File Name : figure s1.tif

Caption : figure s1. b-value curves of fe3o4@ppy composite materials with different fe3o4 contents.

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Caption : figure s2. the cv cure of fe3o4@ppy -x composite materials.



File Name : figure s3.tif

Caption : figure s3. (a, b) cv and gcd curves of fe3o4@ppy-10% composite material under different current density. (c, d) cv and gcd curves o fe3o4@ppy-20% composite material under different current density. (e, f) cv and gcd curves of fe3o4@ppy-40% composite material under different current density.