AC Surface Research Articles

A Novel Elastomeric Dielectric Materials: Natural Rubber/Copper-Modified Activated Carbon

In this research, a new elastomeric dielectric material is created by integrating natural rubber (NR) with activated carbon derived from coconut shells that has been modified with copper (Ac-Cu). Here, The copper content, ranging from 0 to 2%, was meticulously examined on the AC surface through a reduction technique from copper (II) to copper (0), with the Ac-Cu concentration fixed at 15 parts per hundred of rubber (phr). Systematic investigations into the effects of the additive were conducted across various parameters, encompassing optimum curing time (t90), density, crosslink density, mechanical properties, morphology, and dielectric properties. Results revealed a notable influence of copper on the curing process, resulting in decreased cure time, and a corresponding decrease in crosslink density as the copper content increased. Interestingly, copper incorporation demonstrated a positive impact on mechanical properties. Dielectric property analysis further confirmed a direct effect of increasing copper content on the frequency range of 0.85 to 1.15 GHz. This work not only introduces a pioneering dielectric material but also provides crucial insights into the nuanced effects of copper modification, offering avenues for tailored material design in the realm of enhanced dielectric applications.

Photocatalysis and microwave absorption performance of cobalt particles dispersed on activated carbon surface under the role of surface, optical, and magnetic properties

Ensuring the availability of clean water and solve electromagnetic interference are a fundamental action to support a better life. Here, the bifunctional material as photocatalyst and absorber microwave were prepared from activated carbon composite with Cobalt (AC-Co (0, 10, & 20)%) by stirring-assisted impregnation method as an easy and environmentally friendly procedure. The effectiveness of the material as a catalyst is observed from its surface condition as an active site, and we also consider the electrical and magnetic properties as aspects of the role in photodegradation capability. It was found that AC-Co (10) showed a methylene blue and pesticide degradation capability of >90 % for an adsorbent mass of 1.5 g within 5 days treated without artificial irradiation and stirring to imitate the environmental conditions. The microwave absorption capability by the composite shows a maximum absorption of −19.1 dB at 10.12 GHz for AC-Co (0), while the presence of Co manages to provide a higher working frequency shift but reduced absorption performance. These reported performances are supported by the appropriate distribution of Co particles scattered on the AC surface, larger μ'', and higher consistency of Δ(LO−TO) positions.

Synthesis of activated carbon-supported nano copper oxide and its inactivation performance on Escherichia coli in water

Copper oxide (CuO) is limited in inactivating bacteria due to the deficiency of active Cu(I) that can catalyze dissolved oxygen to produce reactive oxygen radicals. A novel sterilization agent was developed to inactivate Escherichia coli (E. coli) by loading nano copper oxide onto activated carbon (nCuO/AC) with a facile impregnation method. Surface techniques proved that CuO with a size of 100–200 nm was evenly loaded on AC surface, which improved its dispersity and reactivity. XPS analysis further revealed a cycle of surface-bonded Cu(II) to Cu(I) in the nCuO matrix that was driven by reducing groups on AC surface such as hydroxyl. The resultant Cu(I) activated dissolved oxygen to produce reactive oxygen species for bacterial inactivation. Superoxide radical (•O2–) was proved to be the primarily oxidative species during the sterilization process by EPR analysis and quenching investigations. Therefore, the nCuO/AC achieved an enhanced inactivation efficiency of 6.0 log CFU/mL as compared to those of 1.1 and 0.4 log CFU/mL by the nCuO and AC, respectively. The above sterilization reaction was pH-dependent and high inactivation efficiency could be achieved under neutral conditions. Additionally, the nCuO/AC exhibited excellent stability with an inactivation efficiency of 5.4 log CFU/mL after 4 cycles. Spent nCuO/AC showed great potential in renewability because it could inactivate 5.5 log CFU/mL of E. coli by peeling off residual nCuO on AC surface with sulfuric acid and reloading new nCuO through impregnation, with a regeneration rate up to 97.2 %. The above results demonstrated that nCuO/AC could be a promising bactericidal material for water treatment.

Effective removal of heavy metals from aqueous solutions using activated biomass: Analytical interpretation via molecular dynamic simulation, mathematical and statistical approaches

Activated carbons basis on low-cost natural materials, Diplotaxis harra (DH) and Glebionis coronaria L. (GCL) were prepared by chemical activation. The optimization of the manufacture conditions is performed by the full factorial design with four variables. Indeed, four activated carbons are prepared, DHACH3PO4, GCLACH3PO4, DHAC-KOH et GCLAC-KOH. The approach used has been evaluated regarding Cd(II) and Co(II) sorption capacities. The optimal conditions for activated carbons preparation are investigated. Therefore, the equilibrium study is assumed using Langmuir and Freundlich isotherm models. Under the optimum conditions, the highest adsorption of Cd(II) is acquired at 118.75 mg/g onto GCLACH3PO4. However, the greater efficiency of Co(II) sorption is obtained onto DHAC- H3PO4 and it was 82.55 mg/g. The current optimization overviews the Cd(II) and Co(II) removal involving various activated carbons. In the theoretical approach, the adsorption affinity of the heavy metal is computed using molecular dynamics (MD) simulation and compared with the adsorption affinity obtained from the experiment. The adsorption energy values were fitted to an empirical interaction energy model to predict the binding energy of arbitrary pollutants. This study used MD simulation to investigate the adsorption mechanism of Cd(II) on the AC (002) surface. The adsorption and interaction energies indicated a feasible, exothermic, and spontaneous adsorption process. MD simulations demonstrate that the adsorption process of Cd(II) on activated carbon is chemical in nature. This result is confirmed by the radial distribution function (RDF) analysis. This research adds new theoretical and experimental findings about heavy metal adsorption using activated carbon.

Enhanced inactivation of Escherichia coli through hydrogen peroxide decomposition assisted by nanoscale cupric oxide-decorated activated carbon

In this study, nanoscale cupric oxide-decorated activated carbon (nCuO@AC) was synthesized by impregnation-calcination and employed to assist the decomposition of H2O2 for effective sterilization with Escherichia coli as target bacteria. Characteristic technologies demonstrated that copper oxide particles of 50–100 nm were uniformly distributed on AC surface. Owing to electron transfer from hydroxyl and aldehyde to CuO on AC, surface-bonded Cu(II) was partially reduced to Cu(I) in the nCuO matrix. The resultant Cu(I) expedited the decomposition of H2O2 and converted it into ·OH radicals which were identified by quenching experiment and electron paramagnetic resonance test. Due to oxidation attack of generated ·OH, the nCuO@AC-H2O2 system achieved a much higher inactivation rate of 6.0 log within 30 min as compared to those of 2.1 and 1.3 log in the nCuO@AC and nCuO-H2O2 systems. It also exhibited excellent pH adaptability and high inactivation efficiency under neutral conditions. After four cycles, the nCuO@AC-H2O2 system could still inactivate 5.5 log bacteria, indicating excellent stability and reusability of nCuO@AC. Spent nCuO@AC could be regenerated by eluting surficial copper oxides with hydrochloric acid, and re-coating nCuO particles through impregnation-calcination with a regeneration rate of 96.6%. Our results demonstrated that nCuO@AC was an efficient and prospective catalyst to assist the decomposition of H2O2 for effective inactivation of bacteria in water.

Formation of Fe2(SO4)3-Fe2O3 interface induced by OCFGs electrostatic anchoring on AC surface: High efficiency NH3-SCR performance at low temperatures

Low-temperature activity and SO2 poisoning were the key factors limiting the application of NH3-SCR catalysts. In this study, Fe2(SO4)3/AC and Fe2(SO4)3/OAC catalysts were prepared by oxidation function modification and incipient wetness impregnation. In the temperature range of 100–250 ℃, the catalytic performance and SO2 resistance of Fe2(SO4)3/AC and Fe2(SO4)3/OAC catalysts were investigated, the denitrification efficiency increased from 28 % (Fe2(SO4)3/AC) to 80 % at 100 °C and reached 100 % at 170 °C, and 100 ppm SO2 was introduced at 250 ℃ for 24 h, the denitrification efficiency remains 100 % unchanged. The mechanism of activity enhancement was further explored by BET, XRD, ICP, TG, XPS, FT-IR, H2-TPR and NH3-TPD. The results showed that (NH4)2S2O8 modification enhanced the surface acidity, and the increase of surface oxygen-containing functional groups improved the redox performance. At the same time, due to electrostatic anchoring effects of oxygen-containing functional groups, Fe3+ and SO42- were adsorbed at different sites and promoted the binding of S to the carbon skeleton to form −C-S-C-. Thus, the interaction between OAC and Fe2(SO4)3 caused part of Fe2(SO4)3 to decompose into Fe2O3, and the formation of Fe2(SO4)3-Fe2O3 interface further enhanced the acidity and redox properties. More importantly, the decomposition temperature of NH4HSO4 was lower and the decomposition was more thorough on the Fe2(SO4)3/OAC than that of Fe2(SO4)3/AC. Finally, the possible mechanism of (NH4)2S2O8-modified Fe2(SO4)3/OAC catalyst to improve NH3-SCR performance was proposed, which is of great significance for the development of NH3-SCR catalyst with sulfur resistance at low temperatures.

Dual-function highly oxidative potassium salts empowering high-performance transition metal oxide/activated carbon for hybrid aqueous supercapacitors

In this work, a novel strategy of high-temperature oxidation-activation followed by rapid low-temperature aqueous-reflux treatment is developed to prepare transition metal oxide-activated carbon (TMO-AC) composites for supercapacitor applications. The super-absorbent polymer is selected as the carbon source, and the highly oxidative potassium salts K2FeO4/KMnO4 serve as both precursors for TMO and activators for AC. AC possesses a well-developed porous structure. Moreover, TMO grows uniformly in-situ on AC surface and displays a small size below 10 nm. The prepared Fe2O3-ACFe and MnO2-ACMn composites exhibit remarkable specific capacitance of 645.0 and 548.0 F g−1, respectively. Hybrid aqueous supercapacitors are assembled with Fe2O3-ACFe and MnO2-ACMn as negative and positive electrodes, respectively. A stable operating voltage of 1.2 V is achieved in the KOH electrolyte, resulting in a remarkable 90.2% capacitance retention over 10,000 cycles. Furthermore, in the Na2SO4 electrolyte, a wide 1.6 V voltage window is obtained, contributing to a substantial energy density of 49.35 Wh kg−1. This work provides an interesting approach for the fabrication of high-performance TMO-carbon composite electrodes.

Green cleanup of styrene-contaminated soil by carbon-based nanoscale zero-valent iron and phytoremediation: Sunn hemp (Crotalaria juncea), zinnia (Zinnia violacea Cav.), and marigold (Tagetes erecta L.)

Accidental chemical spills can result in styrene-contaminated soil. Styrene negatively affects human health and the environment. The objective of this study was to remediate styrene-contaminated soil using a combination of activated carbon-based nanoscale zero-valent iron (nZVI-AC) and phytoremediation by sunn hemp (Crotalaria juncea), zinnia (Zinnia violacea Cav.) and marigolds (Tagetes erecta L.). The results showed that all three plant types could potentially increase the removal efficiency of styrene-contaminated soil. At 28 days, all three plants showed complete removal of styrene from the soil with 1 g/kg of nZVI-AC, activated carbon-based nZVI synthesized by tea leaves (Camellia sinensis) (T-nZVI-AC), or activated carbon-based nZVI synthesized by red Thai holy basil (Ocimum tenuiflorum L.) (B-nZVI-AC). However, styrene removal efficiencies of sunn hemp, zinnia, and marigold without carbon-based nZVI were 30%, 67%, and 56%, respectively. Statistical analysis (ANOVA) revealed that the removal efficiencies differed significantly from those of phytoremediation alone. With the same removal efficiency (100%), the biomass of sunn hemp in nano-phytoremediation treatments differed by approximately 55%, whereas the biomass of zinnia differed by >67%, compared with that of the control experiment. For marigold, the difference in biomass was only 30%. Styrene was adsorbed on surface of soil and AC and then further oxidized under air-water-nZVI environment, while phytovolatilization played an important role in transporting the remaining styrene from the contaminated soil to the air. Marigold was used as an alternative plant for the nano-phytoremediation of styrene-contaminated soil because of its sturdy nature, high biomass, tolerance to toxic effects, and ease of cultivation. Remediation of one cubic meter of styrene-contaminated soil by a combination of carbon-based nanoscale zero-valent iron and phytoremediation by marigolds emitted 0.0027 kgCO2/m3.

Electrical Characteristics of the Insulation Paper Modified by Nano-TiO2 under Electrical-Thermal Aging

The research on the modified insulating paper by adding nano-materials has garnered increasing attentions. Scholars have investigated its performances under electrical aging or thermal aging, but there are few reports on its behaviors under electrical-thermal combined aging. In the laboratory, we prepared the modified insulating paper with different mass fractions of nano-TiO2, and subjected to 10-day accelerated electrical-thermal combined aging test. Samples were experimented at different aging stages to investigate the variations in AC breakdown field strength, relative permittivity and surface microstructure. The results demonstrate that the modified insulating paper samples exhibit better AC breakdown field strength, relative permittivity and other parameters compared to the unmodified samples. Among the modified samples, the one with 3% mass fraction of nano-TiO2 shows the best electrical properties and aging resistance under electrical-thermal combined aging. By adding an appropriate weight percentage of nano-TiO2, it was able to fill microscopic holes and gaps on the surface of the insulating paper, strengthen the connection between the cellulose fibers, and improve the electrical properties and aging resistance of the insulating paper.

Investigation of Electrical Configuration Topologies for Enhancing the Performance of Solar Photovoltaic Water Pumping System

The numerous solar energies provide humans with clean, environmentally friendly, and abundant energy resources. Electricity shortages and high diesel prices have an impact on rural water irrigation systems and drinking water supplies. Solar energy for water pumping could be an alternative to standard electric and diesel pumping systems. The rising importance of solar photovoltaic water pumping systems (SPVWPS) as a feasible power source in rural, inaccessible, and unconnected areas drives the study. These locations, often in poor nations like India, lack conventional power. Solar energy is converted into electrical energy via photovoltaic (PV) technology, which is then used to power a DC or AC submersible or surface water pump. PV module configurations are crucial in improving a PV system’s performance. Many researchers have studied the solar water pumping design on series parallel combination and acquired the best system efficiency, but the other configurations, Total Cross Tied (TCT) and Bridge Link (BL) have never been employed in a solar water pumping system. This research aims to investigate the experimental comparison of different PV configurations for better system efficiency on different operating parameters. These PV array layouts were considered in a uniform situation. The result shows that power increases with increase in radiation and the flow rate provided by (6Sx2P) configuration is 18,956 l/day of water and calculated the best average pump efficiency.

β-1,3-Glucan recognition by Acanthamoeba castellanii as a putative mechanism of amoeba-fungal interactions.

In this study, we conducted an in-depth analysis to characterize potential Acanthamoeba castellanii (Ac) proteins capable of recognizing fungal β-1,3-glucans. Ac specifically anchors curdlan or laminarin, indicating the presence of surface β-1,3-glucan-binding molecules. Using optical tweezers, strong adhesion of laminarin- or curdlan-coated beads to Ac was observed, highlighting their adhesive properties compared to controls (characteristic time τ of 46.9 and 43.9 s, respectively). Furthermore, Histoplasma capsulatum (Hc) G217B, possessing a β-1,3-glucan outer layer, showed significant adhesion to Ac compared to a Hc G186 strain with an α-1,3-glucan outer layer (τ of 5.3 s vs τ 83.6 s). The addition of soluble β-1,3-glucan substantially inhibited this adhesion, indicating the involvement of β-1,3-glucan recognition. Biotinylated β-1,3-glucan-binding proteins from Ac exhibited higher binding to Hc G217B, suggesting distinct recognition mechanisms for laminarin and curdlan, akin to macrophages. These observations hinted at the β-1,3-glucan recognition pathway's role in fungal entrance and survival within phagocytes, supported by decreased fungal viability upon laminarin or curdlan addition in both phagocytes. Proteomic analysis identified several Ac proteins capable of binding β-1,3-glucans, including those with lectin/glucanase superfamily domains, carbohydrate-binding domains, and glycosyl transferase and glycosyl hydrolase domains. Notably, some identified proteins were overexpressed upon curdlan/laminarin challenge and also demonstrated high affinity to β-1,3-glucans. These findings underscore the complexity of binding via β-1,3-glucan and suggest the existence of alternative fungal recognition pathways in Ac.IMPORTANCEAcanthamoeba castellanii (Ac) and macrophages both exhibit the remarkable ability to phagocytose various extracellular microorganisms in their respective environments. While substantial knowledge exists on this phenomenon for macrophages, the understanding of Ac's phagocytic mechanisms remains elusive. Recently, our group identified mannose-binding receptors on the surface of Ac that exhibit the capacity to bind/recognize fungi. However, the process was not entirely inhibited by soluble mannose, suggesting the possibility of other interactions. Herein, we describe the mechanism of β-1,3-glucan binding by A. castellanii and its role in fungal phagocytosis and survival within trophozoites, also using macrophages as a model for comparison, as they possess a well-established mechanism involving the Dectin-1 receptor for β-1,3-glucan recognition. These shed light on a potential parallel evolution of pathways involved in the recognition of fungal surface polysaccharides.

Kraft and organosolv lignin-activated carbon composites for supercapacitor electrode materials

Lignin-activated carbon (AC) composites were employed as electrode active materials to develop more environmentally friendly Supercapacitor (SC) materials with enhanced properties. This way, the hydroquinone/quinone moieties present in lignin molecules added Faradaic processes to the system, and the capacitance of the active material increased, making it appropriate for future applications requiring more efficient and sustainable active materials. Lignin, a sustainable biobased aromatic polymer high in carbon content, was deposited on AC surface employing ultrasound (US) system, and for a better deposition, AC was treated with HNO3. Since the composition and properties of lignin can vary depending on their isolation process, two different types of lignin were used: Kraft lignin (KL) and Organosolv lignin (OL), and the effects on the chemical and electrochemical composition were deduced. Physicochemical, morphological, and electrochemical analyses were carried out on the lignin-AC composite to determine the optimum material combination and treatment process. It was observed that the acid treatment was effective in enhancing the functionality and porosity of the surface. Additionally, it improved the deposition of lignin and facilitated the formation of hierarchically porous structures on the surface of treated activated carbon (TAC), with different tendencies depending on the lignin employed. The creation of highly porous structures also resulted in enhanced electrochemical performance in materials. This validated the process, where eco-innovative technologies like US forces and employment of lignocellulosic biomass compounds like lignin were used as sustainable and efficient alternatives for obtaining electrochemically active materials.

Quasi-Static AC Surface Charging of Polymeric Insulators At Low Pressure

Quasi-Static AC Surface Charging of Polymeric Insulators At Low Pressure

Decoration of 2 H-MoS2 on the surfaces of activated carbon derived from bamboo stem biomass waste: A regenerative novel architecture for effective degradation of methylene blue under natural light

The development of visible light-assisted photocatalyst materials is considered a sustainable technology for textile dye pollutant degradation. In this work, a bamboo stem-derived activated carbon/Molybdenum disulfide (AC/MoS2) composite was synthesized using the wet impregnation method. The synthesized AC/MoS2 (5%) (ACM composite) shows enhanced photocatalytic degradation efficiency (98%) for MB degradation within 90 min compared with AC (94%) and MoS2 (33%) under natural light irradiation. FESEM analysis shows the uniform deposition of 2 H-MoS2 on the surface of AC. HRTEM analysis revealed that ACM composite consists of ultra-small activated carbon nanoparticles with a diameter of ∼20 nm and a layered MoS2 with a lateral thickness of ∼150 nm. The effect of catalyst load, pH effect, and MB concentration were evaluated to optimize the photocatalytic activities of AC and ACM composites. The results reveal that the ACM composite possesses high photocatalytic activity with a catalyst quantity of 10 mg at pH 8. Scavenger trapping analysis confirms that hydroxyl radical (•OH) and photogenerated holes (h+) are the main reactive species for photocatalytic degradation of MB. After three cycle experiments, the ACM composite exhibited a slight decrease in the photocatalytic efficiency (89%) and also possesses high stability, which can be regenerated for sustainable photocatalytic material. Moreover, the ACM composite exhibits a long visible absorption range and high structural stability, enhancing the charge separation efficiency of photogenerated electron-hole pairs. This proposed method offers a cost-effective and biomass-derived photocatalyst for the textile wastewater treatment process.

Fast g-C3N4 sonocoated activated carbon for enhanced solar photocatalytic oxidation of organic pollutants through Adsorb & Shuttle process

To solve low mass transfer in photocatalytic technology for water treatment, the combination of photoactive nanoparticles with highly adsorptive materials has been regarded as a successful approach. The optimization of photoactive particle coating in terms of dispersion on the surface of adsorbing support is the main key to reach a maximum synergism for pollutants removal. This study discusses the coating of as-prepared biomass based activated carbon by g-C3N4 using three routes, namely ball milling (AC-CN@BM), physical stirring (AC-CN@Phy) and ultrasonic assisted coating (AC-CN@US). The coating mechanisms by different processes were discussed using different characterization techniques. Ball milling based coating provides good g-C3N4 dispersion on the surface of AC, however, a partial degradation of g-C3N4 structure and a lower surface area were confirmed by FTIR, XRD and BET analysis. Physically designed sample shows a significant agglomeration of particles on the surface of AC. However, ultrasonic coating provides excellent distribution of g-C3N4 and high surface of the composite. In terms of photoactivity, AC-CN@BM exhibits the lowest adsorption and photocatalytic activity under solar light for the removal of ciprofloxacin. AC-CN@Phy showed medium performance, but less physical stability of g-C3N4 particles on AC, leading to their partial release. AC-CN@US showed the highest efficiency and stability after using; suggesting the good combination between g-C3N4 and AC, which in turn maximizes the removal of ciprofloxacin via Adsorb & shuttle process. The overall costs of composite, including the starting elements and the coating ultrasonic process are relatively low and green as compared to commonly reported routes.

Nitrogen-enriched activated carbon derived from plant biomasses: a review on reaction mechanism and applications in wastewater treatment

As a key kind of evolving carbonaceous adsorbent, nitrogen-enriched activated carbon has drawn a lot of focus due to its better physiochemical ability to eliminate an extensive range of wastewaters contaminants under severe conditions. Its environment-friendly character is one more reason behind this focus. Nitrogen also has immense effect on activated carbon structures’ pollutants adsorption capability; therefore, it is an area of interest. Reports concerning the reaction pathway of C-N (carbon-nitrogen) bond creation on AC surface are limited. Determining such mechanisms is challenging but critical to understand bond characteristics after carbonization. Moreover, it is vital to ascertain real-time kinetics concerning adsorption phenomena in liquid phase. Such a latest trend indicates that regulated nitrogen uses for carbonaceous substances having a biomass-based origin can provide the desired morphological characteristics produced through interconnections, production of enclosed holes, enhanced surface area, better adsorption ability, and many other benefits in contrast to conventional carbon-based substances. This review points out the developments in the main processes to introduce nitrogen atoms into the carbon matrix by utilizing different N-comprising chemical compounds. The nitrogen enrichment processes, reaction mechanisms and effects of nitrogen incorporation on the plant biomass-derived activated carbons (NEACs) are presented in brief. On the basis of their established physicochemical attributes, the adsorption performances of different biomass-derived NEACs have also been dealt with. More significantly, the review covers the technical issues in the present phase, topical trends, research gaps, economic viability along with a technical alignment recommendation to address the prevailing disadvantages.

Highly efficient adsorption of arsenite from aqueous by zirconia modified activated carbon

In the present study, activated carbon decorated with zirconia nanoparticle composite (ZrO2/AC) have been prepared using hydrothermal method and then utilized as an adsorbent for the removal of arsenite from aqueous solution. The composite is composed of highly agglomerated ZrO2 particles on AC surface. The high surface area of the synthesized adsorbent results in its high adsorption capacity toward arsenite. Adsorption isotherm and kinetic data of arsenite adsorption process can be well fitted to the Langmuir isotherm with maximum monolayer adsorption capacity of 64.00 mg.g-1. The experimental results suggest that the adsorption process of arsenite onto ZrO2/AC material involves the formation of both outer-sphere and inner-sphere complexes between arsenite and adsorbent. The high adsorption ability toward arsenite as well as the high recyclable nature of this material makes it a potential alternative material for the removal of toxic heavy metals from wastewater.

Adsorption behavior and mechanism of ultra-low concentration sulfur compounds in natural gas on Cu-impregnated activated carbon

Sulfur compounds critically deteriorate the performance of catalysts and fuel cells in H2 production and natural gas applications. This study aims to elucidate the adsorption characteristics of low-concentration tetrahydrothiophene (THT) and tert-butyl mercaptan (TBM) in CH4 (4.5 ppmv) on Cu-impregnated activated carbon (Cu/AC) by analyzing the state of the Cu and sulfur species during dynamic tests of the 1st desulfurization, regeneration and 2nd desulfurization. Physical adsorption was dominant in THT removal, enabling facile regeneration by the N2 thermal treatment at 100 °C. TBM removal was primarily carried out by the chemical adsorption utilizing CuO, Cu2O, and oxygen on the AC. During desulfurization, CuO acts as a catalyst, an adsorption site, and an oxygen donor. CuO was actively consumed during the initial stage, leading to the complete removal of the TBM. During desulfurization, oxidation to form organic sulfur and copper sulfonate was the primary reaction in the presence of sufficient amounts of CuO and oxygen on the AC. As the oxygen content of AC was consumed with subsequent desulfurization, reactive adsorption on Cu2O to form thiolate became one of the major reactions. Owing to the strong chemisorption of sulfur compounds, the recovery of the removal efficiency was limited by N2 thermal regeneration. However, oxidative regeneration at 250 °C using dilute O2 flow effectively removed chemisorbed organic sulfur and thiolate. Because oxygen consumption was accompanied by both desulfurization and regeneration reactions, this method successfully restored the desulfurization performance by recovering CuO and oxygen on the AC surface and maintaining well-dispersed Cu.

One Step Synthesis of TiO2-Activated Carbon Composite Using Hydrothermal Method with Mass Variation of Activated Carbon

One effort to increase the photocatalytic activity of TiO2 is to immobilize it on the surface of the sorbent material. This study aims to produce TiO2-Activated Carbon (TiO2-AC) composites which have higher photocatalytic activity than TiO2, using a simple method. The synthesis of TiO2-AC composites was carried out using the hydrothermal method. The synthesis process was initiated by mixing TTIP, ethanol, H2O, and activated carbon with various masses (5 g, 10 g, 15 g, and 20 g). The mixture was then put into a hydrothermal autoclave and heated at 180°C for 12 hours. The material is then washed until the pH is neutral, and then dried. The TiO2-AC composite powder was then calcined at 500°C for 3 hours. Based on the photocatalytic test of the TiO2-AC composite on the degradation of methylene blue compounds, it was shown that composite with a mass variation of 10 g activated carbon (TiO2-AC/10) had the highest photocatalytic activity. FTIR characterization of the sample TiO2-AC/10 showed a shift in the peak wave number of the hydroxyl and carbon groups. Meanwhile, the results of morphological analysis using SEM showed that TiO2 particles had adhered to the AC surface, which was also confirmed by EDX data in the presence of Ti and O elements in the synthesized material. The results of the crystallinity analysis showed that the 100% synthesized TiO2 was the anatase phase with a crystalline size of 1.80−14.14 nm. This study open up opportunities for the development of TiO2-based composite materials for large-scale environmental remediation applications.

New imidazolium-based ionic liquids for mitigating carbon steel corrosion in acidic condition

Abstract Two environmentally friendly inhibitors of imidazolium-based ionic liquids namely 3-benzyl-1-hexadecyl-1H-imidazol-3-ium chloride (IL-H), and 3-(4-chlorobenzyl)-1-hexadecyl-1H-imidazol-3-ium chloride (IL-Cl) were manufactured and their chemical structures were confirmed by spectra tools (FT-IR, and 1H NMR). The utilizing of these two new ionic liquids as green corrosion inhibitors for low carbon steel (LCS) in 1.0 M HCl under altered experimental conditions. Mass loss (ML), potentiodynamic polarization (PP), AC impedance spectroscopy (EIS) and surface morphology are take place in this study. The protection performance found to increase with increasing ionic liquid dose and temperature, reaching 92.9% and 95.1% for IL-H and IL-Cl at 120 ppm, respectively. Based on the PP records, the investigated ionic liquids behave as mixed-type inhibitors, influencing both anodic and cathodic responses. The inhibitory activity from these explored ionic liquids was stimulated by their adsorption on the effective surfaces of the steel surface in accordance with the Langmuir adsorption isotherm. The Density Functional Theory (DFT) method is used to analyze the relationship between quantum chemical calculations and the protection efficiency of ionic liquids.