A Facile Design of Solution-Phase Based VS2 Multifunctional Electrode for Green Energy Harvesting and Storage

Abstract

This work reports the fabrication of vanadium sulfide (VS2) microflower via one-step solvo-/hydro-thermal process. The impact of ethylene glycol on the VS2 morphology and crystal structure as well as the ensuing influences on electrocatalytic hydrogen evolution reaction (HER) and supercapacitor performance are explored and compared with those of the VS2 obtained from the standard pure-aqueous and pure-ethylene glycol solvents. The optimized VS2 obtained from the ethylene glycol and water mixed solvents exhibits a highly ordered unique assembly of petals resulting a highly open microflower structure. The electrode based on the optimized VS2 exhibits a promising HER electrocatalysis in 0.5 M H2SO4 and 1 M KOH electrolytes, attaining a low overpotential of 161 and 197 mV, respectively, at 10 mA.cm−2 with a small Tafel slope 83 and 139 mVdec−1. In addition, the optimized VS2 based electrode exhibits an excellent electrochemical durability over 13 h. Furthermore, the superior VS2 electrode based symmetric supercapacitor delivers a specific capacitance of 139 Fg−1 at a discharging current density of 0.7 Ag−1 and exhibits an enhanced energy density of 15.63 Whkg−1 at a power density 0.304 kWkg−1. Notably, the device exhibits the capacity retention of 86.8% after 7000 charge/discharge cycles, demonstrating a high stability of the VS2 electrode.

3D nanoporous NiCoP as a highly efficient electrocatalyst for the hydrogen evolution reaction in alkaline electrolyte

“…In addition, with the increase in current density, the catalytic activity gap between Pt/C and the Ni 2.5 Co 2.5 -P electrode gradually narrows, indicating that Ni 2.5 Co 2.5 -P has a better catalytic performance under a high current density. Importantly, the HER performance of the 3D nanoporous NiCoP is good compared with recently reported catalysts such as MoP@PC, 60 C-Co 2 P, 61 CoMn-P@NG, 62 CoNiP, 63 np-Ni-Co-P, 64 CoNiP-NWs, 65 SnS/NF, 66 VS 2 67 and NC-PB@CNT 68 (Table 1). polarization curve fitting, and it can be seen from the figure that the Ni 2.5 Co 2.5 -P electrode also has the lowest Tafel slope of 93 mV dec À1 (o118 mV dec À1 ), except the 20% Pt/C electrode.…”

In situ-engineered coral-like multiphase NC@NiCoCu–N/NCF nanoarrays for enhanced hydrogen evolution reaction

“…The corresponding overpotentials show slight fluctuations, evidenced by the 23.6% and 17.7% degradation of the potential after 24 h ( j 10 ) and 24 h ( j 50 ) testing, respectively. 40 The in situ growth strategy and the NC shell provide a strong guarantee for the stability of the catalyst. 41 Fig.…”

Self‐standing 2D tin‐sulfide‐based heterostructured nanosheets: An efficient overall urea oxidation catalyst

“…On the other hand, tin (Sn) and sulfur (S) are earth‐abundant and their combination produces layered tin sulfide materials with outstanding electrical and optical properties 20 . Despite the availability of various sulfide polymorphisms, SnS 2 and SnS have been extensively researched in various fields including energy storage and conversion devices due to their nontoxicity, low cost, and impressive durability in acidic and alkaline environments., 9,2122‐24 However, due to their complicated phase‐controlled synthesis, they have rarely been reported in OER and UOR.…”