Surface Elemental Composition Research Articles

Effect of ultraviolet treatment on soft tissue healing and bacterial attachment to titania-coated zirconia

Zirconia is the most promising implant abutment material due to its excellent aesthetic effect, good biocompatibility and corrosion resistance. To obtain ideal soft tissue sealing, the implant abutment surface should facilitate cell adhesion and inhibit bacterial colonization. In this study, pre-sintered zirconia was placed in a suspension of titania (TiO2) and zirconium oxychloride (ZrOCl2) and heated in a water bath for dense sintering. A titania coating was prepared on the zirconia surface and subjected to UV irradiation. The surface morphology, elemental composition and chemical state of each group of samples were analyzed by scanning electron microscope, x-ray energy spectrometer, x-ray photoelectron spectroscopy and x-ray diffraction. The responses of human gingival fibroblasts (HGFs) and common oral pathogensStreptococcus mutans(S. mutans) andPorphyromonas gingivalis(P. gingivalis) to modified zirconia were systematically assessed. Our findings demonstrated that the surface of titania-coated zirconia after UV irradiation produced a large number of hydroxyl groups, and its hydrophilicity was significantly improved. Meanwhile, the UV irradiation also greatly removed the hydrocarbon contaminants on the surface of the titania-coated zirconia. The UV-treated titania coating significantly promoted the proliferation, spreading, and up-regulation of adhesion-related genes and proteins of HGFs. Furthermore, the titania coating irradiated with UV could reduce the adhesion, colonization and metabolic activity ofS. mutansandP. gingivalis. Therefore, UV irradiation of titania-coated zirconia can promote the biological behavior of HGFs and exert a significant antibacterial effect, which has broad clinical application prospects for improving soft tissue integration around zirconia abutments.

Adsorption of Arsenic and Cadmium on Biodegradable and Non-Biodegradable Microplastics in Soil: Comparison Based on Batch Experiment

In the present study, the adsorption of arsenic(V) and cadmium(II) onto microplastics from poly(butylene succinate-co-butylene adipate) (PBSA) and low-density polyethylene (LDPE) plastic mulch films was investigated through batch experiment. The surface morphology and elemental composition of soil and microplastics were analyzed with scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDX) and Fourier-transform infrared (FTIR) spectroscopy. The results show that the adsorption of As(V) and Cd(II) on microplastics led to surfaces with coarseness and more cracks, and many small particles. Under the conditions added with 100 pieces of microplastic, PBSA enhanced the adsorption capacity of As(V) (from 0.43 to 0.49 mg/g), and LDPE increased the adsorption of Cd(II) (from 0.174 to 0.176 mg/g) due to the “superimposed effect” caused by hydrogen bonds. Conversely, LDPE reduced the adsorption of As(V) (from 0.44 to 0.40 mg/g) due to a “dilution effect” of PE. Particularly, PBSA exhibited an insignificant effect on the adsorption of Cd(II) in soil during the present study. Overall, our findings provide new insights into the impacts of microplastics on the fate and behavior of heavy metals in the soil system.

Characterization of Biochar Produced from Cassava Stem

This project focuses on the characterization of biochar derived from cassava stem, a sustainable and abundant agricultural waste. The production of biochar through pyrolysis offers a promising solution for waste management, soil improvement, and carbon sequestration. The study aims to evaluate the physicochemical properties of the biochar, including its surface area, porosity, pH, nutrient content, and elemental composition. Analytical techniques such as scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) will be employed to investigate its structural and functional characteristics. Additionally, the research will explore the influence of pyrolysis conditions—temperature, heating rate, and residence time—on biochar quality. The potential application of cassava stem biochar as a soil amendment, its impact on soil fertility, and its role in reducing greenhouse gas emissions will also be investigated. By characterizing the biochar, this project seeks to promote the use of agricultural residues in sustainable practices and contribute to a circular bioeconomy.

Effect of Molybdenum Concentration and Deposition Temperature on the Structure and Tribological Properties of the Diamond-like Carbon Films

Two series of non-hydrogenated diamond-like carbon (DLC) films and molybdenum doped diamond-like carbon (Mo-DLC) films were grown on the silicon substrate using direct current magnetron sputtering. The influence of molybdenum doping (between 6.3 and 11.9 at.% of Mo), as well as the deposited temperature (between 185 and 235 °C) on the surface morphology, elemental composition, bonding microstructure, friction force, and nanohardness of the films, were characterized by atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and a nanoindenter. It was found that the increase in the metal dopant concentration led to a higher metallicity and graphitization of the DLC films. The surface roughness and sp3/sp2 ratio were obtained as a function of the Mo concentration and formation temperature. The nanohardness of DLC films was improved by up to 75% with the addition of Mo. Meanwhile, the reduction in the deposition temperature decreased the nanohardness of the DLC films. The friction coefficient of the DLC films was slightly reduced with addition of the molybdenum.

Enhanced Specific Capacitance and Cycling Stability of Li2Cu2(MoO4)3 of NASICON Family of Supercapacitor Applications

AbstractNASICON electrode materials exhibit a broad spectrum of electrochemical potentials, robust ionic conductivity, and structural and thermal stabilities. Using solid state reaction method, Li2Cu2(MoO4)3 was synthesized, a member of NASICON family of compounds based on molybdenum. Various analytical techniques employed to assess structural and morphological properties of synthesized nanomaterial. X‐ray diffraction (XRD) pattern indicated that generated Li2Cu2(MoO4)3 nanomaterial exhibited orthorhombic crystalline structure, with crystallite size of approximately 48 nm. The nanomaterial morphology was evaluated using field emission scanning electron microscopy (FESEM), showing columnar‐ or fiber‐like morphology composed of some conductivity points. The elemental composition of Li2Cu2(MoO4)3 was analyzed by EDAX analysis, confirming the presence of elements lithium, copper, molybdenum, and oxygen. The optical properties and band gap of Li2Cu2(MoO4)3 were analyzed by ultraviolet visible diffuse reflectance spectroscopy (UVDRS). Elemental composition of surface along with electronic states and oxidation states of component present in the nanomaterial Li2Cu2(MoO4)3 were investigated from X‐ray photoelectron spectroscopy (XPS). Electrochemical evaluation using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopic (EIS) showed a specific capacitance of 250 F g−1 at 3.5 A g−1 with the high retention rate of 95.82% after 3000 cycles, indicating its potential for high performance supercapacitors.

Improvement in the performance of indium free dye sensitized solar cell by the use of polyaniline composite

The photovoltaic study of the fabricated dye sensitized solar cells is revealed in this paper. To provide indium free approach, fluorine doped tin oxide (FTO) and aluminium doped zinc oxide (AZO) glass substrate were used as charge collectors for counter electrodes and photoanode respectively. Also, a novel and natural mixed dye was used as sensitizer and mixture of doped polymer (polyaniline with metallic oxides of tin, vanadium and cerium) and iodide-triiodide couple was utilized as electrolyte for the cell. Optical band gap and light absorption performance of dyes were studied by ultraviolet-visible (UV-vis) spectroscopy. Surface morphology and elemental composition of polymer composites was studied using scanning electron microscopic (SEM) with energy dispersive X ray (EDX) analysis. Phase analysis of the composites was determined by X-ray diffraction and thermal behavior with the help of thermo gravimetric analysis (TGA). Photovoltaic characteristics (I-V) and induced photon to current efficiency (IPCE) measurements were also investigated. Highest IPCE of 17.7% was observed when polyaniline was doped with oxide of vanadium. Hence an efficient, green, indium free and novel cell is fabricated by the usage of different charge collector substrate, natural dye sensitizer and quasi solid-state electrolyte.

Microscopic characteristics and corrosion rate modeling in galvanized high-strength steel wires

The electrochemical reaction mechanism of galvanized high-strength steel wires (GHSSWs) has not been fully elucidated. Scholars have observed a significant discrepancy between the theoretical mass loss rate calculated using the Faraday equation for electrochemical corrosion and the experimental values. To address this issue, this study conducted electrochemical corrosion tests on 195 sets of GHSSWs. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and non-contact 3D scanning systems were used to characterize the surface morphology and elemental composition of specimens before and after rust removal, revealing the reaction mechanism during electrochemical corrosion in GHSSWs. The correlation between corrosion length, current intensity, and electrolysis time with the corrosion rate was investigated, and a correction function for mass loss in GHSSWs under constant current electrochemical corrosion was established. The results indicate that during the initial stage of electrochemical corrosion in GHSSWs, internal stress between the corrosion products and the GHSSWs substrate leads to the formation of apparent cracks in the corroded wire, increasing the contact area between the specimen and the electrolyte and accelerating the corrosion process. In later stages, the formation of needle-like α-FeOOH corrosion products provides protective effects, leading to a decrease in the corrosion rate.

Synergistic enhancing low-rank coal flotation mechanisms using nanocarrier collector through pore sealing and surface hydrophobicity

Low-rank coal (LRC) is difficult to float using conventional oily collectors due to the rich oxygen-containing functional groups and abundant pores on its surface. In this study, an effective nanocarrier collector containing both nanoemulsion and nanoparticle with droplet size of 10–70 nm was developed, through diesel-beeswax mixture and AEO-7 using low-energy shearing and rapid cooling emulsification to enhance the LRC flotation. The surface morphology and elemental compositions of LRC were firstly characterized using SEM and EDS, identifying its difficult-to-float mechanisms. Then, the macroscopic appearance and microscopic size distribution of nanocarriers, and flotation tests were conducted to determine the optimum formula of nanocarrier collector for LRC. The results indicated that the recovery rate of combustibles was first increased and then decreased, by increasing the mass ratio of beeswax to diesel. When the mass ratio of diesel, beeswax, and AEO-7 was 2:3:5, the recovery rate of combustibles could be achieved to 92.98 %. Finally, the BET specific surface area, water adsorption, contact angle and wrap angle experiments were conducted to clarifying the synergistic enhancing LRC flotation mechanisms of nanocarriers collector. The nanocarriers could permeate into and seal the LRC surface pores, thereby reducing the both surface pore volumes and specific surface area. In addition, the mixtures of diesel and beeswax synergistically improved the surface hydrophobicity. Consequently, this research provides new insight into the development of effective collectors for LRC flotation.

Impact of processing and storage on citrus fiber functionality: Insights from spectroscopic techniques

To deliver their functionality when used in applications, citrus fibers need to be rehydrated. Factors such as chemical composition, structural organization as well as chemical surface composition are known to influence this functionality. Processing and storage conditions can affect these parameters, making it challenging to maintain stable functionality. This study used Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) to evaluate the effects of preparation and storage on citrus fibers. Samples dried at different scales and stored for 360 days under room and accelerated conditions were assessed for water holding capacity (WHC), water swelling capacity (WSC), and gel rigidity (G′). The results showed a decline in WHC, WSC, and G′ over time, confirming that aging negatively impacts moisture retention, particularly under higher water content or temperature. Drying scale had no effect on chemical composition or structure, but changes in the elemental surface composition of carbon and oxygen were noted. While prolonged storage altered the polysaccharides' chemical composition and structure, leading to functionality loss, XPS analysis revealed no changes in surface composition. Loss of functionality cannot be explained by chemical surface composition modifications.

Effect of Pulse Current on Friction Coefficient of 7075-T6 Aluminum Alloy and Microstructure Analysis

Abstract A study on friction is necessary to improve the forming quality of stamped parts. It has been found that pulsed current can improve the forming properties of aluminum alloys, mainly in terms of Joule heat and electroplasticity. Thus, this article revolves around the effect of different current densities on the friction and wear of 7075-T6 aluminum alloy sheets. The change rule of friction coefficient under different current densities is derived through a friction test, and the variable friction simulation model is established. Scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to analyze the micromorphology and elemental composition of the wear surface. The diffraction peaks of Al are analyzed by XRD, and grain size and dislocation density are calculated. Finally, the actual stamping results are compared with the simulation results. The results show that the friction coefficient decreases with the increase of current density when the current density is less than 10 A/mm2, and the wear mechanism is mainly abrasive wear. When the current density is greater than 10 A/mm2, the friction coefficient increases with the increase of current density and the wear mechanism is mainly adhesive and electrical wear. The grain size and dislocation density mainly depend on the electrical plasticity. The variable friction model's simulated thickness distribution and rebound results align more with the situation.

Extraction of nickel ions using nanoporous adsorbent material from waste glass

This study aims to create a porous glass adsorbent from waste glass to extraction nickel ions from its aqueous solution. The process involves converting waste glass to porous glass using 1:1:1:1 lime, sodium chloride, and sodium bicarbonate, followed by reacting with waste glass at 800 ˚C. The porous glass surface morphology, elemental composition, and functional groups, were analyzed using SEM, EDS, and FT-IR techniques.The outcome parameters used in this study are adsorbent dosage (10 g), contact time (150 min), heavy metal ion concentration (100 mg/l), and pH of 6. The adsorption capacity resulting from these parameters is 9.28 mg/g using the porous extract adsorbent for the extraction of nickel ions from its solutions. According to the findings. The proportion of Ni (II) ions extracted increased, coupled with a rise in the adsorbent dosage, heavy metal ion concentration, contact time, and pH. In addition, the Langmuir isotherm (R2 = 0.98,KL=0.072) has shown better performance than the Freundlich adsorption isotherm (R2 = 0.93,N=1.598) for the adsorption of the Ni(II) in this study.

Optimizing Synthesis of Anionic Surfactant‐Modified Carbon Black for Enhanced Ammonium Adsorption

The increasing levels of ammonium in wastewater pose serious environmental issues, highlighting the urgent need for effective adsorbents to facilitate its removal. Although conventional biological treatment methods have certain drawbacks, adsorption using carbonaceous materials, such as carbon black produced from waste tires, presents a promising alternative for ammonium removal. However, the use of these materials has not been thoroughly investigated. This study focuses on optimizing the synthesis of carbon black modified with anionic surfactants to improve its capacity for ammonium adsorption. Utilizing Response Surface Methodology (RSM) and a Box‐Behnken design, the optimization process examined key variables, including reaction time, surfactant concentration, carbon black dosage, and surfactant type. Comprehensive characterization of the adsorbent was conducted to analyze its surface properties, functional groups, morphology, and elemental composition. The regression models produced highly accurate results with an R2 value of 0.9437. The optimal synthesis conditions were identified as a 12.30‐hour reaction time, a surfactant concentration of 8 mmol/L of sodium dodecylbenzene sulfonate, and a carbon black dosage of 30 g, achieving an ammonium removal efficiency of 84.80%. This study offers a scalable solution for ammonium removal in wastewater, promising practical applications and future sustainable waste management research.

Precipitation–Flotation Process for Molybdenum and Uranium Separation from Wastewater

The mining of molybdenum and uranium ores inevitably results in the generation of large volumes of wastewater containing low concentrations of metals, which poses significant threats to the environment. This study presents a novel precipitation–flotation process for the simultaneous separation of molybdenum and uranium from wastewater. A systematic investigation was conducted on the impacts of the type of precipitant, flotation reagent type, and flotation parameters on the experimental results. Ferric salt served better as a precipitant than aluminum salt and humic acid did, and sodium dodecyl sulfate (SDS) was more suitable than sodium dodecyl benzene sulfonate for acting as a surfactant and foaming agent. Under specific conditions, including a pH of 6.6, an Fe3+ dosage of 0.6 mmol·L−1, an SDS dosage of 40 mg·L−1, an air flow rate of 25 mL·min−1, and a flotation time of 10 min, the removal efficiencies of molybdenum and uranium reached 96.6% and 93.6%, respectively. After flotation, the molybdenum concentration, uranium concentration, chemical oxygen demand, and turbidity of the treated water all meet the emission standards. Furthermore, the metal removal mechanisms, including the particle size distribution, functional group structure, surface element composition, microstructure, and element distribution, were elucidated on the basis of characterization of the precipitation–flotation products.

Efficacy of Sodium Fluoride and Fluoridated Calcium Phosphate in Mitigating Dental Erosion on Human Enamel: An In Vitro Analysis.

With increasing prevalence of dental erosion, this study explores the protective role of traditional fluoride-based products and newer formulations on eroded enamel. To assess the protective effectiveness of casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) and sodium fluoride (NaF) on human enamel against erosion using surface microhardness (SMH) and Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses. Ten extracted human third molars were sectioned to obtain 40 enamel sections and randomly assigned into four groups (n = 10) and treated as follows: G1 (Sound Enamel), G2 (Erosive Challenge), G3 (CPP-ACPF + Erosive Challenge), and G4 (NaF + Erosive Challenge). All samples were subjected to Vicker's SMH analysis, while changes in surface morphology and elemental composition were validated in few representative samples using FTIR and SEM, respectively. Paired samples test, Kruskal-Wallis test, and Tukey HSD test were performed using SPSS software version 23 setting P value < 0.05 as statistically significant. The mean SMH1 values for the experimental groups G3 and G4 were significantly higher (426.58VHN and 455.83VHN) when compared to G1 (P = 0.000) and G2 (P = 0.000). In SEM analysis, G2 showed eroded honeycomb appearance compared to the smooth homogenous surface of G1, while both G3 and G4 showed deposition of some precipitates. FTIR analysis revealed that in G3 and G4, a characteristic peak of phosphate vibrations between 528 and 823 cm-1 and carbonate bands at 845-932 cm-1 was observed. Both CPP-ACPF and NaF demonstrated a protective effect on enamel against erosive challenge by an orange juice-based beverage.

Microplastics contamination in popular soft drinks and non-alcoholic beverages marketed in Iran: Quantity and characteristics

Given the increasing reliance on plastic packaging in the beverage industry, this study investigates the presence of microplastics (MPs) in the most popular beverage brands in the Iranian market. A total of 19 bottled beverage brands, including soft drinks and non-alcoholic beverages, were randomly collected and filtered. Quantitative analysis of the MPs was then performed using stereomicroscopy and fluorescence techniques, and classification was based on color, shape, and size. In addition, the polymer type was determined using Fourier transform infrared spectroscopy (FT-IR), and the surface morphology and elemental composition of the MPs were examined using Scanning Electron Microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS). The results showed that approximately 80–90 % of the samples were contaminated with different MP types, with an average of 4.5 ± 4.8 particles/L detected by stereomicroscopy and 21.90 ± 25.72 particles/L by fluorescence microscopy. FT-IR analysis identified polyethylene terephthalate (PET) and polyethylene (PE) as the predominant polymer types and may clarify the possible role of packaging materials in the contamination of MPs. Fragments accounted for the highest proportion of MPs (71 %), followed by fibers (29 %). The size distribution of MPs was dominated by particles in the range of 1–500 μm (48 %), followed by 500–1000 μm (40 %) and 1000–1500 μm (12 %). MPs were black (84 %), with smaller proportions of red (7 %) and green (1 %), which may reflect the source of the contamination. The findings emphasize the necessity of increased monitoring and the application of countermeasures to lessen MPs contamination in the beverage sector.

Experimental and Theoretical Study on Surface Reactivity and CO Generation Mechanism of Bituminous Coal during Room-Temperature Oxidation.

To investigate the evolution of the microscopic chemical structure during the oxidation of bituminous coal at room temperature (25 °C) and infer the formation mechanism of carbon monoxide (CO), a self-designed closed-system coal oxidation experimental setup was employed to measure the CO generation from three bituminous coal samples [Duanwang (DW), Linsheng (LS), and Kunning (KN)]. 13C nuclear magnetic resonance and X-ray photoelectron spectroscopy were used to determine the structures and contents of different carbon atoms and surface elemental compositions and chemical states of the coal samples. Molecular models were constructed on the basis of the experimental data, and reactive force field pyrolysis simulation was used to trace the carbon atoms in the generated CO molecules. In combination with the results of interactive Mantel correlation analysis on the Fourier transform infrared experimental data of coal samples oxidized at room temperature for 0, 12, 24, 36, 48, and 60 h, the main functional groups, structures, and evolution of coal involved in CO formation during normal temperature oxidation were determined. The constructed molecular formulas for the coal samples were C154H122O28N2S for DW, C145H114O16N2S2 for LS, and C155H92O16N2S for KN. The formation of CO was related to the transformation of carbonyl (C═O), phenolic hydroxyl (-OH), ether (C-O-C), aromatic, and aliphatic structures in the coal.

Effect of carbonaceous materials on phosphorus removal in flow-through packed column systems.

Phosphorus (P) overloading in aquatic environments has long-been recognized as the leading cause of water quality deterioration, harmful algal bloom, and eutrophication. This study investigated P removal performance by five cost-effective carbonaceous materials (CMs) in flow-through packed column systems. These CMs include biochars pyrolyzed from feedstocks of Eucalyptus (E-biochar) and Douglas fir (D-biochar), commercial biochar (C-biochar), iron oxide-coated biochar (Fe-biochar), and commercial activated carbon (AC). The physicochemical properties of CMs, such as specific surface area (SSA), pore volume, pore diameter, elemental composition, and surface charge, were characterized. The packed column experimental results showed that P removal performance followed the order: E-biochar < D-biochar < C-biochar < Fe-biochar < AC. Specifically, the sorption capacity of 1mg/L of P in packed columns was 0.0036mg P/g E-biochar, 0.0111mg P/g D-biochar, 0.0369mg P/g D-biochar, 0.077mg P/g Fe-biochar, and 0.088mg P/g AC, respectively. The largest SSA (1012 m2/g) and pore volume (0.57 cm3/g) of AC accounted for the most outstanding P removal efficiency mainly by physical sorption, while electrostatic interaction explained the high P removal by Fe-biochar (SSA as low as 32.4 m2/g). Our findings provide direct practical implications for effectively removing P in water by cost-effective CMs.

Fabrication of copper ion-substituted hydroxyapatite/Silk fiber/Methylcellulose composite: mechanical, antimicrobial, hemocompatibility, bioactivity and cytocompatibility evaluation

Herein, we reported the preparation of copper substituted hydroxyapatite (Cu-HAP) and fabrication of electrospun composites using Cu-HAP, SF (Silk fiber) and MC (Methylcellulose) by E-Spin method. Characterization techniques such as XRD (phase formation), FTIR (chemical bonds), SEM and EDAX (surface morphology and elemental composition) were carried out. Porosity measurement, swelling and mechanical properties were carried out to investigate the physicochemical properties of the fabricated electrospun composites. The hemocompatibility analysis indicated a hemolysis ratio < 2 %, which confirms the blood compatibility nature of the composite. Antibacterial activity of Copper hydroxyapatite/silk fiber/ Methylcellulose electrospun composite showed estimable activity against E.coli (zone of inhibition: 46 ± 0.94 mm) compared with pure SF/MC electrospun composite (33 ± 1.21). Bioactivity study confirmed the development of bone-like apatite on the surfaces of optimized (SF/MC 30 wt% of Cu-HAP) electrospun composite. Furthermore, MG63 cells were utilised to study the biocompatibility of the enhanced electrospun composite and good cell viability (99.93 ± 0.12 % using 25 μg/mL) was observed from microscopic image and the results showed that 30 wt% of Cu-HAP added polymer composite has outstanding osteoinductivity, biocompatibility, and antibacterial results, making it a very valuable aspirant for use in bone tissue engineering (BTE) applications to repair bone defects.

Statistics design for the synthesis optimization of lignin-sulfonate sulfur-doped mesoporous carbon materials: promising candidates as adsorbents and supercapacitors materials

This study employed lignin-sulfonated (LS) to develop biobased carbon materials (LS-Cs) through a sulfur-doping approach to enhance their physicochemical properties, adsorption capabilities, and energy storage potentials. Various characterization techniques, including BET surface area analysis, SEM imaging, XPS, Raman spectroscopy, and elemental composition (CHNS), were employed to assess the quality of the LS-Cs adsorbent and electrode samples. Response Surface Methodology (RSM) was utilized for optimizing the two main properties (specific surface area, ABET, and mesopore area, AMESO) by evaluating three independent factors (i.e., activation temperature, ZnCl2:LS ratio, and sulfur content). According to the statistical analysis, ABET and AMESO were affected by ZnCl2 and sulfur content, while the pyrolysis temperature did not affect the responses in the studied conditions. It was found that increasing the ZnCl2 and sulfur contents led to an increment of the ABET and AMESO values. The LS-C materials exhibited very high ABETvalues up to 1993 m2 g−1 and with predominantly mesoporous features. The S-doping resulted in LS-Cs with high sulfur contents in their microstructures up to 15% (wt%). The LS-C materials were tested as adsorbents for sodium diclofenac (DCF) adsorption and reactive orange 16 dye (RO-16) and as electrodes for supercapacitors. The LS-Cs exhibited excellent adsorption capacity values for both molecules (197–372 mg g−1) for DCF, and (223–466 mg g−1) for RO-16. When tested as electrodes for supercapacitors, notably, LS-C3, which is a doped sample with sulfur, exhibited the best electrochemical performance, e.g. high specific capacitance (156 F/g at 50 mV/s), and delivered an excellent capacitance after 1000 cycles (63 F/g at 1 A/g), which denotes the noteworthy capacitive behavior of the S-doped electrode. Thus, the present work suggests an eco-friendly resource for developing effective, productive carbon materials for adsorbent and electrodes for SC application. However, further studies on the complete application of these materials as adsorbents and electrodes are needed for a deeper understanding of their behavior in environmental and energy storage applications.

Optimization study for chemical activation of biochar derived from sugarcane bagasse for maximum phytohormone adsorption from waste coconut water

Abstract Improper treatment and disposal of sugarcane bagasse (SB) in farms and sugar industries can lead to environmental and health concerns. Instead of burning these wastes, bagasse can be utilized for biochar production which can be applied as adsorbents. Additionally, studies reported that the performance of biochar adsorbents can be improved by activation. Hence, this study aimed to optimize the chemical activation conditions of biochar from SB for maximum adsorption of phytohormones from waste coconut water (WCW). Pretreated SB was first converted into biochar though pyrolysis and was chemically activated using potassium hydroxide (KOH). Response Surface Methodology was used to determine the optimum activation conditions to maximize phytohormone adsorption efficiency. Factors considered were KOH-biochar ratio (1:1 to 5:1 g/g) and carbonization holding time (45 to 90 minutes). Analysis of Variance showed that the adsorption efficiency of activated biochar is significantly affected by KOH-biochar ratio. Increasing the ratio created cavities on the surface which serve as adsorption sites; however, further increase in ratio resulted in pore degradation lowering the adsorption performance of activated biochar. Conversely, carbonization holding time did not have significant effect on the response for the range of factors considered. The optimum conditions which were 3.18:1 KOH-biochar ratio and 65.64 minutes holding time resulted to ~82.14% actual phytohormone adsorption efficiency. The characteristics of the optimized activated biochar (SBAB) were then compared with that of the unmodified biochar (SBB) in terms of morphology, surface elemental composition, functional groups, adsorption efficiency, average particle size, and bulk density. The SBAB produced can be applied in further studies focusing on the adsorption of phytohormones from WCW and desorption from the adsorbent to isolate them. Results of this study can also provide a sustainable solution in minimizing the disposal of sugarcane bagasse and waste coconut water while increasing their economic returns and environmental benefits.