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In this study, a Z-Scheme WO3/CoO p-n heterojunction with a 0D/3D structure was designed and prepared via a simple solvothermal approach to remove the combined pollution of tetracycline and heavy metal Cr(VI) in water. The 0D WO3 nanoparticles adhered to the surface of the 3D octahedral CoO to facilitate the construction of Z-scheme p-n heterojunctions, which could avoid the deactivation of the monomeric material due to agglomeration, extend the optical response range, and separate the photogenerated electronhole pairs. The degradation efficiency of mixed pollutants after a 70 min reaction was significantly higher than that of monomeric TC and Cr(VI). Among them, a 70% WO3/CoO heterojunction had the best photocatalytic degradation effect on the mixture of TC and Cr(VI) pollutants, and the removing rate was 95.35% and 70.2%, respectively. Meanwhile, after five cycles, the removal rate of the mixed pollutants by the 70% WO3/CoO remained almost unchanged, indicating that the Z-scheme WO3/CoO p-n heterojunction has good stability. In addition, for an active component capture experiment, ESR and LC-MS were employed to reveal the possible Z-scheme pathway under the built-in electric field of the p-n heterojunction and photocatalytic removing mechanism of TC and Cr(VI). These results offer a promising idea for the treatment of the combined pollution of antibiotics and heavy metals by a Z-scheme WO3/CoO p-n heterojunction photocatalyst, and have broad application prospects: boosted tetracycline and Cr(VI) simultaneous cleanup over a Z-scheme WO3/CoO p-n heterojunction with a 0D/3D structure under visible light.

With the booming industry, the demand for dyes has increased dramatically and the discharge of wastewater containing dyes has also increased dramatically. Owing to the multi-pore nature and stabilization of UiO-66, the relatively small band gap of Bi2O3 and the good magnetic properties of Fe3O4, Fe3O4@UiO-66@Bi2O3 has good efficiency and reusability to remove methyl orange (MO). The maximum degradation rate is 83.26%, and the magnetic properties of Fe3O4 solved the problem of difficult recovery of UiO-66 as a nanomaterial with a recovery rate of 98.79%. In this work, the results showed that the Fe3O4@UiO-66@Bi2O3 catalysts composite increased the specific surface area, improved the separating efficiency of both holes and electrons as well as significantly enhanced the photo-catalytic efficiency in comparison to single Fe3O4@UiO-66 and Bi2O3@UiO-66 materials. The photocatalytic decomposition procedure is consistent with the primary reaction kinetics. The outcomes suggest that Fe3O4@UiO-66@Bi2O3 (FUB) is a strong contender for the removal of MO.