[RETRACTION] Graphene Oxide/Zinc Oxide (GO/ZnO) Nanocomposite as a Superior Photocatalyst for Degradation of Methylene Blue (MB)-Process Modeling by Response Surface Methodology (RSM)

Abstract

The photocatalytic performance of graphene oxide/zinc oxide (GO/ZnO) nanocomposite was investigated for degradation of methylene blue (MB) from wastewater and was compared with that of zinc oxide (ZnO), graphene oxide (GO) and carbon nanotube/zinc oxide (CNT/ZnO). The properties of the GO/ZnO nanocomposite were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM and TEM results revealed the nanostructure of the composite. The photocatalytic process was modeled by response surface methodology (RSM), considering four independent factors. The significance of the model was approved by analysis of variance (ANOVA) (determination coefficient R² = 0.95, R²_adj = 0.91). The optimum conditions of the process were found to be at photocatalyst dosage, initial pH, H₂O₂ concentration and irradiation time of 2.1 g L^-1, 4.5, 3.5 × 10^-4 mol L^-1 and 140 min, respectively. The removal of MB over GO/ZnO was 99% under the optimum conditions and was superior than that over GO and CNT/ZnO. According to Pareto analysis of the modeling, the irradiation time and photocatalyst dosage were the most effective factors on the decolorization efficiency of methylene blue, respectively.

Keywords:
photocatalyst; nanocomposite; graphene oxide; response surface methodology; dye removal

The Editorial Team of the Journal of the Brazilian Chemical Society (JBCS) announces the formal retraction of the following article: Hosseini, S. A.; Babaei, S. Graphene Oxide/Zinc Oxide (GO/ZnO) Nanocomposite as a Superior Photocatalyst for Degradation of Methylene Blue (MB) - Process Modeling by Response Surface Methodology (RSM), J. Braz. Chem. Soc. 2017, 28(2), 299-307 (https://doi.org/10.5935/0103-5053.20160176).

This article is being retracted due to evidence of image manipulation in Figure 1 (FTIR spectra), which was neither described nor justified in the Experimental section. The manipulation was confirmed by two independent experts: one with subject-matter expertise in the article’s scientific field, and another specialized in image analysis. Multiple attempts were made by the Editorial Team to obtain the original raw data or a reproducible set of experimental results to validate the figure. However, the authors did not provide the requested materials, and the corresponding author ceased responding to further communications.

Although the corresponding author opposed the retraction, no original data were submitted to support a potential correction. Had the raw data been provided and verified, a corrigendum could have been considered instead of a retraction.

The JBCS is a signatory of the Committee on Publication Ethics (COPE) and adheres to its core practices. All procedures related to this case were conducted in accordance with COPE guidelines, including providing the authors with a full opportunity to respond to the concerns raised. All deadline extension requests made by the authors in order to locate and submit the original data for verification were granted.

The Editor-in-Chief followed the entire process and approved the retraction decision, in accordance with the journal’s editorial and ethical guidelines.

This measure aims to preserve the reliability of the scientific record and maintain the journal’s commitment to responsible and ethical publishing.

Publication Dates

• Publication in this collection
  Feb 2017

History

• Received
  17 Mar 2016
• Published
  9 June 2016
• Retracted
  29 June 2025