Table 1.

The atomic percentage (at.%) of the elements found in the XPS analysis of GO and each N-rGO sample.

Material	C (at.%)	O (at.%)	N (at.%)
GO	65.78	34.23	-
N-rGO1	85.79	11.41	2.80
N-rGO2	83.97	11.15	4.53
N-rGO3	84.84	9.58	5.51