The defect is perfect: MoS2/TiO2 modified with unsaturated Mo vacancies to construct Z-scheme heterojunction & improve mobility of e

• Published in: Journal of cleaner production 2022-02, Vol.337, p.130511, Article 130511
• Main Authors: Zhou, Ruifeng, Yang, Shuyi, E, Tao, Liu, Lin, Qian, Jianhua
• Format: Article
• Language: English
• Subjects: Degradation mechanism; DFT calculations; MoS2 defect; Photocatalytic degradation; Z-scheme
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2022.130511

Molybdenum disulfide (MoS2) is a representative of two-dimensional transition metal sulfide (TMDs) materials. In this study, MoS2 with rich defectives is successfully prepared via hydrothermal method to increase the active sites. Then, the MoS2/TiO2 is synthetized via loading TiO2 to enhance the catalytic performance. According to XRD, SEM, TEM, REMAN, XPS, EPR and TG analysis, the structural stability of the material is confirmed, associating with obtaining the optimum defect degree of MoS2/TiO2 (0.045, 0.09, 0.2, 0.3). In addition, a heterojunction is created with TiO2 anchored on the MoS2 plane, which provides a channel for the migration of electrons and promotes the separation of photogenerated electron-hole pairs. The broaden visible response and the narrowed band gap of MoS2/TiO2 are emphasized via employing UV-DRS, model Schottky curves and density functional theory (DFT) calculations. The presence of ·O2−, ·OH as well as charge transfer pathways of Z-scheme heterojunction are determined via carrying out radical capture experiments and ESR. Finally, this study highlights the synthesis method, structural modification, band edge modulation, optoelectronic properties, interface engineering, and catalytic reaction mechanism on MoS2/TiO2, as well as provides new ideas for photocatalytic treatment with TMDs materials. [Display omitted] •Introduction of defective modified MoS2 inert substrates to increase surface active sites.•Construction of Z-scheme heterojunctions to improve the separation rate of e−, h+ pairs.•Facilitating visible light response of TiO2 with narrow band gap MoS2 as co-catalyst.•Vacancy defects expose Mo, S overhanging bonds.