Supporting information to Facile and efficient synthesis of nitrogen ...
Supporting information to
Facile and efficient synthesis of nitrogen-functionalized graphene oxide as a copper adsorbent and its application Kexin Zhang, Haiyan Li, Xingjian Xu and Hongwen Yu 1. Morphological characteristics of GO/NiO nanocomposites.
Figure S1 TEM image of GO (a) and GO-TETA-MA (b); EDX spectrum of GO-TETA-MA (c). The surface morphology of the GO and GO-TETA-MA was investigated by using TEM. TEM image in Figure S1a provide an intuitive insight into the three dimension structure of GO, the folded or wrinkled sheets, as well as crumpled paper, which is attributed to the difference functional groups between the two sides of GO sheets. Figure S1b shows the TEM image of GO-TETA-MA. From the Figure S1b, it is clear that the organic molecule covered the convoluted surface of platelets and so the surface of GO-TETA-MA are very rough, which indicated that GO could stick into 1
the organics matrix and locally stiffen the interface of the resulting composites. This provides direct evidence of the TETA-MA was grafted successfully onto GO surface. In addtion, EDX can also be used to track the grafting process through the analysis of the surface element contents. A representative EDX of GO-TETA-MA is shown in Figure S1c, the presence of C, O, and N at GO-TETA-MA surface is confirmed by the signal of above elements, which proves that the TETA-MA chains is grafted onto the surface of the GO sheets. The presence of copper (Cu) relating to the copper grid.
2. Comparison of adsorption capacity for Cu(II) between GO and GO-TETA-MA
Figure S2 Adsorption capacity of Cu (II) on GO and GO-TETA-MA.
To demonstrate the potential application of the obtained GO-TETA-MA as an adsorbent for heavy metal ions, Cu(II) were chosen to evaluate their affinity to the GO-TETA-MA, with GO as controls. Figure S2 shows the maximum adsorption capacity of two adsorbents towards Cu(II). As is obvious in Figure S2, the maximum 2
Cu(II) removal values were 0.5 and 0.76 mmol/g by the GO and GO-TETA-MA, respectively. The results indicated that the GO-TETA-MA has excellent selectively for the removal of Cu(II).
3. Adsorption capacity of heavy metal by GO-TETA-MA In order to estimate the adsorption properties, the obtained GO-TETA-MA as an adsorbent for different heavy metal ions, Pb(II), Cu(II), Cr(II) and Zn(II) were chosen to evaluate their affinity to the GO-TETA-MA. The result were shown in Figure S3. As shown in Figure S3, the adsorption capacity value of GO-TETA-MA increased with the order of Zn(II)< Pb(II)< Cr(II)< Cu(II). Obviously, the adsorbent exhibited better adsorption selectively for Cu (II) than other metal ions. Cu (II) was therefore chosen as the representative of metal ions in subsequent experiments.
Figure S3 Adsorption capacity of different heavy metal.
4. Adsorption capacities of GO-TETA-MA for various heavy metals Table S1 shows the comparison of the maximum adsorption capacities of various
3
adsorbents for Cu(II) removal. As clear, GO-TETA-MA exhibit excellent adsorption capacity for Cu(II), these uptakes are much higher than commercial avtive carbon, and other adsorption such as chitosan, spent activated clay, bentonite, nanotubes (CNTs), oxidized multi-walls nanotubes (MWCNTs), reported in the literatures.
Table S1 Adsorption capacities (mg/g) of GO-TETA-MA for various heavy metals. Material
Adsorption capacities
Reference
Chitosan
16.8
[4]
Spent activated clay
10.9
[5]
Bentonite
4.75
[6]
CNTs
27.03
[7]
Oxidized MWCNTs
28.49
[8]
GO-TETA-MA
34.4
This work
References: [1] Haitao Xing, Jianhua Chen, Xue Sun et al., NH2-rich polymer/graphene oxide use as a novel adsorbent for removal of Cu(II) from aqueous solution, Chem. Eng. J, 263 (2015) 280–289. [2] Yang Yuan, Guanghui Zhang, Yang Li, Guoliang Zhang et al., Poly (amidoamine) modified graphene oxide as an efficient adsorpbent for heavy metal ions, Polym. Chem, 2013, 4, 2164-2167. [3] Yuehe Lin, Fang Lu, Yi Tu, Zhifeng Ren, Glucose biosensors based on carbon nanotube nanoelectrode ensembles, Nano Lett, 2004, 4, 191-195. [4] Huang, C. P.; Chung, Y. C.; Liou, M. R. Adsorption of Cu(II) and Ni(II) by pelletized biopolymer. J. Hazard. Mater. 1996, 45, 265–277. [5] Weng, C. H.; Tsai, C. Z.; Chu, S. H.; Sharma, Y. C. Adsorption characteristics of copper (II) onto spent activated clay. Sep. Purif. Technol. 2007, 54, 187-197. [6] Rauf, N.; Ikram, M.; Tahir, S. S. Adsorption studies of Cu(II) from aqueous/acidic solutions onto bentonite. Adsorpt. Sci. Technol. 1999, 17, 431-440.
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[7] Hsieh, S. H.; Horng, J. J.; Tsai, C. K. Growth of carbon nanotube on micro-sized Al2O3 particle and its application to adsorption of metal ions. J.Mater. Res. 2006, 21, 1269–1273. [8] Li, Y. H.; Ding, J.; Lun, Z.; Di, Z.; Zhu, Y.; Xu, C.; Wu, D.; Wei, B. Competitive adsorption of Pb2+, Cu2+and Cd2+ions from aqueous solutions by multiwalled carbon nanotubes. Carbon 2003, 41, 2787–2792.
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Facile and efficient synthesis of nitrogen-functionalized graphene oxide as a copper adsorbent and its application Kexin Zhang, Haiyan Li, Xingjian Xu and Hongwen Yu 1. Morphological characteristics of GO/NiO nanocomposites.
Figure S1 TEM image of GO (a) and GO-TETA-MA (b); EDX spectrum of GO-TETA-MA (c). The surface morphology of the GO and GO-TETA-MA was investigated by using TEM. TEM image in Figure S1a provide an intuitive insight into the three dimension structure of GO, the folded or wrinkled sheets, as well as crumpled paper, which is attributed to the difference functional groups between the two sides of GO sheets. Figure S1b shows the TEM image of GO-TETA-MA. From the Figure S1b, it is clear that the organic molecule covered the convoluted surface of platelets and so the surface of GO-TETA-MA are very rough, which indicated that GO could stick into 1
the organics matrix and locally stiffen the interface of the resulting composites. This provides direct evidence of the TETA-MA was grafted successfully onto GO surface. In addtion, EDX can also be used to track the grafting process through the analysis of the surface element contents. A representative EDX of GO-TETA-MA is shown in Figure S1c, the presence of C, O, and N at GO-TETA-MA surface is confirmed by the signal of above elements, which proves that the TETA-MA chains is grafted onto the surface of the GO sheets. The presence of copper (Cu) relating to the copper grid.
2. Comparison of adsorption capacity for Cu(II) between GO and GO-TETA-MA
Figure S2 Adsorption capacity of Cu (II) on GO and GO-TETA-MA.
To demonstrate the potential application of the obtained GO-TETA-MA as an adsorbent for heavy metal ions, Cu(II) were chosen to evaluate their affinity to the GO-TETA-MA, with GO as controls. Figure S2 shows the maximum adsorption capacity of two adsorbents towards Cu(II). As is obvious in Figure S2, the maximum 2
Cu(II) removal values were 0.5 and 0.76 mmol/g by the GO and GO-TETA-MA, respectively. The results indicated that the GO-TETA-MA has excellent selectively for the removal of Cu(II).
3. Adsorption capacity of heavy metal by GO-TETA-MA In order to estimate the adsorption properties, the obtained GO-TETA-MA as an adsorbent for different heavy metal ions, Pb(II), Cu(II), Cr(II) and Zn(II) were chosen to evaluate their affinity to the GO-TETA-MA. The result were shown in Figure S3. As shown in Figure S3, the adsorption capacity value of GO-TETA-MA increased with the order of Zn(II)< Pb(II)< Cr(II)< Cu(II). Obviously, the adsorbent exhibited better adsorption selectively for Cu (II) than other metal ions. Cu (II) was therefore chosen as the representative of metal ions in subsequent experiments.
Figure S3 Adsorption capacity of different heavy metal.
4. Adsorption capacities of GO-TETA-MA for various heavy metals Table S1 shows the comparison of the maximum adsorption capacities of various
3
adsorbents for Cu(II) removal. As clear, GO-TETA-MA exhibit excellent adsorption capacity for Cu(II), these uptakes are much higher than commercial avtive carbon, and other adsorption such as chitosan, spent activated clay, bentonite, nanotubes (CNTs), oxidized multi-walls nanotubes (MWCNTs), reported in the literatures.
Table S1 Adsorption capacities (mg/g) of GO-TETA-MA for various heavy metals. Material
Adsorption capacities
Reference
Chitosan
16.8
[4]
Spent activated clay
10.9
[5]
Bentonite
4.75
[6]
CNTs
27.03
[7]
Oxidized MWCNTs
28.49
[8]
GO-TETA-MA
34.4
This work
References: [1] Haitao Xing, Jianhua Chen, Xue Sun et al., NH2-rich polymer/graphene oxide use as a novel adsorbent for removal of Cu(II) from aqueous solution, Chem. Eng. J, 263 (2015) 280–289. [2] Yang Yuan, Guanghui Zhang, Yang Li, Guoliang Zhang et al., Poly (amidoamine) modified graphene oxide as an efficient adsorpbent for heavy metal ions, Polym. Chem, 2013, 4, 2164-2167. [3] Yuehe Lin, Fang Lu, Yi Tu, Zhifeng Ren, Glucose biosensors based on carbon nanotube nanoelectrode ensembles, Nano Lett, 2004, 4, 191-195. [4] Huang, C. P.; Chung, Y. C.; Liou, M. R. Adsorption of Cu(II) and Ni(II) by pelletized biopolymer. J. Hazard. Mater. 1996, 45, 265–277. [5] Weng, C. H.; Tsai, C. Z.; Chu, S. H.; Sharma, Y. C. Adsorption characteristics of copper (II) onto spent activated clay. Sep. Purif. Technol. 2007, 54, 187-197. [6] Rauf, N.; Ikram, M.; Tahir, S. S. Adsorption studies of Cu(II) from aqueous/acidic solutions onto bentonite. Adsorpt. Sci. Technol. 1999, 17, 431-440.
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[7] Hsieh, S. H.; Horng, J. J.; Tsai, C. K. Growth of carbon nanotube on micro-sized Al2O3 particle and its application to adsorption of metal ions. J.Mater. Res. 2006, 21, 1269–1273. [8] Li, Y. H.; Ding, J.; Lun, Z.; Di, Z.; Zhu, Y.; Xu, C.; Wu, D.; Wei, B. Competitive adsorption of Pb2+, Cu2+and Cd2+ions from aqueous solutions by multiwalled carbon nanotubes. Carbon 2003, 41, 2787–2792.
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