Highly efficient photoelectrocatalytic degradation for ciprofloxacin with a new polyoxometalate-based metal–organic hybrid/BiVO₄ photoanode

Efficient removal of antibiotics is of great significance for the sustainability of aquatic ecosystems. In this work, a new polyoxometalate-based metal–organic hybrid material [Ag₃L_0.5(HSiW₁₂O₄₀)]·2C₂H₅OH·2CH₃CN ( Ag-L-SiW ₁₂) was prepared by using Keggin-type polyoxometalate anion and thiacalix[4]arene-based ligand (L) via solvothermal method. Subsequently, a composite heterojunction Ag-L-SiW ₁₂@BiVO₄ photoanode was fabricated by loading Ag-L-SiW ₁₂ on the surface of BiVO₄. The photoelectrocatalytic degradation performance of ciprofloxacin (CIP) was explored under the simulated solar radiation. Remarkably, the CIP degradation efficiency reached 93% within 240 min using the optimal Ag-L-SiW @BiVO₄ photoanode, which is approximately 2 and 23 times those of pristine BiVO₄ and Ag-L-SiW ₁₂, respectively. Furthermore, density functional theory (DFT) calculations were conducted to elucidate the role of Ag-L-SiW ₁₂ during the photoelectrocatalytic process. This work offers an example of the efficient composite photoelectrocatalysts for the treatment of antibiotic wastewater.