Triethylenetetramine/hydroxyethyl cellulose-functionalized graphene oxide monoliths for the removal of copper and arsenate ions

Figures & data

Table 1. GOMs prepared at different weight ratios of GO/TETA/HEC.

Samples	GO	TETA	HEC
GOM-T1	1	1.5	0
GOM-TH1	1	1.2	0.4
GOM-T2	1	0.5	0
GOM-TH2	1	0.7	0.4

Figure 2. (a) XRD patterns and (b) FTIR spectra of pristine GO, HEC, TETA, and GOMs, respectively.

Figure 3. O1s spectra of (a) HEC, (b) GOM-T1, (c) GOM-TH1, and (d) pristine GO.

Table 2. Elemental composition in atomic percentage (%) derived from XPS survey spectra.

Samples	Pristine GO	HEC	GOM-T1	GOM-T2	GOM-TH1	GOM-TH2
Atomic %
O1s	30.85	35.61	19.85	20.01	21.70	25.26
C1s	61.23	57.14	63.66	63.81	62.20	61.87
N1s	–	–	14.33	14.31	12.89	11.07
Other	7.92	7.25	2.03	1.87	3.21	1.8
Atomic ratios (X/C)
O/C	0.504	0.623	0.312	0.314	0.349	0.408
N/C	–	–	0.226	0.224	0.207	0.179

Table 3. The relative fraction of the O, C, and N contributions derived from peak fitting of high resolution O1s, C1s, and N1s XPS spectra.

Samples		GO	HEC	GOM-T1	GOM-T2	GOM-TH1	GOM-TH2	Assignment
Relative fraction of O, %	O1	17.99	25.13	38.67	31.57	18.06	22.54	C=O, N–C=O
	O2	80.62	68.45	59.62	67.75	79.32	76.41	OH, water, epoxy, glycosidic
	O1/O2	0.223	0.367	0.648	0.466	0.228	0.295
Relative fraction of N, %	N1			56.64	56.78	56.08	62.04	pyrrolic N, amine, secondary amine, imine, amide
	N2			23.63	25.74	24.37	24.07	imide, graphitic N
	N3			19.73	17.48	19.56	13.88	N^+
Relative fraction of C, %	C1	39.44	11.76	34.45	36.77	39.5	22.36	C–H, C–C
	C2	50.31	69.17	53.86	49.98	47.42	66.05	C–O–C, C–N, C=N
	C3	7.76	17.43	9.42	10.58	10.36	10.63	(N–)C=O, O–C–O, N–C–O
	C4	0.89	1.34	2.09	2.55	2.51	0.89	(C=O)–OR, imide group
	C5	0.07	0.3	0.18	0.12	0.21	0.07	urethane, carbonate group
	C2/C1	1.276	5.882	1.563	1.36	1.20	2.954

Figure 4. (a) TGA and (b) DTG curves of pristine GO, HEC, GOM-T1, and GOM-TH1.

Figure 5. (a), (b) SEM images at different magnification, (c) XRD pattern, (d) backscattered electron (BSE) image, and (e) EDX spectra (the data in Table) obtained at positions 7 and 11 of freeze dried GOM-TH1 after adsorption of As(V) and Cu(II).