In situ synthesis of heterogeneous NiSe₂/MoSe₂ nanocomposite for high‐efficiency electrocatalytic hydrogen evolution reaction

Abstract

Developing high-efficiency electrocatalysts for hydrogen evolution reaction (HER) has been considered as a crucial way to reduce energy loss in watersplitting. Herein, heterogeneous NiSe 2 /MoSe 2 (H-NiSe 2 /MoSe 2 ) nanocomposite constructed by metallic NiSe 2 nanocrystallites embedded in few-layer MoSe 2 nanosheets has been in situ synthesized by a simple hydrothermal reaction. As an HER electrocatalyst, it delivers superior performance with an ultra-small onset overpotential of 103 mV, a small overpotential of 147 mV at 10 mA cm −2 , a low Tafel slope of 43.5 mV dec −1 , and long-term stability up to 18 h in 0.5 M H 2 SO 4 . The superior performance for HER can be ascribed to the unique embedded nanostructure, which can not only improve the overall conductivity of the nanocomposite but also greatly increase the exposed active sites. Furthermore, the synergistic effect of NiSe 2 and MoSe 2 hybrid facilitates the rapid electrons transfer from the electrode to the exposed MoSe 2 edges to take part in the HER reaction, and thus promotes the HER performance. This study provides a simple route for fabricating bi-metallic selenides-based nanocomposite as an efficient and stable electrocatalyst for HER.The excessive consumption of natural resources has brought about severe ecological environment and energy crises. [1][2][3] Hydrogen is considered a renewable energy source to replace natural fossil fuels due to its clean combustion products and high energy density. [4][5][6] Up to now, hydrogen evolution from electrochemical water splitting has been regarded as an eco-friendly and promising strategy to fabricate the hydrogen energy resource. 7-10 However, the high overpotential on the cathode electrode of water splitting severely increases the

Construction of Cobalt Molybdenum Diselenide Three‐phase Heterojunctions for Electrocatalytic Hydrogen Evolution in Acid Medium

“…It can be seen that oc‐CoSe 2 /MoSe 2 exhibits the smallest overpotential of −136 mV (at −10 mA cm −2 ) in all the samples except for Pt/C. This overpotential value is better than those of most CoSe 2 and MoSe 2 ‐related materials reported in the literatures (Table S1) [34,37–47] . It should be noted that the overpotential at the current density of −200 mA cm −2 of oc‐CoSe 2 /MoSe 2 is lower than that of Pt/C, indicating that the sample exhibits better performance than Pt/C under high current environment.…”

“…This overpotential value is better than those of most CoSe 2 and MoSe 2 -related materials reported in the literatures (Table S1). [34,[37][38][39][40][41][42][43][44][45][46][47] It should be noted that the overpotential at the current density of À 200 mA cm À 2 of oc-CoSe 2 /MoSe 2 is lower than that of Pt/C, indicating that the sample exhibits better performance than Pt/C under high current environment. The Tafel plots obtained by fitting the data from LSV in the Tafel region are shown in Figure 3b.…”

Recent advances in molybdenum diselenide-based electrocatalysts: preparation and application in the hydrogen evolution reaction

“…118 Note that such an electrocatalyst can be employed as both cathode and anode for overall water splitting, which only needs 161 mV cell voltage at 10 mA cm −2 . Interestingly, three-phase oc-CoSe 2 /MoSe 2 microspheres without CC substrate indicated a considerable overpotential of 136 mV and a low Tafel slope of 47 mV dec −1 compared with that of o-CoSe 2 /c-CoSe 2 /MoSe 2 on CC, 119 lower than those of previous reported electrocatalysts MoSe 2 –CNT, 165 CoSe 2 /MoO 2 /MoSe 2 , 166 0.2CoSe 2 /MoSe 2 , 167 MoSe 2 –CoSe 2 NTs, 168 MoSe 2 /CoSe 2 microcage, 169 CoSe 2 –MoSe 2 /rGO–C, 170 CoSe 2 @MoSe 2 nanocubes, 171 MoSe 2 /CoSe hollow spheres, 172 H-NiSe 2 /MoSe 2 , 173 CoSe/MoSe 2 , 174 and o-CoSe 2 /c-CoSe 2 /MoSe 2 /CC, 118 higher than those of 3Co–MoSe 2 –GNS@CNT 127 and MoSe 2 /CoSe 2 hybrid. 175 Moreover, CC/MOF-CoSe 2 @MoSe 2 catalyst can be used in alkaline HER and showed an excellent catalytic activity with an overpotential of 109.87 mV and a Tafel slope of 68.91 mV dec −1 , much better that those of MoSe 2 –CoSe 2 NTs/G (198 mV vs. RHE, 79 mV dec −1 ), 176 CC/MOF (186.13 mV, 172.16 mV dec −1 ), CC/MoSe 2 (130.88 mV, 131.99 mV dec −1 ), 128 and the previously reported MoSe 2 /CoSe 2 @CFP (137 mV, 55.9 mV dec −1 ).…”

Comparative Study on Hydrogen Evolution Reaction of Various Cobalt-Selenide-Based Electrocatalysts

“…Transition-metal selenides, such as MoSe 2 , WSe 2 , CoSe 2 , and NiSe 2 [18][19][20][21][22], are Pt-free electrocatalysts with high performance for water dissociation, as proved in theoretical and experimental studies. Among these materials, CoSe 2 exhibits a remarkable performance and high stability in various solutions.…”