Degradation Percentage Research Articles

Rapid Degradation of Organic Dyes by Nanostructured Gd2O3 Microspheres

Pollution of freshwater by synthetic organic dyes is a major concern due to their high toxicity and mutagenicity. In this study, the degradation of Congo red (CR) and malachite green (MG) dyes was investigated using nanostructured Gd2O3. It was prepared using the coprecipitation method, using gadolinium nitrate and concentrated formic acid, with subsequent calcination at 600 °C. Its morphology corresponds to hollow porous microspheres with a size between 0.5 and 7.5 μm. The optical bandgap energy was determined by using the Tauc method, giving 4.8 eV. The degradation of the dyes was evaluated by UV-vis spectroscopy, which revealed that dissociative adsorption (in the dark) played a key role. It is explained by the cleavage and fragmentation of the organic molecules by hydroxyl radicals (•OH), superoxide radicals (•O2−) and other reactive oxygen species (ROS) produced on the surface of Gd2O3. For CR, the degradation percentage was ~56%, through dissociative adsorption, while UV light photocatalysis increased it to ~65%. For MG, these values were ~78% and ~91%, respectively. The difference in degradation percentages is explained in terms of the isoelectric point of solid (IEPS) of Gd2O3 and the electrical charge of the dyes. FTIR and XPS spectra provided evidence of the role of ROS in dye degradation.

Biosynthesis, characterization of Ag2O nanoparticles for enhancement of antioxidant and photo degradation activities

Silver oxide (Ag2O) nanoparticles were synthesized via Biosynthesis methods using Croton macrotachyus leaf extract silver sulphate (Ag2SO4) was used as precursors and the extract was used in the reactions as reducing, stabilizing and capping agents which is a very easy and inexpensive synthesis method. Metal oxide nanoparticles characterized using UV–visible, TGA, Fourier transform infrared(FTIR),powder X-ray diffraction(XRD), X-ray photoelectron(XPS), and Scanning Electron Microscopy(SEM) with Energy Dispersive X-Ray(EDX) and Transmission Electron Microscopy(TEM), High Resolution Transmission Electron Microscope(HRTEM), and Selected Area Electron (SAED) which is used for determination of crystalline size, morphology,particle size and oxidation state with composition of elements in the sample. Metal oxide nanoparticles have a significant photo catalytic performance under visible light source confirmed that study supported Ag2O spherical structure, which exhibits enhanced photo catalytic activity and anti-oxidant activities as well as the size of the Ag2O nanoparticles was between 16 nm and 21 nm from the XRD(Scherrer equation),SEM & TEM) imaje software and Photo catalytic activity of Ag2O NPs were assessed against methylene blue (MB) dye degradation under natural sunlight illumination for 60 min. This sustainably photo degraded in direct solar irradiance with remarkable degradation percentage which is greater than 96.35 % and Scavenging activities Ag2O nanoparticles enhanced DDPH scavenging activities was 88 %

Structural, electronic and optical properties of SrMnO3 photocatalyst for dye degradation; experimental and DFT study

Perovskite oxides (PO) are versatile multi-functional materials with wide range of applications. In current study, highly-crystalline perovskite manganite (PM) SrMnO3 has been synthesized via ultrasonic method followed by calcination at 600 °C. Morphology of PM with irregular shape and size was assessed by FESEM and hexagonal geometry with a crystallite size of 13.67nm was determined by XRD studies. As-synthesized PM was further tested as photocatalyst for its dye degradation potential against malachite green (MG) and methylene blue (MB). In the presence of synthesized perovskites, degradation of both the dyes MG and MB was achieved in 12min and 4.5min with the percentage degradation of 80.26% and 89.35% respectively. The factors including pH and temperature affecting degradation of both the dyes were also studied. Additionally, calculations based on simulated DFT (density function theory) have been employed to explore the optical, electronic and structural attributes of SrMnO3 PM through generalized gradient approximation (GGA). The total and partial density of states have been evaluated by GGA confirms the Fermi level (Ef) characteristics of metallic Sr and Mn and found that ‘d’ and ‘p’ orbitals of Sr, Mn and O were responsible for the band formation. The results of the current study advocate the synthesis of PM and related compounds followed by their successful applications as catalyst for dye degradation as well as many other fields involving the use of nanomaterials.

Interpenetrating Polymer Network of Hydroxyethyl Methacrylate and Chitosan as Cryogels for Tissue Engineering Applications

ABSTRACTTissue engineering is a vast expanding field with applications in areas such as tissue/organ transplantation, drug delivery, in vitro models, and so on. Biomaterials form an essential component in tissue engineering by acting as a template for cellular activity, therefore, novel tissue‐engineered biomaterials with innovative properties are in high demand. Hence, this work proposes an interpenetrating polymer network cryogel of chitosan and hydroxyethyl methacrylate (HEMA) as a tissue‐engineered biomaterial with uniform and high cell seeding throughout the cryogel matrix. The physical analysis of the cryogels demonstrated a highly macroporous structure exhibiting uniform pore size distribution and overall porosity through field emission‐scanning electron microscopy (FE‐SEM) analysis with pore sizes lying in the range of 50–200 μm and 150–400 μm in horizontal and transverse plane, respectively. The cryogels were also found to be degradable with an average percent degradation of 17.28 ± 1.47% in 4 weeks, and their mechanical properties revealed an average compressive strength of 0.05 MPa and an elastic modulus of 3 MPa. Further, biological characterization of the cryogel through direct contact test depicted an excellent biocompatibility with L929 mouse fibroblast and MC3T3‐E1 preosteoblasts with negligible presence of dead cells in and around the cryogel. Uniform and high cell seeding with an increasing proliferation trend of MC3T3‐E1 cells was observed on these cryogels through live‐dead staining and MTT assay at day 1, 3, and 7‐time point. Cell adherence studies via FE‐SEM analysis also depicted a similar trend with uniform MC3T3‐E1 cell distribution along with highly flattened morphology and extracellular matrix production. Therefore, based on their promising physico‐chemical and biological properties, HEMA‐Chitosan cryogels exhibit a strong potential application as tissue engineered biomaterials.

Degradation of Triadimefon Compounds in Bayleton 250 EC Pesticides by Sonolysis, Ozonolysis and Sonozolysis

The increase in the agricultural sector is supported by the use of pesticides to kill pests and diseases in plants. However, the continuous use of pesticides in excessive amounts can have a detrimental impact on the environment, especially the waters around agricultural land. Therefore, efforts are needed to degrade pesticide residues containing triadimefon compounds that pollute the environment such as sonolysis, ozonolysis, and sonozoisis methods. These three methods are organic compound degradation methods that utilize OH radicals to degrade organic compounds. Based on the data obtained, the sonolysis method with the addition of TiO2-anatase catalyst produced a degradation percentage of 76.25% after degradation for 150 minutes. While in a much shorter time, namely 15 minutes, using the ozonolysis method without the use of a catalyst, triadimefon can be degraded by 69.10%, and 71.87% with the sonolysis method. Since only a small amount of triadimefon is degraded by the sonozolysis method, it is more effective to use the ozonolysis method to degrade this triadimefon compound.

Spectroscopic approach to optimize the biogenic silver nanoparticles for photocatalytic removal of ternary dye mixture and ecotoxicological impact of treated wastewater

The fabricating of extremely effective, economical, ecologically safe, and reusable nanoparticle (NP) catalysts for the removal of water pollution is urgently needed. This study, spectroscopically optimizes the process parameters for the biogenic synthesis of AgNP catalysts using Cledrdendrum infortunatum leaf extract. The optimization of several synthesis parameters was systematically studied using UV–Vis spectroscopy to identify the ideal conditions for AgNPs formation. The AgNPs are spherical with a size of ~ 20 nm, pure and stable. Mechanistic insights into the biogenic synthesis process were explored. The photocatalytic performance of biogenic AgNPs was evaluated for the degradation of three common (crystal violet, thioflavin T, and methylene blue) dyes as models in ternary mixtures under the influence of sunlight. AgNPs show excellent photocatalytic efficiency in terms of degradation percentage (82.89–96.96% within 110 min), kinetics (0.0247–0.0331 min–1), half-life (20.96–28.11 min), and T80 (48.67–65.28 min) and also easily recovered and reused. Ecological safety assessment of the treated wastewater was assessed on the growths of rice, mustard, and lentil plants, and preliminary findings demonstrated that seedling growths for treated wastewater were nearly similar to the control sample but retarded in dye-contaminated wastewater suggesting potential use of treated wastewater for sustainable agriculture without compromising ecological balance. So, this study explores biogenic AgNPs as cost-effective, safe, and sustainable photocatalytic agents for the remediation of hazardous mix dyes and real-life applications of treated water for agricultural purposes.

Degradation of Low‐Concentration Perfluoroalkyl Substances With a Nonthermal Gas–Liquid Plasma Reactor

ABSTRACTA continuous gas–liquid flowing film reactor with nanosecond pulsed power, where plasma channels generated in argon propagate along the gas–liquid interface, was utilized to degrade aqueous solutions of perfluoroalkyl substances (PFAS). Perfluorooctanoic acid (PFOA) yielded maximum percentage degradations of 81.6% and 76.5% for the low (98 ± 29 ppt) and high (300 ± 30 ppt) concentrations, respectively, at 2 mL/min liquid flow and a pulse repetition frequency of 0.5 to 2 kHz. A mixture of perfluorocarboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) was also degraded. Sequential multi‐pass treatments of PFOA with an initial concentration of 413 ± 142 ppt using 2 kHz resulted in 84.3% degradation in the first pass and no PFOA was detected after additional passes.

CoFe2O4/graphene oxide/Ostrich Eggshell/chitosan/polypyrrole nanocomposite for removal 4-nitrophenol

A nanocomposite comprising CoFe2O4/Graphene Oxide/Ostrich Eggshell/Chitosan/Polypyrrole (CF/GO/ES/CS/PPY) was fabricated as both an adsorbent and photocatalyst to examine the adsorption and degradation efficiency of the organic pollutant 4-nitrophenol (4-NP), both in the absence of light and under visible light irradiation. The nanocomposite material outperformed adsorption in photocatalytic experiments conducted using the Box-Behnken Design (BBD) within response surface methodology (RSM), which investigated the correlation between responses and process variables and identified optimal combinations with Design Expert software. Under optimal conditions, the highest percentage of adsorption and degradation of 4-NP was achieved, with a pH of 5.04, concentration of 4-NP of 24.73 mg/L, nanocomposite mass of 0.04 g, and time of 27.64 min, resulting in reported efficiencies of 89.76, and 99.98% for adsorption and degradation, respectively. Upon statistical analysis, it is clear that the Langmuir isotherm model is the best fit for the studied phenomena, displaying a strong correlation (0.990) and minimal error. The data suggests that the intraparticle diffusion kinetic model has the highest correlation coefficient (0.9925) among the models examined. The value of ΔG° computed for the adsorption process exhibits an increase from 1.3704 to 3.9439 kJ/mol as the temperature rises, indicating the non-spontaneous nature of the adsorption process.

Decolorization of Reactive Dyes by Bacteria Isolated from Textile Dye-Contaminated Soil

Textile dye-contaminated soil samples were collected for the isolation of heterotrophic bacterial population. The isolates were screened primarily for dye decolorization using Luria Bertani broth containing 100 mgL-1 of selected reactive dyes namely Blue FNR (BF), Novacron Navy (NN), or Novacron Deep Cherry (NDC). Secondary screening of dye-decolorizing bacterial isolates was carried out in Bushnell Haas medium. The decolorization efficiency of the isolates was estimated spectrophotometrically. The selected isolates were identified by the analysis of their cultural, biochemical, and molecular characteristics. Among 38 bacterial isolates from the dye-contaminated soil, two bacterial genera Klebsiella pneumoniae strain OS-3 and Bacillus tropicus strain OS-8 were found to have strong ability in selected dye-decolorization. The optimum pH and temperature for dye decolorization in static conditions by both isolates were found to be 6-8 and 37°C within 72 hours, respectively. Efficient dye decolorization was observed under static condition in compared to shaking culture. Both isolates were able to induce decolorization in the presence of co-substrate. Starch, sucrose and glucose as a carbon source and yeast extract as an organic nitrogen source induced the efficiency of Blue FNR, Novacron Navy and NDC dyes decolorization, respectively by both isolates. On the other hand, it was observed that the percentage of dye degradation decreased in the presence of inorganic nitrogen source in the medium. Both isolates retained efficiency to decolorize selected reactive dyes by 70-80% at 5% salinity. The strong decolorizing ability in natural conditions indicates that both bacteria could be used in dye-polluted wastewater treatment. Chittagong Univ. J. B. Sci. Vol. 12 (1 & 2): 91-102, 2024

Synthesis of a Direct Dual Z‐Scheme g‐C3N4/Bi2S3/NiFe2O4 Photocatalyst for Degradation of Organic Pollutants: Optimization Using Response Surface Methodology

ABSTRACTIn photocatalytic reactions, the fast recombination rate of photogenerated charge carriers limits practical application. So, in this study, a new g‐C3N4/Bi2S3/NiFe2O4 nanocomposite was synthesized with dual Z‐scheme heterojunctions to enhance charge carrier separation and visible light absorption. The structure, morphology, composition, magnetic, surface potential, and optical properties of the prepared g‐C3N4/Bi2S3/NiFe2O4 nanocomposite were investigated using XRD, FTIR, Raman, FESEM‐EDS‐Mapping, TEM, VSM, Zeta potential, PL, and UV–vis DRS techniques. Also, the photocatalytic performance and mechanism of enrofloxacin (Enro) and malachite green (MG) degradation under visible light were studied. Also, the photocatalytic performance and photodegradation mechanism were studied by enrofloxacin and malachite green degradation under visible light. The effect of the main parameters on the degradation performance of both pollutants was studied by response surface methodology (RSM). Under the optimum conditions, the highest photocatalytic degradation percentages for enrofloxacin and malachite green were obtained at 91.89% and 95.63%, respectively. The apparent rate constants of Enro and MG photodegradation over g‐C3N4/Bi2S3/NiFe2O4 were found to be 0.0628 min−1 and 0.0504 min−1, respectively. Based on its magnetic characteristics, the as‐prepared catalyst demonstrated facile recovery and good photocatalytic stability after six recycling studies, according to the results.

Insights into Novel Doping Effect of Fe-Doped ZnS Nanostructures Derived from Oxystelma Esculentum: Kinetics-Based Photocatalysis, Nitrogen Fixation, and Antifungal Efficacy

Implementing greener approaches is a sustainable and eco-friendly methodology for nanocomposite synthesis. This work reports the sustainable fabrication of Fe-doped ZnS (Fe0.3Zn0.7S) nanocomposite and its broad-spectrum applications. The systematic characterization was carried out using several advanced analytical techniques. DLS, Zeta potential, SEM, XPS, and TEM performed morphological and size assessments of the engineered nanocomposite. Eventually, XRD provided valuable insights into the crystalline behavior of nanocomposite. The nanocomposites were then treated against the organic dye Safranin O, which displayed 93% degradation within an hour with the rate constant value of 0.0326 min−1. Parameters influencing the percentage degradation, such as temperature, pH, etc., were also discussed. Moreover, an LCMS test was also conducted to evaluate the presence of reactive intermediates. Safranin O’s degradation was confirmed by identifying intermediate products, such as compounds with m/z values of 335.84, 321.81, 306.79, 292.77, and 257.32, which were indicative of progressive dye breakdown. Finally, the photocatalytic enactment examination verified that the prepared nanocomposite’s nitrogen fixation rate (38.96 µmolg−1) was way greater (~4 times) than the pristine compound. In addition, prepared nanoparticles demonstrated a befitting ability to eliminate a wide range of threatening pathogenic fungi. The doping of Fe into ZnS further enhanced the inhibition against Fusarium oxysporum.

Catalytic degradation of aromatic dyes using triazolidine-thione stabilized Nickel nanoparticles

Nanoparticles have been extensively studied for many years due to their important roles in catalysis, metallurgy and high temperature superconductors. But, Nanoparticles are extremely unstable and easily react with other substances. So, to control the size and the shape of nanoparticles they must be stabilized. Organic Ligands have gain more attention for stabilizing Nanoparticles. In the present work, Nickel Nanoparticles have been synthesized by reduction method and then stabilized by synthesized 5-phenyl triazolidine-thione based organic ligand to achieve larger surface area and good catalytic activity. Stabilized Nickel NPs of different ratios were synthesized for analyzing their catalytic performance against dyes that has become one of the most serious environmental problem causing drastic water pollution. The prepared thione stabilized Nickel nanoparticles were confirmed by UV-Visible and Infrared Spectroscopy. UV/Vis analysis displayed the peak at 236 nm which confirms the metallic Ni NPs formation while, in FTIR peak around 720-750cm-1 is due to the nickel and sulphur bond stretching vibrations. The size, surface morphology and the quality of the stabilized Ni Nanoparticles were analyzed by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analysis. SEM images showed uneven morphology with variously sized and shaped particles. Large surface area is visible which is advantageous for catalytic degradation of pollutants. The degradation process was studied by using UV-visible Spectroscopy. The catalytic behavior of stabilized nanoparticles was evaluated by using various parameters i.e. time, concentration and size of NPs. These parameters were optimized during degradation process to get maximum degradation in short period of time. Maximum percentage degradation of Methylene blue, Methyl Orange and Rhodamine B dyes were achieved up to 90%, 88% and 81% respectively, in short duration of time. All the three ratios of thione stabilized Ni Nanoparticles showed good degrading performance for all dyes, but 1:2 thione stabilized Ni NPs had shown maximum catalytic performance.

Remediation of antibiotics-contaminated wastewater through photocatalytic techniques: Implications for SDGs that support a more sustainable future and a healthy planet

ABSTRACT This paper aims to provide information on the remediation of various antibiotics from contaminated wastewater by photocatalytic treatment techniques. The review includes the mechanism of action of pharmaceuticals, pharmaceuticals as environmental pollutants, antibiotics and their metabolites, toxicity and health implication of antibiotics-contaminated wastewater, measures to manage antibiotics in the environment, the different wastewater treatment technologies, the degradation and mechanism of antibiotics via photocatalysis, and the Sustainable Development Goals (SDGs) relating to the treatment of antibiotics-contaminated wastewater. Photocatalysis has more advantages than other treatment techniques due to its simplicity, cost-effectiveness, and higher percentage degradation of antibiotics in wastewater. The use of photocatalytic methods to purify antibiotic-contaminated wastewater has substantial ramifications for several SDGs, hence promoting a healthier world and a more sustainable future. This paper is presumed to offer some insight on the treatment technique that is more efficient and suitable for antibiotics-contaminated wastewater that can be explored on an industrial scale.

Stability-Indicating RP-HPLC Method Development for the Determination of Empagliflozin

Aim: This study aimed to develop and validate a stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method for the quantitative analysis of empagliflozin in pharmaceutical formulations. Materials and Methods: The method was developed using an Agilent C18 column (5μm; 4.6 x 250 mm) and a mobile phase consisting of a mixture of methanol/ 0.05% pH 3.3 acetic acid (75:25) at a flow rate of 1 ml/min with UV detection at 224 nm. The developed RP-HPLC method demonstrated linearity with a correlation coefficient (r) of >0.999. Forced degradation studies revealed the method’s ability to separate and quantify empagliflozin from its degradation products. The actual percentage degradation ranged from 2.85% to 7.43%. Precision was established where the mean interday and intraday RSD were 0.36% and 0.17%, respectively. Result and Discussion: The method’s robustness was confirmed, which had negligible effects on the assay results (<0.2% RSD). The method was applied to commercially available tablets, yielding an average (SD) empagliflozin recovery of 100.44% (0.18). Conclusion: This RP-HPLC method is suitable for routine analysis of empagliflozin in pharmaceutical formulations and can be employed for stability studies and quality control purposes, ensuring the drug’s quality and efficacy throughout its shelf life.

Enhanced cathodic electrodes from V2O5 nanorods: Pioneering organic dye degradation and optimized catalysis for sustainable supercapattery devices

Encapsulating the essence of multifunctionality, the synthesized Vanadium Pentoxide (V2O5) nanorods (NRs) are adaptable innovators of visible-light photocatalytic degradation and sustainable supercapattery device fabrication. Meanwhile, the physicochemical properties are investigated by precise instruments. The V2O5 NRs demonstrate improved photocatalytic performance over a 100-min duration, effectively catalyzing the methylene blue (MB) degradation with a remarkable degradation percentage of 98.37 % (25 mg catalysis) and shows a lower wavelength shift due to MB molecular braking. In a groundbreaking twist, this work utilises tainted V2O5 NRs, ingeniously repurposing them to energy storage tenacities. In addition, the electrochemical assessment of tainted V2O5 NRs demonstrated subtle changes after MB degradation, increasing the specific capacity (Cs) value from 794 to 933C.g−1 due to developing reduced particle agglomeration. Moreover, the better Cs value of tainted V2O5 NRs reached 95.02 % after 500 cycles (5 A.g−1). The fabricated asymmetric supercapattery (ASC) device demonstrates superior ion diffusion processes, as evidenced by Dunn's method calculations, particularly at a scan rate of 5 mV.s−1. Additionally, the assembled device underscored their unique positioning between battery and capacitor materials, distinctly supported by a “b” value of 0.8 and superior capacity retentivity. They reached a superior power (P = 191.75 W.kg−1) with energy (E = 50 Wh.kg−1) and better cyclic stability, maintaining their performance over 4000 cycles at 5 A. g−1 (91.3 %). Furthermore, under exposure to the light of a yellow light emitting diode (LED) for 30 s, the real-time consequences of after cyclic stability material of tainted V2O5 NRs are investigated, providing meaningful insights into their performance dynamics.

Broad photoluminescence and photocatalysis from functional carbonaceous material-metallized porphyrin composites for UV-Vis light harvesting

Abstract Carbon in its many form has attracted huge attraction over the years owing to its biocompatibility, processability, stability and optical properties for its utilization in UV-Vis light harvesting in pure as well as modified schemes such as composite. This study reports green precursor synthesis as well as optical, structural, luminescence and catalysis study of functional carbonaceous material (FCM) in pure and composite form. This high-order self-assembly of FCM possess extraordinary photophysical and chemical properties with its functional groups rich surface making it suitable for π-π* transitions. Further its composite formation with a high absorption coefficient (more than 20,000 cm-1 in broad visible range 400-700 nm) and non-radiative (near IR) fluorescence quenching exhibiting metallized porphyrin is shown to be suitable for photocatalysis applications. These conclusions have been established using XRD, FESEM, EDX, FTIR, UV-Vis, FL and Raman spectroscopy measurements. Broad range photoluminescence for pure FCM (300-550 nm) as well as its porphyrin-based composite (400-550 nm) and further the application of composite in the photocatalytic ability for the degradation of standard methylene blue dye for degradation percentage of 62% in 120 mins in visible light while 30% in 180 mins in dark shows the correlation for sustainable synthesis and application of FCM-porphyrin composite.

Toxic Dye Degradation Employing Phoenix dactylifera Seed Extract for the Green Synthesis of Silver Nanoparticles: Characterization and Application.

This research highlights the facile green synthesis of silver nanoparticles (AgNPs) using Phoenix dactylifera seed extracts and its photocatalytic application for the degradation of toxic dyes. The AgNPs synthesis was confirmed by the appearance of its representative absorption peak at 416 nm in UV-visible absorption spectroscopy. Moreover, the reduction of silver ions to Ag was justified through Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction pattern revealed crystalline AgNPs structure with particle size ranging from 5 to 15 nm calculated using the Debye-Scherrer equation. The rectangular-like structural morphology of synthesized AgNPs was observed in scanning electron micrographs. The as-synthesized AgNPs demonstrated higher photocatalytic activity for the degradation of malachite green (MG) and congo red (CR) followed by methylene blue (MB), and crystal violet (CV) under UV irradiation. In addition, rate constant (k) and percentage degradation were also calculated. The present study presents a facile green synthesis pathway and its potentially successful manipulation in the reduction of toxic dyes under the illumination of UV-light.

Degradation of salicylic acid coordinated to Fe3O4 nanoparticles by H2O2

Salicylic acid (SA) has strong tendency to form complexes with iron (III). Depending upon the concentrations of SA, the complexes formed are FeR+, FeR2+, FeR32+where R represents salicylate ion (-OC₆H₄COO-). Fe3O4 nanoparticles binds with the salicylate ions through the sites having Fe3+ and at the site containing Fe2+ reacts with H2O2 to produces OH* radicals. The OH* radicals oxidise the salicylic acid attached to Fe3O4 nanoparticles. Thus, the degradation occurs through the formation of SA-Fe3O4 nanoparticles complexes and then followed by the reaction with H2O2 at the nanoparticle site. FT-IR, TGA were used to confirm the synthesis of Fe3O4 nanoparticles as well as to investigate SA-Fe3O4 nanoparticles complex formation and the degradation of the complex by H2O2. Spectrophotometric studies were employed for the monitoring of the degradation of SA at the surface. Here, the nanoparticles act as platform to which both the reactants SA and H2O2 get activated and the degradation reaction occurs. The concentrations of SA, H2O2, nanoparticle dosage, surfactants and polymers were changed and the % degradation were noted. It has been observed that the degradation percentage decreased with the increase in nanoparticle dosage, [surfactant] and [polymers]. The [H2O2] and [HClO4] gave peaked-like curve for the degradation of SA for the plot of % degradation versus concentrations of H2O2 and HClO4. Degradation of SA was observed maximum at [H2O2](= 8.0 × 10−4 mol dm−3) and at [HClO4] (= 1.0 × 10−2 mol dm−3).

Novel ACr2O4 (A = Mg, Cu, Ni)/MIL-101(Cr) photocatalysts: Synthesis, characterization, performance prediction and applications for the photo–degradation of tetracycline hydrochloride

The Z-scheme ACr2O4 (A = Mg, Cu, Ni)/MIL-101(Cr) heterojunction photocatalysts have been synthesized by a simple method. By means of phase structure, microstructure and composition analysis, it was determined that the ACr2O4 (A = Mg, Cu)/MIL-101(Cr) photocatalysts only contained the target component, while the NiCr2O4/MIL-101(Cr) photocatalyst also contained a small amount of Cr2O3 impurities. The photocatalytic experiments showed that the degradation percentage of MgCr2O4/MIL-101(Cr) photocatalyst reached 78 % when the mass percentage of MIL-101(Cr), the catalyst content, the initial tetracycline hydrochloride concentration, pH value and illumination time were 10 %, 1 g/L, 50 mg/L, 7 and 120 min, respectively. The neural network model can effectively predict the photocatalytic activity of MgCr2O4/MIL-101(Cr) photocatalyst. Various characterization confirmed that the holes, hydroxyl radicals and superoxide radicals are the main active species involved in photocatalytic degradation of tetracycline hydrochloride. This research will provide experimental basis and theoretical support for exploring the construction of new metal–organic framework (MOF) based heterojunction photocatalysts.

Silk fibroin/gelatin electrospun nanofibrous dressing loaded with roxadustat accelerates wound healing in diabetic rats via HIF-1α stabilization

Diabetes presents significant health risks, including diabetic foot ulcers, which can lead to amputation or death if left untreated. It has been acknowledged that hypoxia-inducible factor-1 alpha (HIF-1α) dysfunction in diabetic wounds delays healing and tissue repair. This study explores the therapeutic potential of roxadustat (ROX), a novel HIF-1α stabilizer, within an optimized electrospun gelatin/silk fibroin nanofibrous dressing (ROX-NF). The dressing's properties were optimized using a 22 full factorial design, with varied gelatin (GN) and silk fibroin (SF) amounts as factors and responses including degradation, porosity, swelling, drug release, and drug content percentages. In vitro characterization of the optimized ROX-NF showed a degradation rate of 90.24 ± 1.29 %, porosity of 84.41 ± 3.04 %, cumulative drug release of 93.13 ± 3.05 % over 48 h, and a high drug content of 99.12 ± 0.02 %, with structural analyses confirming successful ROX integration within the nanofibrous matrix. Additionally, in vivo evaluation of the optimized ROX-NF in diabetic rat models demonstrated accelerated wound closure, achieving 5.17 ± 1.2 % wound area by day 14 compared to 19.3 ± 2.8 % with ROX dispersion. Histological analysis revealed enhanced collagen deposition, neovascularization, and organized epidermal and dermal layers. Furthermore, PCR, ELISA, and Western blot assays demonstrated a marked upregulation of key wound healing markers, including HIF-1α, TGF-β, VEGF, and collagen I, in the ROX-NF group relative to ROX dispersion. These findings underscore the efficacy of combining ROX with nanofiber characteristics, offering a promising approach for diabetic wound management through accelerated wound closure and enhanced tissue regeneration.