MoS2 Nanosheet Arrays Rooted on Hollow rGO Spheres as Bifunctional Hydrogen Evolution Catalyst and Supercapacitor Electrode

Abstract

MoS2 has attracted attention as a promising hydrogen evolution reaction (HER) catalyst and a supercapacitor electrode material. However, its catalytic activity and capacitive performance are still hindered by its aggregation and poor intrinsic conductivity. Here, hollow rGO sphere-supported ultrathin MoS2 nanosheet arrays (h-rGO@MoS2) are constructed via a dual-template approach and employed as bifunctional HER catalyst and supercapacitor electrode material. Because of the expanded interlayer spacing in MoS2 nanosheets and more exposed electroactive S–Mo–S edges, the constructed h-rGO@MoS2 architectures exhibit enhanced HER performance. Furthermore, benefiting from the synergistic effect of the improved conductivity and boosted specific surface areas (144.9 m2 g−1, ca. 4.6-times that of pristine MoS2), the h-rGO@MoS2 architecture shows a high specific capacitance (238 F g−1 at a current density of 0.5 A g−1), excellent rate capacitance, and remarkable cycle stability. Our synthesis method may be extended to construct other vertically aligned hollow architectures, which may serve both as efficient HER catalysts and supercapacitor electrodes. Electronic supplementary materialThe online version of this article (10.1007/s40820-018-0215-3) contains supplementary material, which is available to authorized users.

High-Index-Faceted Ni3S2 Branch Arrays as Bifunctional Electrocatalysts for Efficient Water Splitting

“…Platinum (Pt)/Pt-based alloys and iridium/ruthenium oxides (IrO 2 /RuO 2 ) are regarded as the most efficient electrocatalysts for electrochemical hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively [6][7][8][9][10]. However, their high cost and compromised stability as well as the low earth abundance of these metals impede their widespread application [11][12][13][14][15]. Therefore, it is highly desirable to fabricate alternative noble-metal-free and durable electrocatalysts for both OER and HER systems.…”

Pore Surface Engineering of Covalent Triazine Frameworks@MoS2 Electrocatalyst for the Hydrogen Evolution Reaction

“…For example, heteroatom-doped CMPs was pyrolyzed and doped with cobalt salt, this electrode material achieved aT afel slope of 46 mV dec À1 at ac urrent density of 10 mA cm À2 in 0.5 mH 2 SO 4 . [17] Detailed and systematic comparison of the Tafel slope and overpotential for selected synthesizablec atalysts are shown in Ta ble S3.T here are three primary processes for HER in acidic media based on reported calculation ( Figure S15). [40] Bifunctional hollow rGO spher-es@MoS 2 catalyste xhibited aT afel slope of 105 mV dec À1 .…”

“…With cost-effectiveness and high electrocatalytic performance, non-noblem etal molybdenum disulfide (MoS 2 )n anosheets have been extensively investigated as an efficient catalyst in HER. [16,17] Most of those pore materials were adopted as carriers for loading of active nanoparticles to furtheri mprove catalytic activity. Carbon materials with large surfacearea and rapid electron migration can effectively reduce HER overpotential of MoS 2 by forming ac arbon@MoS 2 combined system,w hen two materials are mutualistic symbiosis in one bulk material.…”

Nanoparticle-Decorated Ultrathin La2O3 Nanosheets as an Efficient Electrocatalysis for Oxygen Evolution Reactions

“…To lead the exciting experimental developments of these energy systems to industrial applications, materials that catalyze OER with a high mass activity, a low overpotential, and a robust kinetic are highly desired [11][12][13]. Recent breakthroughs to lower the overpotential have revealed a large number of promising OER catalysts including carbon-based materials (e.g., graphene, CNT, and g-C 3 N 4 ), and alternatives of transition metals (e.g., Mn, Co, Ni, and Fe) [13][14][15][16][17][18][19][20][21][22][23][24][25]. However, the low mass activity, high cost, and complicated fabrication procedure are still hindering scalable implementations of these materials in replacing the benchmark IrO 2 and RuO 2 that have high cost and limited supply [5,13,15,26].…”