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This study synthesized NiAl-layered double hydroxide (LDH)/Cu-MOF photocatalyst using a simple impregnation method involving NiAl-LDH and Cu-MOF. The successful synthesis was confirmed through Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta potential measurements, thermogravimetric analysis (TGA), ultraviolet diffuse reflectance spectroscopy (UV-DRS), N2 adsorption at −196 °C, and electrochemical impedance spectroscopy (EIS). Photocatalysts based on NiAl-LDH, Cu-MOF, and NiAl-LDH/Cu-MOF were used to remove methyl orange (MO) dye from contaminated water. The impact of various factors, including pH, dye concentration, and photocatalyst amount, on MO degradation efficiency was assessed. FTIR analysis was conducted both before and after dye degradation. The optimal degradation conditions were a photocatalyst dose of 25 mg and a pH of 3. Kinetic studies indicated that the degradation of MO dye onto NiAl-LDH/Cu-MOF followed a pseudo-first-order and an L–H or Langmuir–Hinshelwood model. The value of R2 = 0.94 confirms the validity of pseudo-first-order and Langmuir–Hinshelwood (L–H) kinetic models for the photocatalytic degradation of MO dye. This study highlights the importance of developing novel photocatalysts with improved degradation efficiency to protect the water environment. Antibacterial activity was also performed with antibacterial sensibility testing by disk diffusion to determine minimal inhibitory and bactericidal concentrations. In short, NiAl-LDH/Cu-MOF can be helpful for various biomedical and industrial applications. [ABSTRACT FROM AUTHOR]

Enzyme immobilization can offer a range of significant advantages, including reusability, and increased selectivity, stability, and activity. In this work, a central composite design (CCD) of experiments and response surface methodology (RSM) were used to study, for the first time, the L‐asparaginase (ASNase) immobilization onto functionalized carbon xerogels (CXs). The best results were achieved using CXs obtained by hydrothermal oxidation with nitric acid and subsequent heat treatment in a nitrogen flow at 600 °C (CX−OX‐600). Under the optimal conditions (81 min of contact time, pH 6.2 and 0.36 g/L of ASNase), an immobilization yield (IY) of 100 % and relative recovered activity (RRA) of 103 % were achieved. The kinetic parameters obtained also indicate a 1.25‐fold increase in the affinity of ASNase towards the substrate after immobilization. Moreover, the immobilized enzyme retained 97 % of its initial activity after 6 consecutive reaction cycles. All these outcomes confirm the promising properties of functionalized CXs as support for ASNase, bringing new insights into the development of an efficient and stable immobilization platform for use in the pharmaceutical industry, food industry, and biosensors. [ABSTRACT FROM AUTHOR]

In this study, a novel terpolymer was successfully obtained via the polycondensation polymerization of p-phenylenediamine and 2-aminothiazole with formaldehyde, employing dimethylformamide as a catalyst. The molar ratio of 1:1:2 for the reacting monomers yielded the newly devised p-phenylenediamine-2-aminothiazole-formaldehyde (P2ATF) terpolymer. Subsequently, the terpolymer was utilized as a ligand to form a copper complex by combining it with Cu2+ ions. To check the structure of both the terpolymer and its copper complex, a comprehensive array of techniques like Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, nuclear magnetic resonance, and elemental analysis were employed. Gel permeation chromatography was employed to determine the average terpolymer molecular weight. The surface characteristics of the terpolymer and its metal complex were investigated using scanning electron microscopy, providing insights into their morphology. Furthermore, the thermal properties of the terpolymer and its metal complex were examined using thermogravimetric analysis, allowing for an assessment of their thermal breakdown behavior. They also were subjected to biological evaluations against a diverse range of microorganisms, encompassing Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus niger. The findings from these assessments provide valuable insights into the potential biological activities of both the ligand and its complex, enhancing our understanding of their potential applications. [ABSTRACT FROM AUTHOR]

This study introduces a new strategy for the environmentally friendly catalytic degradation of Reactive Red 24 (RR24) dye using sunlight. We developed a cost-effective quaternary nanocomposite by immobilizing a sodium alginate biopolymer over bioengineered Co-Zn-Ce nanoparticles, forming an SA@Co–Zn–Ce nanocomposite (where SA means sodium alginate). This composite also demonstrated an exceptional antioxidant potential of approximately 89%, attributed to the synergistic effect of sodium alginate and green-synthesized Co–Zn–Ce nanoparticles (biosynthesized using Ocimum sanctum leaf extract as a reducing agent). Scanning electron microscopy revealed grain sizes of 28.6 nm for Co–Zn–Ce NPs and 25.59 nm for SA@Co–Zn–Ce nanocomposites (NCs). X-ray diffraction showed particle sizes of 16.87 nm and 15.43 nm, respectively. Co–Zn–Ce NPs exhibited a zeta potential of 1.99 mV, whereas the sodium alginate-anchored Co–Zn–Ce showed −7.99 mV. This indicated the entrapment of negatively charged ions from sodium alginate, altering the surface charge characteristics and enhancing the photocatalytic degradation of RR24. Dynamic light scattering revealed an average particle size of approximately 81 nm for SA@Co–Zn–Ce NCs, with the larger size due to the influence of water molecules in the colloidal solution affecting hydrodynamic diameter measurement. The SA@Co–Zn–Ce NCs exhibited a CO2 adsorption capacity of 3.29 mmol/g at 25 °C and 4.76 mmol/g at 40 °C, indicating temperature-dependent variations in adsorption capabilities. The specific surface area of Co–Zn–Ce oxide NPs, measured using Brunauer–Emmett–Teller (BET) analysis, was found to be 167.346 m2/g, whereas the SA@Co–Zn–Ce oxide nanocomposite showed a surface area of 24.14 m2/g. BJH analysis revealed average pore diameters of 34.60 Å for Co–Zn–Ce oxide NPs and 9.26 Å for SA@Co–Zn–Ce oxide NCs. Although the immobilization of sodium alginate on Co–Zn–Ce oxide NPs did not increase the adsorption sites and porosity of the composite, as evidenced by the N2 adsorption–desorption isotherms, the SA@Co–Zn–Ce oxide NCs still demonstrated a high photocatalytic degradation efficiency of RR24. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the effectiveness of raw chicken feathers (RCFs), NaOH and ethylenediamine-modified chicken feathers (MCFs), and xanthate-modified chicken feathers (XMCFs), treated with both NaOH, ethylenediamine, and carbon disulfide. The physicochemical characteristics of the biosorbents were analyzed using attenuated total reflection Fourier transform infrared spectrophotometry (ATR-FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), adsorption of N2 at −196°C and point of zero charge determination (pHpzc). The biosorption of Cr(VI) using MCFs and XMCFs was evaluated through various parameters, namely, pH, biosorbent amount, and contact time in batch experiments. The results showed a significant increase in the biosorption capacities of MCFs (90.90 mg/g) and XMCFs (100 mg/g) compared to RCFs (52.63 mg/g). The batch adsorption experiments indicated that the optimal conditions for biosorption were pH 2.0, with an equilibrium contact time of 90 min for RCFs, and 60 min for both MCFs and XMCFs. The optimal biosorbent concentrations were 16 g L−1 for RCFs and 12 g L−1 for both MCFs and XMCFs. The biosorption behavior was well described by the Langmuir isotherm and pseudo-second-order kinetic models. The thermodynamic parameters indicated that the biosorption of Cr(VI) onto the biosorbents was a spontaneous and endothermic process. Desorption analysis was carried out using a 0.1 M NaOH solution. [ABSTRACT FROM AUTHOR]

Catalytic transfer hydrogenation (CTH) is a green and efficient pathway for selective hydrogenation of unsaturated aldehydes and ketones. However, managing the abilities of solid catalysts to adsorb substrates and to convert them into desired products is a challenging task. Herein, we report the synthesis of carbon coated LaFe0.92Pd0.08O3 composites (LFPO-8@C) for CTH of benzaldehyde (BzH) into benzyl alcohol (BzOH), using isopropanol (IPA) as hydrogen source. The coating with carbon improves the ability to adsorb/transfer reactants from solution to active sites, and the doping of Pd2+ at Fe3+ site strengthens the ability of LaFeO3 to convert BzH into BzOH. A balanced point between them (i.e., abilities to adsorb BzH and to convert BzH into BzOH) is obtained at LFPO-8@C, which exhibits a BzOH formation rate of 3.88 mmol⋅ggat-1⋅h-1 at 180 °C for 3 h, which is 1.50 and 2.72 times faster than those of LFPO-8 and LaFeO3@C. A reaction mechanism is proposed, in which the acidic sites (e.g., Fe4+, oxygen vacancy) are used for the activation of C=O bond of BzH and O–H bond of IPA, and the basic sites (e.g., lattice oxygen) for the activation of α–H (O–H) bond of IPA. [ABSTRACT FROM AUTHOR]