A Polarization Boosted Strategy for the Modification of Transition Metal Dichalcogenides as Electrocatalysts for Water‐Splitting

Abstract

The design and fabrication of transition metal dichalcogenides (TMDs) are of paramount significance for water‐splitting process. However, the limited active sites and restricted conductivity prevent their further application. Herein, a polarization boosted strategy is put forward for the modification of TMDs to promote the absorption of the intermediates, leading to the improved catalytic performance. By the forced assembly of TMDs (WS2 as the example) and carbon nanotubes (CNTs) via spray‐drying method, such frameworks can remarkably achieve low overpotentials and superior durability in alkaline media, which is superior to most of the TMDs‐based catalysts. The two‐electrode cell for water‐splitting also exhibits perfect activity and stability. The enhanced catalytic performance of WS2/CNTs composite is mainly owing to the strong polarized coupling between CNTs and WS2 nanosheets, which significantly promotes the charge redistribution on the interface of CNTs and WS2. Density functional theory (DFT) calculations show that the CNTs enrich the electron content of WS2, which favors electron transportation and accelerates the catalysis. Moreover, the size of WS2 is restricted caused by the confinement of CNTs, leading to the increased numbers of active sites, further improving the catalysis. This work opens a feasible route to achieve the optimized assembling of TMDs and CNTs for efficient water‐splitting process.

Tungsten Disulfide‐Interfacing Nickel‐Porphyrin For Photo‐Enhanced Electrocatalytic Water Oxidation

“…However, the lack of active sites for adsorption of oxygen‐related species, in order to catalyze water oxidation, suppresses the widening of its applications. This impediment has been partly alleviated by interfacing WS 2 with carbon nanotubes (CNTs), doping its lattice with first row transition metals (especially Co) or furnishing composite materials with OER active compounds (e. g., CoWO 4 ) [7–10] . In the context of combining WS 2 with transition metals, a handful of works reporting the electrocatalytic activity of WS 2 involve the use of Ni, a first‐row transition metal with good electrical conductivity and higher abundance in nature compared to its more commonly used counterpart Co [11–14] .…”

Engineering the Local Atomic Configuration in 2H TMDs for Efficient Electrocatalytic Hydrogen Evolution

“…Two-dimensional transition metal dichalcogenide (TMD) nanosheets with a high specific surface area have shown great promise as an efficient electrocatalyst for hydrogen evolution reaction (HER) in water electrolysis. − However, in 2H-TMDs, including molybdenum disulfide (MoS 2 ), the HER process primarily proceeds near the edge sites of TMDs, which have an incomplete coordination number. , Various morphological engineering approaches have been studied to increase the edge site exposure by employing various nanostructure formations, such as mesoporous architecture and vertically aligned nanoflakes. − However, the saturated coordinative atoms in the basal plane of TMDs fundamentally limit the available active sites for electrocatalytic reactions and prevent the full utilization of their high specific surface area. This is the primary obstacle in realizing efficient HER activities. , Furthermore, the intrinsically poor electrical conductivity of 2H-TMDs hinders electron transfer kinetics during electrolysis, further limiting their efficient electrocatalytic performance. − Therefore, both surface basal plane activation and electrical property control must be considered when developing a strategy to enhance the intrinsic catalytic activity of TMD materials.…”

Hierarchical Ti3C2Tx MXene/Carbon Nanotubes Hollow Microsphere with Confined Magnetic Nanospheres for Broadband Microwave Absorption

“…The samples are mainly mesoporous and microporous, and the introduction of CNTs also brings more small‐size pores through the entanglement, which are consistent with the pore size distribution results (Figure 3c, Figure S10b,c, Supporting Information). [ 41 ] The increase of the pores is beneficial to increase the reflection and scattering sites and enhance the MA performance. Figure S10d, Supporting Information, exhibits saturation magnetization intensity of samples according to the VSM results: Fe 3 O 4 @Ti 3 C 2 T x /CNTs (21.6 emu g −1 ) > Fe 3 O 4 @Ti 3 C 2 T x (19.6 emu g −1 ) > Fe 3 O 4 @CNTs (18.1 emu g −1 ).…”

“…The samples are mainly mesoporous and microporous, and the introduction of CNTs also brings more small-size pores through the entanglement, which are consistent with the pore size distribution results (Figure 3c, Figure S10b,c, Supporting Information). [41] The increase of the pores is beneficial to increase the reflection and scattering sites and enhance the MA performance. Figure S10d, Supporting Information, exhibits The high resolution of the C 1s spectrum can be divided into three peaks at 282.1, 284.8, 286.5 eV, corresponding to CTi, CC, and CO bonds (Figure 3d).…”