Silver functionalized gC3N4: Photocatalytic potency for chromium(VI) reduction, and evaluation of the antioxidant and antimicrobial properties

Ajiboye, Timothy O.; Imade, Emmanuel Edoghogho; Oyewo, Opeyemi A.; Onwudiwe, Damian C.

doi:10.1016/j.jphotochem.2022.114107

Cited by 12 publications

(6 citation statements)

References 73 publications

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“…At acidic pH, Cr(VI) exists in the form of oxyanions such as dichromate (Cr 2 O 7 –2 ) and hydrogen dichromate (HCrO 4 – ) in the solution, and the reduction reaction proceeds as per eqs and . While in an alkaline medium (pH ≥ 6), Cr(VI) exists in the form of CrO 4 2– . , In acidic conditions, the existence of positively charged H + enhances the electrostatic interaction between Cr 2 O 7 –2 and HCrO 4 – species and the catalyst’s surface . This resulted in the improved photo-reduction ability of the 10N- g -CDs/PCN catalyst in acidic pH.…”

Section: Resultsmentioning

confidence: 99%

“…While in an alkaline medium (pH ≥ 6), Cr(VI) exists in the form of CrO 4 2− . 44,45 In acidic conditions, the existence of positively charged H + enhances the electrostatic interaction between Cr 2 O 7 −2 and HCrO 4 − species and the catalyst's surface. 46 This resulted in the improved photo-reduction ability of the 10N-g-CDs/PCN catalyst in acidic pH.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Nitrogen-Doped Graphitic Carbon Dots Embedded in Carbon Nitride Scaffolds for Water Decontamination

Bhoyar

Saraswat

Jyothirmai

et al. 2023

ACS Appl. Nano Mater.

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Functionalized carbon dots (CDs) exhibit intriguing photo-exciton dynamics. CDs can donate or accept electrons depending on their functional groups and electrostatic characteristics. We exploited the electron-accepting capability of nitrogendoped graphitic carbon dots (N-g-CDs) to improve the chargecarrier separation of the polymeric carbon nitride (PCN) photocatalyst. L-Aspartic acid pyrolyzed at 320 °C yielded ∼25 nm size N-g-CDs that were embedded with PCN. The in-plane infiltration of nanosized N-g-CDs increased the surface area of PCN from 11.5 to 104.9 m 2 g −1 . The N-g-CDs/PCN hybrid catalyst tested for photocatalytic chromium reduction evidenced about a 3-fold higher rate than PCN. Also, the antibiotic tetracycline and rhodamine B dye rapidly degraded with faster degradation kinetics. The carrier dynamic analysis and computational investigations suggest that the electron acceptor feature of N-g-CDs governs the effective separation of photo-excitons and the high surface area of N-g-CDs/PCN contributes to photoactivity enhancement. This study offers insights into designing high-performance metal-free photocatalysts for water treatment applications.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Nitrogen-Doped Graphitic Carbon Dots Embedded in Carbon Nitride Scaffolds for Water Decontamination

Bhoyar

Saraswat

Jyothirmai

et al. 2023

ACS Appl. Nano Mater.

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“…The two peaks at 2 theta values of 13.2 • and 27.5 • emanated from the graphitic carbon nitride and are indexed to the (100) and (002) planes, respectively (Figure 1a). The (100) peak is ascribed to the in-planar structural packing of tris-s-triazine, while the (002) peak is because of the interlayer stacking of the aromatic conjugated systems [7,[32][33][34]. Apart from the peaks indexed for the graphitic carbon nitride, other major peaks in the pattern indexed to (202), (−204), (−112), (−403), (−312), (311), (−514), and (−316) planes corresponded to the base-centred monoclinic structure (JCPDS card No_01-073-1202, space group C2/m (12) (Figure 1b).…”

Section: X-ray Diffraction (Xrd) Studiesmentioning

confidence: 99%

“…As shown in (Figure 8a,b), the rate and percentage of the photocatalytic reduction of Cr(VI) were found to be 0.0076 min −1 and 41.98%, respectively, when the pristine Cu 3.21 Bi 4.79 S 9 was used as the photocatalyst, while they were 0.0286 min −1 and 78.57%, respectively, when the graphitic carbon nitride and the nanocomposite were used as the photocatalysts. The more than three-fold increase could be due to the polymeric nature of graphitic carbon nitride and its ability to adsorb Cr(VI) better than the Cu 3.21 Bi 4.79 S 9 photocatalyst [7,33,47]. Due to its better adsorption property, the photocatalytic performance was higher when graphitic carbon nitride was used as the photocatalyst [48,49].…”

Section: Photocatalytic Investigationsmentioning

confidence: 99%

“…Another characteristic absorption maximum appeared at 394 nm, and it is attributed to the π − π* transition of conjugated heterocyclic aromatic components of graphitic carbon nitride (Figure5a). This transition also accounts for the pale-yellow colouration of graphitic carbon nitride[33,40]. The maximum absorption for Cu 3.21 Bi 4.79 S 9 was found at 218 nm, unlike in the non-fractional phase (Cu 3 BiS 3 ), whose absorption maximum was reported to be at 468 nm[27].…”

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Photocatalytic Reduction of Hexavalent Chromium Using Cu3.21Bi4.79S9/g-C3N4 Nanocomposite

et al. 2022

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The photocatalytic reduction of hexavalent chromium, Cr(VI), to the trivalent species, Cr(III), has continued to inspire the synthesis of novel photocatalysts that are capable of achieving the task of converting Cr(VI) to the less toxic and more useful species. In this study, a novel functionalized graphitic carbon nitride (Cu3.21Bi4.79S9/gC3N4) was synthesized and characterized by using X-ray diffraction (XRD), thermogravimetry analysis (TGA), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), and scanning electron microscope (SEM). The composite was used for the photocatalytic reduction of hexavalent chromium, Cr(VI), under visible light irradiation. A 92.77% efficiency of the reduction was achieved at pH 2, using about 10 mg of the photocatalyst and 10 mg/L of the Cr(VI) solution. A pseudo-first-order kinetic study indicated 0.0076 min−1, 0.0286 min−1, and 0.0393 min−1 rate constants for the nanoparticles, pristine gC3N4, and the nanocomposite, respectively. This indicated an enhancement in the rate of reduction by the functionalized gC3N4 by 1.37- and 5.17-fold compared to the pristine gC3N4 and Cu3.21Bi4.79S9, respectively. A study of how the presence of other contaminants including dye (bisphenol A) and heavy-metal ions (Ag(I) and Pb(II)) in the system affects the photocatalytic process showed a reduction in the rate from 0.0393 min−1 to 0.0019 min−1 and 0.0039 min−1, respectively. Finally, the radical scavenging experiments showed that the main active species for the photocatalytic reduction of Cr(VI) are electrons (e−), hydroxyl radicals (·OH−), and superoxide (·O2−). This study shows the potential of functionalized gC3N4 as sustainable materials in the removal of hexavalent Cr from an aqueous solution.

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Synthesis and characterization of polysiphonia/cerium oxide/nickel oxide nanocomposites for the removal of toxins from contaminated water and antibacterial potential

Alarfaj,

Al Musayeib,

Amina

et al. 2024

Environ Sci Pollut Res

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Silver functionalized gC3N4: Photocatalytic potency for chromium(VI) reduction, and evaluation of the antioxidant and antimicrobial properties

Cited by 12 publications

References 73 publications

Nitrogen-Doped Graphitic Carbon Dots Embedded in Carbon Nitride Scaffolds for Water Decontamination

Nitrogen-Doped Graphitic Carbon Dots Embedded in Carbon Nitride Scaffolds for Water Decontamination

Photocatalytic Reduction of Hexavalent Chromium Using Cu3.21Bi4.79S9/g-C3N4 Nanocomposite

Synthesis and characterization of polysiphonia/cerium oxide/nickel oxide nanocomposites for the removal of toxins from contaminated water and antibacterial potential

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