Efficient degradation of norfloxacin by BiOBr/Ag2CO3 Z-type semiconductor heterojunction: Mechanistic insights and degradation pathways

The investigation of efficient and environmentally benign photocatalytic materials for sustainable water purification is of paramount importance. The present study demonstrates the successful in-situ synthesis of Ag2CO3 nanoparticles on BiOBr nanoflowers through a solvothermal-precipitation method, enabling the construction of highly efficient Z-type semiconductor heterojunctions. The BiOBr/Ag2CO3 composite exhibited enhanced photocurrent and reduced fluorescence intensity in comparison to single BiOBr or Ag2CO3, indicating improved efficiency in the separation of photogenerated carriers. Meanwhile, the time-resolved photoluminescence (TRPL) reveals that BiOBr/Ag2CO3 has a higher carrier lifetime. With norfloxacin (NFX) as contaminant, BiOBr/Ag2CO3 (1:1) achieved a remarkable removal efficiency (90.6 %), outperforming BiOBr (23.7 %) and Ag2CO3 (26.6 %), ascribing to efficient separation of electron holes and high carrier lifetime. The primary active species involved in the efficient degradation of NFX is center dot O2- . Furthermore, density functional theory (DFT) was employed to probebands structures, density of states and work function of photocatalyst for further confirming the construction of Z-type semiconductor heterojunction, along with elaborating the degradation pathway of norfloxacin. This study presents a novel perspective on the utilization of Z-type semiconductors for the treatment of norfloxacin- contaminated wastewater.