Dual role of monolayer MoS2 in enhanced photocatalytic performance of hybrid MoS2/SnO2 nanocomposite

Abstract

The enhanced photocatalytic performance of various MoS2-based nanomaterials has recently been observed, but the role of monolayer MoS2 is still not well elucidated at the electronic level. Herein, focusing on a model system, hybrid MoS2/SnO2 nanocomposite, we first present a theoretical elucidation of the dual role of monolayer MoS2 as a sensitizer and a co-catalyst by performing density functional theory calculations. It is demonstrated that a type-II, staggered, band alignment of ∼0.49 eV exists between monolayer MoS2 and SnO2 with the latter possessing the higher electron affinity, or work function, leading to the robust separation of photoexcited charge carriers between the two constituents. Under irradiation, the electrons are excited from Mo 4d orbitals to SnO2, thus enhancing the reduction activity of latter, indicating that the monolayer MoS2 is an effective sensitizer. Moreover, the Mo atoms, which are catalytically inert in isolated monolayer MoS2, turn into catalytic active sites, making the monolayer MoS2 to be a highly active co-catalyst in the composite. The dual role of monolayer MoS2 is expected to arise in other MoS2-semiconductor nanocomposites. The calculated absorption spectra can be rationalized by available experimental results. These findings provide theoretical evidence supporting the experimental reports and pave the way for developing highly efficient MoS2-based photocatalysts.

Dramatically Enhanced Visible Light Response of Monolayer ZrS2 via Non-covalent Modification by Double-Ring Tubular B20 Cluster

“…4b) by the three-dimensional charge density difference where , , and are the charge densities of the hybrid, monolayer ZrS 2 , and ring B 20 cluster in the same configuration, respectively. Owing to the non-covalent interaction, a very interesting charge redistribution at the hybrid ZrS 2 /B 20 can be clearly seen, which is different from those of the MoS 2 /SnO 2 and Ag 3 PO 4 /GR heterostructures [33, 35]. A strong charge accumulation (blue part in Fig.…”

“…It has been demonstrated that non-covalent modification by graphene or monolayer MoS 2 can extend the absorption edge of semiconductors (like TiO 2 , AgPO 4 and SnO 2 ) to the vis-light region [33, 35, 36]. Similarly, coupling fullerene with photocatalysts is also an effective strategy to enhance the light absorption [34].…”

Insights into the Photoassisted Electrocatalytic Reduction of CO2 over a Two‐dimensional MoS2 Nanostructure Loaded on SnO2 Nanoparticles

“…So, it can improve the interfacial activity and electron transport kinetics. [36] The interplanar distances of 0.37 nm can be identified to (110) planes of tetragonal rutile SnO 2 and lattice fringes with spacing of 0.27 nm corresponds to (100) plane of hexagonal MoS 2 in 5 % MS/SON in Figure 2(d), [27] the DFT calculation results are 3.6 Å of SnO 2 110 and 2.6 Å of MoS 2 100 crystal face, [30] respectively. Besides, the particle size distribution of 5 % MS/SON is not uniform, with the diameter ranging from 22 to 30 nm, and the average particle size is about 26 nm from Figure 2(c) and (d), which is almost consistent with DFT and XRD results.…”

“…In consideration of the large specific surface area of the layered materials and good optical response of MoS 2 and based on density functional theory (DFT) calculation. [30] We envisage combining the granular SnO 2 with MoS 2 not only to expand the specific surface area of the composite but also make full use of the optical performance of MoS 2 . Thus, it can increase the surface adsorption sites to adsorb more CO 2 molecules, we synthesized the two-dimensional nanostructure MoS 2 loaded on SnO 2 nanoparticles (labeled as MS/SON) by two-step processes of facile hydrothermal and pyrolysis methods.…”

Nanocarbons with Different Dimensions as Noble-Metal-Free Co-Catalysts for Photocatalysts

“…As a typical 2D metal sulfide photocatalyst, molybdenum disulfide (MoS 2 ) with a layered structure has been studied extensively [126,127]. Hou et al [128] presented the fabrication of 2D porous g-C 3 N 4 nanosheets/nitrogen-doped graphene/layered MoS 2 (CNNS/NRGO/MoS 2 ) ternary nanocomposites.…”