Multiscale structural and electronic control of molybdenum disulfide foam for highly efficient hydrogen production

Abstract

Hydrogen production through water splitting has been considered as a green, pure and high-efficient technique. As an important half-reaction involved, hydrogen evolution reaction is a complex electrochemical process involving liquid-solid-gas three-phase interface behaviour. Therefore, new concepts and strategies of material design are needed to smooth each pivotal step. Here we report a multiscale structural and electronic control of molybdenum disulfide foam to synergistically promote the hydrogen evolution process. The optimized three-dimensional molybdenum disulfide foam with uniform mesopores, vertically aligned two-dimensional layers and cobalt atoms doping demonstrated a high hydrogen evolution activity and stability. In addition, density functional theory calculations indicate that molybdenum disulfide with moderate cobalt doping content possesses the optimal activity. This study demonstrates the validity of multiscale control in molybdenum disulfide via overall consideration of the mass transport, and the accessibility, quantity and capability of active sites towards electrocatalytic hydrogen evolution, which may also be extended to other energy-related processes.

Stimulated Electrocatalytic Hydrogen Evolution Activity of MOF‐Derived MoS2 Basal Domains via Charge Injection through Surface Functionalization and Heteroatom Doping

“…Although heteroatom doping has been shown to trigger the electrocatalytic activity as explicitly shown in this work and recent studies, [33,[39][40][41] the same heteroatoms with different coordination configuration could result in distinctively different performance. As presented in the polarization curve in Figure S23 (Supporting Information), MoS-CoS-Zn-1pot exhibits inferior catalytic activity compared with MoS-CoS-Zn synthesized by MOF-route.…”

“…[47] In the Co K-edge spectrum of MoS-CoS-Zn, stronger white line intensity and more positive absorption edge position are observed. [41] However, adsorption strength of hydrogen on an electrocatalytic surface can be made favorable by tuning the Bader charge of atoms via changing the electronic structure. According to the analysis of the first shell ( Figure S25b, Supporting Information), MoS-CoS-Zn-1pot exhibits a CoS distance of 1.86 Å, which agrees well with the CoS bond length in CoS 2 crystal structure.…”

“…These results agree well with the observations of Zn K-edge spectra, indicating strong electronic interactions in MoS-CoS-Zn structure. [39][40][41] Depending on the spectroscopic findings, charge injection is realized from Zn centers to Mo, which could subsequently regulate the electron number on S and Mo atoms and offset energy level mismatching for favorable hydrogen adsorption, as revealed by the UPS investigations. [48] The CoS coordination in MoS-CoS-Zn shifts to a lower R-position (1.80 Å), demonstrating that the main Adv.…”

Adsorption-energy-based activity descriptors for electrocatalysts in energy storage applications

“…In addition, as shown in Fig. 1d, Co-doping into the MoS 2 in-plane can increase the REVIEW Wang et al 331 HER activity, because Co-doping lowers the energy level of dangling bonds of S atoms, offsets the energy mismatch from the H 1 s orbital and enhances the adsorption strength between H atoms and edged-S sites [38,42]. Nevertheless, further increasing the Co-doping concentration will lead to too great an adsorption strength between the H and S atoms, which lowers the HER activity.…”

Metallic Porous Iron Nitride and Tantalum Nitride Single Crystals with Enhanced Electrocatalysis Performance

“…[26][27][28] Here we study the HER performance of the as-prepared [001] Ta 5 N 6 single crystal in N 2 -saturated 0.5 m H 2 SO 4 solution using a three-electrode system. Non-noble metal HER catalysts normally face the challenges of high overpotential and low durability in strongly acidic electrolyte.…”