Template‐Assisted Synthesis of Metallic 1T′‐Sn_0.3W_0.7S₂ Nanosheets for Hydrogen Evolution Reaction

Abstract

Crystal phase control still remains a challenge for the precise synthesis of 2D layered metal dichalcogenide (LMD) materials. The T′ phase structure has profound influences on enhancing electrical conductivity, increasing active sites, and improving intrinsic catalytic activity, which are urgently needed for enhancing hydrogen evolution reaction (HER) activity. Theoretical calculations suggest that metastable T′ phase 2D Sn 1−x W x S 2 alloys can be formed by combining W with 1T tin disulfide (SnS 2 ) as a template to achieve a semiconductor-to-metallic transition. Herein, 2D Sn 1−x W x S 2 alloys with varying x are prepared by adjusting the molar ratio of reactants via hydrothermal synthesis, among which Sn 0.3 W 0.7 S 2 displays a maximum of concentration of 81% in the metallic phase and features a distorted octahedral-coordinated metastable 1T′ phase structure. The obtained 1T′-Sn 0.3 W 0.7 S 2 has high intrinsic electrical conductivity, lattice distortion, and defects, showing a prominently improved HER catalytic performance. Metallic Sn 0.3 W 0.7 S 2 coupled with carbon black exhibits at least a 215-fold improvement compared to pristine SnS 2 . It has excellent long-term durability and HER activity. This work reveals a general phase transition strategy by using T phase materials as templates and merging heteroatoms to achieve synthetic metastable phase 2D LMDs that have a significantly improved HER catalytic performance.

Structural Transformation of SnS2 to SnS by Mo Doping Produces Electro/Photocatalyst for Hydrogen Production

“…One explanation is that the Mo‐doping resulted in thinner petals and curly morphology, increasing the surface area of the catalyst. SnS 2 doping with W, which is isoelectronic to Mo, was reported to boost the electrochemical activity of SnS 2 by enhancing the metallic nature of SnS 2 due to the lattice distortion caused by the W incorporation, and by the formation of new catalytic sites: S atoms directly bonded to W and particularly those that are bonded with two W atoms . The Tafel slopes, calculated from the polarization curves, show significant decrease by doping (Figure b).…”

Promoting Electrocatalytic Hydrogen Evolution Reaction and Oxygen Evolution Reaction by Fields: Effects of Electric Field, Magnetic Field, Strain, and Light

“…Hydrogen adsorption affinity is another crucial metric of electrocatalytic HER. [ 60–62 ] Generally, a moderate interaction is favorable since there is an intricate trade‐off between adsorption of hydrogen intermediate and desorption of hydrogen. [ 63 ] However, it is still challenging to achieve a hydrogen adsorption Gibbs free energy (Δ G H ) of 0 eV based on conventional strategies.…”

Seamlessly Splicing Metallic SnxMo1−xS2 at MoS2 Edge for Enhanced Photoelectrocatalytic Performance in Microreactor

“…It has been reported that heteroatom doping can induce the transition of electrical transport behavior of 2D materials, from semiconducting to metallic for M-S heterostructure construction. [16,30] The electronic densities of states (DOS) of MoS 2 and Sn x Mo 1−x S 2 calculated with the density functional theory (DFT) method are shown in Figure 1. The projected DOS and electronic densities at the Fermi level for Sn x Mo 1−x S 2 confirmed that a slight Sn doping (≈2%) in MoS 2 could cause a transition from typical semiconductor to metal.…”