Emerging One-/Two-Dimensional Heteronanostructure Integrating SiC Nanowires with MoS₂ Nanosheets for Efficient Electrocatalytic Hydrogen Evolution

Abstract

MoS2 has emerged as a good application prospect in the electrocatalytic hydrogen evolution reaction (HER). Nevertheless, the catalytic activity of MoS2 is greatly restricted by its inferior electrical conductivity, inadequate exposure of active edge sites, and sluggish water dissociation dynamics. Herein, a 1D/2D heteronanostructure composed of SiC nanowires wrapped with MoS2 nanosheets was prepared via the hydrothermal synthesis of MoS2 on highly connected SiC nanowires (SiCnw). The nanocomposites exhibit an emerging tectorum-like morphology with interface connections of C–Mo bonds, which benefit the efficient interfacial transmission of electrons. Due to the synergetic catalytic effects of MoS2 nanosheets and SiC nanowires, the MoS2/SiCnw nanocomposites possess efficient catalytic performance with a low Tafel slope (55 mV/dec). SiC nanocrystals could reduce the activated water dissociation energy barrier, and the morphologies of connected nanowires could improve the active site exposure and charge transport. The nanocomposites possess favorable hydrogen adsorption free energy from density functional theory (DFT) calculations. The electrocatalytic performance of MoS2/SiCnw nanocomposites could be further improved by assembling the nanocomposites on a carbon fiber paper to enhance the electronic transmission efficiency.

Density Functional Theory Modeling of Photo-electrochemical Reactions on Semiconductors: H2 Evolution on 3C-SiC

“…Yasuda et al doped several polytypes (3C-, 4H-, 6H-) of SiC with p-type impurities and showed that photodriven HER could be achieved with solar irradiation on all SiC polytypes even in the absence of an applied bias. These early successes motivated other studies in several directions, such as doping SiC with p/n-type impurities, , using cocatalysts, modifying the surface via acid oxidation, using heterostructure composites, − and engineering various SiC nanostructures. − …”

Graphene Modified Montmorillonite Based Phase Change Material for Thermal Energy Storage with Enhanced Interfacial Thermal Transfer

“…[26] In the FTIR spectrum of MMT, the bands at 1022 and 471 cm À 1 are corresponding to the stretching and bending vibration of SiÀ O in silicon-oxygen tetrahedron. [27] The bands at 3620 and 1637 cm À 1 are assigned to the stretching and bending vibration of hydroxyl groups, and the broad bands at 3453 cm À 1 are ascribed to stretching vibrations of HÀ OÀ H in water. [28] For SA, the bands corresponding to -CH 2 and -CH 3 are found at 2918, 2849, 1466 and 723 cm À 1 , and the band at 1703 cm is attributed to the vibration of C=O.…”

“…The vibrational bands and interfacial characteristics of samples were studied by Fourier transform infrared (FTIR) spectra(Figure ) . In the FTIR spectrum of MMT, the bands at 1022 and 471 cm −1 are corresponding to the stretching and bending vibration of Si−O in silicon‐oxygen tetrahedron . The bands at 3620 and 1637 cm −1 are assigned to the stretching and bending vibration of hydroxyl groups, and the broad bands at 3453 cm −1 are ascribed to stretching vibrations of H−O−H in water .…”

Atomic‐Layer‐Deposition‐Based 2D Transition Metal Chalcogenides: Synthesis, Modulation, and Applications

“…[174] Besides, 1D-2D heterostructures exhibited high catalytic activity compared with bare 2D TMCs. [175][176][177] By controlling the number of ALD cycles, precisely controlled low-dimensional nanomaterials can be fabricated on 2D TMCs. As the surface of 2D TMCs has limited reaction sites for the chemisorption of precursors, the nuclei start to form islands from defect or edge sites in the early stage of ALD growth.…”