Convenient conversion of hazardous nitrobenzene derivatives to aniline analogues by Ag nanoparticles, stabilized on a naturally magnetic pumice/chitosan substrate
Authors: Kobra Valadi
Ahmed Esmail Shalan
Ali Maleki
Seyedeh Shadi Mirmohammadi
Reza Taheri-Ledari
Journal: RSC Advances (2020)
Discipline: CHEMISTRY
Keywords: silver nanoparticles; reduction process; nitrobenzene derivatives; aniline derivatives; magnetic substrate
Affiliations: Catalysts and Organic Synthesis Research Laboratory, Central Metallurgical Research and Development Institute (CMRDI)

Abstract:  Herein, silver nanoparticles (Ag NPs), as an effective catalyst for the reduction process of nitrobenzene derivatives to non-hazardous and useful aniline derivatives, are conveniently synthesized on an inherently magnetic substrate. For this purpose, an efficient combination of volcanic pumice (VP), which is an extremely porous igneous rock, and a chitosan (CTS) polymeric network is prepared and suitably used for the stabilization of the Ag NPs. High magnetic properties of the fabricated Ag@VP/CTS composite, which have been confirmed via vibrating-sample magnetometer (VSM) analysis, are the first and foremost advantage of the introduced catalytic system since it gives us the opportunity to easily separate the particles and perform purification processes. Briefly, higher yields were obtained in the reduction reactions of nitrobenzenes (NBs) under very mild conditions in a short reaction time. Also, along with the natural biocompatible ingredients (VP and CTS) in the structure, excellent recyclability has been observed for the fabricated Ag@VP/CTS catalytic system, which convinces us to do scaling-up and suggests the presented system can be used for industrial applications. 

Retracted: No

PubPeer comments:
 Figure 6a. appearance of crop marks shadow boxes within the gel ![file] , 
 Figure 7a. appearance of crop marks![file] shadow boxes within the gel , 
 Figure 9 panel a and e (marked in blue boxes) represent different treatment groups but the pictures show unusual similarity![file] , 
 Additional concerns about Figures 6 and 7. * In addition to the possible splice marks, bands appear to be visible multiple times within the same blots, or between blots. Shown with colored arrows. ![file] , 
 Concern about Figure 8. Panels C ( SFN (80 mg kg BW) + Ar: minimal DNA damage ) and D ( SFN alone: no DNA damage ) appear to show an area of overlap. Shown with pink boxes. Image made lighter to bring out details. ![file] , 
 Figure 9, revisited. * As pointed out by Lottia Cassis in #3, panels a (Control rats) and e (SFN alone rats) appear to be identical. This is remarkable, especially since the figure legend states:  treated rats show tissue appearance similar to controls . * In addition, panels b and c appear to be identical as well, if one of the two is rotated 180 degrees. Shown with green boxes. Both are labeled as Ar-treated rats, so this might be OK. However, it is confusing to show the same tissue twice, assuming there were multiple rats in each group. ![file] , 
 Concern about Figure 10. * Panel a (control rats) and panel e (rats treated with SFN alone) appear to be identical if one of the two panels is rotated 180 degrees. Shown with blue boxes. This is of note, since the authors state:  Rats treated with SFN alone: renal tissue histology similar to control was observed - I do not disagree with the observed similarity. ![file] , 
 #3 And panel C is panel B rotated 180 degrees, it looks like. , 
 Last but not least, Figure 11 appears to have some repetitive features too. The orange square is part of the original figure, but the other colored boxes are showing unexpected similarities within or between the four panels. ![file] , 
 #9: To put it another way - Quasi-symmetry in (a) and (c). ![file] (d) is less symmetric, but still reminiscent of (a): ![file] , 
 #9 The panels of Fig 11 also appear as Fig 14 of [Thangapandiyan et al (2018)] . Though there, instead of representing  Effect of **SFN** on **Ar**-induced changes in **podocytes** by electron microscopy study of control and experimental rats. In the control and SFN groups, the ultrastructure of podocytes was normal (a, d). Ar-treated group showed severe degenerative changes including dilated cisternae of endoplasmic reticulum (CS), mitochondrial swelling (M), and degeneration of the nucleolus (NL) were observed in podocytes of the kidney as compared with controls (b). Preadministration of SFN was effective in preventing all pathological changes compared with controls and rats treated with SFN alone (c) they represent  Effect of **EGCG** on **Fl** induced ultra changes in the hippocampus by transmission of electron microphotographs in the hippocampus of control and experimental animals (au2013d). a Control rats: normal **neurons** are shown condensed, regularly shaped, round nucleous (N) and nucleoulus (NL) in normal cells. b EGCG-treated rats: the ultrastructure of cytoplasm (CP) and cytoplasmic organelles showed a normal appearance of nucleous (N), mitochondria (M), and nucleoulus (NL). c Fl-treated rats: disintegrating neuron containing shrunken cytoplasm (SC), slightly dilated cisternae (DC) of endoplasmic reticulum and swollen mitochondria (SM) were observed. Typical necrotic neurons had smaller clumps of irregularly shaped, condensed chromatin with nuclear membrane breakdown. d Fl-treated rats with EGCG: EGCG treatment was effectively preventing the abovementioned findings, compared to control (NL: nucleolus, N: nucleus, CP: cytoplasm, DC: dilated cisternae SC: shrunken cytoplasm, SM: swollen mitochondria (scale bars, 1 u03bcm) ![] ,