Synthesis of TiO2/CuO/GO nanocomposite for the photocatalytic degradation of methylene blue.
Rangel-Contreras, V., Reyes-Vallejo, O. & Subramaniam, V.
Abstract
In this study, the removal of methylene blue from water using photocatalytic treatment with the TiO2/CuO/GO (TCG) nanocomposite under visible light was investigated. All materials, namely TiO2, CuO, GO, and the TCG nanocomposite, were synthesized using the sol–gel, co-precipitation, Tour, and Ball-milling methods, respectively. The material properties, including structural, morphological, compositional, and optical characteristics, were thoroughly analyzed. The XRD results confirm the formation of the tetragonal crystal structure for TiO2, the cubic crystal structure for CuO, and the presence of different phases for the TCG nanocomposite. From the FE-SEM images, grains with semi-spherical, blade-like, rock-like, and fungi-like structures were, respectively, found for TiO2, CuO, GO, and the TCG nanocomposite materials. EDS spectra verify the presence of each element constituting their respective samples. The photocatalytic properties of the TCG nanocomposite were evaluated by varying the dosage (100, 200, 300, 400, and 500 mg, respectively) for the photodegradation of methylene blue. The results reveal that the nanocomposite catalyst exhibits better photocatalytic activity compared to the individual materials due to an enhanced adsorption process and charge transfer. The photodegradation efficiency for MB was 100% after 30 min of irradiation using 500 mg of the composite at pH = 7. The incorporation of CuO and GO into the TiO2 matrix enhanced the absorption of light in the visible region, which, coupled with the large surface area and presence of GO, contributes to removal by adsorption, provoking more efficient MB removal. Holes and superoxide radicals are the reactive chemical species that govern the MB photodegradation process. Finally, adsorption kinetics revealed that the adsorption process occurs by chemisorption and undergoes a multilayer adsorption process, while the photodegradation kinetic fits to pseudo-first-order model.
https://doi.org/10.1007/s10854-024-12986-7