Stable MOF-In2S3/ZnFe layered dioxide heterostructures for improving photocatalytic degradation: Degradation pathways, kinetics, and charge migration.

In this paper, MOF-In 2 S 3 were modified by ZnFe-layered dioxides (LDO) with strong stability to obtain high catalytic performance composite. The successful preparation of ZnFe-LDO/MOF-In 2 S 3 not only retains the advantages of large specific surface area of MOF-In 2 S 3 and the stability of ZnFe-LDO, but also improves its charge separation efficiency and the light absorption region through the construction of heterojunctions. As expected, the experimental results show that ZnFe-LDO/MOF-In 2 S 3 has superior photo-electrocatalytic properties. The photocatalytic degradation efficiency of ZnFe-LDO/MOF-In 2 S 3 for TCH and OTC reach 92.92% and 80%, respectively, within 25 min. And the corresponding degradation rate constants are up to 1.41332 and 0.45451 L·mg−1·min−1, respectively, which are accord with the pseudo-second-order kinetic constants. The intermediate of 0.6LDO/M-I degradation of TCH was proposed by liquid mass spectrometry (LC-MS). Notably, a special transient surface photovoltage (TPV) technique was used for discussing the charge transfer kinetics and the lifetime of photogenerated carriers. Based on Mott-Schottky (M-S), Ultraviolet-visible absorption spectrum (UV), X-ray Photoelectron Spectroscopy (XPS) results, electron paramagnetic resonance (EPR) results, and active substance capture experiment results, a Z-scheme heterojunction system was proposed. The above research work proposed a new approach to enhance the stability of catalytic materials by using the aid of layered dioxides. In addition, the characterization of surface photovoltage provides a new way to study charge transfer. In this paper, a novel ZnFe-LDO/MOF-In 2 S 3 composite material has been successfully prepared, and its general morphology is mainly composed of MOF-In 2 S 3 nanoparticles coated with ZnFe-LDO material. After characterization and conclusion analysis, the catalyst material conforms to Z-scheme heterostructure and has excellent charge transfer rate and catalytic efficiency. [Display omitted] • ZnFe-LDO/MOF-In 2 S 3 Z-scheme composite was prepared successfully for the first time. • ZnFe-LDO/MOF-In 2 S 3 has excellent carrier separation efficiency, wide light absorption range and high redox capacity. • The photocatalytic degradation efficiency of 0.6LDO/M-I for TCH and OTC were 92.92% and 80%, respectively. • The corresponding degradation rate constants of 0.6LDO/M-I accord with the pseudo-second-order kinetic constants. [ABSTRACT FROM AUTHOR]