RETRACTED: Synthesis, Characterization and Photodegradation Studies of Copper Oxide–Graphene Nanocomposites

Abstract

In this work, a simple hydrothermal method was employed to prepare a pristine sample of copper oxide (CuO) and three samples of copper oxide–graphene nanocomposites (CuO-xG) with x = 2.5, 5, and 10 mg of graphene. The synthesized samples were characterized using X-ray powder diffractometry (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV-Vis) spectroscopy. The XRD patterns of CuO-xG nanocomposites exhibited the diffraction peaks related to the crystal planes of monoclinic CuO and hexagonal graphite. The surface morphology of the prepared samples was investigated using FESEM images. EDX analysis was used to investigate the chemical composition of the synthesized samples. FTIR spectroscopy identified the vibrational modes of the covalent bonds present in the samples. The allowed direct optical bandgap energy was calculated for all prepared samples using UV-Vis absorption spectra. The small bandgap of CuO-xG nanocomposites indicates their potential use as an effective photocatalyst in the presence of visible light. Photocatalytic activity of the samples was explored for the degradation of methylene blue (MB) dye contaminant under visible light irradiation. The results showed that the CuO-5G sample has the highest photodegradation efficiency (~56%).

RETRACTED: Raya et al. Synthesis, Characterization and Photodegradation Studies of Copper Oxide–Graphene Nanocomposites. Coatings 2021, 11, 1452

“…The Coatings Editorial Office retracts the article, "Synthesis, Characterization and Photodegradation Studies of Copper Oxide-Graphene Nanocomposites" [1].…”

“…Following the publication, concerns were brought to the attention of the Editorial Office regarding issues related to the accuracy of the authorship list, the origin of the reported study, and the relevancy of the references in [1], as cited above.…”

“…Furthermore, the Editorial Board judged that a significant portion of the literature cited was not sufficiently relevant to this publication and thus does not comply with MDPI's Citation Policies (https: //www.mdpi.com/ethics#_bookmark20, accessed on 7 May 2024). As a result, the Editorial Board has lost confidence in the integrity of the findings and decided to retract this publication [1], as per MDPI's Retraction Policy (https://www.mdpi.com/ethics#_bookmark30 (accessed on 7 May 2024)) and in line with the Committee on Publication Ethics Retraction Guidelines (https://publicationethics.org/retraction-guidelines (accessed on 7 May 2024)).…”