“…Lone bands situated between 800 and 400 cm −1 frequencies are often a characteristic fingerprint of metaloxide-metal (M-O-M) vibrations. 28 Here, the appearance of an intense peak at 618 cm −1 can be attributed to the presence of M-O stretching vibration of the individual metal oxides (Ni− O, Co−O, and Ni−O). 29 The peaks at 1049, 1332, and 1496 cm −1 represent the planar and stretching vibrations of the entire imidazole ring.…”
Section: ■ Results and Discussionmentioning
confidence: 88%
“…As shown in Figure B, the as-synthesized Ni-Co-Zn exhibited intense IR bands at 618, 1067, 1332, 1384, 1496, 2800/2890, and 3460 cm –1 frequencies. Lone bands situated between 800 and 400 cm –1 frequencies are often a characteristic fingerprint of metal-oxide-metal (M-O-M) vibrations . Here, the appearance of an intense peak at 618 cm –1 can be attributed to the presence of M-O stretching vibration of the individual metal oxides (Ni–O, Co–O, and Ni–O) .…”
Section: Resultsmentioning
confidence: 99%
“…The peak located at 1384 cm –1 is associated with the N–O asymmetric stretching vibration from surface-adsorbed NO 3 – arising from the dissociation of nitrate from the precursor compounds in growth solution . Moreover, the peaks between 2800 and 2890 cm –1 frequencies are commonly attributed to both the symmetric and asymmetric stretching vibrations of C–H bands, while the spectrum between 3460 cm –1 is associated with the stretching and bending mode of O–H bond in water . While the presence of metal-oxide bond is often characterized by a distinct and noticeable peak between 400 and 800 cm –1 , here, the M-O band for the samples occurred at 403 cm –1 and can be noticed by expanding the wavenumber range, as shown in Figure S1. , Moreover, as a result of decarboxylation and dehydroxylation stemming from the thermal annealing process, the functional groups and bonding present in the pristine Ni-Co-Zn tMOF were lost and may account for the absence any conspicuous IR spectra.…”
In
this work, a trimetallic (Ni/Co/Zn) organic framework (tMOF),
synthesized by a solvothermal method, was calcinated at 400 and 600
°C and the final products were used as a support for lipase immobilization.
The material annealed at 400 °C (Ni-Co-Zn@400) had an improved
surface area (66.01 m2/g) and pore volume (0.194 cm3/g), which showed the highest enzyme loading capacity (301
mg/g) with a specific activity of 0.196 U/mg, and could protect the
enzyme against thermal denaturation at 65 °C. The optimal pH
and temperature for the lipase were 8.0 and 45 °C but could tolerate
pH levels 7.0–8.0 and temperatures 40–60 °C. Moreover,
the immobilized enzyme (Ni-Co-Zn@Lipase, Ni-Co-Zn@400@Lipase, or Ni-Co-Zn@600@Lipase)
could be recovered and reused for over seven cycles maintaining 80,
90, and 11% of its original activity and maintained a residual activity
>90% after 40 storage days. The remarkable thermostability and
storage
stability of the immobilized lipase suggest that the rigid structure
of the support acted as a protective shield against denaturation,
while the improved pH tolerance toward the alkaline range indicates
a shift in the ionization state attributed to unequal partitioning
of hydroxyl and hydrogen ions within the microenvironment of the active
site, suggesting that acidic residues may have been involved in forming
an enzyme–support bond. The high enzyme loading capacity, specific
activity, encouraging stability, and high recoverability of the tMOF@Lipase
indicate that a multimetallic MOF could be a better platform for efficient
enzyme immobilization.
“…Lone bands situated between 800 and 400 cm −1 frequencies are often a characteristic fingerprint of metaloxide-metal (M-O-M) vibrations. 28 Here, the appearance of an intense peak at 618 cm −1 can be attributed to the presence of M-O stretching vibration of the individual metal oxides (Ni− O, Co−O, and Ni−O). 29 The peaks at 1049, 1332, and 1496 cm −1 represent the planar and stretching vibrations of the entire imidazole ring.…”
Section: ■ Results and Discussionmentioning
confidence: 88%
“…As shown in Figure B, the as-synthesized Ni-Co-Zn exhibited intense IR bands at 618, 1067, 1332, 1384, 1496, 2800/2890, and 3460 cm –1 frequencies. Lone bands situated between 800 and 400 cm –1 frequencies are often a characteristic fingerprint of metal-oxide-metal (M-O-M) vibrations . Here, the appearance of an intense peak at 618 cm –1 can be attributed to the presence of M-O stretching vibration of the individual metal oxides (Ni–O, Co–O, and Ni–O) .…”
Section: Resultsmentioning
confidence: 99%
“…The peak located at 1384 cm –1 is associated with the N–O asymmetric stretching vibration from surface-adsorbed NO 3 – arising from the dissociation of nitrate from the precursor compounds in growth solution . Moreover, the peaks between 2800 and 2890 cm –1 frequencies are commonly attributed to both the symmetric and asymmetric stretching vibrations of C–H bands, while the spectrum between 3460 cm –1 is associated with the stretching and bending mode of O–H bond in water . While the presence of metal-oxide bond is often characterized by a distinct and noticeable peak between 400 and 800 cm –1 , here, the M-O band for the samples occurred at 403 cm –1 and can be noticed by expanding the wavenumber range, as shown in Figure S1. , Moreover, as a result of decarboxylation and dehydroxylation stemming from the thermal annealing process, the functional groups and bonding present in the pristine Ni-Co-Zn tMOF were lost and may account for the absence any conspicuous IR spectra.…”
In
this work, a trimetallic (Ni/Co/Zn) organic framework (tMOF),
synthesized by a solvothermal method, was calcinated at 400 and 600
°C and the final products were used as a support for lipase immobilization.
The material annealed at 400 °C (Ni-Co-Zn@400) had an improved
surface area (66.01 m2/g) and pore volume (0.194 cm3/g), which showed the highest enzyme loading capacity (301
mg/g) with a specific activity of 0.196 U/mg, and could protect the
enzyme against thermal denaturation at 65 °C. The optimal pH
and temperature for the lipase were 8.0 and 45 °C but could tolerate
pH levels 7.0–8.0 and temperatures 40–60 °C. Moreover,
the immobilized enzyme (Ni-Co-Zn@Lipase, Ni-Co-Zn@400@Lipase, or Ni-Co-Zn@600@Lipase)
could be recovered and reused for over seven cycles maintaining 80,
90, and 11% of its original activity and maintained a residual activity
>90% after 40 storage days. The remarkable thermostability and
storage
stability of the immobilized lipase suggest that the rigid structure
of the support acted as a protective shield against denaturation,
while the improved pH tolerance toward the alkaline range indicates
a shift in the ionization state attributed to unequal partitioning
of hydroxyl and hydrogen ions within the microenvironment of the active
site, suggesting that acidic residues may have been involved in forming
an enzyme–support bond. The high enzyme loading capacity, specific
activity, encouraging stability, and high recoverability of the tMOF@Lipase
indicate that a multimetallic MOF could be a better platform for efficient
enzyme immobilization.
“…However, despite possessing a high reversibility, stability, excellent rate capability, and high specific surface area, supercapacitors exhibit low capacitance 16 – 18 . In contrast, transition metal oxides and conducting polymers like NiO 19 – 21 , ZnO 22 , MnO 2 23 , and Co 3 O 4 24 , are the primary electrode materials in pseudo-capacitor 25 , 26 . Although transition metal oxides showed high capacitance, they are expensive, rare, and have poor rate capability.…”
Supercapacitors have emerged as highly efficient energy storage devices, relying on electrochemical processes. The performance of these devices can be influenced by several factors, with key considerations including the selection of electrode materials and the type of electrolyte utilized. Transition metal oxide electrodes are commonly used in supercapacitors, as they greatly influence the electrochemical performance of these devices. Nonetheless, ferrites' low energy density poses a limitation. Hence, it is crucial to create electrode materials featuring unique and distinct structures, while also exploring the ideal electrolyte types, to enhance the electrochemical performance of supercapacitors incorporating magnesium ferrites (MF). In this study, we effectively prepared magnesium ferrites (MgFe2O4) supported on activated carbon (AC) derived from orange peels (OP) using a simple hydrothermal method. The resulting blends underwent comprehensive characterization employing various methods, including FTIR, XRD, TEM, SEM, EDX, and mapping analysis. Moreover, the electrochemical performance of MgFe2O4@AC composites was evaluated using GCD and CV techniques. Remarkably, the MF45-AC electrode material showed exceptional electrochemical behavior, demonstrating a specific capacitance of 870 F·g−1 within current density of 1.0 A g−1 and potential windows spanning from 0 to 0.5 V. Additionally, the prepared electrodes displayed exceptional cycling stability, with AC, MF, and MF45-AC retaining 89.6%, 94.2%, and 95.1% of their initial specific capacitance, respectively, even after 5000 cycles. These findings underscore the potential of MF-AC composites as superior electrode materials for supercapacitors. The development of such composites, combined with tailored electrolyte concentrations, holds significant promise for advancing the electrochemical performance and energy density of supercapacitor devices.
“…3 c. The peaks corresponding to the binding energies of Cu nanorods are shown at around 1, 8, and 9 keV, while the peak at around 0.5 keV corresponds to the binding energy of O 41 . However, the peaks at about 0.25 keV and between 3 to 3.5 keV signified the binding energies of Ag nanoparticles 42 . Figure 2 FESEM micrographs of ( a ) pure Z, ( b ) 0.005 CAZ, ( c ) 0.01 CAZ, ( d ) 0.05 CAZ, and ( e ) 0.10 CAZ and TEM images and average diameter of CuO nanorod in 0.10 CAZ ( f , g ).…”
Novel CuO/Ag nanocomposites added zeolite (CAZ) were successfully fabricated, and their effectiveness as an antibacterial on S. aureus and MB removal was evaluated. EDX, XRD, and FTIR confirm the presence of the elemental compositions of CAZ. Friable CuO nanorods (10–70 nm in diameter) existed on the surface of the zeolite. Pure zeolite had a higher band gap (5.433 eV) and lower MB removal efficiency than CAZ. The adsorption method by CAZ was more effective at removing MB than photodegradation. 0.10 CAZ had the highest removal effectiveness (~ 99%) and adsorption capacity (~ 70.4 mg g−1) of MB. The inhibitory zone diameter for 0.005 CAZ against S. aureus was 20 mm, while 0.01 CAZ had a diameter of 17 mm. Azithromycin, ceftriaxone, and erythromycin antibiotics demonstrated lower or no efficacy against S. aureus than CAZ. Significant antibacterial activities and wastewater treatment were achieved by CAZ. The combination of photodegradation and adsorption enhanced pollutant removal. It will be interesting to study further the optimal molar ratio for MB removal (0.10 CAZ) in future investigations.
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