Boosted Tetracycline and Cr(VI) Simultaneous Cleanup over Z-Scheme WO3/CoO p-n Heterojunction with 0D/3D Structure under Visible Light

Abstract

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.

Synergistic Spatial Confining Effect and O Vacancy in WO3 Hollow Sphere for Enhanced N2 Reduction

“…WO 3 has been widely adopted as a promising photocatalyst due to its appropriate band gap (~2.4 eV), low conduction band edge potential, and fleet electron transport rate [35][36][37]. Moreover, the adjustable crystal structure makes the O defect-rich WO 3 the hotspot in N 2 reduction.…”

Photocatalytic Oxygen Evolution under Visible Light Mediated by Molecular Heterostructures

“…), and both the architectures and properties of polymers could be easily tailored by delicate structure design [19]. However, most mono-component polymers suffer from low solar-to-oxygen conversion efficiencies due to the fast recombination of photogenerated charge carriers [20,21]. Thus, exploiting the diversity of polymer structures to develop novel CPs with efficient photocatalytic properties is extremely important [10].…”