Synthesis and Characterization of MWCNT-COOH/Fe3O4 and CNT-COOH/Fe3O4/NiO Nanocomposites: Assessment of Adsorption and Photocatalytic Performance

Abstract

In this study the adsorption and photodegradation capabilities of modified multi-walled carbon nanotubes (MWCNTs), using tartrazine as a model pollutant, is demonstrated. MWCNT-COOH/Fe3O4 and MWCNT-COOH/Fe3O4/NiO nanocomposites were prepared by precipitation of metal oxides in the presence of MWCNTs. Their properties were examined by X-ray diffraction in powder (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, synchrotron-based Scanning PhotoElectron Microscopy (SPEM), and Brunauer-Emmett-Teller (BET) analysis. It was found that the optimal adsorption conditions were pH 4 for MWCNT-COOH/Fe3O4 and pH 3 for MWCNT-COOH/Fe3O4/NiO, temperature 25 °C, adsorbent dose 1 g L−1, initial concentration of tartrazine 5 mg L−1 for MWCNT-COOH/Fe3O4 and 10 mg L−1 for MWCNT-COOH/Fe3O4/NiO and contact time 5 min for MWCNT-COOH/Fe3O4/NiO and 15 min for MWCNT-COOH/Fe3O4. Moreover, the predominant degradation process was elucidated simultaneously, with and without simulated sunlight irradiation, using thermal lens spectrometry (TLS) and UV–Vis absorption spectrophotometry. The results indicated the prevalence of the photodegradation mechanism over adsorption from the beginning of the degradation process.

The Antibacterial Properties of Nanocomposites Based on Carbon Nanotubes and Metal Oxides Functionalized with Azithromycin and Ciprofloxacin

“…The MWCNT functionalized with COOH groups and MWCNT-COOH/Fe 3 O 4 nanocomposites were synthesized according to the methods published in our previous papers [ 33 , 34 , 35 ].…”

“…The synthesis of MWCNT-COOH/Fe 3 O 4 /NiO has been reported previously [ 34 ]. To obtain the MWCNT-COOH/Fe 3 O 4 /CuO nanocomposite, a similar synthesis chain was performed as follows: the mixture of CNT-COOH/Fe 3 O 4 was sonicated for 30 min in water at a ratio of 1.66:1 ( w / v ).…”

Exploring the Enigma: Decoding the Mystery behind Noiselike Patterns in Thermal Lens Signal

“…Though TL spectroscopy has emerged as a potential nondestructive evaluation technique since 1964, the fluctuations superimposed on the TL signal remained as a matter of curiosity that were considered as noise. But when we started analyzing the TL signal using single and dual beam experimental set up under diverse environmental conditions, including media of varying viscosity, , different categories of nanoparticles, ,, porous materials, biological samples, , and oils, , using time series and complex network, we could understand that it is not noise, but carry information regarding the particle or molecular dynamics of the medium. The present work is a comprehensive and confirmative study to disprove the notion of considering the superimposed fluctuations in the TL signal as noise.…”

Electrochemical Detection of Cd2+, Pb2+, Cu2+ and Hg2+ with Sensors Based on Carbonaceous Nanomaterials and Fe3O4 Nanoparticles

“…While the synthesis process was carefully controlled to ensure the formation of Fe 3 O 4 nanoparticles, the focus of this research was on the development and application of nanocomposites and the synthesis method for Fe 3 O 4 nanoparticles was based on established protocols [ 67 , 68 ].…”