Synthesis of a novel NiCo-LDH/Bi2WO6 Z-scheme heterojunction composite for photocatalytic degradation of tetracycline

This article aims at preparing of Z-scheme heterojunction NiCo-LDH/Bi ₂WO ₆ (LDH: layered double hydroxides) via a solvothermal technique, addressing the rapid recombination of electron-hole pairs caused by the narrow bandgap of Bi ₂WO ₆. Successful loading of NiCo-LDH onto Bi ₂WO ₆ was confirmed through various characterization techniques, assessing the composite`s crystal structure, morphological traits, and performance. Notably, the NiCo-LDH/Bi ₂WO ₆ composite exhibited excellent photocatalytic performance in the degradation of tetracycline (TC), achieving an optimal reaction rate of 0.03 min ⁻¹, which is 4.8 times faster than that of Bi ₂WO ₆ alone. The findings demonstrate that the formation of the heterojunction structure facilitated the separation of photogenerated electron-hole pairs by reducing recombination in monomers. Free radical trapping experiments showcased that the decomposition of TC is primarily driven by h ⁺ and ∙O ₂ ⁻. Additionally, liquid chromatography-mass spectrometry analysis identified the degradation products of TC and suggested two potential degradation pathways. The present research provides a novel approach for preparing LDH photocatalytic materials using NiCo-LDH/Bi ₂WO ₆.