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

Abstract

This article aims at preparing of Z-scheme heterojunction NiCo-LDH/Bi2WO6 (LDH: layered double hydroxides) via a solvothermal technique, addressing the rapid recombination of electron-hole pairs caused by the narrow bandgap of Bi2WO6. Successful loading of NiCo-LDH onto Bi2WO6 was confirmed through various characterization techniques, assessing the composite's crystal structure, morphological traits, and performance. Notably, the NiCo-LDH/Bi2WO6 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 Bi2WO6 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 ∙O2−. 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/Bi2WO6.