Table 1. Bond concentrations as measured by XPS.

	O 1s conc. (%)			C 1s conc. (%)
	C–OH			C–OH
	C=O	C–O–C	H2O	C=C	C sp3	C–O–C	C=O	O–C–O	C–(C=O)
GO	7.78	24.7	1.11	30.01	0	22.88	6.9	4.17	1.37
rGO 0.06	3.5	18.36	1.02	48.46	7.01	16.68	3.12	1.53	0.32
rGO 0.12	1.62	14.9	2.59	55.11	7.14	14.19	3.51	0.95	0
rGO 0.24	2.55	8.35	0.46	74.44	6.05	4.73	2.47	0.96	0
rGO 0.47	3.24	6.91	0.32	76.47	6.02	4.55	1.62	0.87	0
rGO 0.95	3.29	7.17	0.2	76.53	6.97	4.43	0.78	0.63	0