Results of C 1s, N 1s, and O 1s core level XPS spectra of Car[900]_CNF samples.

Sample	C 1s (at%)	O 1s (at%)	N 1s (at%)	Nitrogen functional groups (at%)
				N-Q	N-5 + N-6
Car[900]_CNF_0	84.04	9.48	6.46	3.94	2.50
Car[900]_CNF_10	81.46	13.41	5.13	3.11	2.02
Car[900]_CNF_20	81.01	13.71	5.26	3.00	2.26
Car[900]_CNF_30	81.68	12.59	5.71	3.22	2.49