Influence of Preparation Method on Oxidation Degree of Graphene Oxide and Adsorption for Th (IV) and U(VI)

doi:10.15541/jim20150486

Abstract

Abstract:

Graphene oxide (GO) was prepared from graphite using Hummers' method, improved Hummers' method and modified Hummers' method. The samples were characterized by FT-IR spectroscope, TGA, XRD, XPS,SEM and element analysis. The results showed that graphene oxide was more oxidized prepared by the improved Hummers' method(IGO). The isothermal adsorption experiments of Th(IV) and U(VI) on graphene oxide showed that the maximum adsorption capacity of Th(IV) on IGO was 192.3 mg/g, increased by 38.5% as compared with that of GO prepared by Hummers’ method. The maximum adsorption capacity of U(VI) was 156.2 mg/g, increased by 28.1%. Both of above values are in accord with Langmuir isotherm model. Furthermore, kinetic and thermodynamic parameters of Th (IV) and U(VI) adsorption on IGO were investigated by using batch experiments, confirming that adsorption fits pseudo-second kinetic equations, which are spontaneous and endothermic.

Key words: preparation of graphene oxide, structure, adsorption, Th (IV), U (VI)

CLC Number:

TB34
X591

WANG Xiao-Ning, MENG Hu, MA Fu-Yin, LI Zheng, ZHANG Lan. Influence of Preparation Method on Oxidation Degree of Graphene Oxide and Adsorption for Th (IV) and U(VI)[J]. Journal of Inorganic Materials, 2016, 31(5): 454-460.

Figures/Tables 11

Fig. 1 Infrared spectra (a), TGA curves (b) and XRD patterns (c) of HGO, IGO and MGO

Fig. 2 C1s XPS spectra of (a) HGO, (b) IGO and (c) MGO

Table1 C1s XPS results of HGO, IGO and MGO

	C=C/%	C-O/%	C=O/%	O=C-O/%	C/O*
HGO	54.8	30.8	10.4	4.0	2.36
IGO	49.3	34.1	8.7	7.9	1.91
MGO	53.2	30.4	9.4	7.0	2.14

Table 2 Element analysis results of HGO, IGO and MGO

	C/%	H/%	O/%
HGO	47.72	2.37	49.91
IGO	40.67	2.43	56.90
MGO	41.95	2.40	55.65

Fig. 3 SEM images of graphene oxide (a) HGO, (b) IGO and (c) MGO

Table 3 Parameters for the Langmuir and Freundlich models of U(VI) and Th(IV) sorption

		Langmuir			Freundlich
		Q_max/(mg·g^-1)	K_L/(L·mg^-1)	R²	K_F/(mg^1-ⁿ·Lⁿ·g^-1)	1/n	R²
U(VI)	HGO	121.9	0.3306	0.997	48.11	0.2207	0.972
	IGO	156.2	0.1688	0.994	31.43	0.3987	0.963
	MGO	161.2	0.1294	0.993	32.48	0.3801	0.973
Th(IV)	HGO	138.8	0.4199	0.984	53.54	0.2279	0.973
	IGO	192.3	0.6753	0.991	93.13	0.1786	0.971
	MGO	188.6	0.5773	0.975	61.86	0.2981	0.976

Fig. 4 Adsorption isotherms of U(VI) (a) and Th(IV) (b) on the HGO, IGO and MGO C(GO)=0.3 g/L, C(U)=0.05-0.5 mmol/L, pH=4±0.05 (a) and C (Th)= 0.05-0.5 mmol/L (b), pH=3±0.05, (T=298.15 K, t=12 h)

Fig. 5 Adsorption of Th(IV) and U(VI) on IGO at a function of pH C(GO)=0.4 g/L, C(Th)=0.5 mmol/L, T=298.15 K, t=12 h; C(GO)=0.4 g/L, C(U)= 0.5 mmol/L, T=298.15 K, t=12 h

Fig. 6 The species of U(VI) (a) and Th(IV) (b) in solution

Fig. 7 Effect of contact time (a) and temperature (b) on the Th(IV) and U(VI) adsorption on IGO C(GO)=0.4 g/L,C(Th)=0.5 mmol/L, pH=3±0.05,T=298.15 K; C(GO)= 0.4 g/L,C(U)= 0.5 mmol/L, pH=4±0.05, T=298.15 K

Table 4 Thermodynamic parameters of Th(IV) and U(VI) adsorption on IGO

Temp./K		ΔH⁰/ (kJ•mol^-1)	ΔS⁰/ (J•mol^-1•K^-1)	ΔG⁰/ (kJ•mol^-1)
Th(IV)	300	5.43	92.05	-22.18
	308			-22.92
	318			-23.84
	328			-24.76
	338			-25.68
U(VI)	300	3.23	80.72	-20.98
	308			-21.62
	318			-22.43
	328			-23.24
	338			-24.05

References 16

[1]	CHAPMAN N, HOOPER A.The disposal of radioactive wastes underground.Proceedings of the Geologists Association, 2012, 123(1): 46-63.
[2]	EJNIK J W, TODOROV T I, MULLICK F G, et al.Uranium analysis in urine by inductively coupled plasma dynamic reaction cell mass spectrometry.Analytical &Bioanalytical Chemistry, 2005, 382(1): 73-79.
[3]	LIAO XUE-PIN, LU ZHONG-BI, DU XIAO, et al.Collagen fiber immobilized Myricarubra tannin and its adsorption to UO22+.Environmental Science & Technology, 2004, 38(1): 324-328.
[4]	YAKOUT S M, METWALLY S S, EL-ZAKLA T.Uranium sorption onto activated carbon prepared from rice straw: competition with humic acids.Applied Surface Science, 2013, 280(8): 745-750.
[5]	FASFOUS I I, DAWOUD J N.Uranium (VI) sorption by multiwalled carbon nanotubes from aqueous solution.Applied Surface Science, 2012, 259(2): 433-440.
[6]	ZHAO GUI-XIA, LIJIA-XING, RENXUE-MEI, et al.Few-layered graphene oxide nanosheets as superior sorbents for heavy metal ion pollution management.Environmental Science & Technology, 2011, 45(24): 10454-10462.
[7]	ZHAO GUI-XIA, REN XUE-MEI, GAO XING, et al.Removal of Pb(II) ions from aqueous solutions on few-layered graphene oxide nanosheets.Dalton Transactions, 2011, 40(41): 10945-10952.
[8]	LIAN PEI-CHAO, ZHU XUE-FENG, LIANG SHU-ZHAO, et al.Large reversible capacity of high quality graphene sheets as an anode material for lithium-ion batteries.Electrochimica Acta, 2010, 55(12): 3909-3914.
[9]	LI YAN, WANG CHUN-LI, GUOZHI-JUN, et al.Sorption of thorium(IV) from aqueous solutions by graphene oxide.Journal of Radio Analytical& Nuclear Chemistry, 2014, 299.
[10]	ZHAO GUI-XIA, WEN TAO, YANG XIN, et al.Preconcentration of U(VI) ions on few-layered graphene oxide nanosheets from aqueous solutions.Dalton Transactions, 2012, 41(20): 6182-6188.
[11]	YANG SHUANG, LI LING-YUN, PEI ZHI-GUO, et al.Effects of humic acid on copper adsorption onto few-layer reduced graphene oxide and few-layer graphene oxide.Carbon, 2014, 75(10): 227-235.
[12]	WANG XIANG-XUE, CHENZHONG-SHAN, YANGSHU-BING.Application of graphene oxides for the removal of Pb(II) ions from aqueous solutions: Experimental and DFT calculation. Journal of Molecular Liquids, 2015, 211: 957-964.
[13]	DANIELAC MARCANO, DMITRYV KOSYNKIN, JACOB M.BERLIN, et al. Improved synthesis of grapheneoxide.ACS Nano, 2010(4): 4806-4814.
[14]	PENG CHENG, HU WEN-BIN, ZHOU YUN-TAO, et al.Intracellular imaging with a graphene-based fluorescent probe.Small, 2010, 6(15): 1686-1692.
[15]	SHEN JIAN-FENG, HU YI-ZHE, SHI MIN, et al. Fast and facile preparation of graphene oxide and reduced graphene oxide nanoplatelets.Chemistry of Materials, 2009(15): 3514-3520.
[16]	MOO J G S, KHEZRI B, WEBSTER R D, et al. Graphene oxides prepared by Hummers’, Hofmann’s, and Staudenmaier’s methods:Dramatic Influences on Heavy-Metal-Ion Adsorption. Chemphyschem, 2014, 15(14): 2922-2929.