Activated Carbon Research Articles

Facile synthesis of Co/Fe bimetallic doped Ni3S2 nanosheets and supercapacitor performance

Ni3S2 is an outstanding electrode material due to its high theoretical specific capacity, however, in practical research, the higher theoretical capacity is difficult to show, and the change of the structure in the cycling process affects the cycling stability, which limits its practical application. To address these issues, this study presents a strategy to synthesize Fe and Co bimetallic doped Ni3S2 nanosheets on nickel foam (NF) surface. This strategy introduces bimetallic atoms quickly and easily while synthesizing nanosheet structures, and the resulting synergistic interactions between the bimetals and the mutual support effect of the nanosheets can effectively enhance electron transfer and improve cycling stability. The electrochemical results show that the Fe and Co-doped sample (Ni3S2-Co/Fe-5) exhibits a specific capacitance of 3351 F·g−1 at 1 A·g−1 in the three-electrode system, which is nearly five times higher than the specific capacity of the undoped Fe and Co-doped sample (Ni3S2), and the capacity retention rate after cycling 5000 cycles at a current density of 10 A·g−1 is 100 %, the prepared sample (Ni3S2-Co/Fe-5) was assembled with activated carbon (AC) to form a hybrid supercapacitor, which could provide a maximum power density of 9818 W·kg−1, a maximum energy density of 66.25 Wh·kg−1, and a capacity retention of 94.5 % after 10,000 cycles, with a capacity loss of only 5.6 %.

Global characterization of modelled micronekton in biophysically defined provinces

Micronekton are the mid-trophic level of the ecosystem and contribute to active carbon export to the deep ocean through diel vertical migrations. Better characterization of micronekton functional groups depending on relationships to environmental variables is useful for the management of marine resources, the conservation of biodiversity and a better understanding of climate change impacts. For this purpose, regionalization of global ocean into homogeneous provinces is an approach that is generating increasing interest. However, published regionalizations efforts (i) derived from environmental forcings, that do not specifically focus on micronekton and (ii) derived from acoustic backscatter, which do not allow direct estimates of micronekton biomass. Here, we propose to fill the gap between biophysical regionalizations and micronekton biomass. We notably defined biophysical biomes using global environmental variables known to affect micronekton: temperature of the epipelagic layer, temperature stratification, and net primary production (NPP). Six biophysical biomes were defined with a clustering method. A characterization of these biophysical biomes with simulated micronekton from the SEAPODYM-LMTL model displayed biome-specific relationships between biomass and the environmental variables used in the clustering (i.e. biomasses mostly structured by NPP and temperature). Biophysical biomes also displayed specific vertical structures suggested by modelled micronekton functional groups ratios. Then, a validation of biophysical biomes’ boundaries was performed to identify potential vertical structure reorganization in acoustic backscattering response from adjacent biomes. The regionalization identified homogeneous areas in terms of acoustic vertical structure, which were also different between adjacent biomes. Finally, a comparison with another biomes’ definition computed from micronekton biomasses suggested that environmental variables can account for only some of the variability of the micronekton structures.

The Spatial Spillover Effect and Mechanism of Carbon Emission Trading Policy on Pollution Reduction and Carbon Reduction: Evidence from the Pearl River–West River Economic Belt in China

Abstract: China faces issues such as air pollution and global climate change, and the Carbon Emission Trading Policy (CETP) has attracted considerable attention as a core policy tool for achieving the "dual carbon" goals. Based on panel data from the Pearl River–West River Economic Belt (PRWREB) from 2008 to 2021, we use the Synthetic Control Method (SCM) and Spatial Difference-in-Differences (S-DID) models to explore the pollution reduction and carbon reduction effects of the CETP and its spatial heterogeneity. Our analysis reveals several interesting insights. First, the CETP has promoted a 34.1% overall reduction in pollution and carbon levels in the pilot areas, with sustained effects. Moreover, spatial spillover effects can reduce the pollution and carbon levels in the economic belt by 29.9%. Second, the pollution and carbon reduction effects of the CETP are more significant in regions with better economic development and active carbon trading. It has the best synergistic reduction effects on CO2 and SO2 but is less effective in reducing PM2.5. Third, the spillover effects of the CETP on technological innovation are greater than the direct effects, with the most noticeable pollution and carbon reduction outcomes. The overall negative effect on industrial structure is that it fails to promote pollution and carbon reduction. The emission reduction mechanisms vary for different targets: CO2 and PM2.5 are related to energy efficiency, SO2 to advancing industrial structure, and smoke and dust to technological innovation. Based on the research conclusions, we propose to improve the coordinated governance system for carbon and pollution, advance pollution and carbon reduction according to local conditions, and implement targeted emission reduction and efficiency enhancement.

A state-of-the-art review on lignocellulosic biomass-derived activated carbon for adsorption and photocatalytic degradation of pollutants: a property and mechanistic study.

A promising water treatment method involves using biomass-derived activated carbon (AC) to remove emerging pollutants from wastewater due to its adsorption capacity, cost-effectiveness, and sustainability. Notwithstanding, the existing literature lacks comprehensive studies that specifically focus on removing contaminants in water by comparing the effectiveness of adsorption and photocatalytic degradation methods. Additionally, there is not much emphasis on analyzing the combined processes of adsorption-photocatalytic degradation utilizing AC. Herein, this paper investigates the intricacies of adsorption-photocatalytic degradation mechanisms and contributing variables in the enhancement of performances using biomass-derived AC. Furthermore, this review paper presents a comprehensive examination of different biomass sources employed in the synthesis of AC. It also discusses the diverse techniques utilized for the fabrication of AC, including physical and chemical activation methods. Finally, the shortcomings and future prospects of biomass-derived AC have been addressed. This study offers significant insights for the development of future biomass-derived AC, with the goal of improving their efficiency and expanding their uses in wastewater treatment.

Pharmaceutical Wastewater Treatment Using Activated Carbon in a Fixed-Bed Column

Though beneficial for health, pharmaceuticals have emerged as persistent environmental contaminants over recent decades. Discharges from wastewater treatment plants are a primary source of these pharmaceuticals in natural water bodies, as conventional treatment methods often fail to remove them effectively. Fixed-bed columns with GRANULATED ACTIVATED CARBON (GAC) are widely used in water treatment facilities to eliminate organic micropollutants; however, their efficiency in systematically removing pharmaceutical waste from wastewater still needs to be explored. This study evaluates the performance of a GAC fixed-bed adsorption column for removing ibuprofen, paracetamol, and ciprofloxacin from wastewater, focusing on contact time as a critical parameter. Key Findings: Initial concentrations of ibuprofen, paracetamol, and ciprofloxacin in the wastewater were 0.068 mg/L, 0.08486 mg/L, and 0.068 mg/L, respectively. After 45 minutes, the column achieved removal efficiencies of 100% for ibuprofen, 92.8% for paracetamol, and 67.6% for ciprofloxacin, with no significant changes in concentrations observed at 90 minutes. These results suggest that GAC fixed-bed adsorption columns can rapidly and effectively reduce pharmaceutical concentrations in wastewater, with ibuprofen showing complete removal in under an hour. This study contributes to understanding GAC’s effectiveness in treating pharmaceutical wastewater. It highlights the potential of optimised contact time for efficient removal, underscoring its viability as an industrial treatment option. Keywords: Pharmaceutical wastewater; emerging contaminants, adsorption

Dual State Emissive AIE Active Carbon Dots with Matrix-Free Room Temperature Phosphorescence.

Long-lived triplet excitons are kingmakers to generate high efficiency optoelectronic OLEDs. However, it is difficult to produce matrix-free solid state emissive room temperature phosphorescence (RTP) from carbon dots (CDs). In the present work, limited rotation of the two naphthol rings in (R)-1,1-Bi-2-naphthol (R-Binol) has been used to synthesize CDs aimed to obtain emission in the aggregated and RTP states. The R-Binol-derived CDs were prepared using an easy one-pot solvothermal treatment of the precursor. In-depth structural analysis reveals the presence of twisted naphthalene moiety that resists π-π stacking to make it dual emissive. These CDs are prone to accumulate producing spherical aggregates with 32-fold enhanced emission in binary THF-water mixture. Nevertheless, for the first time, we harvested triplet excitons from matrix free CDs generating 23% PLQY. A phosphor converted light emitting diode (pc-LED) was also fabricated with the CDs.

Influence of Precursor Structure on the Formation of Active Carbon Deposition Sites and Helical Graphite Cones Growth Mechanism

Influence of Precursor Structure on the Formation of Active Carbon Deposition Sites and Helical Graphite Cones Growth Mechanism

Indium oxide thick-films decorated with PdO and PtO2 particles for oxygen detection in humid environments

Abstract Thick film indium oxide chemiresistive sensors decorated with PdO and PtO2 particles were investigated for oxygen detection under humid conditions (tested ranging from 20%- 80% RH) across a temperature range of 50 °C to 400 °C. The PtO2-decorated In2O3 sensors demonstrated a significantly higher response to oxygen, showing a 500% increase at 200 °C compared to the PdO-decorated sensors (response values of 41 and 8, respectively). Tests in dry air were conducted to assess the effect of humidity on sensor performance, revealing a maximum response of 74 for PtO2-In2O3 at 400 °C, more than three times higher than the response of 22 for PdO-In2O3. Selectivity tests confirmed that the sensors responded more strongly to oxygen than to interfering gases. The integration of an active carbon cloth (ACC) filter effectively reduced interferences from isobutylene and ethylene, enhancing sensor’s selectivity. A comparison of both sensors demonstrated that PtO2-decorated In2O3 has greater potential as an alternative to existing Pb-based electrochemical oxygen sensors, particularly in humid environments.

Physical and chemical properties of soils from different geological formations affecting Tuber melanosporum plantations: a case study in Acqualagna area (central Italy)

Soil properties play a pivotal role in the fructification of the Périgord black truffle (Tuber melanosporum Vittad.). However, the precise manner in which soil composition influences truffle production remains unclear. This study considered three plantation sites located in Acqualagna (central Italy), an important area for the cultivation of black truffles. The sites differed in terms of productivity and geological terrains. Site 1, which produced 4 kg yr−1, was on Schlier sediments (marls and clayey marls; Miocene age), site 2, which yielded 12 kg yr−1, was on alluvial deposits (heterogeneous, mainly sandy gravels and gravels; Holocene age), and site 3 produced 40 kg yr−1 was on Scaglia variegata (alternating marly limestones, calcareous marls, and marls; Eocene age). A total of 62 soil samples were collected and analyzed for their physical, chemical, organic, and mineralogical composition. Among the samples a control area without the presence of truffle was included. The soils composition differed for the content in phyllosilicates and calcite which ranged from 124 to 398 g kg−1 and 98 to 450 g kg−1, respectively. Principal component analysis extracted three factors, accounting for 82% of the total variance. Factor 1 (46.2% of the variance) was strongly and positively correlated with sheet silicates, smectite, clay and negatively with skeleton (fraction > 2 mm). The soils from Scaglia variegata and Schlier clustered around the active carbonate content which was 266 g kg−1 in Scaglia and 250 g kg−1 in Schlier. These soils clustered also for the clay fraction (389 g kg−1 and 428 g kg−1, respectively) as well as for the smectite (268 g kg−1 and 307 g kg−1, respectively). In spite, the soils from alluvial deposits clustered per skeleton (638 g kg−1). In terms of soil productivity, it can be posited that the contribution of the skeleton was always dominant. The carbonate contents allow for the differentiation between intermediate soils (alluvial deposits) and low-productivity soils (Schlier). Additionally, the clay component was found to be high in both low (428 g kg−1) and high productivity soils (389 g kg−1). Conversely, it was low in medium productivity soils (125 g kg−1). The automatic linear modelling (ALM) indicated that among all of the variables considered in this study, six of them were included in the equation and explained 94.3% of the variation in soil classified as suitable for black truffle production. In particular, calcite was identified as the most important predictor variable, followed by available P and K. Regarding the influence of functional groups of humic substances, amide I (1641 cm−1) exerted a positive effect while lignin residues (1510 cm−1) had a negative one. The findings of this study may assist in the selection of optimal soils for black truffle cultivation.

TEA Guiding Bimetallic MOF with Oriented Nanosheet Arrays for High-Performance Asymmetric Supercapacitors.

The development of supercapacitors with ultrahigh power density, high energy density, and compatible integration for wearable microelectronic devices is significant but challenging. Herein, a bimetallic metal-organic framework (Ni/Co-MOF) with oriented nanosheets was obtained via triethylamine (TEA) guiding using a hydrothermal treatment, in which the TEA guides the vertically oriented array structures of the Ni/Co-MOF and ensures a fast ion/electron transmission path. Subsequently, an asymmetric supercapacitor was rationally designed by applying the bimetallic MOF cathode and an activated carbon (AC) anode. The obtained Ni/Co-MOF sample offers a high storage capacity of 2034 F g-1 at 0.5 A g-1 by harnessing the optimized Ni/Co-MOF with uniformly oriented nanosheet arrays. The constructed asymmetric supercapacitors exhibited a large voltage window of 1.4 V in 3.0 M KOH and an outstanding energy density of 29.5 Wh kg-1 at a power density of 199.1 W kg-1 was obtained, with a remarkable capacitance retention of 89% after 2000 cycles.

Integration of Grain Legumes and Mbeya Manure Improves Maize Productivity on Smallholder Farms in Central Malawi

Legumes are integrated in maize-based systems to improve soil fertility and crop productivity. However, the ecosystem services from legumes vary. Crop rotation on-farm studies were conducted over two cropping seasons (2018/19 and 2019/20) in Mkanakhoti and Kaluluma Extension Planning Areas (EPAs) in Kasungu district, central Malawi. The main objective of this study was to evaluate maize response to legume cropping systems and mbeya manure. In the first season (2018/19), five treatments including sole groundnut (Gn), sole soybean (soy), sole pigeon pea (PP), and doubled-up legumes (legume + legume intercrop) - pigeon pea intercropped with groundnut (Gn+PP), and pigeon pea intercropped with soybean (Soy+PP) were grown. In the second season (2019/20), maize was planted on plots that had either sole or doubled-up legumes. These plots were split into two, one half was top dressed with 23kg N ha-1 only and the other half received 23kg N ha-1+1000kg ha-1 mbeya manure. The experiments were replicated in 2019/2020 and 2020/2021 seasons. Soil fertility was low and highly variable between farms in the study sites. Soil pH, total nitrogen (N), available phosphorus (P), organic matter (SOM) and active carbon in topsoil (0-15cm) averaged 5.1±0.5, 0.19±0.18%, 31±19.6 ppm, 1.4±0.34 %, and 193±74 mg kg-1, respectively. Application of mbeya manure to maize increased leaf chlorophyll and plant height (p<0.05). There were variations in maize yield responses to legumes with higher benefits obtained from maize rotated with doubled-up legumes than sole legumes. The results also showed that on non-responsive soils, overall, the use of mbeya manure in combination with legume systems increased the rotational maize grain yield by 88% over maize following legumes only (p<0.05), with highest yields from doubled up legumes/maize rotations followed by groundnut/maize rotations. It is therefore recommended that on highly degraded soils, farmers can increase maize productivity through integrated soil fertility management involving a combination of 23kg N/ha and 1000kg/ha of mbeya manure applied to maize rotated with doubled-up legumes (Gn+PP or Soy+PP) and sole groundnut (Gn). Key words: Doubled-up legumes, crop rotation, groundnut, pigeon pea, soybean, maize, mbeya manure

The effect of humidity on the enhanced CO2 adsorption of amine-functionalized microporous activated carbon.

Cost-effective and environmentally friendly sorbents were created for capturing CO2 by incorporating monoethanolamine (MEA) and tetraethylenepentamine (TEPA) onto a microporous activated carbon (AC) material. The application of a KOH reagent enhanced the surface area and pore volume of the carbon material. The BET, SEM, EDX, and FTIR techniques were employed to analyze the structural and surface properties of the developed samples. Raw AC possessed the highest surface area and largest micropore volume equal to 786 m2/g and 0.33 cm3/g, respectively. The amine impregnation increased the nitrogen content of the carbon material, but it also significantly reduced the BET surface area and total pore volume, which are primarily responsible for physically adsorbing CO2 towards ACs. The CO2 adsorption performance of the raw and impregnated ACs was experimentally evaluated using thermogravimetric analysis (TGA) at different adsorption temperatures (25 and 50 °C) and CO2 concentrations (10 and 90 vol.%). The findings demonstrated that the raw AC exhibited the highest capacity for CO2 adsorption. Specifically, at a temperature of 25 °C and pressure of 1 bar (10 vol.% CO2, N2 balance), the raw AC achieved an uptake of 1.2 mmol/g, which was 60.3% and 79.3% higher compared to the CO2 uptake of MEA-AC (0.5 mmol/g) and TEPA-AC (0.3 mmol/g), respectively. It is surprising that the combined uptake of CO2 + H2O increased by 12.5 and 23.4 wt.% (equivalent to 7 and 13 mmol/g) for MEA-AC and TEPA-AC, respectively, when humid flue gas was taken into account under the conditions of 50 °C, with 10 vol.% CO2, 4 vol.% H2O, and N2 balance. These results indicate that the presence of H2O facilitates the chemisorption of CO2 by the novel and highly promising carbon-based sorbent prepared in this study, leading to an increased capacity for adsorbing CO2 under water vapor containing flue gases.

Enhancing activated carbon supercapacitor electrodes using sputtered Cu-doped BiFeO3 thin films

This work describes the fabrication of a composite supercapacitor electrode made of Cu-doped BiFeO3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_3$$\\end{document} (Cu-BFO) films on an activated carbon (AC) electrode using radio-frequency (RF) magnetron sputtering. To prevent exfoliation of Cu-BFO and AC upon immersion in an electrolyte, the nickel foam sandwiching electrode technique was introduced. The Cu-BFO films significantly enhanced electrochemical properties, increasing specific capacitance by up to 151% compared to that of an AC electrode. This was attributed to Faradaic reactions and specific surface area in the Cu-BFO/AC electrode. The highest specific capacitance achieved was 169 F g-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {g}^{-1}$$\\end{document} at 0.5 A g-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {g}^{-1}$$\\end{document} , and cycling stability retention was 93.12% after 500 cycles. However, the remaining percentage of the specific capacitance decreased differently with increasing thickness, which is also discussed. Furthermore, an asymmetric supercapacitor using Cu-BFO/AC and AC electrodes demonstrated a high energy density of 4.71 Wh kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {kg}^{-1}$$\\end{document} , power density of 2.66 kW kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {kg}^{-1}$$\\end{document}, and over 90% retention after 1000 cycles, highlighting its durability. The uniform RF magnetron sputtering deposition is vital for mass production. Combined with impressive retention in asymmetric supercapacitors, this scalability suggests a promising pathway for large-scale manufacturing. Consequently, this work could pave the way for the large-scale production of supercapacitors.

Effects of Straw Addition on Soil Priming Effects Under Different Tillage and Straw Return Modes.

This study aims to investigate the impact of straw addition on soil activation effects under different tillage practices, providing a scientific basis for establishing reasonable straw return measures in the southern Northeast Plain, thus enhancing soil fertility, and mitigating greenhouse effects. Soil samples were collected from various straw return practices that were conducted continuously for two years as follows: rotary tillage without straw return (RTO), deep tillage combined with straw incorporation (PT), rotary tillage with straw incorporation (RT), and no-till with straw cover (NT). The samples were incubated in the dark at 25 °C for 70 days. We measured the CO2 release rate and cumulative release, apparent activation effect, soil organic carbon, active microbial biomass organic carbon, soluble organic carbon, and easily oxidizable organic carbon to clarify the effects of straw addition on soil activation under different tillage practices. The results indicate that a straw addition promotes the mineralization of soil organic carbon while also increasing the content of active organic carbon components. The CO2 release rates and cumulative release under different tillage practices were as follows: PT > NT > RT. The contents of the active microbial biomass organic carbon, soluble organic carbon, and easily oxidizable organic carbon increased by 16.62% to 131.88%, 4.36% to 57.59%, and 12.10% to 57.97%, respectively, compared to the control without the straw addition. Except for the RT practice, the addition of straw significantly enhanced the instability of soil organic carbon in the PT, NT, and RTO practices, with increases of 51.75%, 48.29%, and 27.90%, respectively. Different straw return practices altered the physical and chemical properties of the soil, resulting in significant differences in the strength of the apparent activation effect. Notably, the apparent activation effect of RT was reduced by 86.42% compared to RTO, while that of NT was reduced by 36.99% compared to PT. A highly significant positive correlation was observed between the apparent activation effect and the unstable carbon components in the soil, indicating that higher levels of easily decomposable organic carbon corresponded to stronger apparent activation effects. In conclusion, it is recommended that in this region, rotary tillage should be adopted for straw return in the first 2 to 3 years, as this practice is beneficial for the formation and stabilization of organic carbon in the short term. As the duration of straw return increases, adjustments can be made based on the degree of soil organic carbon retention and soil fertility status.

Fundamentals and Implication of Point of Zero Charge (PZC) Determination for Activated Carbons in Aqueous Electrolytes.

The point of zero charge (PZC) is a crucial parameter for investigating the charge storage mechanisms in energy storage systems at the molecular level. This paper presents findings from three different electrochemical techniques, compared for the first time: cyclic voltammetry (CV), staircase potentio electrochemical impedance spectroscopy (SPEIS), and step potential electrochemical spectroscopy (SPECS), for two activated carbons (ACs) with 0.1molL-1 aqueous solution of LiNO3, Li2SO4, and KI. The charging process of AC operating in aqueous electrolytes appears as a complex phenomenon - all ionic species take an active part in electric double-layer formation and the ion-mixing zone covers a wide potential region. Therefore, the so-called PZC should not be considered as an absolute one-point potential value, but rather as a range of zero charge (RZC). SPECS technique is found to be a universal and fast method for determining RZC, as applied here together with the EQCM. In most cases, the RZC covers a potential range from ≈100 to ≈200mV and the correlation of the range with the carbon microtexture is clear, highlighting the role of the ion-sieving effect. It is postulated that PZC for porous materials in aqueous electrolytic solutions should be considered instead as RZC.

KOH Activation Mechanism in the Preparation of Brewer’s Spent Grain-Based Activated Carbons

Understanding the mechanism of KOH activation in the preparation of activated carbon (AC) enables more efficient utilization of biomass. In this study, brewer’s spent grains (BSGs) were carbonized at 500 °C to produce biochar (BC), followed by KOH activation under different activation conditions. The gas and solid products generated during the activation process were analyzed by gas chromatography (GC), X-ray diffraction (XRD), Raman analysis, a surface area and pore size analyzer, and X-ray photoelectron spectroscopy (XPS). The results show that increasing the KOH/BC ratio or the activation temperature could both promote gas production. XPS results indicated that the activator reacted first with -COOH and then with -OH of ACs, with AC5-700 having the highest C-OH content (50.04%). As the KOH/BC ratio increased, more aromatic structures were destroyed, and the porosity of ACs was significantly enhanced, with AC7-700 having the highest Brunauer–Emmett–Teller (BET) specific surface area (SBET) (2997.69 m2/g). At low temperatures, KOH reacted with the active groups of BC and carbon at the edge of the aromatic structure. At high temperatures, the activator (KOH, K2O, and K2CO3) reacted with carbon in the aromatic structure to generate a large number of pores on ACs and expand them. ACs exhibited more pores with higher KOH addition, and a higher activation temperature did not generate more new pores, but expanded the pores more significantly than high KOH addition.

Conversion Single Reagent of n-Propanol to 1,1-Dipropoxypropane Using Cr/Activated Carbon Catalyst

Synthesis of 1,1–dipropoxypropane from a single reagent of n-propanol using Cr/Activated Carbon (Cr/AC) as a catalyst has been done. Activated carbon (AC) was prepared by activating coconut shell carbon at 650 °C in the atmosphere of N2 at a flow rate of 20 mL/min for 4 h, and then it was washed using acetone in a Soxhlet for 15 rounds, washed three times by 1.0 M HCl, and finally, it was sieved at 60–80 mesh. Metal content was analyzed using atomic absorption spectroscopy (AAS) and represented by Na, Ca, and Fe. The AC was impregnated with Cr (VI) solution and reduced with H2 at 650 °C. The acidity of the Cr catalyst was determined by the adsorption of ammonia. Optimation of n-propanol conversion to 1,1-dipropoxypropane using Cr/AC catalyst in the atmosphere of N2 was conducted in an oven using variations of temperature of 450, 500, and 550 °C, amount of catalyst of 5, 10, and 15 g, and flow rate of alcohol of 0.10, 0.50, and 0.90 mL/min. The conversions of 1,1-dipropoxypropane were analyzed by GC-MS and 1H-NMR. The results showed that the AC's metal content significantly decreased after washing with acetone and 1.0 M HCl. The AC and Cr/AC had 2.49 and 8.27 mmol/g acidity, respectively. The highest product of 1,1-dipropoxypropane of 65.0% was reached at 450 °C using a 5 g catalyst at a flow rate of the alcohol 0.10 mL/min.

Strong Replaces Weak: ​Hydrogen Bond‐Anchored Electrolyte Enabling Ultra‐Stable and Wide‐Temperature Aqueous Zinc‐Ion Capacitors

Despite aqueous electrolytes offer a great opportunity for large‐scale energy storage owing to their safety and cost‐effectiveness, their practical application suffers from the parasitic side reactions and poor temperature adaptability stemming from weak hydrogen‐bond (HB) network in free water. Here, we propose the guiding thought “strong replaces weak” to design hydrogen bond‐anchored electrolyte by introducing sulfolane (SL) for disrupting the regular weak HB network and contributing to superior temperature tolerance. Judiciously combined experimental characterization and theoretical calculation confirm that SL can remodel the primary solvation shell of metal ions, customize stable electrode interface chemistry and restrain the side reactions. Consequently, symmetric supercapacitor constructed by activated carbon (AC) electrodes is able to fully work within a voltage range of 2.4 V and reach high capacitance retention of 89.8% after 60000 cycles. Additionally, Zn anodes exhibit ultra‐stable Zn plating/stripping behaviors and a wide temperature range (‐20 ~ 60 °C), and zinc‐ion capacitor (Zn//AC) also delivers an excellent cycling stability with capacity retention of 99.7% after 55000 cycles, implying that the designed electrolyte has practical application potential in extreme environments. This work proposes a novel critical solvation strategy that paves the route for the construction of ultra‐stable and wide‐temperature aqueous energy storage devices.

IoT real-time monitoring system implemented to observe sunlight-influenced methylene blue degradation by AC/HAp.

Activated carbon (AC) and hydroxyapatite (HAp) composite were successfully prepared via mechanical mixing and exhibited a crushed snack-like morphology compared to the well-defined pore structure of pure AC. The purpose of this research was to explore the potential of AC/HAp for the degradation of methylene blue (MB) dye and hydrogen production. Despite the morphological changes, AC and AC/HAp achieved a high MB degradation rate (92.75 and 82.05) % under sunlight, at a temperature of 26.24°C and pH of 4.18, and showed optimum hydrogen production (3579mol/g.h). These performances are suspected from the decrease in crystallite size and narrowed and confirmed by image processing results with RBG enhancement showing more light transmitted by the solution. Increasing in indicates the potential for improved light interaction. IoT-enabled real-time monitoring system demonstrates its efficacy in facilitating wastewater treatment and hydrogen production, offering a promising solution for aquatic ecosystem restoration.

A comprehensive investigation of the impact of carbon-supported metal complexes of triaminoguanidine on the characteristics of a double-base propellant

ABSTRACT In this study, triaminoguanidine complexes grafted onto activated carbon (AC-TAG-Fe and AC-TAG-Co) were designed and investigated for their catalytic effect on the thermolysis of a double base propellant consisting of nitrocellulose (NC) and diethylene glycol dinitrate (DEGDN). The successful synthesis of transition metal complexes with triaminoguanidine and their subsequent grafting onto activated carbon were confirmed using various analytical techniques, including Fourier Transform Infrared Spectroscopy, Raman Spectroscopy, X-ray Diffraction, and Scanning Electron Microscopy. Thermal characterization using Thermogravimetric Analysis and Differential Scanning Calorimetry provided valuable insights into the thermal properties and reactivity of the elaborated NC/DEGDN-based composites. Importantly, the addition of various additives resulted in notable improvements in both the enthalpy of reaction and density. Isoconversional kinetic studies revealed that the incorporation of TAG-Fe and TAG-Co complexes reduced the apparent activation energy of the NC/DEGDN composite from 137.4 kJ/mol to 135.4 kJ/mol and 114.8 kJ/mol, respectively, suggesting their catalytic effect. Furthermore, it is found that the addition of activated carbon (AC) resulted in an increase in activation energy to 154 kJ/mol, whereas grafting TAG-Fe and TAG-Co complexes onto AC as a catalytic support subsequently reduced activation energy to 119 kJ/mol and 112 kJ/mol, respectively. Overall, this research serves as a valuable reference for future studies focusing on investigating the catalytic combustion characteristics of double-base solid propellants.