Construction of all-solid-state Z-scheme CdZnS/CNT/CuCo2S4 heterojunction for enhanced photocatalytic hydrogen production and tetracycline degradation

Simultaneous achievement of green hydrogen production and pollutant removal is an attractive approach for mitigating energy scarcity and environmental pollution. This work successfully constructed an all-solid-state CdZnS/CNT/CuCo 2 S 4 Z-scheme heterojunction via a combined hydrothermal and solvent evaporation approach, enabling highly efficient bifunctional photocatalytic performance in hydrogen production and tetracycline removal. Benefiting from visible light excitation, the tailored CdZnS/CNT/CuCo 2 S 4 heterostructure delivered an outstanding photocatalytic H 2 generation activity, as high as 10.29 mmol g −1  h −1 . The catalytic performance was 3.3 times superior to pristine CdZnS. Moreover, it achieved 92.3% degradation of tetracycline within 30 min. The boosted photocatalytic performance originates from the Z-type charge transmission pathway supported by CNT electron bridges, significantly promoting carrier separation and transport. Excited electrons in CdZnS reduce water to produce hydrogen, while the holes in CuCo 2 S 4 degrade tetracycline. This study paves a rational pathway for the fabrication of Z-scheme heterojunction photocatalysts that employ carbon nanotubes as electron mediators.