This study explores the controlled synthesis of a novel Fe₃O₄@C magnetic nanocomposite derived from FeBTC metal–organic framework (MOF) and its application as an efficient adsorbent for the removal of rhodamine dye from wastewater. The FeBTC MOF was first synthesized and then thermally decomposed in a controlled oxygen atmosphere at 375°C (1 h) to form the Fe₃O₄@C nanocomposite with a magnetic Fe₃O₄ core embedded in a porous carbon matrix. A comprehensive characterization of the nanocomposite was performed using x-ray diffraction (XRD), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS) to confirm the successful formation and to evaluate its structural and morphological properties. The morphological investigation revealed that the particles of Fe₃O₄ had a spherical shape with diameter of 10–15 nm. The carbon coating appeared as a thin amorphous layer surrounding the Fe₃O₄ nanoparticles. The adsorption capacity of Fe₃O₄@C for rhodamine B (RhB) dye was assessed under various conditions, including different pH values, contact times, initial dye concentrations, and temperatures. Complete dye removal was attained in 45 min using 50 mg of the nanocomposite and 50 mL of 5.0 ppm RhB at the optimum pH of 9.1. Under the same experimental conditions, the highest adsorption capacity of 13.0 mg/g was obtained, but using 15.0 mg of the nanocomposite. Fe₃O₄@C nanocomposite exhibits high adsorption efficiency, with a maximum removal capacity of 100%, which is clearly superior to many conventional adsorbents. This performance can be attributed to the synergistic effects of the magnetic Fe₃O₄ and the large surface area of the carbon matrix. Kinetic models were employed to understand the adsorption mechanism. The adsorption kinetics followed a pseudo-second-order model. The reusability of the adsorbent was tested over multiple cycles and showed a minimal loss of performance (drops to 93.0% after five removal cycles). The study demonstrates that the Fe₃O₄@C nanocomposite is a promising candidate for the effective removal of organic dyes from wastewater, offering potential benefits for environmental remediation and sustainable water management.

Three different types of Zr-based MOFs derived from benzene dicarboxylic acid (BDC) and naphthalene dicarboxylic acid as organic linkers (ZrBDC, 2,6-ZrNDC, and 1,4-ZrNDC) were synthesized. They were characterized using X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform IR spectroscopy (FT-IR), and Transmission electron microscopy (TEM). Their hydrophilic/hydrophobic nature was investigated via contact angle measurements; ZrBDC MOF was hydrophilic and the other two (ZrNDC) MOFs were hydrophobic. The three MOFs were combined with MWCNTs as electrode modifiers for the determination of a hydrophobic analyte, flibanserin (FLB), as a proof-of-concept analyte. Under the optimized experimental conditions, a significant enhancement in the oxidation peak current of FLB was observed when utilizing 2,6-ZrNDC and 1,4-ZrNDC, being the highest when using 1,4-ZrNDC. Furthermore, a thorough investigation of the complex oxidation pathway of FLB was performed by carrying out simultaneous spectroelectrochemical measurements. Based on the obtained results, it was verified that the piperazine moiety of FLB is the primary site for electrochemical oxidation. The fabricated sensor based on 1,4-ZrNDC/MW/CPE showed an oxidation peak of FLB at 0.8 V vs Ag/AgCl. Moreover, it showed excellent linearity for the determination of FLB in the range 0.05 to 0.80 μmol L⁻¹ with a correlation coefficient (r) = 0.9973 and limit of detection of 3.0 nmol L⁻¹. The applicability of the developed approach was demonstrated by determination of FLB in pharmaceutical tablets and human urine samples with acceptable repeatability (% RSD values were below 1.9% and 2.1%, respectively) and reasonable recovery values (ranged between 97 and 103% for pharmaceutical tablets and between 96 and 102% for human urine samples). The outcomes of the suggested methodology can be utilized for the determination of other hydrophobic compounds of pharmaceutical or biological interest with the aim of achieving low detection limits of these compounds in various matrices.

Global environmental problems, especially those related to water contamination brought on by rapid industrialization and economic growth, are among the most dangerous threats facing humanity today. In this research work, Al³⁺ based metal–organic framework with 1,4-benzenedicarboxylic acid (H₂BDC) linker has been synthesized by a simple and economic coprecipitation method. The obtained Al-BDC MOF was utilized as an adsorbent for sequestering iron from wastewater, but only 54.0% of iron concentration was eliminated after 120 min. To boost the removal efficiency, modification of the Al-BDC MOF was carried out. MnO₂@Al-BDC nanocomposite was prepared and applied as a nanoadsorbent for iron remediation from water. The adsorption capability of Al-BDC MOF was greatly enhanced by facile modification. The adsorption efficiency reached 97.0% using 35.0 mg of the nanocomposite after 120 min compared to 54.0% iron removal using the un-modified MOF. The effect of pH of the medium was then studied using MnO₂@Al-BDC nanocomposite. The best elimination efficacy of iron was accomplished at pH ~ 2.2. The adsorption of iron on the surface of MnO₂@Al-BDC nanocomposite attains 97.0% (120 min) using a 35.0 mg dose of adsorbent and reaches 98.7% utilizing a 50.0 mg dose of adsorbent. In contrast, at pH = 9.2, the removal efficiency drops to 90.0% (after 120 min, 35.0 mg adsorbent). The adsorption capability was examined also using a variety of iron concentrations, i.e., 2.5, 5.0, and 7.5 mg/L where the adsorption efficiency dropped notably upon increasing the concentration. It dropped from 96.3% to 87.0% using 35.0 mg of MnO₂@Al-BDC nanocomposite at 90 min. The newly developed adsorbent showed a pronounced efficiency for Fe³⁺ removal against real samples collected from different water sources. Ultimately, this research introduces a novel MnO₂@Al-BDC nanocomposite, synthesized through a simple and economical coprecipitation method, to address water contamination by iron. The innovation lies in the significant enhancement of iron elimination efficiency, from 54.0% with unmodified Al-BDC MOF to 97.0% with the MnO₂@Al-BDC nanocomposite.

Energy production is one of the most crucial issues presently attracting global attention. In this work, a CuMOF@Faujasite nanocomposite was synthesized and utilized as a novel efficient catalyst for hydrogen production. The produced composite was first characterized using X-ray diffraction (XRD), Fourier- transform infrared (FT-IR), thermogravimetric analysis (TGA), and differential scanning calorimetry. Surface properties were analyzed via nitrogen adsorption–desorption isotherms. All characterization results revealed the formation of a pure and well-defined crystalline phase, with a high specific surface area (S_BET) of 286 m²/g (S_BET of Faujasite is 35 m²/g). Moreover, the morphology and compositional analysis of the nanocomposite were assured through the scanning (SEM) and transmission (TEM) electron microscope and X-ray photospectroscopy (XPS). SEM and TEM images revealed sponge-like spheres that are related to Faujasite besides small spherical particles related to CuBDC MOF. XPS analysis revealed a low content of CuMOF in the nanocomposite. The catalytic activity of the nanocomposite was tested for the dehydrogenation of NaBH₄. The impact of NaBH₄ concentration, weight of the catalyst, and the reaction temperature on NaBH₄ hydrolysis was investigated. A hydrogen generation rate (HGR) of 484 mLmin⁻¹ g⁻¹ at 30 °C was achieved using 50 mg of the catalyst and 0.05 mol/l of NaBH₄ owing to the high specific area and the selective active sites for such hydrolytic reaction. The kinetic analysis of the activity data indicates the first-order behavior at low concentrations of NaBH₄. Furthermore, at concentrations ≥0.065 mol L⁻¹, zero-order kinetics was predominant. The time needed for completion of the hydrolysis reaction was found to be decreased (~20 min) by increasing the catalyst mass as well as NaBH₄ concentration or even by elevating the reaction temperature (~4 min at 60 °C). The activation energy was estimated; it was found to be 70.5 KJ mol⁻¹. Ultimately, our catalyst showed a reasonable rate of hydrogen production, as compared to others reported earlier.

Remediation of the dye-contaminated water has received a broad interest due to the health problems and defects in the ecological system originating from the presence of such toxic materials in water. Herein, MnO@C nanocomposites as efficient adsorbent/photocatalyst materials for the removal of cationic and anionic dyes were synthesized via a simple and new precursor-assisted method. Manganese malonate was prepared and calcined at 350 °C for 1 h under air, argon, and H₂ atmospheres. Pristine MnO was obtained under argon and H₂. The obtained nanocomposites are highly crystalline and have sphere-like shapes as evidenced by TEM, HRTEM, and SAED. EDX analysis demonstrated the presence of C in the prepared samples. The study of the surface texture via the BJH method and V_a-t plots has revealed the presence of both microporous and mesoporous pores. BET surface areas of 22.7 and 50.1 m²/g were found for MnO@C nanocomposites prepared under Ar and H₂, respectively. Removal of MB as a cationic dye from water was explored via adsorption of the dye over the surface of MnO@C nanocomposites. The MnO@C sample prepared under H₂ exhibited the largest removal efficacy, removal of 97% of the dye occurs in 6 h. Furthermore, the MnO@C nanocomposite was utilized as a photocatalyst for removal of the anionic dye, eosin Y. Complete removal of eosin Y color was achieved after exposure to sunlight for 2 h. The mechanism of the photocatalytic degradation of eosin Y was investigated. The possible degradation products were detected through HPLC-UV analysis. The prepared nanocomposite showed good recyclability and even preserving its structure after 4 cycles.

Chitinase, an enzyme that hydrolyzes glycosidic bonds in chitin, holds significant potential for industrial applications, including biological control, antifungal treatments, and antibiofilm strategies. In this study, chitinase derived from Planomicrobium sp. (PP133202) was immobilized onto a cobalt metal-organic framework (Co-MOF), and its properties were extensively analyzed using various biological, chemical, and physical characterization techniques. The microbial source was identified via 16S rRNA sequencing, and enzyme activity was optimized under submerged conditions using Response Surface Methodology (RSM). Structural and morphological characterization of the chitinase/Co-MOF complex was conducted through FTIR, SEM, TEM, XPS, XRD, EDX, and surface area analyses. The encapsulation efficiency and loading capacity were determined to be 42 % and 20 %, respectively. Notably, the immobilized chitinase exhibited a threefold increase in enzymatic activity compared to its free form. Additionally, the chitinase/Co-MOF complex demonstrated enhanced biological control efficacy, effectively inhibiting Tribolium castaneum and multiple pathogenic microorganisms, including Pseudomonas aeruginosa, Aspergillus flavus, Aspergillus terreus, and Beauveria bassiana. These findings highlight the potential of chitinase/Co-MOF as a promising agent for antimicrobial and pest control applications.

Hydrogen gas (H₂) is an environmentally benign and sustainable energy fuel. Because of its high energy content, hydrogen presents a viable clean energy source alternative to fossil fuels and is regarded as a one of the most promising energy sources. In the current investigation, CuWO₄ was applied, for the first time, as an efficient catalyst for the green generation of H₂ from the hydrolysis of NaBH₄. CuWO₄ was fabricated via a co-precipitation assisted hydrothermal method. The synthesized catalyst was characterized by XRD, XPS, VSM, FTIR, SEM, TEM, and nitrogen sorption analyses. XRD and XPS analyses confirmed the successful formation of CuWO₄. It was estimated that, values of hydrogen generation rate (HGR) 818, 1250, 2467, and 2920 ml min⁻¹ g⁻¹ were respectively obtained at reaction temperatures of 28, 35, 40, and 45 °C. According to the pseudo-first-order equation, CuWO₄ have an estimated apparent activation energy of 59.2 kJ mol⁻¹. Thermodynamic parameters like ∆H^#, ∆S^#, and ∆G^# were also calculated. The antibacterial efficacy of CuWO₄ was evaluated against four Gram positive pathogenic strains; Bacillus subtilis, Bacillus cereus, Staphylococcus aureus and Micrococcus luteus with concentration range 0–150 µg ml⁻¹ comparing with chloramphenicol (CHL) antibacterial agent. Minimum inhibitory concentration (MIC) was determined for CuWO₄ and CHL for the four strains. CuWO₄ clear promising antibacterial properties with growth inhibition (%) of 82.79 (49.9 CHL) %, 73.56 (67.89 CHL) %, 61.38 (58.18 CHL) %, and 50.47 (43.4 CHL) % at 150 µg ml⁻¹ of B. subtilis, S. aureus, B. cereus, and Micrococcus luteus, respectively.

Vardenafil (VRE) is one of the most important drugs in the phosphodiesterase 5-inhibitors (PDE5) group. The usage of VRE must be carefully controlled if patients are taking certain medications that interact with it. Hence, to examine this critical need, a novel ternary nanocomposite consisting of conductive acetylene black (CAB) anchored with gold nanoparticles (GNP) (GNP@CAB) incorporated composite pencil graphite paste electrode (CPGPE) was prepared (GNP@CAB/CPGPE) and used for electrochemical detection of VRE drug. The nanostructural and morphological characteristics of GNP@CAB were examined using EDX, HRTEM and TEM techniques. The electrochemical properties of GNP@CAB/CPGPE were analyzed with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). By employing the GNP@CAB/CPGPE electrode, the developed probe exhibited remarkable sensitivity and selectivity using adsorptive stripping square-wave voltammetry (AdS-SWV). The limits of detection and quantification for VRE were calculated to be 4.2 × 10⁻¹¹ M and 1.39 × 10⁻¹⁰ M, respectively. The practicality and reliability of the new electrode to determine the concentration of VRE in its commercial tablets and human biological fluids were achieved with good recoveries. To compare the electroanalytical method with an independent technique, the HPLC method was employed; nonsignificant differences were found between the two methods. Furthermore, for the first time, the interaction between VRE and the antihypertensive drug doxazosin on GNP@CAB/CPGPE was investigated using AdS-SWV. The large values of binding constants (K), ranging from 10⁶ to 10⁷, indicate a strong binding affinity between the two drugs. Additionally, thermodynamic parameters, including Gibbs free energy (ΔG), entropy (ΔS), and enthalpy (ΔH), were evaluated. The results indicate that the interaction between VRE and doxazosin is predominantly hydrophobic, with the binding process being entropy-driven, thermodynamically favorable, and spontaneous.