Table 1.

The contents of Mn—O—Mn, Mn—O—H, and Mn—O—C in all samples

	Samples
	MnO2	GQDs/MnO2‐1	GQDs/MnO2‐3	GQDs/MnO2‐5	GQDs/MnO2‐10
Mn—O—Mn	63.6%	64.1%	30.8%	23.7%	47.7%
Mn—O—H	36.4%	16.4%	21.8%	21.2%	24.3%
Mn—O—C	0%	19.5%	47.4%	55.1%	28%