Elucidating the Origin of Enhanced Photocatalytic Hydrogen Production on Tuned Cu 7 S 4 /CdS Heterostructures.

Direct Z-scheme Cu 7 S 4 /CdS Janus photocatalysts are successfully prepared by cation exchange method. Extensive studies containing single-nanoparticle impact electrochemistry are performed and reveal that optimizing the Cu 7 S 4 /CdS ratio can decrease the accumulation of holes on valence band of CdS for inhibiting photo-corrosion and promote the accumulation of electrons on the conduction band of Cu 7 S 4 for boosting the electron reducibility. With the optimized heterostructures, hydrogen evolution is remarkable promoted up to 21.62 mmol/g/h and quantum efficiency is up to 14.37% using polylactic acid plastic waste as feedstock.