Single-Layered MoS₂ Directly Grown on Rutile TiO₂(110) for Enhanced Interfacial Charge Transfer

Abstract

Interfacial charge transfer is critical for the photocatalytic activities of compositional photocatalysts. In this work, we have developed a strategy of growing single-layer MoS2 sheets on the rutile TiO2(110) single-crystal surface using a chemical vapor deposition method. Both on-site and off-site characterizations confirmed the monolayer thickness and single crystallinity of the MoS2 adlayer as well as the atomic flatness of the composite surface. Without the presence of contamination, the charge flow across the interface of MoS2 and TiO2 is greatly enhanced, which hence favors the charge separation under excitations and boots up the catalytic activity of the composite system. Moreover, we found the luminescing property of MoS2 is significantly tailored upon coupling with the TiO2 surface. Our work has established a method for revealing the interface properties of the transition-metal dichalcogenides and oxide semiconductors at the atomic level.

Ultrasonic‐Ball Milling: A Novel Strategy to Prepare Large‐Size Ultrathin 2D Materials

“…When the layer number decreases, the attenuated interlayer van der Waals force in MoS 2 reduces the bondage to atom vibration, resulting in higher force constants, which makes the frequency of A 1g peak decreased. [ 33,34 ] On the contrary, the E 2g 1 peak shows a blue‐shift, suggesting that the increased interlayer van der Waals force plays a minor role while stacking induced structure changes or long‐range Coulombic interlayer interactions in multilayer MoS 2 may dominate the change of atomic vibration. [ 33–35 ] In addition, Figure 3h exhibits a reduced A 1g vibration mode of WS 2 nanosheet, causing by weaker interlayer contributions to the phonon restoring forces, which is similar to previous reports.…”

“…[ 33,34 ] On the contrary, the E 2g 1 peak shows a blue‐shift, suggesting that the increased interlayer van der Waals force plays a minor role while stacking induced structure changes or long‐range Coulombic interlayer interactions in multilayer MoS 2 may dominate the change of atomic vibration. [ 33–35 ] In addition, Figure 3h exhibits a reduced A 1g vibration mode of WS 2 nanosheet, causing by weaker interlayer contributions to the phonon restoring forces, which is similar to previous reports. [ 24 ] In general, the results of Raman spectra suggest a high quality of the obtained nanosheets prepared by the proposed exfoliation method with vigor.…”

Molecules and heterostructures at TiO2 surface: the cases of H2O, CO2, and organic and inorganic sensitizers

“…Reproduced with permission from Ref. [146] Concerning the synthesis of more ordered systems, it is noteworthy a recent paper by Liu et al [150] that, by using MoO3 and sulphur powder as solid precursors, have successfully synthesized by in situ CVD high-quality single-layer MoS2 sheets on the atomically flat rutile TiO2(110) single-crystal surfaces. The as-grown triangularly shaped sheets on TiO2 (110) single-crystal substrate are AFM imaged in Fig.…”

Pt/Mo2C heteronanosheets for superior hydrogen evolution reaction

“…Therefore, developing effective and stable catalysts has become the most urgent challenge in the research field of electrocatalytic hydrogen production. By considering the target of reducing the platinum dependence of HER catalysis, platinum-free catalysts have been widely synthesized, including oxides [3 , 4] , chalcogenides [5][6][7] , phosphates [8][9][10] , nitrides [11] and borides [12] of transition metals and carbon based metalfree catalysts [13 , 14] . Unfortunately, Pt based catalyst still domains the commercial water-electrolysis market.…”