Coupling Long‐Range Facet Junction and Interfacial Heterojunction via Edge‐Selective Deposition for High‐Performance Z‐Scheme Photocatalyst. Issue 18 (24th April 2022)

• Record Type: Journal Article
• Authors: Li, Xuan; Anwer, Shoaib; Guan, Qiangshun; Anjum, Dalaver H.; Palmisano, Giovanni; Zheng, Lianxi
• Is Part Of: Advanced science. Volume 9:Issue 18(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-24
• Subjects: 2D material -- facet junction -- heterojunction -- photocatalyst -- photodegradation -- selective growth -- Z‐scheme; Science -- Periodicals; 505
• DOI: 10.1002/advs.202200346
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: The construction of photocatalytic systems that have strong redox capability, effective charge separation, and large reactive surfaces is of great scientific and practical interest. Herein, an edge‐connected 2D/2D Z‐scheme system that combines the facet junction and the interfacial heterojunction to achieve effective long‐range charge separation and large reactive surface exposure is designed and fabricated. The heterostructure is realized by the selective growth of 2D‐layered MoS2 nanoflakes on the edge‐sites of thin TiO2 nanosheets via an Au‐promoted photodeposition method. Attributed to the synergetic coupling of the facet junction and the interfacial heterojunction that assures the effective charge separation, and the tremendous but physically separated reactive sites offered by layered MoS2 and highly‐exposed (001) facets of TiO2, respectively, the artificial Z‐scheme exhibits excellent photocatalytic performance in photodegradation tests. Moreover, the junctional plasmonic Au nanoclusters not only act as electron traps to promote the edge‐selective synthesis but also generate "hot electrons" to further boost photocatalytic performance. The Z‐scheme charge‐flow direction in the heterostructure and the roles of electrons and holes are comprehensively studied using in situ irradiated X‐ray photoelectron spectroscopy and photodegradation tests. This work offers a new insight into designing high‐performance Z‐scheme photocatalytic systems. Abstract : An efficient MoS2 /Au/TiO2 Z‐scheme photocatalytic system is fabricated by Au‐induced selective growth of MoS2 nanoflakes on the edge‐sites of TiO2 nanosheets. The ternary structure synergistically couples the facet junction and the heterojunction to separate the photogenerated charges in relays and maintains the highly exposed surfaces for redox reactions. The junctional Au nanoclusters generate "hot electrons" to further boost photocatalytic performance.