Cadmium-Sulfide Doped Carbon Nanoflakes Used for Sunlight-Assisted Selective Photodegradation of Indigo Carmine

Abstract

Herein, we have fabricated cadmium-sulfide (CdS)-doped glucose-derived carbon nanoflakes (CNF) via a simple two-step methodology. The as-prepared CdS-doped CNF (CdS-CNF) shows selective photocatalytic activity toward the degradation of organic dye named Indigo Carmine (IC) from the tested nine model organic dyes importantly under the influence of sunlight. The viability of sunlight-promoted photodegradation was supported via comparative half-life (t 1/2) values, which is ∼14 min–1 for sunlight compared to ∼125 min–1 for artificial bulb light. The photodegradation of IC follows pseudo-first-order kinetics, and the rate associated with the sunlight-promoted photodegradation is ∼8 times faster compared to the reaction under artificial bulb light. Based on the trap experiments, the photocatalytic degradation mechanism showed the involvement of superoxide radicals. The photodegradation results are supported via a comparative proton nuclear magnetic resonance and Fourier transform infrared spectroscopic analysis. Additionally, CdS-CNF is used to degrade IC dye from industrially spiked wastewater samples to demonstrate its potential as a photocatalyst for real-life applications.

Melamine–Formaldehyde Polymer-Based Nanocomposite for Sunlight-Driven Photodegradation of Multiple Dyes and Their Mixture

“…The elemental composition, type of chemical binding, and percentage of CdS nanoparticles on the surface of MFP-CdS have been analyzed using XPS analysis, Figure . The characteristic peaks at ∼ 283.5 eV for C 1s , ∼398 eV for N 1s , ∼531 eV for O 1s , ∼404 eV for Cd 3d , and ∼160 eV for S 2p are shown in the XPS full survey scan spectra as shown in Figure a. ,,, The percentage of elemental (atomic %) composition shows that the percentage of C 1s , N 1s , O 1s , Cd 3d , and S 2p is ∼68, ∼15, ∼4, ∼7, and ∼6%, respectively. The weight % of the elements is found to be ∼39.16 for C, ∼10.8% for N, ∼3.07% for O, ∼37.76% for Cd, and ∼9.21% for S. The high-resolution deconvoluted spectrum of C 1s shows four peaks at ∼283.72 eV for CC, ∼284.44 eV for C–C, ∼285.78 eV for N–C–N/N–C–O, and ∼287.10 eV for N–CN, respectively, in Figure b. , The N 1s high-resolution spectrum is fitted in four peaks at ∼397 eV for C–N–C, ∼397.9 eV for CN–C, ∼398.7 eV for pyridinic-N, and ∼399.58 eV for pyrrolic-N, Figure c. ,− The high-resolution deconvoluted spectrum of O 1s is fitted in two peaks at ∼530.61 eV for CO and ∼531.93 eV for C–O, respectively, in Figure d .…”

“…40,62−64 The highresolution deconvoluted spectrum of O 1s is fitted in two peaks at ∼530.61 eV for C�O and ∼531.93 eV for C−O, respectively, in Figure 2d. 40 The Cd 3d high-resolution deconvoluted spectrum shows peaks at ∼404.53 and ∼411.16 eV corresponding to Cd3d 5/2 and Cd3d 3/2 , respectively, Figure 2e. 40,42,65 The high-resolution deconvoluted spectrum of S 2p (Figure 2f) shows three peaks at ∼160.09, ∼160.71, and ∼161.84 attributed to Cd−S2p 3/2 , Cd−S2p 1/2 , and C−S−C, respectively.…”

“…At first, melamine and formaldehyde form the Schiff-base complex, 53,58 and polymerization occurs at 180 °C through a polycondensa- 2a. 40,42,59,60 The percentage of elemental (atomic %) composition shows that the percentage of C 1s , N 1s , O 1s , Cd 3d , and S 2p is ∼68, ∼15, ∼4, ∼7, and ∼6%, respectively. The weight % of the elements is found to be ∼39.16 for C, ∼10.8% for N, ∼3.07% for O, ∼37.76% for Cd, and ∼9.21% for S. The high-resolution deconvoluted spectrum of C 1s shows four peaks at ∼283.72 eV for C�C, ∼284.44 eV for C−C, ∼285.78 eV for N−C−N/N−C−O, and ∼287.10 eV for N−C�N, respectively, in Figure 2b.…”

“…For the photodegradation of organic dyes, different types of nanomaterials have been used; among them, carbon-based nanocomposites have drawn more attention in photocatalysis, such as based on graphene, carbon nanoflakes, carbon dots, aerogels, and carbon nanotube , - nanomaterials. However, polymer-based nanomaterials, specifically, melamine–formaldehyde polymer (MFP) , -based nanocomposite (MFP-CdS) as a photocatalyst, have yet to be explored well for the degradation of organic dyes.…”

Fe3O4 Nanoparticles Synthesized from Waste Iron Dust for Sunlight-Boosted Photodegradation of Nitrophenols and Their Mixtures

“…The real-life assessment of Fe 3 O 4 -NPs was also checked by studying the photodegradation ability of N-PhOHs in various wastewater samples that were collected from tap water (S 1 ), undergraduate laboratory wastewater (S 2 ), and different textile industries (S 3 , S 4 , and S 5 ). After that, 1000 mg L –1 PNP, TNP, and DNP were separately spiked externally in S 1 , S 2 , S 3 , S 4 , and S 5 . − After that, Fe 3 O 4 -NPs and H 2 O 2 were added to the above samples and placed in sunlight illumination for 180 min as shown in Figure S5 (a–c, see the Supporting Information). Figure S6 (see the Supporting Information) shows the C / C 0 vs time plot for PNP, DNP, and TNP.…”