Defect assisted coupling of a MoS₂/TiO₂interface and tuning of its electronic structure

Abstract

Although MoS2 based heterostructures have drawn increased attention, the van der Waals forces within MoS2 layers make it difficult for the layers to form strong chemical coupled interfaces with other materials. In this paper, we demonstrate the successful strong chemical attachment of MoS2 on TiO2 nanobelts after appropriate surface modifications. The etch-created dangling bonds on TiO2 surfaces facilitate the formation of a steady chemically bonded MoS2/TiO2 interface. With the aid of high resolution transmission electron microscope measurements, the in-plane structure registry of MoS2/TiO2 is unveiled at the atomic scale, which shows that MoS2[1-10] grows along the direction of TiO2[001] and MoS2[110] parallel to TiO2[100] with every six units of MoS2 superimposed on five units of TiO2. Electronically, type II band alignments are realized for all surface treatments. Moreover, the band offsets are delicately correlated to the surface states, which plays a significant role in their photocatalytic performance.

Enhancement of the Photoelectrocatalytic H2 Evolution on a Rutile-TiO2(001) Surface Decorated with Dendritic MoS2 Monolayer Nanoflakes

“…However, the practical applications of the HER for a single-component semiconductor photocatalyst such as TiO 2 are always limited by the unsuitable energy band gap and positions of the conduction band (CB) and valence band (VB), which inhibit the photocatalysts from harvesting visible light and lead to easy recombination of the electron–hole pairs, eventually degrading the photocatalysts’ redox capability. − Therefore, enhancing the light-absorption ability and hindering the charge carrier recombination are critical for the development of highly efficient photocatalysts for energy conversion. TiO 2 -based cocatalyst materials, such as TiO 2 modified by doping or combined with another material as a heterostructure, have attracted considerable interest because the energy band gap and band positions can be deliberately tuned so that the photoadsorption range can be extended to the visible light. − ,− Simultaneously, the cocatalysts can provide more active sites and decrease the recombination of photogenerated electron–hole pairs, thus facilitating the reduction of protons to form hydrogen.…”

Substrate Impact on the Structure and Electrocatalyst Properties of Molybdenum Disulfide for HER from Water

“…The resulting film also demonstrated nanoplatelet's morphology (Figure 7b) and nice adhesion to the titania nanotubes (Figure 7c). Worth noticing that apart deposition onto the surface, MoS 2 species tightly filled titania tubes, cracks, and intertube gaps (Figure 7c), likely due to a strong chemical attachment to the TiO 2 surface [49]. As such, this electrode exhibited a high HER activity in the acidic solution (Figure 8a).…”

MoS2‐TiO2 Nanocomposite with Excellent Adsorption Performance and High Antibacterial Activity

“…The red shift of modes corresponding to the anatase TiO 2 possibly occurs due to the growth of MoS 2 around the TiO 2 forming the MoS 2 ‐TiO 2 nanocomposites. Moreover the B 1g mode overlaps with the MoS 2 mode, causing hindrance to the clear appearance of the Raman peaks of MoS 2 . As a whole on the basis of the observations from XRD, XPS and Raman it is clear that in this synthesized series of MoS 2 ‐TiO 2 composite slight existence of MoO 3 phase cannot be discarded and the phenomena is understandable as well …”