Defect-Rich Heterogeneous MoS2/rGO/NiS Nanocomposite for Efficient pH-Universal Hydrogen Evolution

Abstract

Molybdenum disulfide (MoS2) has been universally demonstrated to be an effective electrocatalytic catalyst for hydrogen evolution reaction (HER). However, the low conductivity, few active sites and poor stability of MoS2-based electrocatalysts hinder its hydrogen evolution performance in a wide pH range. The introduction of other metal phases and carbon materials can create rich interfaces and defects to enhance the activity and stability of the catalyst. Herein, a new defect-rich heterogeneous ternary nanocomposite consisted of MoS2, NiS and reduced graphene oxide (rGO) are synthesized using ultrathin αNi(OH)2 nanowires as the nickel source. The MoS2/rGO/NiS-5 of optimal formulation in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS only requires 152, 169 and 209 mV of overpotential to achieve a current density of 10 mA cm−2 (denoted as η10), respectively. The excellent HER performance of the MoS2/rGO/NiS-5 electrocatalyst can be ascribed to the synergistic effect of abundant heterogeneous interfaces in MoS2/rGO/NiS, expanded interlayer spacings, and the addition of high conductivity graphene oxide. The method reported here can provide a new idea for catalyst with Ni-Mo heterojunction, pH-universal and inexpensive hydrogen evolution reaction electrocatalyst.

Multi-interface MoS2/Ni3S4/Mo2S3 composite as an efficient electrocatalyst for hydrogen evolution reaction over a wide pH range

“…5b). The overpotential of MoS 2 /Ni 3 S 4 /Mo 2 S 3 /CC-24 h is 193 mV at 100 mA cm −2 which is lower than 233 mV of 20% Pt/C, 279 mV of CoS 2 @MoS 2 @CC-30 h, 24 and 301 mV of MoS 2 /rGO/NiS-5 30 and higher than 174 mV of Ni 3 S 4 @MoS 2 /CC-3 and 176 mV of NiMo@MoS 2 . 52,53 As indicated in Fig.…”

“…7. 24–31,55–58 and Table S1 †. Meanwhile, to better support the advantage of the multi-interface design strategy, MoS 2 /Ni 3 S 4 /CC was prepared, characterized (Fig.…”

“…22,23 As we know, reported MoS 2 -based composite electrodes are mostly unsteady over a wide pH range, especially, the activity of MoS 2 -based composites for the HER has still not been thoroughly explored in alkali electrolytes. More recently, quite a few efforts were made to explore MoS 2 -based composite electrocatalysts for the HER over a broad pH range, such as CoS 2 @MoS 2 @CC-30 h composite, 24 MoSe 2 -ts@MoS 2 -ts (thin sheets abbreviated to ts), 25 NbS 2 /MoS–carbon nanofiber, 26 PCN@MoS 2 @C (polypyrrole-derived carbon nanotube abbreviated to PCN), 27 CoS 2 @MoS 2 /CP (carbon paper abbreviated to CP), 28 CN/CNL/MoS 2 /CP (CoNi alloys abbreviated to CN and CoNi layered double hydroxides abbreviated to CNL), 29 MoS 2 /rGO/NiS nanocomposite (reduced graphene oxide abbreviated to rGO), 30 and Ru@2H–MoS 2 . 31 However, few MoS 2 -based composite electrocatalysts over a wide pH range are still far from satisfactory for practical applications of HER.…”

Enhancing Mg2+ and Mg2+/Li+ Storage by Introducing Active Defect Sites and Edge Surfaces in MoSe2

“…Such result is consistent with the above XRD results. Furthermore, abundant defects in the Se‐Mo‐Se layers are obviously observed in the HRTEM images of the UTRDE‐MoSe 2 and marked by the yellow dash box (Figure 2d) [29,30] . These crystal defects are either the Mo vacancies or Se vacancies, and the lattice fringes are separated by these vacancy defects.…”

Defect-rich Fe-doped NiS/MoS2 heterostructured ultrathin nanosheets for efficient overall water splitting

“…The interfaces between NiS and MoS 2 are shown to promote HER activity. 22 Zhou et al reported MoS 2 /NiS heterostructure nanoflowers with enhanced HER performance. DFT calculations show that electron modulation on heterointerfaces leads to decreased Δ G H .…”