Similar Specific Surface Area Research Articles

Bio-enriched composite materials derived from waste cooking oil for selective reduction of odour intensity

Currently, pathogenic microorganisms are becoming more active in public utility areas like parking lots and waste shelters due to the accumulation of organic waste. This uncontrolled waste leads to decay, altering its composition and presenting a microbiological risk to public health. Additionally, it emits unpleasant odors containing chemicals that irritate the mucous membranes, causing discomfort in the nose, throat, and eyes by stimulating the trigeminal nerve. These odors can have various negative effects on both quality of life and public health. The study investigated the physicochemical properties of oil composites enriched with natural additives and determined their effectiveness in reducing the intensity of nuisance odours. The research showed over 82% reduction in decaying meat odour and almost 65% reduction in ammonia odour. A higher impact of the given composites on reducing the odour from decaying meat than from ammonia was observed. This may be due to the biocidal properties of the additives used (turmeric, thymol, salicylic acid, hops and curly sorrel) and the higher intensity of ammonia odor compared to meat-derived odour. Despite the non-porous nature of the solids tested (with similar specific surface areas ranging from 0.66 to 0.88 m2/g), they were capable of sorbing NH3.

Influence of preparative parameters on the morphology and reactivity of synthetic hexagonal birnessite

Birnessite is a phyllomangante mineral widely found in surficial environments. Its morphology not only affects its adsorption and oxidation properties but also indicate changes in the climatic conditions of ancient Earth. This study explored how preparative parameters affect the morphology and reactivity birnessite. Synthesized at boiling temperatures, birnessite nanoflowers measured 265 nm with a specific surface area (SSA) of 34.87 m2/g, while at 65 °C, they increase to 2251 nm with a similar SSA of 30.33 m2/g. Lowering KMnO4 or HCl concentrations increased nanoflower size. Reduced concentration of KMnO4 hindered Coulombic forces, fostering a parallel petal arrangement and a higher SSA (59.11 m2/g). Lower concentration of HCl led to perpendicular petals and a reduced SSA (12.33 m2/g). Decreased concentrations of both KMnO4 and HCl reduced initial δ-MnO2 concentration, allowing time for edge-to-edge assembly and nanoflake substrate formation. Subsequently, δ-MnO2 vertically assembled on substrates to form microwalls with SSA of 85.39 m2/g. Organic acids as capping agents disrupted this assembly. Adsorption tests for Cd2+ revealed microwalls achieved 7102 mmol/kg, surpassing original birnessite nanoflowers at 2114 mmol/kg. These results provide insights into the crystallization processes and reactivity of natural birnessite, as well as methods for the controllable synthesis of nanoflowers.

Stability of Iodine Species Trapped in Titanium-Based MOFs: MIL-125 and MIL-125_NH2.

Two titanium-based MOFs MIL-125 and MIL-125_NH2 are synthesized and characterized using high-temperature powder X-ray diffraction (PXRD), thermogravimetric analysis(TGA), N2 sorption, Fourier transformed infrared spectroscopy (FTIR), Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), and electron paramagnetic resonance (EPR). Stable up to 300°C, both compounds exhibited similar specific surface areas (SSA) values (1207 and 1099m2g-1 for MIL-125 and MIL-125_NH2, respectively). EPR signals of Ti3+ are observed in both, whith MIL-125_NH2 also showing ─NH2 ●+ signatures. Both MOFs efficiently adsorbed iodine in continuous gas flow over five days, with MIL-125 trapping 1.9g.g-1 and MIL-125_NH2 trapping 1.6g.g-1. MIL-125_NH2 exhibited faster adsorption kinetics due to its smaller band gap (2.5 against 3.6eV). In situ Raman spectroscopy conducted during iodine adsorption revealed signal evolution from "free" I2 to "perturbed" I2, and I3 -. TGA and in situ Raman desorption experiments showed that ─NH2 groups improved the stabilization of I3 - due to an electrostatic interaction with NH2 ●+BDC radicals. The Albery model indicated longer lifetimes for iodine desorption in I2@MIL-125_NH2, attributed to a rate-limiting step due to stronger interaction between the anionic iodine species and the ─NH2 ●+ radicals. This study underscores how MOFs with efficient charge separation and hole-stabilizer functional groups enhance iodine stability at higher temperatures.

Evaluation of CH4/N2 separation performances on ultra-microporous FDCA-based MOFs using experimental and numerical methods

A comprehensive investigation was conducted to explore the adsorption behaviors of CH4 over N2 on ultra-microporous Al/Zr-FDCA frameworks, which were synthesized specifically using the eco-friendly and bio-sourced 2,5-furandicarboxylic acid (FDCA). Characterization results revealed that both Al-FDCA and Zr-FDCA exhibited similar specific surface area and surface groups, leading to comparable methane uptake per-unit mass at atmospheric pressure. However, the presence of Zr nodes generated ultra-micropores around 0.43 nm in size, leading to a pronounced affinity for CH4. Zr-FDCA demonstrated a higher CH4/N2 selectivity (8.90) calculated from the isotherms compared to Al-FDCA (3.86). Furthermore, breakthrough experiments indicated that under the same dynamic conditions, Zr-FDCA exhibited 1.5 times higher CH4 uptake per unit volume and 2.5 times higher CH4/N2 selectivity when compared to Al-FDCA. Initially, a four-step VPSA process was simulated to investigate the separation of CH4/N2 mixture, in which the effects of feed-gas flow rate, adsorption time, adsorption pressure, and desorption pressure in VPSA cycle were extensively evaluated to enhance the purity and recovery of methane. Subsequently, a six-step process was employed for further optimization, achieving a purity of 95.9 % and a recovery of 99.1 %. The obtained results demonstrated the reliability of the established model and highlighted the significant potential of Zr-FDCA for CH4/N2 separation.

Effect of pore size distribution of biomass activated carbon adsorbents on the adsorption capacity

AbstractBACKGROUNDIn order to investigate the correlation between the pore size distribution of biomass activated carbon adsorbents (BACAs) and VOCs (volatile organic compounds) adsorption/desorption performance. Four BACAs with same specific surface area but different pore size distribution were prepared under different experimental conditions and processes.RESULTSThe impact of the pore size distribution of BACAs on the adsorption/desorption performance of benzene, toluene and xylene was investigated. The results indicated that the adsorption ability of the prepared BACAs for benzene, toluene and xylene was mostly affected by the pore sizes distributed in the 2.60 ~ 3.25, 2.68 ~ 3.35and 4.20 ~ 4.90 nm ranges, respectively, when the studied BACAs had similar specific surface area (SBET ≈ 1080 m2 g−1). However, the desorption amount of adsorbed benzene molecules mainly relied on the pore structures of BACAs having pore sizes in the 3.95 ~ 4.60 nm range.CONCLUSIONThe pore structures of BACAs distributed in different pore size ranges have various effects on the phenyl VOCs adsorption capacity. Benzene adsorption on the BACAs was mainly affected by the microporous structures. The pore structure with larger pore size was more favorable for the desorption of the adsorbed toluene and xylene molecules compared to the adsorbed benzene molecules. Benzene, toluene and xylene had low residual rates in the studied activated carbon adsorbents attesting to their superior regenerative properties. This work could provide an important reference for the design, preparation, and selection of activated carbon adsorbents for the adsorption capacity of benzene, toluene and xylene. © 2024 Society of Chemical Industry (SCI).

Advances in design, scale and operability of the Rotating Liquid Sheet (RLS) contactor: Pressure drop, flood-point and mass transfer – Comparison to random packing

The Rotating Liquid Sheet (RLS) contactor is a novel packing-less gas-liquid contactor where multiple continuous liquid sheets form at the outlet of helical slots in a rotating central feed tube. Each liquid sheet is auger-shaped, and the rotation of the feed tube transfers momentum from the sheets to the gas. Multiple sheets travel in parallel to arrive unbroken at the column wall. The gas travels through the space between adjacent sheets providing close contact between the gas and liquid. Careful design ensures that liquid sheets travel in parallel arcs, enabling scale-up from 150–600 mm diameter column, a size suitable for the speciality chemical or pharmaceutical industries. Pressure drop and flooding measurements using an air/water system compared the RLS contactor with 25 mm Pall Rings. Results for the Pall Rings matched expected performance, while RLS contactor pressure drop was 10% of that measured for the Pall Rings. Mass transfer experiments using an air+CO2/NaOH solution system showed measured mass transfer coefficients using the RLS contactor were comparable to a packed bed (25 mm Pall Rings) of similar specific surface area, while foaming in the packed bed did not occur in the RLS contactor using the same liquid sample. The RLS contactor also displayed minimal entrainment.

Structural properties and electrochemical performances of mesoporous carbon towards enhanced lithium-ion storage

This study analyzes the structural characteristics of mesoporous carbon (CMK-3) and how they affect the specific capacity of Li-ion batteries (LIBs). To achieve this, CMK-3 is synthesized with and without the addition of oxalic acid as a catalyst to polymerize furfuryl alcohol (carbon precursor) in the template-assisted synthesis process using mesoporous silica. CMK-3 (without oxalic acid) and CMK-3_O (with oxalic acid) exhibit rod-like particles with cylindrical pores, showing high specific surface area (SSA) of 998 and 1067 ​m2 ​g−1 and oxygen-to-carbon ratios of 0.23 and 0.43, respectively. At 178 ​mA ​g−1, the electrodes demonstrate specific capacities of 993 ​mA ​h ​g−1 (CMK-3) and 520 ​mA ​h ​g−1 (CMK-3_O). According to the cyclic voltammetry technique, the non-diffusion-controlled process (approximately 55 ​%) significantly contributes to the total charge storage in CMK-3. Although electrodes (CMK-3 and CMK-3_O) have similar SSA, this study highlights the significance of the disordered and defective structure in achieving a higher specific capacity from the same material without any changes in morphology, particle size, or synthesis route. Consequently, this work emphasizes the necessity of considering the structural properties of porous carbon electrodes when developing high-performance batteries for electric vehicles, where specific capacity and cyclic stability are crucial.

Comparison of crude nano-hydroxyapatite extracted from calcified seaweed in terms of composition, antibacterial activity, and cytotoxicity

The objectives of this study were to synthesize nano-hydroxyapatite (nHAp) from red seaweed by an optimized and environmentally friendly thermal and chemical treatment method using minimal chemicals. Calcified tissues from seaweed were thermally treated to obtain calcium carbonate, which reacted with potassium dihydrogen phosphate to synthesize nHAp. Nano-hydroxyapatite materials, nHAp-Jr and nHAP-Co were produced from the seaweeds Jania rubens and Corallina officinalis, respectively. Results showed that the developed method successfully produced high yields of nHAp-Jr and nHAp-Co powders (>78 %). The crude composition of the synthesized nHAp-Jr and nHAp-Co materials was characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scan electron microscopic (SEM), Energy dispersive X-ray spectroscopy (EDAX), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), and thermal gravimetric analysis (TGA). XRD patterns confirmed the formation of nHAp and calcium phosphate phases. SEM images showed the nanoparticle size of nHAp-Jr and nHAp-Co with an average distribution of 16.70 ± 0.71 nm. EDAX spectra identified the relative similar elemental compositions of nHAp-Jr and nHAp-Co. BET and BJH patterns revealed relatively similar specific surface area, total pore volume and average pore diameter for mesoporous size nHAp powders (2–50 nm). Antibacterial activity of nHAp-Jr and nHAp-Co showed good efficacy against the caries-causing agent, Streptococcus mutans compared to ciprofloxacin using the modified XTT assay. Cytotoxicity testing of nHAp-Jr and nHAp-Co against WISH cell line using modified MTT assay confirmed the relevant antibacterial effects without any side effect on hepatocytes. This sustainable method produced nHAp compounds from seaweed that show promising antibacterial properties and biocompatibility, highlighting the potential for biomedical applications.

Highly dispersed V2O5-WO3 in modified morphology of flower-like TiO2 for NH3-selective catalytic reduction over wide temperatures

NOX, a first-class carcinogen, and secondary particulate matter are produced in Various industrial processes form stationary sources such as steel mills and thermal power plants. Selective catalytic reduction is a method of repeatedly exposing used as V2O5-WO3/TiO2 to high temperatures by used NH3 reduction agent to N2 and H2O. Consequently, the catalytic performance decreases during the aggregation of transition metal and support, and industries need catalysts that react in a wide temperature range. In this study, flower-type TiO2 (FL-Ti) that changes the morphology of TiO2 was synthesized through hydrothermal method, anatase TiO2 with a similar specific surface area to commercial TiO2 was synthesized, and the dispersibility of transition metals was increased. Synthesis was conducted by changing the ratio of commercial TiO2 to FL-Ti to increase economic efficiency and reduce aggregation of transition metal and TiO2, thus resulting in their high dispersion. The presence of Ti3+ in FL-Ti increased the hydroxyl group owing to increased Ti-O bonds and the V4+ ratio, which positively influenced the catalyst at low temperatures. The catalyst with added FL-Ti reacted with the Eley-Rideal mechanism. Additionally, NOX conversion and N2 selectivity were approximately 93–99% at temperatures ranging from 250–420 ℃.

Enhanced adsorption of organic pollutants using N-doped porous carbon derived from hemp stems: Insights into the mechanism

Nitrogen (N) doping is commonly used to modify biochar and enhance its adsorption performance. However, the significance of pyrrolic-N in pollutant adsorption is frequently overlooked. In this study, N-doped porous carbon materials (NBC) have been synthesized using hemp stems as the carbon source through pyrolysis in one step for the efficient removal of organic pollutants. The incorporation of the pyrrolic-N functional group in NBC leads to an increase in surface defects, electronegativity, and electron conductivity. As a result, the Qmax of tetracycline (TC) reaches 577.60 mg/g, which is twice as much as activated carbon with a similar specific surface area. The characterization and theoretical calculation demonstrate that the NBC adsorbent adsorbs TC primarily through cation-π and π-π interactions facilitated by pyrrolic-N, as well as weak electrostatic interactions induced by –COOH. In actual landfill leachate adsorption experiments, the NBC effectively reduced chemical oxygen demand and ammonia–nitrogen levels in wastewater. Additionally, the growth of sprouts planted on contaminated soil treated with NBC (sulfamethoxazole, 50 mg/kg) is restored to levels observed on uncontaminated soil, thus demonstrating its practicality.

Catalytic Performance of Bimetallic Cobalt–Nickel/Graphene Oxide for Carbon Dioxide Reforming of Methane

The design of economical and robust catalysts is a substantial challenge for the dry reforming of methane (DRM). Monometallic nickel-based catalysts used for DRM reactions had comparable activity to noble metals. However, they turned out to be less stable during the reactions. As a continuation of the interest in synthesizing catalysts for DRM, this paper evaluates the catalytic performance of bimetallic Co–Ni catalysts regarding their synergy effect, with graphene oxide (GO) as support for the first time. The synthesized bimetallic catalysts prepared via the wet-impregnation method were characterized using N2 physisorption analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The catalytic test was performed in a stainless-steel tubular reactor in atmospheric conditions with a reaction temperature of 800 °C, time-on-stream (TOS) of 300 min and CH4: CO2 being fed with a ratio of 1:1. The bimetallic 10 wt%Co–10 wt%Ni/GO and 20 wt%Co–10 wt%Ni/GO catalysts had a similar BET specific surface area in N2 physisorption analysis. The XRD pattern displayed a homogeneous distribution of the Co and Ni on the GO support, which was further validated through SEM–EDX. The conversion of CO2, CH4, and H2 yield decreased with reaction time due to the massive occurrence of side reactions. High conversions for CO2 and CH4 were 94.26% and 95.24%, respectively, attained by the bimetallic 20 wt%Co–10 wt%Ni/GO catalyst after 300 min TOS, meaning it displayed the best performance in terms of activity among all the tested catalysts.

Effect of Supplementary Cementitious Materials with Similar Specific Surface Area on Cementitious Composite Systems

Abstract This study investigated the effect of the mechanical and durability properties of cementitious composite systems with supplementary cementitious materials (SCMs), including fly ash (FA), ground granulated blast furnace slag (GGBS), and bottom ash (BA), with similar specific surface areas (∼3,300 cm2/g). FA, GGBS, and BA were ground to a specific surface area of ∼3,300 cm2/g (about the cement-specific surface area) and then replaced with cement at 5 %, 10 %, 15 %, and 20 % replacement ratios. The compressive strength, flexural strength, length change, and rapid chloride ion permeability of the cementitious composites incorporating FA, GGBS, and BA with similar specific surface areas were recorded after 7-, 28-, and 90-day curing periods. As a result, cementitious composites containing GGBS improved the mechanical and durability properties at the maximum rate. It was shown that the properties of cementitious composites containing 20 % GGBS yielded better results than the control specimens without any SCMs.

Effect of alternative sweetener and carbohydrate polymer mixtures on the physical properties, melting and crystallization behaviour of dark compound chocolate

This study aims to evaluate the effect of sucrose replacer mixtures (erythritol, mannitol, or tagatose in combination with inulin or polydextrose) on the crystal morphology, particle size distribution, rheology, melting properties, and fat polymorphism of dark compound chocolate. The result showed that the replacer mixture’s hygroscopicity, particle size, and sugar crystal shape might significantly impact dark compound chocolate's rheological and textural properties but had no substantial impact on the melting properties and fat crystallization. Mannitol-containing samples exhibited the highest rheological value, likely related to their high moisture content, small particle size, and elongated crystal shape. Due to the similar specific surface area and comparable D90 value, the sample containing erythritol-polydextrose mixture resulted in a similar (P ≥ 0.05) Casson yield value (46.184 ± 2.45 Pa) compared to the sample containing sucrose (38.348 ± 1.68 Pa). It could be a potential sucrose replacer in the dark compound chocolate.

Adsorption of Phenols on Carbonaceous Materials of Various Origins but of Similar Specific Surface Areas

The adsorption of phenol (Ph), 4-chlorophenol (CP), and 4-cresol (MP) from aqueous solutions on three carbonaceous materials of diverse origins but similar specific surface areas was investigated. Vulcan XC72 carbon black (CB), AKP-5 activated coke (AC), and activated tire pyrolysis char (AP) were examined as adsorbents. The kinetics and equilibrium adsorption, as well as the influence of pH and ionic strength of each solution on the adsorption process, were studied. The results revealed that the adsorption was pH-dependent and preferred an acidic environment. The presence of an inorganic salt in the solution (ionic strength) did not affect the adsorption processes of the three adsorbates. The pseudo-first- and pseudo-second-order equations, as well as the Weber–Morris and Boyd kinetic models, were used to describe the adsorption kinetics. It was found that equilibrium was reached for all adsorbates after approximately 2–3 h. Adsorption kinetics followed a pseudo-second-order model, and the adsorption rate was determined by film diffusion. The adsorption isotherms were described using the Langmuir and Freundlich equations. The results revealed that the adsorption processes of Ph, CP, and MP on all three adsorbents from the water were better described by the Langmuir model. The adsorption of CP was the most efficient, the adsorption of MP was slightly weaker, and the adsorption of phenol was the least efficient.

A detailed experimental comparison on the hydrogen storage ability of different forms of graphitic carbon nitride (bulk, nanotubes and sheets) with multiwalled carbon nanotubes

The reversible hydrogen storage of graphitic carbon nitride (g-C3N4) nanotubes at room temperature was first studied through experimental methods in this work and was compared to multiwalled carbon nanotubes (MWCNT), bulk g-C3N4, and g-C3N4 nanosheets. Compared with MWCNT which had a similar specific surface area around 60 m2/g, g-C3N4 nanotubes had a higher room temperature hydrogen storage capacity up from 0.46 wt% for MWCNT to 0.78 wt%. This value for the g-C3N4 nanotubes was also higher than the hydrogen storage capacity of bulk g-C3N4 (0.51 wt%) and g-C3N4 nanosheets (0.73 wt%), even though g-C3N4 nanosheets had the highest specific surface area of 161 m2/g. Temperature programming desorption (TPD) was applied to study the desorption behaviours and it was found that chemisorption contributed to the relative high storage capacity of g-C3N4 nanotubes.

New Carbamoyl Surface-Modified ZrO2 Nanohybrids for Selective Au Extraction from E-Waste

Efficient and selective extractions of precious and critical metal ions such as Au(III) and Pd(II) were investigated using zirconia nanoparticles surface modified with different organic mono- and di-carbamoyl phosphonic acid ligands. The modification is made on the surface of commercial ZrO2 that is dispersed in aqueous suspension and was achieved by optimizing the Bronsted acid-base reaction in ethanol/H2O solution (1:2), resulting in inorganic-organic systems of ZrO2-Ln (Ln: organic carbamoyl phosphonic acid ligand). The presence, binding, amount, and stability of the organic ligand on the surface of zirconia nanoparticles were confirmed by different characterizations such as TGA, BET, ATR-FTIR, and 31P-NMR. Characterizations showed that all the prepared modified zirconia had a similar specific surface area (50 m2.g-1) and the same amount of ligand on the zirconia surface in a 1:50 molar ratio. ATR-FTIR and 31P-NMR data were used to elucidate the most favorable binding mode. Batch adsorption results showed that (i) ZrO2 surface modified with di-carbamoyl phosphonic acid ligands had the highest adsorption efficiency to extract metals than mono-carbamoyl ligands, and (ii) higher hydrophobicity of the ligand led to better adsorption efficiency. The surface-modified ZrO2 with di-N,N-butyl carbamoyl pentyl phosphonic acid ligand (ZrO2-L6) showed promising stability, efficiency, and reusability in industrial applications for selective gold recovery. In terms of thermodynamic and kinetic adsorption data, ZrO2-L6 fits the Langmuir adsorption model and pseudo-second-order kinetic model for the adsorption of Au(III) with maximum experimental adsorption capacity qmax = 6.4 mg.g-1.

Removal of diclofenac by adsorption process studied in free-base porphyrin Zr-metal organic frameworks (Zr-MOFs).

As the world population continues to grow, there is also a rising concern regarding water pollution since this condition could negatively impact the supply of clean water. One of the most recent concerns is related to the pollution that comes from various pharmaceuticals, in particular non-steroidal anti-inflammatory drugs (NSAIDs) since they have been industrially produced at large scale and can be easily purchased as an over-the-counter medicine. Diclofenac is one of the most popular NSAIDs because of its high-effectiveness, which leads to its excessive consumption. Consequently, its presence in water bodies is also continuously increasing. An adsorption process could then be employed as a highly effective method to address this issue. In comparison to other conventional adsorbents such as activated carbon, the use of metal-organic frameworks (MOFs) as an alternative adsorbent is very attractive since it can offer various advantages such as tailorability and high adsorption capacity. In this study, the performance of three water-stable, free-base porphyrin MOFs assembled using zirconia-based nodes, namely MOF-525, MOF-545, and NU-902, for diclofenac adsorption was thoroughly investigated. Interestingly, although all three free-base porphyrin MOFs are assembled using the same building block and have a similar specific surface area (based on the experimental argon physisorption and calculation based on non-localized density functional theory), their diclofenac adsorption capacity is substantially different from one another. It is found that the highest diclofenac adsorption capacity is shown by MOF-525, which has maximum capacity around 792 mg g-1. This is then followed by MOF-545 and NU-902 that have adsorption capacities around 591 and 486 mg g-1, respectively. Some possible adsorption mechanisms are then thoroughly discussed that might contribute to this phenomenon. Lastly, their performance is also compared with other MOFs that are also studied for this purpose to show their performance superiority not only in terms of adsorption capacity but also their affinity towards the diclofenac molecule, which might be useful as an adsorption performance indicator in the real condition where the contaminant concentration is considerably low.

Activated carbons with extremely high surface area produced from cones, bark and wood using the same procedure.

Activated carbons have been previously produced from a huge variety of biomaterials often reporting advantages of using certain precursors. Here we used pine cones, spruce cones, larch cones and a pine bark/wood chip mixture to produce activated carbons in order to verify the influence of the precursor on properties of the final materials. The biochars were converted into activated carbons with extremely high BET surface area up to ∼3500 m2 g-1 (among the highest reported) using identical carbonization and KOH activation procedures. The activated carbons produced from all precursors demonstrated similar specific surface area (SSA), pore size distribution and performance to electrodes in supercapacitors. Activated carbons produced from wood waste appeared to be also very similar to "activated graphene" prepared by the same KOH procedure. Hydrogen sorption of AC follows expected uptake vs. SSA trends and energy storage parameters of supercapacitor electrodes prepared from AC are very similar for all tested precursors. It can be concluded that the type of precursor (biomaterial or reduced graphene oxide) has smaller importance for producing high surface area activated carbons compared to details of carbonization and activation. Nearly all kinds of wood waste provided by the forest industry can possibly be converted into high quality AC suitable for preparation of electrode materials.

Are Fractal-Like Structures Beneficial for Supercapacitor Applications? A Case Study on Fe2O3 Negative Electrodes

The question of whether fractal-like structures are beneficial for supercapacitor applications is investigated by hydrothermally synthesizing Fe2O3 in fern, flake, and microsphere morphologies with similar specific surface areas. Their negative electrodes are prepared by supporting them on nickel foam (NF). The fractal dimensions (FDEIS) of these morphologies estimated from electrochemical impedance spectroscopy are ∼2.50, ∼2.36, and ∼2.19, respectively. The Fern@NF electrode exhibits the highest specific capacitance (Csp) of ∼2708 and ∼104 F g–1 at 1 and 5 A g–1, respectively, with an ∼94% capacitance retention after 2000 cycles. The capacitive (nonfaradaic) surface charge storage contribution from cyclic voltammetry increases with FDEIS from microspheres to ferns. Interestingly, such an increase in FDEIS leads to a decrease in the estimated impedance (ZCPE) in that order enhancing the performance of ferns. Hence, fractal-like structures are beneficial for supercapacitor applications by promoting capacitive surface charge storage through low ZCPE. The emphasis of this work is to study the effect of fractal dimension on the charge storage performance of Fe2O3 electrodes, which is scarcely addressed in the literature. The methodology presented here can be useful in designing/synthesizing a novel supercapacitor material possessing fractal-like structures with a potential for scale-up and commercialization.

Characterization of porous LaCoO3 prepared from wood powder template and its catalysis for diesel particulate matter

In this paper, LaCoO3 porous perovskite was synthesized using wood powder template combined with sol–gel process, while LaCoO3 prepared by traditional sol–gel method was used as a comparison. The catalysts prepared by different methods were characterized by X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), N2 adsorption–desorption, and the particulate matter (PM) trapping and catalytic oxidation tests were carried out by engine bench test and thermogravimetric analyzer (TGA). The results showed that the porous LaCoO3 successfully replicated the structural features of wood powder from macroscopic to tracheid, forming a porous structure. Porous LaCoO3 exhibits better catalytic activity than powdered LaCoO3 with similar specific surface area, this can be attributed to the porous structure of LaCoO3, which increases the contact area and the number of contact points between PM and catalyst.