All-solid-state Z-scheme FeOOH/GO/g-C3N4 heterojunction for efficient tetracycline degradation via visible-light-driven peroxydisulfate activation

Recently, a visible-light-driven photocatalysis coupled peroxydisulfate (PDS) activation system was developed for improving the efficiency of antibiotics degradation in wastewater. A Z -scheme FeOOH/CNNS photocatalyst was successfully applied for tetracycline (TC) degradation. In this study, graphene oxide (GO) was introduced into the fabrication procedure of the former catalyst. The optimzed FeOOH/GO/CNNS photocatalyst achieved 98.8 % TC degradation within 40 min (k = 0.0964 min −1 ), which was 2.58 and 8.53 times compared to FeOOH/CNNS and CNNS, respectively. This significant improvement can be attributed to the fact that 2D porous CNNS and GO can increase the surface area and active sites, avoiding FeOOH aggregation. Next, narrow-bandgap FeOOH improves visible-light utilization, while GO acts as an interfacial bridge to form an all-solid-state Z -scheme heterojunction, accelerating carrier separation and inhibiting recombination. Finally, radical trapping confirms • O 2 − , • OH, SO 4 •- , and h + synergistically degrade TC. This design provides a novel strategy for PDS-based efficient photocatalytic advanced oxidation.