Construction of defect-containing UiO-66/MoSe2 heterojunctions with superior photocatalytic performance for wastewater treatment and mechanism insight

Metal-organic frameworks are recognized as promising multifunctional materials, especially metal-organic framework-based photocatalysts, which are considered to be ideal photocatalytic materials. Herein, a new type of UiO-66/MoSe2 composite was prepared using the solvothermal method. The optimum composite was selected by adjusting the mass ratio of UiO-66 and MoSe2. X-ray diffraction analysis showed that the mass ratio influenced the crystal plane exposure rate of the composite, which may have affected its photocatalytic performance. The composite is composed of ultra-thin flower-like MoSe2 that wrapped around cubic UiO-66, a structure that increases the abundance of active sites for reactions and is more conducive to the separation of carriers. The photocatalytic properties of the composite were evaluated by measuring the degradation rate of Rhodamine B and the catalyst's ability to reduce Cr(VI)-containing wastewater under visible light irradiation. Rhodamine B was decolorized completely in 120 min, and most of the Cr(VI) was reduced within 150 min. The photochemical mechanism of the complex was studied in detail. The existence of Mo6+ and oxygen vacancies, in addition to the Z-type heterojunction promote the separation of electrons and holes, which enhances the photocatalytic effect.

Automated summary

Metal-organic frameworks, particularly metal-organic framework-based photocatalysts, have shown great potential as multifunctional materials. In this study, a UiO-66/MoSe2 composite was synthesized using the solvothermal method, and the optimum composite was selected based on the mass ratio of UiO-66 and MoSe2. X-ray diffraction analysis revealed that the mass ratio affected the crystal plane exposure rate and the photocatalytic performance of the composite. The composite consisted of flower-like MoSe2 wrapped around cubic UiO-66, which increased the active sites for reactions and improved carrier separation. The composite exhibited high photocatalytic activity in degrading Rhodamine B and reducing Cr(VI)-containing wastewater under visible light irradiation. The presence of Mo6+ ions, oxygen vacancies, and the Z-type heterojunction contributed to the efficient separation of electrons and holes, enhancing the photocatalytic effect.