Synergistically Configuring Intrinsic Activity and Fin-Tube-Like Architecture of Mn-Doped MoS₂-Based Catalyst for Improved Hydrogen Evolution Reaction

Abstract

Hydrogen generation by electrocatalysis water splitting is considered as one of the most promising techniques to address the energy crisis and environmental pollution. Highly efficient, low-cost, and stable catalysts are crucial to speed sluggish kinetics of the hydrogen evolution reaction (HER). Molybdenum disulfide has been considered to be a promising substitute to Pt-based materials, but its inherently low conductivity, finite active edge sites due to the thermodynamically stable basal plane, and the self-stacking and agglomeration properties still impede the HER activity. In addition, optimization of the electrode structure is equally critical for industrial high-rate hydrogen production. Herein, on the basis of the system engineering concept, we report a manganese-doped MoS2 ultrathin nanosheet anchoring on a fin-tube-like hierarchical carbon skeleton vertically to achieve the synergistic optimization of intrinsic activity and electrode architecture. The superhydrophilic and superaerophobic electrode with conductive carbon nanoarray structure can accelerate the mass transport (gas bubbles and electrolyte) and electron transfer processes. In addition, theoretical calculation reveals that all the hydrogen adsorption free energies of basal planes, S-edge, and Mo-edge for doped MoS2 have decreased. Moreover, the electronic structure of the Mn-doped MoS2 monolayer shows the absence of band gap, indicating improved inherent conductivity. This finely crafted self-supported binder-free electrode with integrated architecture shows a low overpotential of 130 mV at −10 mA/cm2, a Tafel slope as low as 44 mV/dec, and excellent durability even at a high cathodic current density of 200 mA/cm2 in 0.5 M H2SO4. This system engineering optimizing strategy may pave the way for the design of commercially available electrocatalysts.

Ni/Mo Bimetallic‐Oxide‐Derived Heterointerface‐Rich Sulfide Nanosheets with Co‐Doping for Efficient Alkaline Hydrogen Evolution by Boosting Volmer Reaction

“…The control sample MoS 2 /CC is directly synthesized by a one-step hydrothermal method according to our previous report. [31] As shown in Figure S3 (Supporting Information), crescent-shaped MoS 2 nanosheets grow vertically on carbon fibers uniformly and luxuriantly. The control sample Ni 3 S 2 /CC is prepared by a hydrothermal step and a vulcanization step.…”

“…The preparation of fin-tubelike hierarchical carbon framework (CA/CC) is according to our previous report. [31] A two-step procedure is applied to prepare cobalt-doped Ni 3 S 2 /MoS 2 nanosheets via first hydrothermal synthesis of highly composition-segregated NiMoO 4 nanosheets and followed chemical vapor vulcanization at a suitable temperature (see details in the Supporting Information). In this regard, we consider that the key point of obtaining rich heterogeneous interfaces is making the size of MoS 2 and Ni 3 S 2 as small as possible and letting them fully discrete and form interfaces, that is, Ni and Mo elements are sufficiently separated.…”

Bioinspired Fractal Design of Waste Biomass‐Derived Solar–Thermal Materials for Highly Efficient Solar Evaporation

“…Briefly, 6.11 g Na 2 HPO 4 and 4.8 g NaH 2 PO 4 were dissolved in 200 mL DI water to obtain the phosphate buffer solution, which was followed by adding 3.9 g sodium p-toluenesulfonate and 1.4 mL pyrrole to obtain the electrochemical deposition solution. [37][38][39] The as-prepared CPP clamped by Pt electrode was used as the working electrode while Pt plate and a saturated calomel electrode (SCE) were used as the counter and reference electrode, respectively. The electrochemical deposition was carried out by using an electrochemical workstation (Bio-Logic) with a typical voltage of 1.00 V for 30 min.…”

Inhibition of In‐Plane Charge Transport in Hole Transfer Layer to Achieve High Fill Factor for Inverted Planar Perovskite Solar Cells

“…Apart from the optimization of the perovskite layer per se, efficient hole and electron extraction from the perovskite layer are equally important in achieving high performance PSCs, especially in the planar architecture . To date, a large number of high performance charge transfer layers (CTLs) were developed and optimized, including organic materials, transition metal oxides, metallic salts, and so on . Most works aimed to achieve high carrier concentration and mobility in CTL to ensure fast charge transport from perovskite to the electrode .…”