PMID- 27474817
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20161227
LR  - 20161230
IS  - 1095-7103 (Electronic)
IS  - 0021-9797 (Linking)
VI  - 481
DP  - 2016 Nov 1
TI  - Mechanism of highly efficient adsorption of 2-chlorophenol onto ultrasonic 
      graphene materials: Comparison and equilibrium.
PG  - 168-80
LID - S0021-9797(16)30508-2 [pii]
LID - 10.1016/j.jcis.2016.07.049 [doi]
AB  - The deficiencies of the recently reported improved Hummers method for the 
      synthesis of graphene oxide (GO), such as high reaction temperature (60 degrees C) and 
      long reaction time (10h), were successfully solved using a low-intensity 
      ultrasonic bath for 30min at 40 degrees C. Furthermore, compared to its conventional 
      synthesis counterpart, a facile and fast, one-step ultrasonic method that 
      excluded hydrazine hydrate was developed to synthesize reduced GO (rGO) from 
      graphite (10min, 50 degrees C) in the presence of hydrazine hydrate (rGO-C, 12h, 90 degrees C). 
      The adsorption characteristics of 2-chlorophenol (2-CP) from an aqueous solution 
      were investigated using rGOs and GOs prepared by ultrasonic (rGO-Us/GO-Us) and 
      conventional (rGO-C/GO-C) methods. Whereas 2-CP was completely removed with 
      rGO-Us after 50min, only 40% of 2-CP was eliminated with rGO-C. The maximum 
      adsorption capacity of 2-CP calculated by the Langmuir model onto rGO-Us 
      (208.67mg/g) was much higher than that onto GO-Us (134.49mg/g). In addition, the 
      ultrasonic graphene adsorption capacities were much higher than the corresponding 
      values of rGO-C (49.9mg/g) and GO-C (32.06mg/g). The enhanced adsorption for 
      rGO-Us and GO-Us is attributed to their greater surface areas, excellent 
      oxygenated groups for GO-Us and superior pi-electron-rich matrix for rGO-Us, 
      compared to other adsorbents. The adsorption of 2-CP on the rGO materials 
      increased with increasing solution pH to a maximum around its pKa (pKa=8.85), 
      while the adsorption for the GO materials increased with decreasing solution pH. 
      The adsorption mechanism proceeded via hydrogen bonding in neutral and acidic 
      media, but via pi-pi electron donor-accepter (EDA) interactions between 2-CP and 
      graphene materials in basic medium. The FTIR spectrum of GO-Us after adsorption 
      indicates that the position and intensity of many peaks of GO-Us were affected 
      due to the adsorption of different 2-CP groups at different pHs.
CI  - Copyright (c) 2016 Elsevier Inc. All rights reserved.
FAU - Soltani, Tayyebeh
AU  - Soltani T
AD  - Department of Civil and Environmental Engineering, University of Ulsan, Nam-gu, 
      Daehak-ro 93, Ulsan 680-749, Republic of Korea.
FAU - Lee, Byeong-Kyu
AU  - Lee BK
AD  - Department of Civil and Environmental Engineering, University of Ulsan, Nam-gu, 
      Daehak-ro 93, Ulsan 680-749, Republic of Korea. Electronic address: 
      bklee@ulsan.ac.kr.
LA  - eng
PT  - Journal Article
DEP - 20160722
PL  - United States
TA  - J Colloid Interface Sci
JT  - Journal of colloid and interface science
JID - 0043125
SB  - IM
OTO - NOTNLM
OT  - 2-chlorophenol
OT  - Adsorption mechanism
OT  - Graphene oxide
OT  - Reduced graphene oxide
OT  - Ultrasound
EDAT- 2016/07/31 06:00
MHDA- 2016/07/31 06:01
CRDT- 2016/07/31 06:00
PHST- 2016/06/08 00:00 [received]
PHST- 2016/07/19 00:00 [revised]
PHST- 2016/07/20 00:00 [accepted]
PHST- 2016/07/31 06:00 [entrez]
PHST- 2016/07/31 06:00 [pubmed]
PHST- 2016/07/31 06:01 [medline]
AID - S0021-9797(16)30508-2 [pii]
AID - 10.1016/j.jcis.2016.07.049 [doi]
PST - ppublish
SO  - J Colloid Interface Sci. 2016 Nov 1;481:168-80. doi: 10.1016/j.jcis.2016.07.049. 
      Epub 2016 Jul 22.