Dielectric Barrier Discharge Plasma Processing and Sr-Doped ZnO/CNT Photocatalyst Decoration of Cotton Fabrics for Self-Cleaning Application.

Nonthermal plasma processing is a chemical-free and environmentally friendly technique to enhance the self-cleaning activity of nanoparticle-coated cotton fabrics. In this research, Sr-doped ZnO/carbon nanotube (CNT) photocatalysts, namely, S10ZC2, S15ZC2, and S20ZC2 with different Sr doping concentrations, were synthesized using the sol-gel method and coated on plasma-functionalized fabric to perform the self-cleaning tests. The fabrics were treated with dielectric barrier discharge plasma in an open environment for 3 min to achieve a stable coating of nanoparticles. The energy band gap of the photocatalyst decreased with an increase in the level of Sr doping. The band gap of S10ZC2, S15ZC2, and S20ZC2 photocatalysts was estimated to be 2.85, 2.78, and 2.5 eV, respectively. The hexagonal wurtzite structure of ZnO was observed on the fabric surface composited with CNTs and Sr. The S20ZC2 photocatalyst showed better homogeneity and photocatalytic response on the fabric when compared with S10ZC2- and S15ZC2-coated fabrics. The S20ZC2 photocatalyst showed 89% dye degradation efficiency after 4 h of light exposure in methylene blue solution, followed by S15ZC2 (84%) and S10ZC2 (80%) photocatalysts.

Gold Nanoparticle-Loaded Silica Nanospheres for Sensitive and Selective Electrochemical Detection of Bisphenol A.

In this work, silica nanospheres were used as support for gold nanoparticles and applied for bisphenol A electrochemical detection. The development of new silica-supported materials has attracted increasing attention in the scientific world. One approach of interest is using silica nanospheres as support for gold nanoparticles. These materials have a variety of applications in several areas, such as electrochemical sensors. The obtained materials were characterized by solid-state UV-vis spectroscopy, electron microscopy, X-ray diffraction, and electrochemical techniques. The electrode modified with AuSiO2700/CHI/Pt was applied as an electrochemical sensor for BPA, presenting an oxidation potential of 0.842 V and a higher peak current among the tested materials. The AuSiO2700/CHI/Pt electrode showed a logarithmic response for the detection of BPA in the range of 1-1000 nmol L-1, with a calculated detection limit of 7.75 nmol L-1 and a quantification limit of 25.8 nmol L-1. Thus, the electrode AuSiO2700/CHI/Pt was presented as a promising alternative to an electrochemical sensor in the detection of BPA.

Effect of Ionic Liquids on Mechanical, Physical, and Antifungal Properties and Biocompatibility of a Soft Denture Lining Material.

This study aims to evaluate the effect of ionic liquids and their structure on the mechanical (tensile bond strength (TBS) and Shore A hardness), mass change, and antifungal properties of soft denture lining material. Butyl pyridinium chloride (BPCL) and octyl pyridinium chloride (OPCL) were synthesized, characterized, and mixed in concentrations ranging from 0.65-10% w/w with a soft denture liner (Molloplast-B) and were divided into seven groups (C, BPCL1-3, and OPCL1-3). The TBS of bar-shaped specimens was calculated on a Universal Testing Machine. For Shore A hardness, disc-shaped specimens were analyzed using a durometer. The mass change (%) of specimens was calculated by the weight loss method. The antifungal potential of ionic liquids and test specimens was measured using agar well and disc diffusion methods (p ≤ 0.05). The alamarBlue assay was performed to assess the biocompatibility of the samples. The mean TBS values of Molloplast-B samples were significantly lower (p ≤ 0.05) for all groups except for OPCL1. Compared with the control, the mean shore A hardness values were significantly higher (p ≤ 0.05) for samples in groups BPCL 2 and 3. After 6 weeks, the OPCL samples showed a significantly lower (p ≤ 0.05) mass change as compared to the control. Agar well diffusion methods demonstrated a maximum zone of inhibition for 2.5% OPCL (20.5 ± 0.05 mm) after 24 h. Disc diffusion methods showed no zones of inhibition. The biocompatibility of the ionic liquid-modified sample was comparable to that of the control. The addition of ionic liquids in Molloplast-B improved the liner's surface texture, increased its hardness, and decreased its % mass change and tensile strength. Ionic liquids exhibited potent antifungal activity.

Methyl esters synthesis from Luffa cylindrica seeds oil using green copper oxide nanoparticle catalyst in membrane reactor.

This study investigates the potential role of Juglans sp. root extract-mediated copper oxide nanoparticles of Luffa cylindrica seed oil (LCSO) into methyl esters. The synthesized green nanoparticle was characterized by Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning electron microscopy (SEM) spectroscopies to find out the crystalline size (40 nm), surface morphology (rod shape), particle size (80-85 nm), and chemical composition (Cu = 80.25% & O = 19.75%), accordingly. The optimized protocol for the transesterification reaction was adjusted as oil to methanol molar ratio (1:7), copper oxide nano-catalyst concentration (0.2 wt %), and temperature (90 °C) corresponding to the maximum methyl esters yield of 95%. The synthesized methyl esters were characterized by GC-MS, 1H NMR, 13C NMR, and FT-IR studies to know and identify the chemical composition of newly synthesized Lufa biodiesel. The fuel properties of Luffa cylindrica seed oil biofuel were checked and compared with the American Biodiesel standards (ASTM) (D6751-10). Finally, it is commendable to use biodiesel made from wild, uncultivated, and non-edible Lufa cylindrica to promote and adopt a cleaner and sustainable energy method. The acceptance and implementation of the green energy method may result in favourable environmental effects, which in turn may lead to better societal and economic development.

Low Overpotential Amperometric Sensor Using Yb2O3.CuO@rGO Nanocomposite for Sensitive Detection of Ascorbic Acid in Real Samples.

The ultimate objective of this research work is to design a sensitive and selective electrochemical sensor for the efficient detection of ascorbic acid (AA), a vital antioxidant found in blood serum that may serve as a biomarker for oxidative stress. To achieve this, we utilized a novel Yb2O3.CuO@rGO nanocomposite (NC) as the active material to modify the glassy carbon working electrode (GCE). The structural properties and morphological characteristics of the Yb2O3.CuO@rGO NC were investigated using various techniques to ensure their suitability for the sensor. The resulting sensor electrode was able to detect a broad range of AA concentrations (0.5-1571 µM) in neutral phosphate buffer solution, with a high sensitivity of 0.4341 µAµM-1cm-2 and a reasonable detection limit of 0.062 µM. The sensor's great sensitivity and selectivity allowed it to accurately determine the levels of AA in human blood serum and commercial vitamin C tablets. It demonstrated high levels of reproducibility, repeatability, and stability, making it a reliable and robust sensor for the measurement of AA at low overpotential. Overall, the Yb2O3.CuO@rGO/GCE sensor showed great potential in detecting AA from real samples.

Rapid elimination of antibiotic gemifloxacin mesylate and methylene blue over Pt nanoparticles dispersed chitosan/g-C3N4 ternary visible light photocatalyst.

Appropriate material selection and proper understanding of bandgap modification are key factors for the development of efficient photocatalysts. Herein, we developed an efficient, well-organized visible light oriented photocatalyst based on g-C3N4 in association with polymeric network of chitosan (CTSN) and platinum (Pt) nanoparticles utilizing a straightforward chemical approach. Modern techniques like XRD, XPS, TEM, FESEM, UV-Vis, and FTIR spectroscopy were exploited for characterization of synthesized materials. XRD results confirmed the involvement of α-polymorphic form of CTSN in graphitic carbon nitride. XPS investigation confirmed the establishment of trio photocatalytic structure among Pt, CTSN, and g-C3N4. TEM examination showed that the synthesized g-C3N4 possesses fine fluffy sheets like structure (100 to 500 nm in size) intermingled with a dense layered framework of CTSN with good dispersion of Pt nanoparticles on g-C3N4 and CTSN composite structure. The bandgap energies for g-C3N4, CTSN/g-C3N4, and Pt@ CTSN/g-C3N4 photocatalysts were found to be 2.94, 2.73, and 2.72 eV, respectively. The photodegradation skills of each created structure have been examined on antibiotic gemifloxacin mesylate and methylene blue (MB) dye. The newly developed Pt@CTSN/g-C3N4 ternary photocatalyst was found to be efficacious for the elimination of gemifloxacin mesylate (93.3%) in 25 min and MB (95.2%) just in 18 min under visible light. Designed Pt@CTSN/g-C3N4 ternary photocatalytic framework exhibited ⁓ 2.20 times more effective than bare g-C3N4 for the destruction of antibiotic drug. This study provides a simple route towards the designing of rapid, effective visible light oriented photocatalyts for the existing environmental issues.

Application of QPPO/PVA based commercial anion exchange membrane as an outstanding adsorbent for the removal of Eosin-B dye from wastewaters.

Commercially available QPPO/PVA based anion exchange membrane (AEM) BIII was to inquire the percentage discharge of anionic dye Eosin-B (EB) at terrain temperature from wastewater. The impact of EB initial concentration, membrane dosage, ionic strength, contact time and temperature on EB percentage removal was contemplated. The EB percentage removal was increased from 22 to 99.56% and 38.15-99.56% with contact time and membrane dosage respectively while decreased from 99.56 to 29%, 99.56 to 54.61% and 99.56 to 92.22% with enhancing initial concentration of EB, ionic strength and temperature respectively. Nonlinear isotherm models were utilized to demonstrate EB adsorption onto AEM BIII. Attained results exhibited that nonliner Freundlich isotherm model best fitted to EB adsorption onto AEM BIII. For EB adsorption onto AEM BIII, adsorption kinetics were inquired in detail by using several kinetic models but EB adsorption nicely fitted to pseudo-second-order kinetics. Similarly thermodynamic analysis was performed and results pointed to an exothermic adsorption of EB onto AEM BIII. The membrane could be reused for four concecutive cycles with loosing its efficiency.

A Sensitive Hydroquinone Amperometric Sensor Based on a Novel Palladium Nanoparticle/Porous Silicon/Polypyrrole-Carbon Black Nanocomposite.

Exposure to hydroquinone (HQ) can cause various health hazards and negative impacts on the environment. Therefore, we developed an efficient electrochemical sensor to detect and quantify HQ based on palladium nanoparticles deposited in a porous silicon-polypyrrole-carbon black nanocomposite (Pd@PSi-PPy-C)-fabricated glassy carbon electrode. The structural and morphological characteristics of the newly fabricated Pd@PSi-PPy-C nanocomposite were investigated utilizing FESEM, TEM, EDS, XPS, XRD, and FTIR spectroscopy. The exceptionally higher sensitivity of 3.0156 µAµM-1 cm-2 and a low limit of detection (LOD) of 0.074 µM were achieved for this innovative electrochemical HQ sensor. Applying this novel modified electrode, we could detect wide-ranging HQ (1-450 µM) in neutral pH media. This newly fabricated HQ sensor showed satisfactory outcomes during the real sample investigations. During the analytical investigation, the Pd@PSi-PPy-C/GCE sensor demonstrated excellent reproducibility, repeatability, and stability. Hence, this work can be an effective method in developing a sensitive electrochemical sensor to detect harmful phenol derivatives for the green environment.

Smart waste management perspective of COVID-19 healthy personal protective materials in concrete for decorative landscape pavements and artificial rocks.

This paper presents a new method for determining the effect of healthy personal protective material (HPPM) stripes, such as surgical masks, protective suits, and overhead and foot covers, on the durability and physicomechanical characteristics of concrete for use in architectural forms. Because of the current global epidemic caused by coronavirus (COVID-19), the use of HPPM, such as surgical masks, protective suits, and overhead and foot covers, has increased considerably. COVID-19's second and third waves are currently affecting various countries, necessitating the use of facemasks (FM). Consequently, millions of single FM have been discharged into the wild, washing up on beaches, floating beneath the seas, and ending up in hazardous locations. The effect of stripe fibers on the physicomechanical characteristics of concrete, such as the workability, Uniaxial Compressive Strength UCS, flexural strength, impact strength, spalling resistance, abrasion resistance, sorptivity, Water absorption Sw, porosity (ηe), water penetration, permeability, and economic and eco-friendly aspects, need to be determined. With a focus on HPPM, especially single-use facemasks, this study investigated an innovative way to incorporate pandemic waste into concrete structures. Scanning electron microscope and X-ray diffraction patterns were employed to analyze the microstructures and interfacial transition zones and to identify the elemental composition. The HPPM had a pore-blocking effect, which reduced the permeability and capillary porosity. Additionally, the best concentrations of HPPM, particularly of masks, were applied by volume at 0, 1, 1.5, 2.0, and 2.5%. The use of mixed fibers from different HPPMs increased the strength and overall performance of concrete samples. The tendency of growing strength began to disappear at approximately 2%. The results of this investigation showed that the stripe content had no effect on the compressive strength. However, the stripe is critical for determining the flexural strength of concrete. The UCS increased steadily between 1 and 1.5% before falling marginally at 2.5%, which indicates that incorporating HPPM into concrete had a significant impact on the UCS of the mixture. The addition of HPPM to the mixtures considerably modified the failure mode of concrete from brittle to ductile. Water absorption in hardened concrete is reduced when HPPM stripes and fibers were added separately in low-volume fractions to the concrete mixture. The concrete containing 2% HPPM fibers had the lowest water absorption and porosity percentage. The HPPM fibers were found to act as bridges across cracks, enhancing the transfer capability of the matrices. From a technological and environmental standpoint, this study found that using HPPM fibers in the production of concrete is viable.

Transformation of waste seed biomass of Cordia myxa into valuable bioenergy through membrane bioreactor using green nanoparticles of indium oxide.

Depletion of non-renewable fuel has obliged researchers to seek out sustainable and environmentally friendly alternatives. Membranes have proven to be an effective technique in biofuel production for reaction, purification, and separation, with the ability to use both porous and non-porous membranes. It is demonstrated that a membrane-based sustainable and green production can result in a high degree of process intensification, whereas the recovery and repurposing of catalysts and alcohol are anticipated to increase the process economics. Therefore, in this study sustainable biodiesel was synthesized from inedible seed oil (37 wt%) of Cordia myxa using a membrane reactor. Transesterification was catalyzed by heterogenous nano-catalyst of indium oxide prepared with leaf extract of Boerhavia diffusa. Highest biodiesel yield of 95 wt% was achieved at methanol to oil molar ratio of 7:1, catalyst load 0.8 wt%, temperature 82.5 °C and time 180 min In2O3 nanoparticles exhibited reusability up to five successive transesterification rounds. The production of methyl esters was confirmed using Fourier-transform infrared spectroscopy and Nuclear Magnetic Resonance. The predominant fatty acid methyl ester detected in the biodiesel was 5, 8-octadecenoic acid. Biodiesel fuel qualities were determined to be comparable to worldwide ASTM D-6571 and EN-14214 standards. Finally, it was concluded that membrane technology can result in a highly intensified reaction process while efficient recovery of both nano catalysts and methanol increases the economics of transesterification and lead to sustainable production.

Efficient application of newly synthesized green Bi2O3 nanoparticles for sustainable biodiesel production via membrane reactor.

Introduction of waste and non-edible oil seeds coupled with green nanotechnology offered a pushover to sustainable and economical biofuels and bio refinery production globally. The current study encompasses the synthesis and application of novel green, highly reactive and recyclable bismuth oxide nanocatalyst derived from Euphorbia royealeana (Falc.) Boiss. leaves extract via biological method for sustainable biofuel synthesis from highly potent Cannabis sativa seed oil (34% w/w) via membrane reactors. Advanced techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Diffraction X-Ray (EDX), and FT-IR were employed to illustrate the newly synthesized green bismuth oxide nanoparticles. 92% of FAMEs were produced under optimal reaction conditions such as a 1.5% w/w catalyst weight, 1:12 oil to methanol molar ratio, and a reaction temperature of 92 ⸰C for 3.5 h via membrane reactor. The synthesized Cannabis biodiesel was identified using the FT-IR and GC-MS techniques. The fuel properties of synthesized biofuels (acid number 0.203 mg KOH/g, density 0.8623 kg/L, kinematic viscosity 5.32 cSt, flash point 80 °C, pour point -11 °C, cloud point -11 °C, and Sulfur 0.00047 wt %, and carbon residues 0.2) were studied and established to be comparable with internationally set parameters. The experimental data (R2 = 0.997) shows that this reaction follow pseudo first-order kinetics. These findings affirm the application of green bismuth oxide nanoparticles as economical, highly reactive and eco-friendly candidate for industrial scale biodiesel production from non-edible oil seeds.

Nonwoven/Nanomembrane Composite Functional Sweat Pads.

Sweat is a natural body excretion produced by skin glands, and the body cools itself by releasing salty sweat. Wetness in the underarms and feet for long durations causes itchiness and an unpleasant smell. Skin-friendly reusable sweat pads could be used to absorb sweat. Transportation of moisture and functionality is the current challenge that many researchers are working on. This study aims to develop a functional and breathable sweat pad with antimicrobial and quick drying performance. Three layered functional sweat pads (FSP) are prepared in which the inner layer is made of an optimized needle-punched coolmax/polypropylene nonwoven blend. This layer is then dipped in antimicrobial ZnO solution (2, 4, and 6 wt.%), and super absorbent polymer (SAP) is embedded, and this is called a functional nonwoven (FNW1) sheet. Electrospun nanofiber-based nanomembranes of polyamide-6 are optimized for bead-free fibers. They are used as a middle layer to enhance the pad's functionality, and the third layer is again made of needle-punched optimized coolmax/polypropylene nonwoven sheets. A simple nonwoven-based sweat pad (SSP) is also prepared for comparison purposes. Nonwoven sheets are optimized based on better comfort properties, including air/water vapor permeability and moisture management (MMT). Nonwoven webs having a higher proportion of coolmax show better air permeability and moisture transfer from the inner to the outer layer. Antimicrobial activity of the functional nonwoven layer showed 8 mm of bacterial growth, but SSP and FSP showed only 6 mm of growth against Staphylococcus aureus. FSP showed superior comfort and antibacterial properties. This study could be a footstone toward highly functional sweat pads with remarkable comfort properties.

Electrospun Nanofiber/Textile Supported Composite Membranes with Improved Mechanical Performance for Biomedical Applications.

Textile-supported nanocomposite as a scaffold has been extensively used in the medical field, mainly to give support to weak or harmed tissues. However, there are some challenges in fabricating the nanofiber/textile composite, i.e., suitable porous structure with defined pore size, less skin contact area, biocompatibility, and availability of degradable materials. Herein, polyamide-6 (PA) nanofibers were synthesized using needleless electrospinning with the toothed wheel as a spinneret. The electrospinning process was optimized using different process and solution parameters. In the next phase, optimized PA nanofiber membranes of optimum fiber diameter with uniform distribution and thickness were used in making nanofiber membrane-textile composite. Different textile fabrics (woven, non-woven, knitted) were developed. The optimized nanofiber membranes were combined with non-woven, woven, and knitted fabrics to make fabric-supported nanocomposite. The nanofiber/fabric composites were compared with available market woven and knitted meshes for mechanical properties, morphology, structure, and chemical interaction analysis. It was found that the tear strength of the nanofiber/woven composite was three times higher than market woven mesh, and the nanofiber/knitted composite was 2.5 times higher than market knitted mesh. The developed composite structures with woven and knitted fabric exhibited improved bursting strength (613.1 and 751.1 Kpa), tensile strength (195.76 and 227.85 N), and puncture resistance (68.76 and 57.47 N), respectively, than market available meshes. All these properties showed that PA nanofibers/textile structures could be utilized as a composite with multifunctional properties.

Efficient Detection of 2,6-Dinitrophenol with Silver Nanoparticle-Decorated Chitosan/SrSnO3 Nanocomposites by Differential Pulse Voltammetry.

Herein, an ultra-sonication technique followed by a photoreduction technique was implemented to prepare silver nanoparticle-decorated Chitosan/SrSnO3 nanocomposites (Ag-decorated Chitosan/SrSnO3 NCs), and they were successively used as electron-sensing substrates coated on a glassy carbon electrode (GCE) for the development of a 2,6-dinitrophenol (2,6-DNP) efficient electrochemical sensor. The synthesized NCs were characterized in terms of morphology, surface composition, and optical properties using FESEM, TEM, HRTEM, BET, XRD, XPS, FTIR, and UV-vis analysis. Ag-decorated Chitosan/SrSnO3 NC/GCE fabricated with the conducting binder (PEDOT:PSS) was found to analyze 2,6-DNP in a wide detection range (LDR) of 1.5~13.5 µM by applying the differential pulse voltammetry (DPV) approach. The 2,6-DNP sensor parameters, such as sensitivity (54.032 µA µM-1 cm-2), limit of detection (LOD; 0.18 ± 0.01 µM), limit of quantification (LOQ; 0.545 µM) reproducibility, and response time, were found excellent and good results. Additionally, various environmental samples were analyzed and obtained reliable analytical results. Thus, it is the simplest way to develop a sensor probe with newly developed nanocomposite materials for analyzing the carcinogenic contaminants from the environmental effluents by electrochemical approach for the safety of environmental and healthcare fields in a broad scale.

Membrane reactor based synthesis of biodiesel from Toona ciliata seed oil using barium oxide nano catalyst.

Membrane technology has been embraced as a feasible and promising substitute to the traditional technologies employed for biodiesel synthesis which are energy and time consuming. It needs less energy, has high stability, is environmentally friendly, and is simple to operate and control. Therefore, in our current study membrane technology was employed to synthesize biodiesel from Toona ciliate novel and non-edible seed oil. Since Toona ciliata has affluent oil content (33.8%) and is effortlessly and extensively available. In fact, we intended to scrutinize the effects of green synthesized barium oxide nanoparticles for one step transesterification of biodiesel production using membrane technology followed by characterization of prepared catalyst via innovative techniques. Optimal yield of biodiesel attained was 94% at 90 °C for 150 min with methanol to oil molar ratio of 9:1 and amount of about 0.39 wt %. Quantitative analysis of synthesized Toona ciliata oil biodiesel was carried out by advance techniques of Gas chromatography mass spectrometry (GC-MS), Fourier-transform infrared (FTIR) spectroscopy and Nuclear magnetic resonance (NMR) which authorize the synthesis of fatty acid methyl ester compounds using oil from Toona ciliata seeds. Values of Toona ciliata fuel properties for instance flash point (70°C), density (0.89 kg/m3), viscosity (5.25 mm2/s), cloud point (-8°C) and pour point (-11°C) met the specifications of international standards i. e American (ASTM D-6751), European (EN-14214) and China (GB/T 20,828). Subsequently, it is concluded that membrane technology is environmentally friendly and efficient technique for mass-production of sustainable biodiesel using green nano catalyst of barium oxide.

Facile Synthesis of Low-Cost Copper-Silver and Cobalt-Silver Alloy Nanoparticles on Reduced Graphene Oxide as Efficient Electrocatalysts for Oxygen Reduction Reaction in Alkaline Media.

Copper-silver and cobalt-silver alloy nanoparticles deposited on reduced graphene oxide (CuAg/rGO and CoAg/rGO) were synthesized and examined as electrocatalysts for oxygen reduction reaction (ORR) and hydrogen peroxide reduction reaction (HPRR) in alkaline media. Characterization of the prepared samples was done by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), and scanning electron microscopy with integrated energy-dispersive X-ray spectroscopy (SEM-EDS). CuAg/rGO and CoAg/rGO nanoparticles diameter ranged from 0.4 to 9.2 nm. The Ag loading was ca. 40 wt.% for both electrocatalysts, with that for Cu and Co being 35 and 17 wt.%, respectively. CoAg/rGO electrocatalyst showed a Tafel slope of 109 mV dec-1, significantly lower than that for CuAg/rGO (184 mV dec-1), suggesting faster ORR kinetics. Additionally, a higher diffusion current density was obtained for CoAg/rGO (-2.63 mA cm-2) than for CuAg/rGO (-1.74 mA cm-2). The average value of the number of electrons transferred during ORR was 2.8 for CuAg/rGO and 3.3 for CoAg/rGO electrocatalyst, further confirming the higher ORR activity of the latter. On the other hand, CuAg/rGO showed higher peak current densities (-3.96 mA cm-2) for HPRR compared to those recorded for CoAg/rGO electrocatalyst (-1.96 mA cm-2).

Platinum-Dysprosium Alloys as Oxygen Electrodes in Alkaline Media: An Experimental and Theoretical Study.

Platinum-dysprosium (Pt-Dy) alloys prepared by the arc melting technique are assessed as potential electrodes for the oxygen reduction reaction (ORR) using voltammetry and chronoamperometry in alkaline media. A relatively small change (10 at.%) in the alloy composition brought a notable difference in the alloys' performance for the ORR. Pt40Dy60 electrode, i.e., the electrode with a lower amount of Pt, was identified to have a higher activity towards ORR as evidenced by lower overpotential and higher current densities under identical experimental conditions. Furthermore, DFT calculations point out the unique single-atom-like coordination and electronic structure of Pt atoms in the Pt40Dy60 surface as responsible for enhanced ORR activity compared to the alloy with a higher Pt content. Additionally, Pt-Dy alloys showed activity in the oxygen evolution reaction (OER), with the OER current density lower than that of pure Pt.

Treatment of Saussurea heteromalla for biofuel synthesis using catalytic membrane reactor.

Membrane technology has been adopted as a prospective and promising alternative to the standard technology used for biodiesel production since the time when it had some limitations. During this research project, the inedible seed oil generating feedstock known as Saussurea heteromalla was put through a biodiesel production process that utilized membrane technology with an effort to increase the yield of methyl ester. The transesterification process was mediated by zirconium oxide nanoparticles that were generated using an aqueous extract of Portulaca oleracea leaf. With an oil to methanol ratio of 1:9, a catalyst concentration of 0.88 (wt. %), temperature of 87 °C, and reaction time of 180 min, the highest possible biodiesel yield of 93% was achieved. The findings of the catalyst characterization demonstrated the purity of the zirconium oxide nano particles and their nanoscale nature with average particle size of 31 nm. Using gas chromatography and mass spectrometry (GC/MS), an examination of biodiesel revealed the presence of four different peaks of methyl esters. Using Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance, we were able to verify that the production of methyl esters in the biodiesel sample was successful (NMR). Zerconium oxide nanoparticles were found reusable up to five consecutive cycles of transesterification. The fuel-related properties of methyl ester have been determined and are in line with the requirements of the international standards ASTM D-6571 and EN 14214. In the course of our ongoing research, we made use of membrane technology, which led to the production of biodiesel from the seed oil of Saussurea heteromalla that was better for the environment, more cost effective, and produced in greater quantities.

Kinetics and Adsorption Isotherms of Amine-Functionalized Magnesium Ferrite Produced Using Sol-Gel Method for Treatment of Heavy Metals in Wastewater.

This study is focused on the kinetics and adsorption isotherms of amine-functionalized magnesium ferrite (MgFe2O4) for treating the heavy metals in wastewater. A sol-gel route was adopted to produce MgFe2O4 nanoparticles. The surfaces of the MgFe2O4 nanoparticles were functionalized using primary amine (ethanolamine). The surface morphology, phase formation, and functionality of the MgFe2O4 nano-adsorbents were studied using the SEM, UV-visible, FTIR, and TGA techniques. The characterized nanoparticles were tested on their ability to adsorb the Pb2+, Cu2+, and Zn2+ ions from the wastewater. The kinetic parameters and adsorption isotherms for the adsorption of the metal ions by the amine-functionalized MgFe2O4 were obtained using the pseudo-first-order, pseudo-second-order, Langmuir, and Freundlich models. The pseudo-second order and Langmuir models best described the adsorption kinetics and isotherms, implying strong chemisorption via the formation of coordinative bonds between the amine groups and metal ions. The Langmuir equation revealed the highest adsorption capacity of 0.7 mmol/g for the amine-functionalized MgFe2O4 nano-adsorbents. The adsorption capacity of the nanoadsorbent also changed with the calcination temperature. The MgFe2O4 sample, calcined at 500 °C, removed the most of the Pb2+ (73%), Cu2+ (59%), and Zn2+ (62%) ions from the water.

Rational design of mixed ionic-electronic conducting membranes for oxygen transport.

The mixed ionic-electronic conducting (MIEC) oxides have generated significant research efforts in the scientific community during the last 40 years. Since then, many MIEC compounds, most of which are based on perovskite oxides, have been synthesized and characterized. These compounds, when heated to high temperatures, form solid ceramic membranes with high oxygen ionic and electrical conductivity. The driving force for oxygen ion transport is the ionic transfer of oxygen from the air as a result of the differential partial pressure of oxygen across the membrane. Electronic and ionic transport in a range of MIEC materials has been studied using the defect theory, particularly when dopants are introduced to the compound of interest. As a result, many types of ionic oxygen transport limits exist, each with a distinct phase shift depending on the temperature and partial pressure of oxygen in use. In combination with theoretical principles, this work attempts to evaluate the research community's major and meaningful achievements in this subject throughout the preceding four decades.