Janus WSSe Monolayer: An Excellent Photocatalyst for Overall Water Splitting

Abstract

Stable photocatalysts with excellent optical adsorption and low reaction barrier are the key for the water splitting. Here, we find that a two-dimensional Janus WSSe monolayer possesses the compelling photocatalytic properties from density functional theory simulations, which can be well modulated with strain deformation. Comprehensive investigations indicate that the Janus material not only exhibits strong optical absorbance in the visible spectrum, suitable band edge potentials, high carrier separation, and transfer efficiency but also has adequate driving forces of photoexcited carrier for water redox reaction and good resistance against photoinduced corrosion. Janus WSSe is therefore predicted to be a promising photocatalyst for water splitting. Moreover, we also find that tensile strains could further improve the photocatalytic performance for water splitting by effectively increasing the energy conversion efficiency and reducing the exciton binding energy. Our results not only predict a photocatalyst, which can utilize the visible light for overall water splitting, but also propose an effective path to extend the absorption spectra and raise the photocatalytic efficiency.

A first principles investigation on the structural, mechanical, electronic, and catalytic properties of biphenylene

“…According to Fig. 4 b, the Gibbs free energy for HER is 0.29 eV at U = 0 eV, which is much smaller than that of 2H-MoS 2 (2 eV) 34 , better than that of g-C 3 N 4 (0.54 eV) 35 and WSSe (0.58 eV) 36 , and comparable to that of recently reported Pd 4 S 3 Te 3 (0.18 eV) 37 . The Gibbs free energy change of pristine graphene for HER is also shown in Fig.…”

Rolling the WSSe Bilayer into Double-Walled Nanotube for the Enhanced Photocatalytic Water-Splitting Performance

“…In order to avoiding the interactions with neighboring mirror images, we set a 20 Å vacuum space vertical to each Janus WSSe bilayer, and more than 15 Å vacuum spaces along x and y directions for each Janus WSSe DWNT, whose periodic boundary condition is along the z axis. We apply the DFT-D3 approach of Grimme to address the van der Waals (vdW) force [17,23]. The Brillouin zone is regulated with a 9 × 9 × 1 gamma-pack k-mesh for the Janus WSSe bilayers, and a 1 × 1 × 7 one for the Janus WSSe double-walled nanotube.…”

“…Thereby, compared with the Janus MoSSe monolayers, the bilayer samples have a more excellent photocatalytic performance. Lately, due to the excellent optical absorption and high carrier separation, Janus WSSe monolayer has been also reported to possess a great potential for the application of photocatalytic overall watersplitting [17]. However, for the Janus WSSe bilayer, the photocatalytic properties is yet unclear.…”

“…Nanomaterials 2021, 11, x FOR PEER REVIEW 3 of 10 verified to be unremarkably [17], here we do not apply the SOC correction in our calculations for saving the computing resource. More computational details of theoretical STH efficiency and DWNT surface ΔΦ can be found in the Supplementary Materials.…”

Controllable CO2 electrocatalytic reduction via ferroelectric switching on single atom anchored In2Se3 monolayer

“…Despite latest advances, there is still plenty of room to improve the catalytic activity and selectivity of CO 2 reduction in order to satisfy large-scale industrial applications. Recent studies have shown that electric polarization plays an important role in determining catalytic activities and selectivities, and can greatly improve the catalytic performance compared with the unpolarized counterparts 19 – 21 . For instance, Janus TM dichalcogenides possess better catalytic abilities for water splitting and N 2 fixation 19 – 21 , since the catalysis-related properties, including surface stoichiometry, electronic structure 22 – 26 , adsorption strengths, and reaction activation energies, can be tuned by the polarization 27 ; Moreover, by utilizing the polarization from the substrate, the overpotential of oxygen evolution reaction on TiO 2 surface can be strongly reduced 28 .…”