Preparation of a Nitrogen-Doped Reduced Graphene Oxide-Modified Graphite Felt Electrode for VO²⁺/VO₂⁺ Reaction by Freeze-Drying and Pyrolysis Method

Table 2

Surface species content of N-rGO-modified GF samples by XPS results.

Sample	Species concentration (at.%)
	C	O	N
N-rGO-500/GF	93.18	4.60	2.22
N-rGO-700/GF	93.72	4.16	2.11
N-rGO-900/GF	92.98	3.70	3.32