direct-current stimulation (HD-tDCS) has been demonstrated to modulate brain activity in the primary somatosensory cortex (S1). Based on those findings, we hypothesized that anodal HD-tDCS over the right S1 would enhance interoceptive abilities and heighten emotional perception. Methods: Thirty-six healthy adults participated in two sessions separated by at least one week. A 20-min HD-tDCS stimulation (2 mA), and a sham stimulation, were applied in randomized order. Both conditions involved pre-tDCS physical activation by ergometer cycling. Interoceptive abilities were assessed before and after both sessions using a heartbeat-perception and respiratory-load task. Emotional perception was measured using four matched international affective picture system (IAPS) picture sets presented randomly. Results: Active HD-tDCS did not significantly improve interoceptive accuracy, interoceptive emotion evaluation, or interoceptive sensibility. However, a notable increase in cardiac interoceptive awareness was observed after active HD-tDCS. The expected enhancement of emotional processing was not observed. Conclusions: This study represents the first attempt to modulate interoceptive and emotional processing using HD-tDCS over S1. Although consistent enhancement was not observed, our findings provide insights into the modulation of interoceptive and emotional processes with HD-tDCS, suggesting avenues for further research. Further studies should consider the nuanced effects of stimulation techniques and the complex interplay between interoception and emotion. [ABSTRACT FROM AUTHOR]

Abstract In this study, activated carbon was synthesized using the almond shell and palm kernel by physical activation with water vapor and chemical activation with phosphoric acid (H3PO4) methods. Then, the structural and optical properties of the activated carbons were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and UV–Vis spectroscopy. The SEM images showed that in the raw sample of hard almond shell and palm kernel, there is no porosity and pores, but in the activated carbon samples, porosity and structural defects were clearly observed. The XRD patterns showed that porous and amorphous structure was formed in all samples synthesized with physical and chemical activation. The results of FTIR spectra of activated carbons showed that there are carbon functional groups in all samples. The optical absorption coefficient (α) of the activated carbon with physical and chemical activation methods was obtained in order of 105–106. The band gap measurement of porous nanostructures showed that the activated carbon synthesized with chemical and physical activation methods have energy gap (Eg) in region = 2.80 to 3.15 eV and urbach energy (EU) in region = 120 to 210 meV.

In this study, saturated and superheated agents were used to produce activated carbon from red calliandra (Calliandra calothyrsus) hydrochar. Proximate, ultimate, XRD, FTIR, thermal gravity analyzer, and SEM were used to characterize the prepared activated carbon. Chemical pollutants, such as benzene, chloroform, methylene blue (MB), and iodine, were used to test the adsorption ability. The hydrothermal and activation procedures were conducted at 250 °C and 800 °C, respectively. The activation of superheated agents effectively increased the BET surface area compared to saturation and thermal methods alone. The BET surface areas were measured as 470, 759, and 766 m²/g for thermal, saturation, and superheated methods, respectively. The superheated method preserved tiny mesopores (2–10 nm), while saturation produced large mesopores (20–50 nm), and the thermal method was more favorable for macropore development (>50 nm). Analyses of the structure of superheated activated carbon (HC–SS) showed that the aromatic layer (Lc) was thinner, which led to pores that were smaller. The adsorption test confirmed the superiority of the superheated method. For the pollutant species benzene, chloroform, MB, and iodine, HC–SS exhibited adsorption abilities of 146, 240, 81, and 618 mg/g, respectively.

In this study, activated carbon was synthesized using the almond shell and palm kernel by physical activation with water vapor and chemical activation with phosphoric acid (H3PO4) methods. Then, the structural and optical properties of the activated carbons were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and UV–Vis spectroscopy. The SEM images showed that in the raw sample of hard almond shell and palm kernel, there is no porosity and pores, but in the activated carbon samples, porosity and structural defects were clearly observed. The XRD patterns showed that porous and amorphous structure was formed in all samples synthesized with physical and chemical activation. The results of FTIR spectra of activated carbons showed that there are carbon functional groups in all samples. The optical absorption coefficient (α) of the activated carbon with physical and chemical activation methods was obtained in order of 105–106. The band gap measurement of porous nanostructures showed that the activated carbon synthesized with chemical and physical activation methods have energy gap (Eg) in region = 2.80 to 3.15 eV and urbach energy (EU) in region = 120 to 210 meV. [ABSTRACT FROM AUTHOR]

In this work, the Honduras Mahogany (Swietenia macropnylla King, SMK) seed husk was used as a novel biomass resource for producing activated carbon by physical activation. The texture characteristics and chemical characterization of resulting products were investigated in correlation with the process parameters. Based on the thermochemical properties of the SMK biomass, the process conditions were set to a rate of about 10 °C/min under nitrogen (N2) flow of 500 cm3/min heated to 500 °C, then switched to carbon dioxide (CO2) flow of 100 cm3/min in the specified activation conditions (i.e., temperature of 700–850 °C for holding times of 0–60 min). Our findings showed that the texture characteristics (i.e., surface area and pore volume) increased with an activation temperature increase from 700 to 800 °C for a holding time of 30 min but gradually decreased as the temperature increased thereafter. Similarly, the texture characteristics also indicated an increasing trend with the residence time extending from 0 min to 30 min but slightly decreased as the time was extended to 60 min. Therefore, the optimal activation conditions for producing SMK-based activated carbon should be set at 800 °C for a holding time of 30 min to obtain the maximal texture characteristics (i.e., BET surface area of 966 m2/g and total pore volume of 0.43 cm3/g). On the other hand, the chemical characteristics were analyzed by energy dispersive X-ray spectroscopy (EDS) and Fourier Transform infrared spectroscopy (FTIR), showing oxygen complexes contained on the hydrophilic surface of the resulting activated carbon. [ABSTRACT FROM AUTHOR]

In this study, we systematically study the efficient production method and electrochemical characteristics of activated carbons (AC) derived from rice husk (RH) and walnut shell (WS). In particular, the effectiveness of physical activation using carbon dioxide (CO2) was investigated and compared with the more common chemical activation method using potassium hydroxide (KOH). The results show that the KOH–activated samples have remarkable specific capacities, reaching 157.8 F g−1 for RH and 152 F g−1 for WS at 1 A g−1. However, the rate capability of AC obtained via KOH decreases significantly as the scanning rate increases, retaining only 51.5% and 68% of their original capacities for RH–KOH and WS–KOH, respectively, at 20 A g–1. In contrast, CO2–activated samples show a superior rate performance with a capacity retention of 75.6% for WS and 80% for RH at the same current density. In addition, electrochemical impedance spectroscopy (EIS) analysis shows that AC obtained via CO2 has a lower charge transfer resistance compared to its KOH counterparts. CO2–activated RH and WS electrodes show Rct values of 0.1 Ω and 0.24 Ω, respectively, indicating improved ion transport kinetics and surface area utilization. These results highlight the importance of activation techniques in tailoring the electrochemical behavior of biomass–derived carbon. This study not only expands the understanding of the interaction between activation, morphology, and performance but also indicates the potential of CO2 activation as an environmentally friendly and efficient alternative. As the field of sustainable energy storage advances, this work provides valuable guidance for the development of high–performance supercapacitor electrodes with less environmental impact. [ABSTRACT FROM AUTHOR]

The Indo-Gangetic plain of northern India is known for prevalent rice farming. Due to the lack of a rice straw waste management system, a large volume of rice straw is burned in the field. Therefore, we add value to rice straw by converting it into activated biochar and utilizing it to remove toxic metals from natural water. In this work, single-step physical activation (CO2 and H2O) of rice straw was planned and optimized the activation process parameters to get better biochar yield and surface area. The biochar activation parameters were optimized using the central composite design method. The CO2 activated biochar has an optimum surface area and product yield of 399.99 m2/g and 26.79 %, whereas H2O activated biochar has an optimum product yield and surface area of 31.53 % and 300 m2/g. The SEM analysis shows that CO2 activated biochar has a more uniform porous structure than H2O activated biochar. Cost analysis revealed that CO2 and H2O activated biochar had a lower manufacturing cost of 1.287 and 1.672 U.S. $/kg, respectively compared to other adsorbents. Arsenic and manganese removal efficiency in natural water was found to be greater than 95 % for both activated biochar.

Waste biomass, a renewable energy source, is inexpensive material that has great potential in sorption and electrochemical application. The selected waste materials (corncobs, coconut shells, walnuts, and pistachio husks) allow to close the production cycle and enable material recycling, which are important aspects in the hierarchy of waste management. The proposed methodology for production and activation of biochars can be used industrially due to highly porous structure, developed surface area, and sorption ability of the obtained activated carbons (AC). A significant increase (from 4 up to more than 10 times) in specific surface area (SSA) is observed for all samples after the CO2 activation process (0.5 h at 800 °C) up to 725 m2 g−1 for corncobs, 534.9 m2 g−1 for pistachio husks, 523 m2 g−1 for coconut shells, and 393 m2 g−1 for walnut husks. The highest value of SSA is achieved for the AC derived from corncobs. This material is evaluated for use as an adsorbent, revealing 99% removal of Rhodamine B (dye/AC ratio of 0.0017) and 69% removal of chromium (dye/AC ratio of 0.0028). Based on the adsorption kinetics analysis, it is demonstrated that the Cr(VI) undergoes physical adsorption, while RhB undergoes chemisorption. In addition, corncob-derived AC exhibits superior electrochemical performance in 6 M KOH compared to the nonactivated biochar. A specific capacitance of 70 F g−1 at 5 A g−1 is achieved, along with outstanding rate capability (45 F g−1 at 50 A g−1) and cycling stability (94% at 10 A g−1 after 10,000 cycles). In contrast, the nonactivated sample shows only 34 F g−1 at 5 A g−1 and 13 F g−1 at 50 A g−1, with a stability of 91.4%. [ABSTRACT FROM AUTHOR]

In this study, biocarbon was obtained from the waste material corn digest. Carbon adsorbents were obtained by physical activation of the precursor with CO2. Detailed physicochemical characterization of the biocarbon was carried out using low-temperature nitrogen adsorption/desorption, Boehm titration, zero-charge point (pHpzc) and iodine number. In addition, the sorption capacity of the biocarbon agents towards an aqueous solution of methylene blue and methyl red was determined, and the kinetics of the adsorption process were determined. The biocarbon adsorbents were characterized by an average developed specific surface area covering the range from 320 to 616 m2/g. The sorption capacity of the biocarbon adsorbents against methylene blue ranged from 40 mg/g to 146 mg/g, and for methyl red it covered the range from 31 mg/g to 113 mg/g. It was shown that the efficiency of organic dye removal by the obtained biocarbons depends on the initial concentration of the adsorbate solution, its mass, shaking rate, adsorbent–adsorbate contact time and temperature. The results obtained from the Langmuir and Freundlich kinetic models showed that the Langmuir model is the most suitable model for describing the adsorption of the studied pollutants on biocarbon. In turn, the adsorption kinetics of dyes is described according to the pseudo-second-order model. Adsorption studies also showed that as the process temperature increases, the removal efficiency of methylene blue and methyl red increases. [ABSTRACT FROM AUTHOR]

The increase in burning, deforestation, and the exorbitant use of fossil fuels have contributed to the increase in carbon dioxide emissions; this gas is responsible for the intensification of the greenhouse effect and radical climate changes. In this way, it becomes necessary to find alternatives to reduce its emission. Porous carbon materials synthesized from lignocellulosic waste can be employed in technologies for capture and utilization of CO2 due to the advantages such as selectivity, low-cost synthesis, high surface area and pore volume, and thermal and chemical stability. Considering the availability of Brazil nut biomass residues in the Amazon region, this article proposes to synthesize activated carbon from the lignocellulosic residue using physical and chemical activation methods for CO2 capture. The analysis of N2 adsorption–desorption isotherms proves the predominance of a microporous structure when using the two synthesis methods described here. In physical activation, the surface area was 912 m2/g, while, in chemical activation, it was 1421 to 2730 m2/g. The sample treated via the chemical method (BS6-K1) showed better performance in CO2 adsorption, with adsorption results of 3.8 and 6 mmol/g of CO2 at 25 ℃ and 0 °C, respectively, at 101 kPa. CO2 adsorption capacity is due to the high volume of ultramicropores. It is believed that the microporous carbon material synthesized from Brazil nut residues is an alternative precursor for carbon materials used as CO2 capture. [ABSTRACT FROM AUTHOR]

The main objective of the study was to prepare a series of new activated biocarbons by means of physical and chemical activation of elderberry inflorescence. The influence of carbon matrix nitrogenation/oxidation on the physicochemical properties and sorption abilities of the carbonaceous materials was investigated. The impact of initial dye concentration, pH and temperature of the system on methylene blue and rhodamine B removal efficiency was checked. It was shown that activation of elderberry inflorescences with CO2 or H3PO4, and their further modification by introducing nitrogen or oxygen functional groups, allowed us obtain a wide range of materials that differ significantly in terms of the chemical nature of the surface, degree of specific surface development and the type of porous structure generated. The samples prepared by chemical activation proved to be very effective in terms of cationic dyes adsorption. The maximum sorption capacity toward methylene blue and rhodamine B reached the level of 277.8 and 98.1 mg/g, respectively. A better fit to the experimental data was achieved with a Langmuir isotherm than a Freundlich one. It was also shown that the efficiency of methylene blue and rhodamine B adsorption from aqueous solutions decreased with increasing temperature of the system. [ABSTRACT FROM AUTHOR]

In the presented research, activated carbons from wheat bran were obtained as a result of pyrolysis and physical activation (CO2 or/and steam). In addition, the obtained materials were subjected to additional modification with superheated steam using the microwave radiation as an energy source. The detailed materials characterization was performed using low-temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction, thermal analysis (TG), Boehm's titration, point of zero charge (pHpzc), scanning electron microscopy (SEM) and FT-IR/ATR methods. Moreover, the sorption capacity towards methylene blue (MB) was determined. The activated carbons were characterized with a well-developed surface and pore structure (SBET = 339.6–594.0 m2/g; Vp = 0.157–0.356 cm3/g). Activation in the presence of steam and additional modification with microwave radiation resulted in much better development of the porous structure (SBET = 600.4 m2/g; Vp = 0.380 cm3/g). The materials were shown to possess amorphous structure and thermal stability up to the temperatures of ~450–500 °C. They have good adsorption capacity towards MB varying from 150 mg/g to 241 mg/g depending on activation manner. The adsorption can be described by the pseudo-second order model (R2 = 0.99) and fitted to the Langmuir isotherm. [ABSTRACT FROM AUTHOR]

The investigated materials were new biocarbons: FC (Fir Cone), FS (Fir Sawdust), FB (Fir Bark), BS (Birch Sawdust), BB (Birch Bark), AS (Acacia Sawdust), AB (Acacia Bark), OS (Oak Sawdust), OB (Oak Bark), HS (Hornbeam Sawdust)) obtained via pyrolysis and CO2 activation of wood waste (lignocellulosic biomass). In order to study the influence of the carbon precursor on the physicochemical properties of biocarbons there were used the precursors: cones, sawdust, and bark of various tree species. The obtained adsorbents were characterized based on the results, of the N2 adsorption, scanning electron microscopy (SEM), elemental analysis (CHNS), thermogravimetry (TG), derivative thermogravimetry (DTG), and differential thermal analysis (DTA), Fourier Transform Infrared Spectroscopy FT-IR (ATR) and the Boehm's titration method as well as pHpzc (the point of zero charge). The adsorption capacity and the temperature-programmed desorption (TPD) of ammonia were also studied. The obtained activated biocarbons were characterized by the large specific surface area (515 to 1286 m2/g) and the total pore volume (0.27 to 0.46 cm3/g) as well as the well-developed microporous structure (76 - 90%). The maximum NH3 adsorption capacity of the activated biocarbon was determined to be 2.93 mmol/g (FC (Fir Cone)). These results prove that the lignocellulosic precursors are appropriate for preparation of environmentally friendly and costeffective biocarbons. [ABSTRACT FROM AUTHOR]

This study used a physical activation method to prepare asphalt-pitch-derived activated carbon (Pitch AC) for an electric double-layer capacitor (EDLC) electrode. X-ray diffraction analysis and Raman spectroscopy were used to estimate the change in the crystal structure of Pitch AC with activation time. In addition, the textural properties of Pitch AC were studied by Brunauer-Emmett-Teller (BET), Dubinin-Radushkevich (DR) and non-localized density functional theory (NLDFT) equations with N2/77K isotherm adsorption-desorption curves. The electrochemical performance of the Pitch AC was analyzed using a coin-type EDLC with 1 M SBPBF4/PC via galvanostatic charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The specific surface area and total pore volume were 990–2040 m2/g and 0.42–1.51 cm3/g, respectively. The pore characteristics of the Pitch AC varied according to the activation time and changed from a microporous structure to a micro-mesoporous structure as the activation time increased. The electrochemical performance analysis also found that the specific capacity was increased from 43.6 F/g to 84.5 F/g at 0.1 A/g as activation time increased. In particular, Pitch AC-9 exhibited the best electrochemical performance (rectangular CV curve, reversible GCD, lowest ion charge transfer resistance and Warburg impedance). In addition, Pitch AC-9 was confirmed to have a specific capacitance similar to commercial activated carbon for EDLC (YP-50F). Therefore, it was considered that Pitch AC could replace commercial activated carbon for EDLC because it has excellent pore characteristics and electrochemical performance despite being manufactured through a very low-cost precursor and a simple process (physical activation method). [ABSTRACT FROM AUTHOR]

In the work, water caltrop husk (WCH), locally agricultural residue generated in large quantities, was evaluated as a potential precursor for preparing mesoporous activated carbon (AC) by physical activation under the matrix of activation temperature (600–900℃) and holding times (i.e., 0–150 min). The pore and chemical properties of the resulting AC products, including porosity, true density, elemental analysis (EA), scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS), and Fourier-transform infrared spectroscopy (FTIR), were determined to find the optimal activation conditions. From the data on the analysis of AC properties, the activation temperature at around 800℃ for holding time of 45 min was observed to produce the optimal WCH-AC product with the Brunauer–Emmett–Teller (BET) surface area of 972.56 m2/g, total pore volume of 0.55 cm3/g, and porosity of 0.476. Its corresponding mesopore volume and mesopore percentage reached up to 0.19 cm3/g and 35%, respectively. In addition, the opposite effect was also observed for the resulting AC products activated at 800℃ under different holding times, indicating the pore enlargement and/or collapse at holding time increased from 45 to 60 min. Based on the chemical analyses, the high oxygen content was found on the surface of the resulting AC product, which could be indicative of slight polar nature (i.e., hydrophilicity) due to the oxygen-containing functional groups. [ABSTRACT FROM AUTHOR]

A new composite adsorbent was created by activating bentonite, a sludge, to improve its adsorption capability. These innovative adsorbents address sulfate ion pollution in wastewater treatment. Researchers used various techniques to study the composite’s surface structure, chemical, elemental, and mineralogical characteristics. The composite adsorbs over 864 mg/L of sulfate ions from wastewater with an initial concentration of 900 mg/L, demonstrating its high removal efficiency of 96%.

Background: Interoception, the processing and integration of bodily signals, is crucial for emotional experiences and overall well-being. The interoceptive network, including the somatosensory cortices, has been recognized for its role in interoceptive and emotional processing. High-definition transcranial, direct-current stimulation (HD-tDCS) has been demonstrated to modulate brain activity in the primary somatosensory cortex (S1). Based on those findings, we hypothesized that anodal HD-tDCS over the right S1 would enhance interoceptive abilities and heighten emotional perception. Methods: Thirty-six healthy adults participated in two sessions separated by at least one week. A 20-min HD-tDCS stimulation (2 mA), and a sham stimulation, were applied in randomized order. Both conditions involved pre-tDCS physical activation by ergometer cycling. Interoceptive abilities were assessed before and after both sessions using a heartbeat-perception and respiratory-load task. Emotional perception was measured using four matched international affective picture system (IAPS) picture sets presented randomly. Results: Active HD-tDCS did not significantly improve interoceptive accuracy, interoceptive emotion evaluation, or interoceptive sensibility. However, a notable increase in cardiac interoceptive awareness was observed after active HD-tDCS. The expected enhancement of emotional processing was not observed. Conclusions: This study represents the first attempt to modulate interoceptive and emotional processing using HD-tDCS over S1. Although consistent enhancement was not observed, our findings provide insights into the modulation of interoceptive and emotional processes with HD-tDCS, suggesting avenues for further research. Further studies should consider the nuanced effects of stimulation techniques and the complex interplay between interoception and emotion.

In recent years, porous carbon materials with high specific surface area and porosity have been developed to meet the commercial demands of supercapacitor applications. Carbon aerogels (CAs) with three-dimensional porous networks are promising materials for electrochemical energy storage applications. Physical activation using gaseous reagents provides controllable and eco-friendly processes due to homogeneous gas phase reaction and removal of unnecessary residue, whereas chemical activation produced wastes. In this work, we have prepared porous CAs activated by gaseous carbon dioxide, with efficient collisions between the carbon surface and the activating agent. Prepared CAs display botryoidal shapes resulting from aggregation of spherical carbon particles, whereas activated CAs (ACAs) display hollow space and irregular particles from activation reactions. ACAs have high specific surface areas (2503 m2 g−1) and large total pore volumes (1.604 cm3 g−1), which are key factors for achieving a high electrical double-layer capacitance. The present ACAs achieved a specific gravimetric capacitance of up to 89.1 F g−1 at a current density of 1 A g−1, along with a high capacitance retention of 93.2% after 3000 cycles. [ABSTRACT FROM AUTHOR]

• Municipal GW can be used as a sustainable and low-cost precursor to generate AC. • Activation process enhanced the surface area and internal micro-mesoporous structure. • Higher activation temperature has significant influence on AC characteristics. • No significant difference in AC characteristics generated in 1-step and 2-step. • Carbon structure, thermal stability of synthetic AC is comparable to commercial AC. This research aims to investigate the potential of the municipal garden waste as a new precursor to generate activated carbon by CO 2 activation. TGA analysis shows the distinctive thermal degradation nature of garden waste. The activation of the garden waste enhanced its surface area where well-developed internal micro-mesoporous structure is also noticed. The results suggest that most of the volatiles decomposed at temperatures beyond 450 °C. A decrease in char yield, increase in surface area and pore volume and weakening of oxygen and hydrogen-containing groups were observed at higher pyrolysis temperatures. Raman and XRD support the amorphous and porous graphitic structure of carbon. Carbonization temperature of 500 °C and activation temperature of 800 °C were shown to produce the better-quality AC where highest surface area of 363.32 m2/g and highest pore volume of 0.095 cm3/g was achieved. Compared to the pyrolysis temperature, pyrolysis steps did not have notable contribution to the AC characteristics. [ABSTRACT FROM AUTHOR]

Coal and biomass are two important carbonaceous feedstocks for producing carbon materials. Distinct composition of them might affect pore development of resulting activated carbon (AC) during activation. This was investigated herein via activating anthracite coal and poplar biomass via physical activation (activators: CO 2 and H 2 O) and chemical activation (activators: K 2 C 2 O 4 and ZnCl 2) under the same conditions. The results indicated that the activation of highly aromatic coal produced much higher yield of AC than that from poplar sawdust (ca. 90 % versus ca. 25–37 %). Nonetheless, this was at the cost of limited development of pore structure of AC-coal (121.1 m2g-1 with K 2 C 2 O 4 and 190.8 m2g-1 with H 2 O as an activator). Conversely, abundant aliphatics in poplar created more developed pore structures in AC-poplar (949.0 m2g-1 with K 2 C 2 O 4 and 588.6 m2g-1 with H 2 O), which also enhanced yields of AC-poplar through condensation reactions catalyzed with ZnCl 2 (AC yield: 33.7 % vs 22.8 % from blank experiment). The fused ring structures in coal were hardly activated via cracking with K 2 C 2 O 4. However, H 2 O could oxidize some carbonaceous organics on AC-coal, introducing oxygen-containing species, further cracking of which formed pores. This was an important route for generating pore structures in AC-coal. [Display omitted] • Highly fused aromatic rings in coal inhibit pore development via physical/chemical activation. • Aliphatic structures in poplar are main contributor to pores but diminishes solid yield. • H 2 O is more active than CO 2 for creating pores via cracking/gasification of poplar or coal. • H 2 O oxidizes coal to generate aliphatic O-containing species and then forms pores via cracking. • Ethers, ketones and esters/lactones in coal are cracked over K 2 C 2 O 4 or ZnCl 2 , forming limited pores. [ABSTRACT FROM AUTHOR]

Because of its high adsorption capacity, activated carbon is frequently employed as an effective adsorbent. Activated carbon is a main element for treatment of wastewater, groundwater and water purification. The activating agents greatly affects the porosity and surface area of the produced activated carbon. In this study, the use of agricultural leftovers for the production of activated carbon is discussed in detail. The pyrolysis stage is investigated in relation to a number of process variables. The effects of physical and chemical activation circumstances on the properties of activated carbon are discussed. Under controlled process conditions, many active carbons with Brunauer–Emmett–Teller surface areas ranging from 250 to 2,410 m2/g and pore volumes ranging from 0.022 to 91.4 cm3/g were produced. A review of reaction kinetic modelling applied to pyrolysis of agricultural wastes is also carried out. In this study, effort has been given to show the preparation of activated carbon from various agricultural residues. Also the comparisons of different activated carbon prepared from various agricultural residues have been shown. In the present review, the preparation of activated carbon by treating with different chemicals has also been incorporated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyrolysis of four types of citrus wastes was studied; • The derived biochars and activated carbons could be used as Cu(II) adsorbents; • The adsorption capacity of the biochars are comparable with the literature. A route based on pyrolysis and physical activation with H 2 O and CO 2 was proposed to reuse citrus waste traditionally discarded. The citrus wastes were orange peel (OP), mandarine peel (MP), rangpur lime peel (RLP), and sweet lime peel (SLP). The main aim was to use the solid products of this new route as adsorbents for Cu(II) ions. Copper ions are among the most important water pollutants due to their non-degradability, toxicity, and bioaccumulation, facilitating their inclusion and long persistence in the food chain. Besides the solid products, the liquid and gaseous fractions were evaluated for possible applications. Results showed that the citrus waste composition favored the thermochemical treatment. In addition, the following yields were obtained from the pyrolysis process: approximately 30 % wt. of biochar, 40 % wt. of non-condensable gases, and 30 % wt. of bio-oil. The biochars did not present a high specific surface area. Nevertheless, activated carbons with CO 2 and H 2 O presented specific surface areas of 212.4 m2/g and 399.4 m2/g, respectively, and reached Cu(II) adsorption capacities of 28.2 mg g−1 and 27.8 mg g−1. The adsorption kinetic study revealed that the equilibrium was attained at 60 min and the pseudo-second-order model presented a better fit to the experimental data. The main generated gases were CO 2 , which could be employed as an activating agent for activated carbon production. d -limonene, used for food and medicinal purposes, was the main constituent of the bio-oil. [ABSTRACT FROM AUTHOR]

In this study, biocarbon was obtained from the waste material corn digest. Carbon adsorbents were obtained by physical activation of the precursor with CO2. Detailed physicochemical characterization of the biocarbon was carried out using low-temperature nitrogen adsorption/desorption, Boehm titration, zero-charge point (pHpzc) and iodine number. In addition, the sorption capacity of the biocarbon agents towards an aqueous solution of methylene blue and methyl red was determined, and the kinetics of the adsorption process were determined. The biocarbon adsorbents were characterized by an average developed specific surface area covering the range from 320 to 616 m2/g. The sorption capacity of the biocarbon adsorbents against methylene blue ranged from 40 mg/g to 146 mg/g, and for methyl red it covered the range from 31 mg/g to 113 mg/g. It was shown that the efficiency of organic dye removal by the obtained biocarbons depends on the initial concentration of the adsorbate solution, its mass, shaking rate, adsorbent–adsorbate contact time and temperature. The results obtained from the Langmuir and Freundlich kinetic models showed that the Langmuir model is the most suitable model for describing the adsorption of the studied pollutants on biocarbon. In turn, the adsorption kinetics of dyes is described according to the pseudo-second-order model. Adsorption studies also showed that as the process temperature increases, the removal efficiency of methylene blue and methyl red increases.

The main objective of the study was to prepare a series of new activated biocarbons by means of physical and chemical activation of elderberry inflorescence. The influence of carbon matrix nitrogenation/oxidation on the physicochemical properties and sorption abilities of the carbonaceous materials was investigated. The impact of initial dye concentration, pH and temperature of the system on methylene blue and rhodamine B removal efficiency was checked. It was shown that activation of elderberry inflorescences with CO2 or H3PO4, and their further modification by introducing nitrogen or oxygen functional groups, allowed us obtain a wide range of materials that differ significantly in terms of the chemical nature of the surface, degree of specific surface development and the type of porous structure generated. The samples prepared by chemical activation proved to be very effective in terms of cationic dyes adsorption. The maximum sorption capacity toward methylene blue and rhodamine B reached the level of 277.8 and 98.1 mg/g, respectively. A better fit to the experimental data was achieved with a Langmuir isotherm than a Freundlich one. It was also shown that the efficiency of methylene blue and rhodamine B adsorption from aqueous solutions decreased with increasing temperature of the system.

In this work, both pyrochar and activated carbon were prepared by physical activation (i.e., saturation and superheated) by involving a thermal agent as a comparison. The effects of three agents on the pore development of activated carbon from a new material, Calliandra calothyrsus, were observed in detail. The BET surface area and the iodine index of the prepared activated carbon were used as pyrochar selection. Proximate, ultimate, XRD, FTIR, TGA, and SEM were used to characterize the physical and chemical properties of the product. Pyrochar pores were found to develop significantly at 350 °C, indicated by an increase in the BET surface area and iodine index. Pyrochar from a temperature of 350 °C was then selected as a precursor of activated carbon. S–SS and SS–S activated carbon samples were declared to have the highest iodine index (870 mg/g) and the highest BET surface area (642 m2/g), respectively. The pore distribution data showed that the superheated agent widened the pore and provided an active site for iodine adsorption, while the saturation agent resulted in a narrower pore for an increase in the BET surface area. S–SS has a lower C fraction and higher O fraction than SS–S. The SS–S samples have both Vol and Volmic for an increased BET surface area. The number of aromatic layers and –OH functional groups of the S–SS sample is more convenient for iodine enhancement than for increasing the BET surface area. Less water droplets and greater energy from superheated resulting pores widen, increasing the aromatic layer and providing additional functional groups. [ABSTRACT FROM AUTHOR]

The objective was to show the implementation of a strategy for physical. activation in Mexican Institute of Social Security (IMSS-of its acronym in spanish: Instituto Mexicano del Seguro Social-), for 27 adults and older adults (74% women and 26% men) aged 53-71 (M=62.4, DT=5.3); evaluated through a sociodemographic and health card, an inventory of symptoms and a test of Physical Activity -AF-(Méndez, 2008). The magnitude of the strategy's effect on physical performance was evaluated using Cohen's d, getting big changes (d=0.868 - d=0.997) in symptoms, balance, arm strength, flexibility and speed; medium changes were observed (d= 0.440-d=0.650) in the effect on health, legs strength, agility and endurance. The conclusion focuses the imperative need to adapt health programs for their effectiveness and the positive effect of the strategy on the participants' health, symptoms and physical ability. [ABSTRACT FROM AUTHOR]

The use of porous carbon materials for fabrication of high-performance supercapacitors has attracted significant attention in recent years especially for applications in supercapacitors. In the present work, carbon nanoparticle is successfully fabricated by the home-made thermal plasma system and acetylene gas as the raw materials. To achieve this, a direct current (DC) plasma torch is employed. Also, a cooling chamber is used to create a neutral environment and collect carbon nanoparticles. Further, the structure and morphology of the nanoparticles are examined. Through the proposed procedure, carbon nanoparticles with spherical geometry and size of about 20 nm can be produced. In this approach, nanoparticles are physically activated by steam while the specific surface area reaches 1165 m 2 g - 1 and the average pore diameter is measured at 1.7141 nm. The activated carbon nanoparticles are employed in the production of supercapacitor electrodes showing significantly higher specific capacitances reaching up to 853 F g - 1 . Furthermore, this supercapacitor shows a high energy density of 76 Wh kg - 1 at 0.5 A g - 1 with competent cycling performance indicative of its potential suitability for use in electrochemical capacitor production. Therefore, the results of this study verify that activated carbon nanoparticles produced with thermal plasma technique possess suitable properties for supercapacitor production. [ABSTRACT FROM AUTHOR]

The generation of liquid waste containing dyes and complex organic compounds is a problem in the textile industries. In this work, we evaluated the use of macadamia nut residue as a precursor of a biochar for the treatment of these effluents through the adsorption process. The macadamia nut endocarp undergoes a sequential treatment involving pyrolysis at 600 °C followed by physical activation with CO 2 and H 2 O vapor at 700 °C. Characterization of the resulting macadamia nut residue-derived biochar (MB) is accomplished through various techniques, including X-ray diffractometry (XRD), thermogravimetric analysis (TGA), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), nitrogen physisorption analysis and the pH at the zero charge point (pH ZCP). Performance studies reveal that pH exerts minimal influence on the adsorption phenomenon. The Elovich kinetic model effectively describes the adsorption kinetics for both β-naphthol and Reactive Black 5 (RB5), with adjusted coefficients of determination (R2 adj) of 0.99 and 0.94, respectively. Further analysis using the intraparticle diffusion model demonstrates that β-naphthol adsorption kinetics involve multiple mechanisms, while RB5 adsorption is predominantly governed by intraparticle diffusion. Equilibrium adsorption data for both adsorbates fit well with the Sips isothermal model, yielding maximum adsorption capacities of q max β-naphthol = 15.16 mg∙g−1 and q max RB5 = 3.08 mg∙g−1 at 55 °C. The adsorption process for both compounds is spontaneous and endothermic, based on the enthalpy values, it can be inferred that the β-naphthol adsorption is governed by weak van der Waals forces, indicating physisorption. As for RB5, the enthalpy value suggests that the phenomenon occurs due to electrostatic interactions between the molecule and the surface groups with higher energy involved. This study highlights the potential of macadamia nut residue biomass as a precursor for biochar, demonstrating its favorable attributes for application as an effective adsorbent material in the removal of organic compounds such as β-naphthol and RB5 from wastewater streams within the textile industry. [Display omitted] • Macadamia biochar as a potential support for catalytic materials and dyes removal. • Accurate adsorption kinetics described by the Elovich model for β-naphthol and RB5. • Study unveils the nature of adsorption interactions in textile wastewater treatment. • Promising results highlight residue-derived biochar as an eco-friendly solution. [ABSTRACT FROM AUTHOR]

The properties of three types of CoMo/USY catalysts with different synthesized methods have been studied. The sequential and co-impregnation methods followed by activation using calcination and reduction process have been conducted. The properties of the catalysts were examined using Fourier-transform-infrared (FTIR) spectroscopy, X-ray diffraction (XRD) with refinement, and surface area analyzer (SAA). The FTIR spectrum study revealed the enhanced intensity of its Bronsted acid site, and the XRD diffractogram pattern verified the composition of pure metals, oxides, and alloys in the catalyst. The SAA demonstrated the mesoporous features of the catalyst. Scanning electron microscopy showed an irregular particle morphology. Additional analysis using the transmission electron microscopy indicated that the metal has successfully impregnated without damaging the USY structure.

In the presented research, activated carbons from wheat bran were obtained as a result of pyrolysis and physical activation (CO2 or/and steam). In addition, the obtained materials were subjected to additional modification with superheated steam using the microwave radiation as an energy source. The detailed materials characterization was performed using low-temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction, thermal analysis (TG), Boehm’s titration, point of zero charge (pHpzc), scanning electron microscopy (SEM) and FT-IR/ATR methods. Moreover, the sorption capacity towards methylene blue (MB) was determined. The activated carbons were characterized with a well-developed surface and pore structure (SBET = 339.6–594.0 m2/g; Vp = 0.157–0.356 cm3/g). Activation in the presence of steam and additional modification with microwave radiation resulted in much better development of the porous structure (SBET = 600.4 m2/g; Vp = 0.380 cm3/g). The materials were shown to possess amorphous structure and thermal stability up to the temperatures of ~450–500 °C. They have good adsorption capacity towards MB varying from 150 mg/g to 241 mg/g depending on activation manner. The adsorption can be described by the pseudo-second order model (R2 = 0.99) and fitted to the Langmuir isotherm.

[Display omitted] • Self-doped porous activated biochar derived from Venice lagoon's Sargassum brown macroalgae. • Thermochemical carbonization followed by CO 2 physical activation. • ABS exhibits a remarkable specific surface area of 821 m2/g and heteroatoms (N, O, and S) doping. • ABS-based electrodes reached energy densities in supercapacitor of 12.4 Wh kg−1 at 57.4 W kg−1. • Flexible solid-state supercapacitor displayed a remarkable 97% specific capacitance retention. In this study, self-doped porous activated biochar derived from Venice lagoon's Sargassum brown macroalgae (ABS) has been successfully prepared through thermochemical carbonization (pyrolysis) followed by CO 2 physical activation and used as electrodes for supercapacitor (SC) applications. The ABS exhibits a remarkable specific surface area of 821 m2g–1 and heteroatoms (N, O, and S) doping, both key features to attain high-performance carbon-based SC electrodes. The electrochemical performances of ABS-based SCs were assessed in three different electrolytes. Two are aqueous (i.e., 1 M H 2 SO 4 and 8 M NaNO 3), while the third one is the prototypical organic, namely 1 M TEABF 4 in acetonitrile. In these three electrolytes, the ABS-based electrodes exhibited specific capacitance values (C g) of 109.5, 79.0, and 64.3Fg–1, respectively, at a current density of 0.1 Ag–1. The capacitive performance resulted in SC energy densities of 3.45 Wh kg−1 at 22.5 W kg−1, 6.3 Wh kg−1 at 36.1 W kg−1, and 12.4 Wh kg−1 at 57.4 W kg−1 and maximum power densities of 147, 222, and 378 kW kg−1 in the acidic, quasi-neutral aqueous electrolyte and organic electrolyte, respectively. The ABS electrodes were used to realize a flexible solid-state SC based on the sulfonated polyether ether ketone (SPEEK):functionalized niobium disulfide flakes (f-NbS 2) composite membrane. The flexible solid-state SC displayed a remarkable 97% C g retention even under various mechanical stresses, including bending up to 1000 times and folding angles up to 180°, while keeping a Coulombic efficiency above 98%. This study reveals ABS as a promising sustainable source of active materials for SCs. The remarkable performance of ABS-based SCs can be attributed to their multi-scale porosity, heteroatom doping, and enhanced surface wettability, providing abundant active sites for charge accumulation, and efficient electrolyte diffusion, thus highlighting its potential as a sustainable solution for energy storage applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly porous activated carbon was synthesized through physical method. • Biomass from Strychnos Potatorum was used as a raw material. • Symmetric supercapacitor devices exhibit a specific capacitance of 281 F g−1 at 0.2 A g−1. • Excellent retention of more than 98.2 % after 5000 cycles. Herein, low-cost activated carbon (AC) prepared from Strychnos Potatorum shells using CO 2 as an activating agent via physical activation technique. Waste biomass-derived AC have the merits of excellent conductivity and highly porous with high-surface area. Electrochemical assessments indicated that the prepared Strychnos Potatorum derived activated carbon (SPAC) electrode exhibited superior electrochemical performance. The experimental data showed that the specific capacitance of 352.5 F g−1 at 0.5 A g−1 and retained 140 F g−1 at 20 A g−1. Symmetric supercapacitors SPAC//SPAC device displayed an impressive specific capacitance of 147 F g−1 at 0.1 A g−1 and an energy density of 20.41 W h kg−1 at 100 W kg−1 and retained 2.7 Wh kg−1 at 10000 W kg−1. Furthermore, these supercapacitors demonstrated exceptional cyclability, maintaining capacity retention of 92.3 % over 10,000 charge–discharge cycles at 1 A g−1. This research work underscores the promising potential of AC materials derived from Strychnos Potatorum shells in development of high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

[Display omitted] • The CO 2 /H 2 O co-activation and the NO-char reaction are systematically studied. • The mechanism of the synergistic activation of CO 2 and H 2 O is described. • C − O promotes the conversion of NO. • The co-activated carbon has many micropores, oxygen groups and ordered structures. • The co-activated carbon has high adsorption and reducing properties. Adsorption and reduction of NO by coal-based activated carbon has the advantages of cleanliness, wide distribution of raw materials and low cost. In this paper, activated carbons with 30, 50 and 70 wt% burn-off rates were prepared via physical activation of Zhundong coal by CO 2 , H 2 O and 40 % H 2 O/60 % CO 2 at 700 °C, and NO removal rates were tested in both temperature-programmed and isothermal experiments. The synergistic effects of CO 2 /H 2 O co-activation on the morphology, pore and chemical structures of activated carbons and the adsorption and reduction of NO by activated carbon are systematically investigated for the first time. The results show that the pore size distribution and functional group contents of activated carbons varied with the burn-off rate. At a low burn-off rate of 30 wt%, the H 2 O/CO 2 co-activated carbon exhibits the best adsorption and reduction performance for NO among all samples, which may be attributed to its largest microporous area and abundant oxygen-containing functional groups. As the burn-off rate increased, the micropores were deeply etched, enlarged and/or merged to form mesoporous structures, leading to a decrease in the number of micropores and the NO conversion. At the same burn-off rate and similar specific surface area, the NO conversion increases with increasing C − O content, suggesting that NO reduction is encouraged by C − O enrichment. Coal-based porous carbons from H 2 O/CO 2 co-activation at a low burn-off rate has the advantage of high adsorption and reduction performance for NO. In addition, the effect of active metal elements in coal-based activated carbon on the catalytic reduction of NO was briefly discussed. A novel synergistic activation method was used to prepare activated carbon for reduction of NO at moderate temperatures and the synergistic mechanism is proposed. [ABSTRACT FROM AUTHOR]

As the most commonly used method for industrial activated carbon preparation, physical activation is usually accompanied by significant loss of raw materials, especially when the pore structure of activated carbon is well developed. This not only reduces yields, but also increases costs. To enhance both yield and pore structure of activated carbon, we proposed a facile and scalable method called "fast pyrolysis-physical activation". After fast pyrolysis, although the initial pore volume of the semi-coke decreases, the rapid release of volatiles promotes the increase of mesopore and macropore volumes and the development of micron-scale cracks, which is beneficial for CO 2 mass transfer and reduces diffusion resistance. Therefore, compared to slow pyrolysis, the activated carbon produced through this method has a higher pore volume (increased by 25.9 %–30.0 %) and a larger S BET (increased by 26.7 %–38.3 %), while the yield remains almost unchanged. Consequently, due to the increase in pore volume and high yield of the activated carbon, the CO 2 adsorption capacity (25 °C, 1 bar) of ACB-K700 increases from 2.02 mmol/g to 2.37 mmol/g compared to ACB-M700, and the total CO 2 adsorption capacity of activated carbon prepared from the same mass of raw coal (1 g) increases from 1.07 mmol to 1.16 mmol. Due to the pre-formed pores inside the semi-coke, the gas activator molecules are able to penetrate deep into the particles, which not only reduces the ineffective etching that occurs on the surface, but also promotes the development of pore structure. In conclusion, this study provides a new pore development model for physical activation, and also provides a new method to produce activated carbon rapidly and massively, while the pore structure is well developed. • A new pore-forming mechanism is proposed based on fast pyrolysis-physical activation. • The S BET significantly increases by 26.7–38.3 % at similar yields (49.12–53.01 %). • The rapid escape of volatiles increases the pore volume for semi-coke. • Pre-formed pores in the semi-coke reduces ineffective etching of activator. • The CO 2 absorption capacity at 25 °C and 1 bar can be up to 2.37 mmol/g. [ABSTRACT FROM AUTHOR]

The rising levels of pollutants has provoked the search for advanced technologies to minimize their effect on environments. The continuous adsorption column is applied to study CO2 adsorption using two types of adsorbents. The commercial activated carbon Norit-RB2 and developed activated carbon from economic date stone are utilized for the adsorption study. The morphological and surface characteristics have been examined by BET analyzer and scanning electron microscope. The effect of flow rate, temperature, and initial adsorbate volume on breakthrough performance has been investigated. The effectiveness of the CO2 capture was examined in terms of adsorbate capacity, column efficiency, usable bed length, LMTZ, and utilization factor. The very steep adsorption profiles specify acceptable adsorbent uptake utilization under a breakthrough state. The CO2 loading of 1.66 mmol/g was reached with a column efficiency of 94.9% for biomass-derived adsorbent at 298 K temperature. The lower CO2 loading of 0.99 mmol/g and column efficiency of 92.8% have been determined for commercial activated carbon. The reduced LMTZ equal 1.29 cm and enhanced f equals to 0.974 at 298 K and Co = 5% are observed for the biomass-derived adsorbent. The findings acclaim that activated carbon derived from date pits is decidedly promising to capture CO2 by adsorption. [ABSTRACT FROM AUTHOR]