Coupling Long‐Range Facet Junction and Interfacial Heterojunction via Edge‐Selective Deposition for High‐Performance Z‐Scheme Photocatalyst

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 MoS 2 nanoflakes on the edge-sites of thin TiO 2 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 MoS 2 and highly-exposed (001) facets of TiO 2 , 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.

Fabrication of an S-Scheme AgBr–PI Heterojunction for Biphenyl A Degradation and Its Degradation Pathways and Mechanism

“…The photocurrent density follows the sequence of PI < AgBr < 0.5-AP. These results indicated that 0.5-AP exhibited evidently high carrier separation efficiency compared with PI and AgBr. − Simultaneously, 0.5-AP expresses the minimum Nyquist cycle (Figure b), indicating that the charge transfer resistance of 0.5-AP is the least among the prepared samples. − At the same time, Figure c illustrates that when the excitation wavelength is 380 nm, all samples have a strong absorption peak around 480 nm, which is due to the photoinduced electrons and holes recombining. Nevertheless, the PL emission intensity was decreased after AgBr combination with PI, implying enhanced charge separation efficiency. − To obtain further evidence for the photoinduced carriers separation rates of the three abovementioned samples, time-resolved photoluminescence was conducted.…”

Efficient Visible-Light-Driven Tetracycline Degradation and Cr(VI) Reduction over a LaNi1–xFexO3 (0 ≤ x ≤ 1)/g-C3N4 Type-II Heterojunction Photocatalyst

“…19 However, an ideal semiconductor photocatalyst should simultaneously achieve a broad light absorption range and strong redox ability. 20 The construction of suitable heterointerfaces and unique charge transport pathways is one of the effective solutions to address the insufficient photocatalytic ability of single-component LaNiO 3 . The most important and challenging step is to design an efficient heterogeneous photocatalytic system to achieve efficient degradation of pollutants by enhancing the redox capacity.…”

“…However, an ideal semiconductor photocatalyst should simultaneously achieve a broad light absorption range and strong redox ability . The construction of suitable heterointerfaces and unique charge transport pathways is one of the effective solutions to address the insufficient photocatalytic ability of single-component LaNiO 3 .…”

Detecting and Quantifying Wavelength‐Dependent Electrons Transfer in Heterostructure Catalyst via In Situ Irradiation XPS

“…[ 1 , 2 , 3 , 4 , 5 , 6 ] Generally, the band structure theory companying with electron paramagnetic resonance were applied to evaluate the electrons migration through heterojunction. [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ] Traditional methods could only provide an explanation of electrons migration theoretically. However, it is a challenge to monitor and observe the photoelectron transfer process experimentally.…”