Retracted Article: Tuning the chemistry of graphene oxides by a sonochemical approach: application of adsorption properties
Authors: Yubing Sun
Shubin Yang
Congcong Ding
Zhongxiu Jin
Wencai Cheng
Journal: RSC Advances (2015)
Discipline: CHEMISTRY
Keywords: Graphene oxides; Sonochemical approach; Chemical properties; Ultrasonic time; Adsorption
Affiliations: Institute of Plasma Physics, Chinese Academy of Science, Hefei, P. R. China, School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Faculty of Engineering, King Abdulaziz University, Jeddah 21589

Abstract: The change in the chemical properties of graphene oxides (GOs) can be tuned by the sonochemical approach. The layers of GOs were significantly decreased by the sonochemical approach as seen from high resolution transmission electron microscopy and atomic force microscopy analysis. Abundant hydroxyl groups and carboxyl groups were introduced with increasing ultrasonic time by the analysis of Raman, FTIR, UV-vis absorbance spectroscopy and XPS techniques. The adsorption of U(VI) on GOs significantly increased at pH 1.0–6.0, whereas decreased adsorption was observed at pH > 8.0. The adsorption capacities of GOs increased with increasing ultrasonic time. According to EXAFS analysis, the interaction mechanism between radionuclides and GOs was inner-sphere surface complexation. Such an efficient approach to control the chemical properties of GOs further promotes its applications in environmental cleanup.

Retracted: Yes

PubPeer comments:
 Left:  Figure 1. Characterization of **GO** (...(B) TEM image...) . From  Enhanced Adsorption of Zn(II) onto Graphene Oxides Investigated Using Batch and Modeling Techniques [(Pan et al 2018)] . Right:  Figure 1. HRTEM images (A and B) ... of GO0 and **GO3** . . ![file] I am curious about (1) the nature of the material, and (2) the ownership of the image, since there is no overlap between the authorship lists of these two papers. , 
  Figure 1. ... AFM images (C and D) of GO0 and GO3.  (D) is unexpectedly similar to an enlarged detail from (C), despite the different materials. ![file] , 
 #1 My paper published in 2015, whereas Panu2019s paper published in 2018. I donu2019t know the author how to get this high resolution TEM image. , 
 #2 In fact, GO1 and GO3 have the similar morphology due to the same synthetic method used in this study. , 
 Different samples prepared in the same way may have u201csimilar morphologyu201d, but not exactly identical AFM images. , 
 Top:  Fig. 4 B: EXAFS spectra of U(VI)-reacted GO, pH 4.0, T u00bc 293 K, I u00bc 0.01 mol L1 NaClO4. Bottom:  Figure 4. K2 -weighted U LIII-edge EXAFS spectra (A) and the corresponding Fourier Transforms (B) of the reference and samples before and after desorption, m V = 0.25 g L, C[UO2 2+] = 60.0 mg L, I = 0.01 mol L NaClO4, T = 293 K. From  Adsorption and Desorption of U(VI) on Functionalized Graphene Oxides: A Combined Experimental and Theoretical Study [(Sun et al 2015)] . ![file] Three of the sonochemically-tuned U-bound graphene-variants EXAFS spectra can be matched to the spectrum of a different functionalised graphene. The 4th upper spectrum matches the reference UO22+ spectrum at bottom. ![file] ![file] This in itself is curious. More curious still, the Fourier-transformed versions of these matching spectra do **not** match. The difference between **two** main peaks and **three** main peaks is hard to overlook. I urge the authors to check their data, and their calculations. , 
 #3 Perhaps Pan s group can shed some light on their 2018 acquisition and use of a large TEM image, of which a subsection had previously been published in 2015 by Sun et al. I believe that they have been invited to join the discussion. Pan et al also had access to an SEM image, previously published by Sun et al in [a different 2015 paper] , which only adds to the mystery. , 
  The Royal Society of Chemistry, with the agreement of the named authors, hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data in the published article. The TEM image in Fig. 1B duplicates data published in another publication by Pan et al., but presented as different materials.1 The AFM images in Fig. 1C and D illustrate duplication of data, given that these experiments were reported under different reaction conditions. The EXAFS spectra in Fig. 4 duplicate data in another publication, but reported as different materials.2 Given the number and significance of the concerns about the validity of the data, the findings presented in this paper are no longer reliable. Signed: Yubing Sun, Shubin Yang, Congcong Ding and Wencai Cheng Date: 27th March 2020 Zhongxiu Jin was contacted but did not respond. Retraction endorsed by Laura Fisher, Executive Editor, RSC Advances https: pubs.rsc.org en content articlelanding ra 2020 d0ra90040k ,