A new kind of 3D material, reduced graphene oxide/ascorbic acid hydrogel (rGO/AAH), was used for the first time to recover the complex Au(CN)2− ion from aqueous solution. The as-prepared rGO/AAH was characterised by XRD, FT-IR, SEM and EDS. The experimental results indicate that the adsorption isotherm data of Au(CN)2− on rGO/AAH are well fitted by the Langmuir model, and the obtained maximum saturated adsorption capacity was up to 47.6 mg g−1. The adsorption kinetics was well described by the pseudo-second-order kinetic model, indicating that the overall rate of Au(CN)2− adsorption process is chemically controlled. In addition, the adsorption thermodynamics indicate that the adsorption process is spontaneous and exothermic. It is considered that the hexagonal rings of graphene in the rGO/AAH mainly contribute to the adsorption of the Au(CN)2− complex.
Andre MkhoyanK, ContrymanAW, SilcoxJ, StewartDA, EdaG, MatteviC, MillerS, ChhowallaM.2009. Atomic and electronic structure of graphene-oxide. Nano Lett. 9:1058–1063. doi: 10.1021/nl8034256
2.
Bhattacharyya,KG, SharmaA.2005. Kinetics and thermodynamics of methylene blue adsorption on neem (Azadirachta indica) leaf powder. Dyes Pigments. 65:51–59. doi: 10.1016/j.dyepig.2004.06.016
3.
ChangY-C, ChenD-H.2006. Recovery of gold (III) ions by a chitosan coated magnetic nano-adsorbent. Gold Bull. 39:98–102. doi: 10.1007/BF03215536
4.
FlemingCA, MezeiA, BourricaudyE, CanizaresM, AshburyM.2011. Factors influencing the rate of gold cyanide leaching and adsorption on activated carbon, and their impact on the design of CIL and CIP circuits. Miner Eng. 24:484–494. doi: 10.1016/j.mineng.2011.03.021
5.
FreundlichH.1906. Over the adsorption in solution. J Phys Chem. 57:1100–1107.
6.
GuD, FeinJB.2015. Adsorption of metals onto graphene oxide: surface complexation modeling and linear free energy relationships. Colloid Surf A. 481:319–327. doi: 10.1016/j.colsurfa.2015.05.026
7.
Ho,Y.2000. The kinetics of sorption of divalent metal ions onto sphagnum moss peat. Water Res. 34:735–742. doi: 10.1016/S0043-1354(99)00232-8
8.
HummersWSJr, OffemanRE.1958. Preparation of graphitic oxide. J Am Chem Soc. 80:1339–1339. doi: 10.1021/ja01539a017
9.
HuX, YuY, HouW, ZhouJ, SongL.2013. Effects of particle size and pH value on the hydrophilicity of graphene oxide. Appl Surf Sci. 273:118–121. doi: 10.1016/j.apsusc.2013.01.201
10.
IbradoA, FuerstenauD.1992. Effect of the structure of carbon adsorbents on the adsorption of gold cyanide. Hydrometallurgy. 30:243–256. doi: 10.1016/0304-386X(92)90087-G
11.
JiaY, SteeleC, HaywardI, ThomasK.1998. Mechanism of adsorption of gold and silver species on activated carbons. Carbon. 36:1299–1308. doi: 10.1016/S0008-6223(98)00091-8
12.
LamKF, FongCM, YeungKL.2007. Separation of precious metals using selective mesoporous adsorbents. Gold Bull. 40:192–198. doi: 10.1007/BF03215580
13.
LangmuirI.1918. The adsorption of gases on plane surfaces of glass, mica and platinum. J Am Chem Soc. 40:1361–1403. doi: 10.1021/ja02242a004
14.
McallisterMJ, LiJ-L, AdamsonDH, SchnieppHC, AbdalaAA, LiuJ, Herrera-AlonsoM, MiliusDL, CarR, Prud'hommeRK., 2007. Single sheet functionalized graphene by oxidation and thermal expansion of graphite. Chem Mater. 19:4396–4404. doi: 10.1021/cm0630800
15.
MishraAK, RamaprabhuS.2011. Functionalized graphene sheets for arsenic removal and desalination of sea water. Desalination. 282:39–45. doi: 10.1016/j.desal.2011.01.038
16.
NakajimaA, OheK, BabaY, KijimaT.2003. Mechanism of gold adsorption by persimmon tannin gel. Anal Sci. 19:1075–1077. doi: 10.2116/analsci.19.1075
17.
NuhogluY, MalkocE.2009. Thermodynamic and kinetic studies for environmentally friendly Ni(II) biosorption using waste pomace of olive oil factory. Bioresour Technol. 100:2375–2380. doi: 10.1016/j.biortech.2008.11.016
18.
OkYS, JeonC.2014. Selective adsorption of the gold–cyanide complex from waste rinse water using Dowex 21 K XLT resin. J Ind Eng Chem. 20:1308–1312. doi: 10.1016/j.jiec.2013.07.010
19.
PengW, LiH, LiuY, SongS.2016. Adsorption of methylene blue on graphene oxide prepared from amorphous graphite: effects of pH and foreign ions. J Mol Liq. 221:82–87. doi: 10.1016/j.molliq.2016.05.074
20.
RameshaGK, KumaraAV, MuralidharaHB, SampathS.2011. Graphene and graphene oxide as effective adsorbents toward anionic and cationic dyes. J Colloid Interface Sci. 361:270–277. doi: 10.1016/j.jcis.2011.05.050
21.
Ramirez-MunizK, JiaF, SongS.2012. Adsorption of AsV in aqueous solutions on porous hematite prepared by thermal modification of a siderite – goethite concentrate. Environ Chem. 9:512. doi: 10.1071/EN12120
22.
Ramirez-MunizK, SongS, Berber-MendozaS, TongS.2010. Adsorption of the complex ion Au(CN)2- onto sulfur-impregnated activated carbon in aqueous solutions. J Colloid Interface Sci. 349:602–606. doi: 10.1016/j.jcis.2010.05.056
23.
SchnieppHC, LiJ-L, McallisterMJ, SaiH, Herrera-AlonsoM, AdamsonDH, Prud'hommeRK, CarR, SavilleDA, AksayIA.2006. Functionalized single graphene sheets derived from splitting graphite oxide. J Phys Chem B. 110:8535–8539. doi: 10.1021/jp060936f
24.
SynaN, ValixM.2003. Modelling of gold (I) cyanide adsorption based on the properties of activated bagasse. Miner Eng. 16:421–427. doi: 10.1016/S0892-6875(03)00053-0
25.
TasdelenC, AktasS, AcmaE, GuvenilirY.2009. Gold recovery from dilute gold solutions using DEAE-cellulose. Hydrometallurgy. 96:253–257. doi: 10.1016/j.hydromet.2008.10.006
26.
WangH, YuanX, WuY, HuangH, ZengG, LiuY, WangX, LinN, QiY.2013. Adsorption characteristics and behaviors of graphene oxide for Zn(II) removal from aqueous solution. Appl Surf Sci. 279:432–440. doi: 10.1016/j.apsusc.2013.04.133
27.
XuY, ShengK, LiC, ShiG.2010. Self-assembled graphene hydrogel via a one-step hydrothermal process. ACS Nano. 4:4324–4330. doi: 10.1021/nn101187z
28.
YalcinM, ArolAI.2002. Gold cyanide adsorption characteristics of activated carbon of non-coconut shell origin. Hydrometallurgy. 63:201–206. doi: 10.1016/S0304-386X(01)00203-1
29.
YangX, ChenC, LiJ, ZhaoG, RenX, WangX.2012. Graphene oxide-iron oxide and reduced graphene oxide-iron oxide hybrid materials for the removal of organic and inorganic pollutants. RSC Adv. 2:8821. doi: 10.1039/c2ra20885g
30.
ZhaoG, LiJ, RenX, ChenC, WangX.2011. Few-layered graphene oxide nanosheets as superior sorbents for heavy metal ion pollution management. Environ Sci Technol. 45:10454–10462. doi: 10.1021/es203439v
31.
ZhaoG, RenX, GaoX, TanX, LiJ, ChenC, HuangY, WangX.2011. Removal of Pb(II) ions from aqueous solutions on few-layered graphene oxide nanosheets. Dalton Trans. 40:10945–10952. doi: 10.1039/c1dt11005e
