BET-BJH Analyses Research Articles

Green Approach for the Synthesis of 2-Phenyl-2H-indazoles and Quinazoline Derivatives Using Sustainable Heterogeneous Copper Oxide Nanoparticles Supported on Activated Carbon and OER Study.

This research work reports the synthesis of copper oxide (CuO) nanoparticles supported on activated carbon by a simple impregnation method using 2-propanol as a green solvent, followed by calcination. The synthesized CuO@C is used as an efficient heterogeneous nanocatalyst for the synthesis of 2H-indazoles and quinazolines utilizing commercially available 2-bromobenzaldehydes, primary amines, and sodium azide under ligand-free and base-free conditions. The present methodology demonstrates the formation of new N-N, C-N, and C═N bonds under one-pot reaction conditions using PEG-400 as a green solvent. The reaction pathways are supported by control experiments and mechanistic elucidation. Further, the synthesized catalyst was characterized by a range of microscopic and spectroscopic techniques such as powdered X-ray diffraction, fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray, UV-vis, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and BET-BJH analysis. Importantly, the study focused on the recyclability of the catalyst and successfully showed gram-scale production. Significantly, our active catalyst exhibited an outstanding performance in the oxygen evolution reaction, with an overpotential of 290 mV and a swallow Tafel slope of 91 mV dec-1.

The potential of catalyst based on palm leaves in biodiesel production as part of palm oil life cycle assesment

The advantages offered by biomass-based heterogeneous catalysts, such as being easily separated from reaction products, being used many times, having low production costs, and being widely available in nature. One of the heterogeneous catalysts that can be used is a sodium silicate catalyst, especially one obtained by impregnating Na metal on a SiO2 matrix derived from biomass ash. In this study, palm leaves have the potential to be used as raw material for the SiO2 matrix because their utilization has yet to be optimal. This research aims to synthesize, characterize, and apply a sodium silicate catalyst based on palm leaves ash in the production of biodiesel from Refined, Bleached, Deodorized, Palm Oil (RBDPO). SiO2 was obtained by calcining palm leaves at a temperature of 700 °C for 3 hours, followed by washing using 1 N HCl solution. In this research, variations in the mole ratio of NaOH: SiO2 were carried out in the synthesis of sodium silicate, namely 1:1, 1.5:1, 2:1, and 2.5:1. This research also evaluates the reusability of the sodium silicate catalyst and the effect of washing using methanol on the biodiesel yield produced. The best sodium silicate catalyst was obtained at a NaOH: SiO2 molar ratio of 1.5:1, with a biodiesel yield of 74.485 % and an ester content of 97.293 %. SEM analysis shows the presence of a porous structure on the catalyst. The existence of the Si-O-Na group has been confirmed using FTIR. BET-BJH analysis has confirmed the presence of a mesoporous structure in the catalyst, with a surface area of 6.4343 m2/g and a pore size of 5.3127 nm. The resulting sodium silicate catalyst can be used up to three times, with a yield of 62.388 %. Catalyst regeneration using methanol is capable of producing biodiesel with a yield of 45.198 %

Molecularly imprinted polymer based on MIL-101 (Cr) MOF incorporated polyvinylidene for selective adsorption and separation dye with improved antifouling properties

In this work, new membrane was fabricated from polyester fabric (PF) as a substrate which was coated by a casting solution containing polyvinylidene fluoride (PVDF) blending by addition of MIL-101 (Cr) metal-organic framework (MOF)-molecularly imprinted 3-aminophenolhexamethylenetetramine (MIAPH) as filler and sodium dodecyl sulfate (SDS) as hydrophilic agent. The membrane was fabricated by phase inversion method (PVDF/MIAPH). The MIAPH has selective functional groups and was applied as filler in the mixed matrix membrane. The as-prepared MIAPH was characterized by FE-SEM, EDS, XRD, FTIR and BET-BJH analyses. The hydrophilic property, dye adsorption and filtration properties of the MIAPH/PVDF/PF membrane were studied for removal Trypan blue (TB) based on central composite design (CCD) technique through investigating operational variables (pH, TB concentration, pressure). In the fabrication of membranes, the optimal filtration properties appear at the 30 μL of SDS solution and 0.005 g MIAPH fillers. The fabricated MIAPH/PVDF/PF membrane indicates a high removal efficiency up to 94.9 % for the TB removal and has high selectivity. The data of the adsorption equilibrium were described by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. The findings illustrated that appropriate of MIAPH in membranes could be an efficient and selective technique for TB elimination.

Synthesis and photocatalytic properties of zinc-copper bimetallic oxide nanoparticles for removal of reactive blue 19 dye in aqueous suspension

ABSTRACT This research investigates the photocatalytic removal of reactive blue 19 (RB19) dye utilising Zn-Cu (zinc-copper) bimetallic oxide nanocatalysts under UV irradiation. The nanocatalysts were prepared via the co-precipitation technique and thoroughly characterised using different procedures including XRD, FTIR, BET-BJH, FESEM, TEM, and EDX. BET-BJH analysis revealed a specific surface area of 59.774 m2/g for the Zn-Cu bimetallic oxide nanocatalyst. Response surface methodology (RSM) was employed to optimise operational factors such as catalyst amount, pH, H2O2 amount, and UV power, with a quadratic model showing high reliability (R2 = 0.89). Under optimal conditions (4 mg catalyst amount, pH 6.68, 0.42 mL H2O2 dose, 23 W UV power, and 45 min reaction time), the maximum RB19 removal reached 77.14%, increasing to 98.33% after 120 min. The kinetic study revealed a reaction rate constant of 0.884 min−1, indicating efficient removal. Zn-Cu bimetallic oxides demonstrated superior RB19 removal capacity, with only a 5.92% reduction in removal yield after 5 consecutive reuse cycles. This study underscores the potential of Zn-Cu bimetallic oxide nanocatalysts for efficient removal of RB19 dye in suspension media.

Ceria-Terbium-based electrospun nanofiber catalysts for soot oxidation activity and its kinetics

BackgroundCeria-based materials have an excellent potential to be catalysts for catalytic three-way converters in the automobile industry. Developing Ceria-based nanofiber catalysts can be a significant approach for further exploring the application of these materials in automobile industries. MethodsIn this study, Ag, Cu, or Co doped Ceria–Terbium nanofibers were synthesized using the electrospinning technique. The obtained nanofiber catalysts were characterized using FE-SEM, XRD, FT-Raman Spectroscopy, and BET-BJH analysis and tested for soot oxidation activity and its kinetics. Significant findingsFE-SEM examination reveals that the obtained nanofibers have a diameter ranging from around 100 to 600 nm. CeTbCo nanofibers exhibited a reduced particle size and enhanced pore formation. The XRD investigation revealed that all the nanofibers displayed a face-centered fluorite structure of CeO2. In Raman spectroscopy analysis, CeTbCo nanofibes showed the emergence of a secondary Co3O4 phase. The CeTbCo nanofiber catalyst showed better SBET (specific surface area) (66 m2/g) and average pore size (12.08 nm) and total pore volume (0.223 cc/g)), better soot oxidation activity (T50 = 347 ℃) than other nanofiber catalysts. The CeTbCo nanofiber catalyst exhibited an activation energy of 132 kJ mol−1 and a pre-exponential factor (ln (A)) of 25.63 min−1.

Double Z-scheme Ag2CrO4/Bi2O3–KBi6O9Br nanophotocatalysts designed via microwave-assisted combustion-precipitation method for degrading toxic organic dyes

This study introduces novel double Z-scheme Ag2CrO4/Bi2O3–KBi6O9Br nanophotocatalysts for effectively degrading organic dyes, namely Crystal Violet, Acid Orange 7, Rhodamine B, and Eosin Y, from contaminated wastewater. The photocatalysts were thoroughly characterized using advanced techniques, including X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX-Dot Mapping), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), Diffuse Reflectance Spectroscopy (DRS), and Photoluminescence (PL). XRD confirmed the formation of desired crystalline phases without impurities. FESEM and TEM observations revealed the unique morphology of Bi2O3–KBi6O9Br, with distributed Ag2CrO4 nanoparticles on the surface, as confirmed by EDX-dot mapping. BET-BJH analyses indicated a specific surface area of 7.33 m2/g, including meso and macro pores with an average diameter of 10 nm and a total pore volume of 0.018 cm3/g for Ag2CrO4(25%)/Bi2O3–KBi6O9Br sample. DRS revealed notable shifts in absorption edges, suggesting the formation of a heterojunction, and PL analysis indicated a reduced charge carrier recombination rate, further enhancing the photocatalyst's efficacy. In a series of photocatalytic experiments lasting 240 min, using 1 g/L of Ag2CrO4(25%)/Bi2O3–KBi6O9Br, remarkable degradation efficiencies of 95.1%, 94.2%, 98.0%, and 89.6% were achieved for Crystal Violet, Acid Orange 7, Rhodamine B, and Eosin Y, respectively, at an initial concentration of 10 mg/L. The nanophotocatalyst also showed favourable stability after five consecutive reuses. Overall, the double Z-scheme heterostructure in the composite significantly improved the sample's properties and photocatalytic performance, making it highly effective in removing various organic dyes from wastewater.

Preparation and utilization of Zn-La oxide nanocatalyst as a binary composite for photocatalytic degradation of methylene blue dye: Optimization through RSM-BBD

In this research, the photocatalytic degradation of methylene blue (MB) dye was explored by employing Zn-La (zinc-lanthanum) oxide nanocatalysts under UV irradiation. Preparation of Zn-La oxide nanocatalysts was executed utilizing the co-precipitation technique, and the surface and morphology of the fabricated nanocatalyst were examined via X-Ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) methods. BET-BJH analysis demonstrated that the specific surface area of the Zn-La oxide nanocatalyst was 20.43 m2/g. Moreover, the response surface methodology (RSM) procedure was utilized to influence the operational factors i.e., catalyst amount, pH, H2O2 dose, and UV power. The quadratic model proposed via the RSM technique with a high R2 value of 0.89, demonstrates its reliability. Besides, the maximum percentage of MB dye removal reached 75.18% under optimal conditions, which include a catalyst amount of 12.05 mg, pH of 9, H2O2 dose of 0.44 mL, UV power of 23 W, and a reaction time of 45 min. Further, under the mentioned conditions, after 120 min, the MB degradation efficiency reached 98.8%. The kinetic study exhibited that the reaction rate constant was 0.0363 min−1. According to the outcomes, Zn-La oxides have a higher ability to remove MB. After 5 consecutive reuse rounds, the reduction in the yield of MB removal using Zn-La oxide nanocatalysts was 5.4%. This study demonstrates that the Zn-La oxide nanocatalyst can be promisingly utilized for the degradation of MB dye suspension solution.

Construction of a magnetic BiOBr-rGO-ZnFe2O4 heterojunction photocatalyst for refinery wastewater treatment under simulated solar light

Considering the importance of sunlight as a free, abundant, and sustainable source of energy, in this paper, first, the removal of phenol from model refinery wastewater under simulated solar light was studied. Then magnetic BiOBr-rGO-ZnFe2O4 photocatalyst with different percentages of BiOBr (0, 30, 45, and 55 %) was synthesized and evaluated in degradation of phenol under simulated solar light. The results showed that the sample containing 45 % wt. of BiOBr was the most active and after 3 h, it succeeded in removing 94 % of the phenol from a 20-ppm phenol solution. The characteristics of the synthesized photocatalysts were analyzed by XRD, BET-BJH, UV–Vis DRS, PL, FESEM, TEM, and EDX analyses. The results showed that by increasing the weight percentage of BiOBr from 30 % to 55 %, the crystal size of BiOBr increased from 22 to 29 nm. FESEM analysis showed that with the increasing amount of BiOBr, more lamellar structures were observed in the sample, and in the sample containing 45 % BiOBr, these structures became flower-like. However, with a further increase in the percentage of BiOBr to 55 %, thick and stacked sheet structures were formed, which resulted in the reduction of porosity and surface area according to BET-BJH analysis. According to PL analysis, the addition of BiOBr to rGO-ZnFe2O4 reduced the rate of recombination of charge carriers. However, increasing the weight percentage of BiOBr declined the light absorption and shifted the absorption edge towards the ultraviolet region. The effect of operational parameters such as pH, amount of photocatalyst, initial concentration of phenol, light intensity, and the presence of oxidant as well as the stability of the selected photocatalytic sample was evaluated. Studying the effect of scavengers also showed that the most active species that degrade phenol are the holes formed on the surface of the BiOBr-rGO-ZnFe2O4 photocatalyst.

Potato-on-rod like of Z-scheme plasmon Ag2CrO4-Ag2Mo2O7 heterojunction nanophotocatalyst with high stability and accelerated photo-degradation evolution of organic contaminants

The shocking increase of resistant dye pollutants in the environment and their harmful effects has become a potential threat to the ecosystem. In the current work, the novel and highly efficient potato-on-rod-like Z-scheme plasmon Ag2CrO4–Ag2Mo2O7 heterojunction nano-photocatalyst was synthesized by precipitation method to photodegrade different organic dyes under artificial sunlight. The required analysises were carried out to characterize nanophotocatalysts. FESEM and TEM results showed the placement way of potato-like Ag2CrO4 between/on rod-like Ag2Mo2O7 which was leading to suitable structure and surface morphology. Besides, the morphology observations released the meso-/macroporous potato-on-rod like architecture self-assembled by nanoparticles. DRS analysis also confirmed two band gap energies of 2.55 and 1.72 eV in Ag2CrO4–Ag2Mo2O7 (3:1) resulting from forming a heterojunction structure and the plasmon Ag. Ag2CrO4–Ag2Mo2O7 (3:1) nanophotocatalyst exhibited the most remarkable activity in the photodegradation of 10 mg/L 2-naphthol orange (97.8%), 10 mg/L rhodamine B (99.7%), 10 mg/L crystal violet (98.9%), and 10 mg/L methyl orange (56.1%) with a catalyst dosage of 0.1 gr for about 90 min. The appropriate energy band gap, the formation of the heterostructure, the presence of meso (0.0038 cm3/g) and macro (0.0044 cm3/g) holes, and pore diameter at about 17.2 nm based on BET-BJH analysis that facilitated the penetration of pollutant molecules, increased pollutant adsorption and demonstrated stunning capability of efficient light harvesting, the reason was electron-hole pairs recombination rate reduction. Moreover, the fabricated samples showed tremendous catalyst constancy and reusability even after the fourth run. Results have shown the remarkable photocatalytic activity under visible light and provide an environment-friendly and green strategy to overcome the challenges of organic pollutants present in aqueous solutions.

Effects of deacetylation degree of chitosan on the structure of aerogels

Chitosan aerogels, obtained by (supercritical) CO2 drying of hydrogels, are novel adsorbents because of their large surface area and high porosity. Intrinsic properties of chitosan such as molecular weight (MW) and degree of deacetylation (DDA) had large impacts on the characteristics of chitosan aerogels. Although there are a few studies about the effects of solely DDA or MW on aerogel structure, none of them has focused on the mutual effects. The study aims to investigate the combined effects of MW and DDA of chitosan on aerogel properties. Hydrogels were produced in beads form by physical gelation of the chitosan solutions (2 % w/v in acetic acid of 1 %, v/v) in an alkaline environment (NaOH, 4 N). Supercritical CO2 dried aerogels were examined with respect to the bulk density, diameter as well as pore characteristics, and surface area by Barrett-Joyner-Halenda (BJH) and Brunauer-Emmett-Teller (BET) methods, respectively. Morphologies of aerogels were also examined by Scanning Electron Microscopy (SEM) images and structural changes of aerogels were observed by Fourier Transform Infrared (FTIR) Spectroscopy. Additional to BET-BJH analysis, proton relaxation dispersion was measured by Fast Field Cycling NMR (FFC-NMR) to determine the pore volume of the aerogels. Compact structures were obtained for higher MW chitosan and lower MW chitosans with higher DDA increasing the aerogel diameters. All types of aerogels obtained by different chitosan characteristics (MW and DDA) showed a porous structure and the highest DDA with the lowest MW caused the minimum bulk density with the highest water absorption rate. Although different N2 adsorption-desorption profiles were obtained in terms of pore volumes; all aerogels had Type IV isotherms with Type H1 hysteresis curve. FFC-NMR experiments showed that the coherence length values were associated with the pore volumes and FFC-NMR experiments were found to be meaningful as supportive experiments for the characterization of aerogels.

Development of a potential carrageenan-based hard capsule as the alternative of conventional capsules by implementing the oligomerization reaction

Carrageenan-based (CRG) hard capsules have a slower disintegration rate compared to that of gelatin capsules. Therefore, there is an urgent need to optimize the performance of this material using the oligomerization process. The preparation was conducted by oligomerizing CRG, cross-linking it with maltodextrin (MD), and plasticizing it with sorbitol (SOR). Based on our research, we found that the capsule prepared with the code CRG(O)-MD/SOR had an ash content of 11.80% and a water content of 17.20 ± 1.20 %. No microbes or yeast were found in the capsule, and only negligible amounts of heavy metal traces were present. Scanning electron microscopy (SEM) morphology analysis of the capsule surface showed that no pores were observed, even at a magnification of 10,000 times. This result was supported by the BET-BJH analysis, which showed that the pores had an average diameter of 49.26 Ǻ. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed that the Tg of the prepared capsules was at 51.4 °C. Fourier-transform infrared spectroscopy (FTIR) analysis showed that the presence of citric acid as the oligomerization agent had changed the chain composition of the carrageenan. Acute toxicity analysis showed that the capsule was safe even at a dose of 3,000 mg/bw. The Young's modulus of CRG(O)-MD/SOR was determined to be 1.500 ± 0.52 MPa. In vitro disintegration testing of CRG(O)-MD/SOR showed that the capsule required 20.01 ± 1.13 mins, 23.13 ± 1.14 mins, and more than 120 mins to disintegrate at pH 1.2, 4.5, and 6.8, respectively. Release kinetics analyses showed that the drugs paracetamol (PCT) and salicylamide (SCA) followed the zeroth-order model at pH 1.2 and 4.5, while they were best described by the Peppas-Sahlin model at pH 6.8. Finally, the maximum swelling degree of the CRG(O)-MD/SOR hard capsule was determined to be 708.88%, which was reached in 15.22 mins. This capsule has the potential to be used as an alternative to conventional hard capsules on a broader scale. Furthermore, this work supports Sustainable Development Goals (SDGs) point 3, good health and well-being, by providing a capsule made from biomaterial.

Ultrasound-assisted ionic exchange and solvothermal synthesis of Bi2MoO6/Bi2SiO5/Bi12SiO20 ternary nanophotocatalysts for visible light-driven degradation reaction of pharmaceutical pollutants

The novel ternary Bi2MoO6/Bi2SiO5/Bi12SiO20 nanophotocatalyst as a cascaded pseudo-type II configuration was synthesized at different values of Si and Bi2MoO6 via a simultaneous ultrasound-boosted ionic exchange-solvothermal approach to degrade fluoroquinolones contaminants under solar light. The influence of ultrasound irradiation was assessed and Bi2MoO6/Bi2SiO5/Bi12SiO20 (Si-2)-U sample was designated as the most effective sample with the best performance. To illustrate the efficacious performance of the referred sample, PL, XRD, UV–Vis DRS, FESEM, TEM, BET-BJH analyses were carried out. Regarding the phase diagram obtained by XRD analysis, the amount of Bi2MoO6, Bi2SiO5, and Bi12SiO20 for Bi2MoO6/Bi2SiO5/Bi12SiO20 (Si-2)-U was 27%, 13% and 60%, respectively. In contrast, without ultrasound irradiation, these amounts were obtained which are 39.6%, 37.6%, and 22.8% for Bi2MoO6, Bi2SiO5, and Bi12SiO20, correspondingly. BET-BJH technique displayed 20.8 m2/g surface area, 0.1805 cm3/g pore volume, and 34.7 nm mean pore diameter. DRS presented two absorption edges for the best nanocomposite at 414.7 (2.99 eV) and 489.3 (2.53 eV) nm. In addition, morphology observations proved the microcube architecture covered by nanosheets assembled of spherical nanoparticles. The photodegradation of levofloxacin, ofloxacin and ciprofloxacin over Bi2MoO6/Bi2SiO5/Bi12SiO20 (Si-2)-U was 96.9%, 83.6%, and 70.3%, subsequently that the kinetic constant was 2.6 times of nanocomposite synthesized without the usage of ultrasound energy. The perfect performance and suitable reusability of Bi2MoO6/Bi2SiO5/Bi12SiO20 (Si-2)-U nanophotocatalyst can be attributed to the proper composition and presence of ultrasound energy during synthesis, leading to the operative mass transfer, pollutant adsorption, light harvesting/diffusion, and charge separation.

Ultrasound-assisted heterogeneous Fenton-like process for efficient degradation of tetracycline over SmFeO3/Ti3C2Tx catalyst

The relatively low performance of Fe(II) regeneration is an important problem of the conventional Fenton system. Novel SmFeO3/Ti3C2TX (SFO/TCT) catalysts were synthesized using a self-assembly method to address this shortcoming. XRD, FT-IR, XPS, SEM, HR-TEM, and BET-BJH analyses confirmed the successful synthesis of the SFO/TCT-10 composite material. The synthesized catalysts were used to degrade tetracycline (TC) under sonocatalytic and sono-Fenton catalytic processes. The SFO/TCT-10 catalyst showed excellent efficiency (99 % in 30 min) for the degradation of TC compared to SFO and TCT bare materials under the sono-Fenton process. In fact, TCT acted as the electron trapper to boost the separation and transition of generated carriers in composite material and improved its catalytic activity. The effects of different parameters on the degradation of TC with SFO/TCT-10 catalyst were studied, and the catalytic mechanism was explained. In addition, the possible degradation pathways were proposed. This study provides new insights into the synergy between SFO perovskite nanoparticles and TCT MXene in the sono-Fenton catalytic system for the degradation of TC.

Synthesis of MCM-41 Silica Mesoporous Modified with Zn Metal

MCM-41 and Zn-MCM-41 were successfully synthesized using hydrothermal and impregnation methods. The synthesized silica mesoporous was confirmed by characterizing the material using XRD, SEM-EDS, and BET-BJH analyses. XRD results showed three main peaks at angles of 2θ = 2.40° (100), 3.87° (200), and 4.49° (210), which are characteristics of mesoporous materials with hexagonal structures. SEM analysis showed that the surface morphology of Zn-modified MCM-41 formed aggregates of smaller particles. The EDS results showed that the amount of Zn in MCM-41 was 1.25%. Modification with Zn metal also affected the surface area and porosity of MCM-41, where the surface area, pore volume, and pore diameter decreased. Based on the adsorption-desorption analysis of N2 gas, both materials exhibit a type IV isotherm typical for mesoporous materials with an H1 hysteresis loop.

Composite functional particle enhanced gravity driven ceramic membrane bioreactor for simultaneous removal of nitrogen and phosphorus from groundwater

Recently, the emergency of ammonia (NH3-N) and phosphorus (TP) in groundwater becomes the serious environment problem. Herein, a composite functional particle enhanced gravity driven ceramic membrane bioreactor (GDCMBR) was developed to ensure the safety of potable water. After the composite granulation of bentonite and steel slag, the specific surface area, pore diameter and pore volume of particles increase continuously via specific surface area and pore size distribution analyses (BET-BJH analysis), thus providing more adsorption sites for the adsorption of ammonia nitrogen and phosphorus. Moreover, using SEM-EDS-Mapping, X-ray Diffraction (XRD) and Fourier Transform Infrared Spectrometer (FTIR), PO43− presented a precipitation reaction with steel slag, and NH4+ could replace metal ions inside bentonite. Besides, in the 60 days operation, GDCMBR enabled to enhance the bacteria enrichment, shorten the ripening period (10 ∼ 15d) of nitrogen and phosphorus removal, and then achieved the desirable effluent quality (TP: below 0.05 mg/L, NH3-N: no detected). During long-term continuous operation, the intensity biological activity within bioreactors was demonstrated by Total Organic Carbon (TOC) measurement, Excitation-Emission Matrix (EEM) spectrum and Confocal laser scanning microscope (CLSM). At the same time, the nitrifying bacteria (i.e., Nitrospira) and denitrifying phosphorus accumulating bacteria (i.e., Exiguobacterium and Pseudomonas) existed in the biofilter for removing nitrogen and phosphorus. Afterwards, the GDCMBR flux dropped to 9.8 L·m−2·h−1 and kept it stable after 14 days’ operation, due to the microorganism accumulation on membrane. Finally, the particles of GDCMBR could be transferred quickly to promote the flux and obtain a sustainable water purification efficiency. The composite functional particle enhanced GDCMBR combines the advantages of adsorption and biological process, and is expected to become an effective water treatment technology.

Effect of Water-Ethanol Extraction as Pre-Treatment on the Adsorption Properties of Aloe vera Waste.

The adsorption properties of Aloe vera (Aloe barbadensis Miller) for the uptake of Methylene Blue (MB) from water were investigated after pre-treating the material with water–ethanol solutions at different ethanol concentrations: 0% v/v (AV0), 25% v/v (AV25), and 50% v/v (AV50). The pre-treated materials were characterized as follows: the pHZC was evaluated to be 6, 5.7, and 7.2 for AV0, AV25, and AV50, respectively; from BET-BJH analysis the mesoporous nature of the material and an increase from 108.2 (AV0) to 331.7 (AV50) m2/kg of its solid surface area was observed; TG analysis revealed a significat increase in volatile compounds from the untreated (5.4%) to the treated materials (8.9%, 10.3%, and 11.3% for AV0, AV25, and AV50, respectively). Adsorption batch tests were then performed to investigate the equilibrium, the kinetics, and the thermodynamics of the process. Results suggested that the Langmuir model was in agreement with the experimental results, and values for qmax of 199 mg/g, 311 mg/g, and 346 mg/g were calculated for AV0, AV25, and AV50, respectively. The kinetic results were used to develop a mathematical model to estimate the effective diffusion coefficient for each type of Aloe adopted. Effective diffusion coefficients of 5.43·10−7 cm2/min, 3.89·10−7 cm2/min, and 5.78·10−7 cm2/min were calculated for AV0, AV25, and AV50, respectively. It was found that pre-treatment, on the one hand, enhances the adsorption capacity of the material and on the other, reduces its affinity toward MB uptake.

BioMOF-Mn: An Antimicrobial Agent and an Efficient Nanocatalyst for Domino One-Pot Preparation of Xanthene Derivatives.

In this paper, a new Mn-based metal-organic framework [UoB-6] was obtained via a one-step ultrasonic irradiation method with the ligand (H2bdda: 4,4'-(1,4-phenylenebis(azaneylylidene))bis(methaneylylidene))dibenzoic acid. The structural integrity of the synthesized BioMOF-Mn was corroborated by FT-IR, EDX, ICP, XRD, TEM, DLS, FESEM, and BET-BJH analyses. The aerobic oxidative domino reaction of benzyl alcohols or aldehydes with dimedone derivatives was performed in the presence of the UoB-6 catalyst to produce xanthene derivatives in good yields. Hot filtration and Hg poisoning tests proved the heterogeneous nature of the catalyst. Novel synthesized xanthene-based bis-aldehydes were introduced as potent HDAC1 inhibitors according to molecular docking calculations. Finally, the inhibitory activities of Mn-MOF nanoparticles were evaluated on Escherichia coli and Candida albicans. The MIC, MBC, and MFC values were determined from 2048 to 4096 μg·mL-1 according to antimicrobial susceptibility testing methods. The inhibitory effects of antimicrobial agents can be exacerbated when loaded on BioMOFs.

Synthesis and Characterization of TiO2 – Ag-Cellulose Nanocomposite and evaluation of photo catalytic degradation efficiency for Congo Red

Photocatalytic degradation of toxic organic contaminants in aquatic environments is a cost-effective, efficient, and long-term solution for environmental restoration. The capacity to fine-tune the structures and compositions of photocatalysts is vital for optimizing photocatalytic decontamination processes, as is a deep understanding of the mechanisms that govern photocatalytic interfacial molecular changes. We created a ternary TiO2/Ag/cellulose nanocomposite particle by hydrothermal process that acts as a photocatalyst for the photodegradation of congo red CR dye into mineralized small moleculesThe morphology, size and crystalline structure of the TiO2 – Ag – Cellulose nanocomposite were investigated by scaning electron microscopy SEM, transmission electron microscopy (TEM) and X-ray diffraction XRD respectively. Surface functional groups were analyzed using FTIR analysis. Specific surface area of the composite was characterized by BET-BJH analysis and the elemental composition of the composite was study using EDX analysis. Interestingly, the prepared TiO2 – Ag – Cellulose nanocomposites showed high catalytic degradation activity for CR dye. The photocatalytic degradation of the azo dye was monitored spectrophotometrically, a high degradation efficiency 81,76 % under visible radiation were obtained for composite after 120 min of reaction compared to 30% for pure TiO2.

Textural/structural evolution of cube/cauliflower-like MgSn(OH)6 nanophotocatalyst with excellent photocatalytic degradation of toxic dye pollutants

In this research, Mg–Sn hydroxide (MgSn(OH)6) nano semiconductor was synthesized using three different routes to investigate the texture/structure of MgSn(OH)6 on the photocatalytic properties of MgSn(OH)6 in RhB degradation. The nano semiconductors were characterized using XRD, FE-SEM, TEM, EDX, BET-BJH, DRS, PL, and the pHpzc. Morphological analyses for sono-hydrothermal sample showed 3D cubic microstructure. However, 3D cauliflower-like morphology was observed in the other samples. XRD analysis demonstrated the higher crystallinity of the sono-hydrothermal sample. BET-BJH analysis showed that the specific surface area and pore volume of this sample were 138.7 m2/g and 0.111 cm3/g, respectively. DRS analysis showed band-gap energy of about 4.1eV for all samples. Photocatalytic degradation experiments were conducted under UV-C light irradiation. The results demonstrated the advantage of the sono-hydrothermal sample owing to the cubic morphology, higher crystallinity and SBET, and lower recombination rate of the charge carriers. The photocatalytic degradation performance of the sample was evaluated in degradation of RhB, AO7, MO, and MB, which were 96, 93, 60, and 40%, respectively. The reusability study of sono-hydrothermal and hydrothermal samples was conducted in which the sono-hydrothermal sample showed higher efficiency and stability in four successive runs.

A Novel Pd-P Nano-Alloy Supported on Functionalized Silica for Catalytic Aerobic Oxidation of Benzyl Alcohol

Catalytic aerobic oxidation of benzyl alcohol (BnOH) to benzaldehyde (PhCHO) over supported noble metal catalysts has grabbed the attention of researchers due to the critical role of PhCHO in numerous industrial syntheses. In the present study, a novel catalyst, Pd-P alloy supported on aminopropyl-functionalized mesoporous silica (NH2-SiO2), was prepared through in situ reduction and characterized by BET-BJH analysis, SEM, TEM, XRD, FTIR, TG-DTA, and XPS. Chemical properties and catalytic performance of Pd-P/NH2-SiO2 were compared with those of Pd° nanoparticles (NPs) deposited on the same support. Over Pd-P/NH2-SiO2, the BnOH conversion to PhCHO was much higher than over Pd°/NH2-SiO2, and significantly influenced by the nature of solvent, reaching 57% in toluene at 111 °C, with 63% selectivity. Using pure oxygen as an oxidant in the same conditions, the BnOH conversion increased up to 78%, with 66% selectivity. The role of phosphorous in improving the activity may consist of the strong interaction with Pd that favours metal dispersion and lowers Pd electron density.