File Name : fig. s1.tif

Caption : figure s1. sem image of zn-fe precursors/nf.

File Name : fig. s2.tif

Caption : figure s2. sem image of znfe2o4/nf.

File Name : fig. s3.tif

Caption : figure s3. sem image of ni3s2/nf.

File Name : fig. s4.tif

Caption : figure s4. hrtem image of znfe2o4@ ni3s2/nf.

File Name : fig. s5.tif

Caption : figure s5. saed pattern of znfe2o4@ni3s2/nf.

File Name : fig. s6.tif

Caption : figure s6. hrtem image and corresponding profile of znfe2o4@ni3s2/nf.

File Name : fig. s7.tif

Caption : figure s7. c 1s high-resolution spectra of the znfe2o4/nf, ni3s2/nf and znfe2o4@ni3s2/nf.

File Name : fig. s8.tif

Caption : figure s8. polarization curves of znfe2o4@ni3s2/nf at different electrodeposition cycle.

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Caption : figure s9. cv curves for nf at scan rates from 20 to 120 mv s-1.

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Caption : figure s10. cv curves for znfe2o4/nf at scan rates from 20 to 120 mv s-1.

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Caption : figure s11. cv curves for ni3s2/nf at scan rates from 20 to 120 mv s-1.

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Caption : figure s12. cv curves for znfe2o4@ni3s2/nf at scan rates from 20 to 120 mv s-1.

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Caption : figure s13. oer polarization curve of znfe2o4@ni3s2/nf initial and after 1000 cv cycles.

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Caption : figure s14. oer polarization curve of znfe2o4@ni3s2/nf initial and after 1000 cv cycles.

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Caption : figure s15. xrd image of znfe2o4@ni3s2/nf initial and after 1000 cv cycles.

File Name : fig. s16.tif

Caption : figure s16. sem image of znfe2o4@ni3s2/nf initial.

File Name : fig. s17.tif

Caption : figure s17. sem image of znfe2o4@ni3s2/nf after 1000 cv cycle.