Peroxydisulfate activation by CuFe2S3 nanocrystal doped C/N catalyst for phenanthrene degradation: Experimental, mechanism, and density functional theory calculation

•CuFe2S3-C/N catalyst with Fe-S-Cu sites was first synthesized.•CuFe2S3-C/N showed an excellent catalytic performance for PDS activation.•Experiments and DFT results indicated Fe and Cu atoms dominated electron transfer.•O-O bond of S2O82- was weakened by Fe-S-Cu sites on CuFe2S3-C/N.•Cu atom exhibited higher electron donating capacity than Fe.